OXIDANT AIR POLLUTANT EFFECTS
ON A WESTERN CONIFEROUS
FOREST ECOSYSTEM
TASK B REPORT:
Historical Background and
Proposed Systems Study of
the San Bernardino Mountain Area.
UNIVERSITY OF CALIFORNIA
FOREST SERVICE
UNITED STATES DEPARTMENT
of AGRICULTURE
Supported By:
U. S. Environmental Protection Agency
Grant No. 68-O2-O3O3
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OXIDANT AIR POLLUTANT EFFECTS ON A
WESTERN CONIFEROUS FOREST ECOSYSTEM
Task B
Historical Background and Proposed
Systems Study of the San Bernardino
Mountain Area
JAN 1373
Principal Investigator:
0. C. Taylor, Associate Director
Statewide Air Pollution Research Center
University of California, Riverside, CA 92502
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OXIDANT AIR POLLUTANT EFFECTS ON A
WESTERN CONIFEROUS FOREST ECOSYSTEM
Advisory Committee Chairmen:
Vegetation - R. V. Bega, Pacific Southwest Forest
and Range Experiment Station, U.S.
Forest Service, Berkeley, CA
Vertebrates - J. T. Light, U.S. Forest Service,
Supervisors Office, San Bernardino
National Forest, San Bernardino, CA
Arthropods - D. L. Wood, Division of Entomological
Sciences, University of California,
Berkeley, CA
Meteorology - J. G. Edinger, Department of
Meteorology, University of
California, Los Angeles, CA
Soils and Hydrology - L. J. Lund and A. L. Page,
Department of Soil Science
and Engineering, University
of California, Riverside, CA
Sociology - E. W. Butler, Department of Sociology
University of California, Riverside, CA
Systems Integration - Bland Ewing, Division of
Modeling Biological Control, University
of California, Berkeley, CA
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ii
OXIDANT AIR POLLUTANT EFFECTS ON A
WESTERN CONIFEROUS FOREST ECOSYSTEM
CONTENTS
SECTION pAGE
Summary ^v
Introduction 1
A. Vegetation Committee Report
Introduction 1
Direct Effects of Oxidants 22
Physiological Effects 26
Histological and Histochemical Effects 27
Community Composition Induced by Pollutants 31
Recommendations for Future Study 35
B. Vertebrate Animal Committee Report
Vertebrate Pathology
Summary and Recommendations 12
C. Arthropod Committee Report
Terrestrial Habitats 1
Western Pine Beetle 3
Vegetational Changes Induced by Bark Beetle. ... 5
Soil Arthropods 6
Sucking Insects 7
Insects that Influence Tree Growth 9
Arthropods Important to Reproductive Biology ... 11
Spider-prey Relationships 12
Insectivorous Birds 14
Aquatic Habitats 15
Appendix: Tree Losses in Vicinity of
Lake Arrowhead 1
Interpretation of Tree Loss 2
Historical Notes 3
Discussion 4
D. Meteorology Committee Report
Introduction 1
Large-scale Features 3
Small-scale Phenomena 5
Distribution of Oxidant 6
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ill
SECTION PAGE
E. Geology, Soils and Hydrology Committee Report
Geology 2
Soils 5
Chawanakee Series 7
Shaver Series 10
Drainage and Runoff 12
Erosion, Sedimentation and Water Quality 16
F. Sociology Committee Report
Introduction 1
Historical Background of Lake Arrowhead 2
Human Population and Use of Habitat 6
Possible Effect of Oxidant Pollutants 10
Future Studies 21
G. Systems Integration and Modeling Committee Report
Introduction 1
Modeling 2
Information System 10
Data Capture Subsystem , 11
File Management Subsystem 14
Data Interpretation Subsystem 16
Systems Coordination 17
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iv
Summary
Physical characteristics of the San Bernardino Mountains, i.e. geology,
topography, soils, hydrology, and climate are described in the following
report. Histories of the vegetation, vertebrate and arthropod populations
and human activity are also included to illustrate the evolutionary
changes of modern times. An attempt has been made to superimpose the
known and suspected influences of oxidant air pollution on this already
complex mosaic of physical and biological factors. Finally, the available
knowledge of techniques needed to develop an elaborate conceptual model of
the forest ecosystem are presented and discussed.
Essentially, all of the recent air pollutant research has been concerned
with direct effects of oxidants on a few plant species, principally
ponderosa and Jeffrey pine. These two species dominate a majority of
stands in the San Bernardino Mountains and thus are responsible for the
present structure which has special esthetic qualities valuable to
recreationists and the integrity of the present ecosystem.
Strongly discipline-oriented information about the forest system, e.g.
soils characteristics, meteorological phenomena, tree physiology, etc.
has been produced by most of the previous investigations. Other studies,
directed towards community biology, have described the various constituents
of the system in qualitative, and sometimes quantitative terms. Both
approaches may have spatial information incorporated into the studies.
However, the interactions among components, information necessary to
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operate a dynamic model of the system, are poorly identified and have
received little scientific attention since they require more than simply
an enumeration of the components of the system.
Future studies should be directed towards the establishment of life tables
for ponderosa and Jeffrey pine as well as other associated species. This
approach will establish relative importance of the direct effect of
oxidant air pollutants and the various biotic and abiotic agents as
mortality factors during each stage of the life cycle from flowering and
anthesis through the intermediate size or age classes up to the mature
tree. Construction of life tables will provide the core data needed for
the modeling process and associated studies will begin to describe the
indirect effects or reverberations in the ecosystem which are caused by
oxidant air pollutants.
A large group of professional scientists who consulted together about the
ecology of smog in this forest system, had several recommendations emerge
from their observations.
It was acknowledged that there are many more components in the system than
can be studied adequately. The scientists felt that past studies have
adequately identified only a few of the principal components in the system
since many of these are probably the emergent properties of interactions
which simply have not been studied. They believe that time is of the
essence in attempting to discover the important operating factors in the
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vi
system. Recent observations indicate an accelerating rate of air pollu-
tant damage. There was serious concern that continued deterioration of
the forest ecosystem may reach a point at which there is no longer an
ability to recover, and that the changes observed would permanently
modify the system, very possibly in an undesirable manner. Vegetation
and its dynamics were considered to be the principal objects of concern.
The major tree species should receive much greater attention than they have
in the past, and this attention should be focused on the life history
dynamics of the principal conifers and hardwoods. Parallel with these
studies, major efforts should begin in order to understand the roles of
predators (herbivores) and parasites (pathologic organisms) in the life
history of the major vegetation.
Finally, the scientists involved in this review consider it necessary to
develop an elaborate conceptual model ofthis system based on what needs
to be known in order to describe its dynamics and to provide an oppor-
tunity to intelligently manipulate (manage) it, both through simulation
techniques and on the ground. There was strong agreement that the develop-
ment of.this model was an integral part of any system's research done on
the San Bernardino National Forest. They cautioned that the model must
conceptualize the system in such a manner that its complexity can be
analyzed, rather than to proceed to simplify the real features of the
system prematurely and thus lose the opportunity to investigate that
complexity.
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vii
Appendix_to^ Summary
More detailed observations about needs, and recommendations can be found
on the following pages of the Task B report:
Vegetation: pp. 35-36
Vertebrates: p, 12
Arthropods: pp. 2, 4-7, 9-10, 12, 14-17
Meteorology: p. 14
Soils: see R. Arkley's "Research Needs", 2 pp.
Sociology: p. 10-18, 20, 22-26
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INTRODUCTION
Extensive urban development and industrial growth in the South-
coastal basin of California during the past three decades has caused an
alarming increase in air pollutants. Reactive hydrocarbons and nitrogen
oxides, precursors of oxidant pollutants, are generated in large quantities
during combustion of petroleum fuels to meet the energy demands of a
growing population.
Ozone and peroxyacetyl nitrate (PAN) are two of the most damaging
pollutants in the complex mixture known popularly as "smog" or photochemical
oxidant air pollution. These agents which cause serious damage to plants,
animals and humans are formed in the atmosphere above urban areas when
nitrogen dioxide and hydrocarbons react in the presence of sunlight. Local
weather provides both the means of concentrating the contaminants e.g., the
temperature inversion, and lateral air movement or delivery system which
can transport heavily polluted air up to 80 miles downwind.
In the Southcoast air basin, oxidant air pollutants have increased
phenomenally since the mid-1940's affecting broader and broader areas.
Similar increases have been witnessed in other large urban areas of Califor-
nia and in other states. Very often the downwind areas typically agricul-
tural or mountainous with forests and other valuable wildland vegetation
receive longer durations of exposure to heavy pollution than the urban
source area.
The mixed conifer forests of the Angeles and San Bernardino National
Forests, the extensive citrus and wine grape plantings and many acres of
vegetable crops - all downwind from the Los Angeles metropolitan area -
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have provided mute testimony of the serious damage by ozone and PAN.
Losses of agricultural crops have been estimated in the millions of dollars
annually and many sensitive crops can no longer be grown profitably.
In the local National Forests, sensitive species such as ponderosa
pine began to show injury in the early 1950's. Severely pollutant-injured
trees are made dangerously susceptible to the pine bark beetle which
quickly kills trees outright. The result of moderate to severe oxidant
damage to nearly 100,000 acres of the total of 160,000 acres of mixed
conifer type in the San Bernardino National Forest has been the need to
select or salvage cut some management units as often as three times in ten
years to remove bark beetle susceptible trees.
The effects of air pollutant damage to the forest cannot be estimated
in terms of timber volume or dollars because the principal use of the forest
is for the various recreational pursuits of the nearly 12 million people
who live within two hours drive. Forest managers seek first to enhance
the visual properties of the landscape and to increase the quality of the
visitor's recreation experience.
In the mixed conifer forests of the western Sierra Nevada Mountains
where oxidant damage is just beginning to be evaluated, both timber and
recreational values are at stake.
Beyond the visible deterioration of several key species of the mixed
conifer forest, what additional events may be shaping up which may pro-
foundly affect all elements of this ecosystem? What are the important
interactions between plants, animals and their physical environment which
will determine the future state of the system? We do not have answers
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to these questions and cannot answer them with independent, highly frag-
mented, short-term research efforts. A highly integrated systems approach
using many research disciplines will be required to determine the future
state of the mixed conifer forest of the San Bernardino mountains. An
understanding of successional trends of vegetation and the subsequent effects
on arthropods, birds, animals and people can have these foreseeable benefits:
1. information for forest management.
2. upgrading, secondary standards for air quality.
3. providing a method for doing a systems study on other conifer
forests threatened by pollution.
4. provide information to inform the public of the need for their
support in controlling air pollution sources.
The following report includes detailed historical information about
the biological and physical characteristics of the forested area proposed
for the interdisciplinary investigation of air pollutant impact and con-
cludes with suggestions for an integrated systems study designed to prepare
a predictive model.
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Section A
Vegetation Committee Report
History and Suggested Protocol
for
Environmental Protection Agency
Study of the Impact of Oxidant Air Pollution
on the Mixed Conifer Forest Ecosystem
Committee Chairman:
R. V. Bega, Pacific Southwest Forest and
Range Experiment Station, U.S. Forest
Service, Berkeley, California
Researched and Written By:
P. R. Miller, Pacific Southwest Forest and
Range Experiment Station, U.S. Forest
Service, Riverside, California
and
J. R. McBride, School of Forestry and
Conservation, University of California,
Berkeley, California '
Principle Contributors:
Richard Minnich, University of California, Los Angeles
J. S. Horton, U.S. Forest Service, Rocky Mountain Station
H. C. Fritts, University of Arizona
Jerry Light, U.S. Forest Service, San Bernardino N.F.
Hatch Graham, U.S. Forest Service, San Bernardino N.F.
Ross Thibaud U.S. Forest Service, San Bernardino N.F.
Philip Lord, U.S. Forest Service, San Bernardino N.F.
Fields Cobb, Jr., University of California, Berkeley
Hyram Johnson, University of California, Riverside
J. R. Parmeter, Jr., University of California, Berkeley
Rita Laird, University of California, Riverside
0. C. Taylor, University of California, Riverside
Kenneth Swain, U.S. Forest Service, Pest Control Region 5
Michael Srago, U.S. Forest Service, Pest Control Region 5
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A-l
INTRODUCTION
Green vegetation is the most important element of the biological community
because it captures and stores solar energy and releases oxygen. The other
members of the community, i.e. herbivores, carnivores, and decomposer organisms
are completely dependent on green vegetation—the "producer". This guiding
principle underscores the importance of healthy vegetation as a "stablilizer"
of organization among the communities of organisms .in their controlling physical
environment. An understanding of the changes in the plant communities suffering
chronic air pollution injury is vitally necessary to predict the fate of the
ecosystem.
This section describes the plant communities of the San Bernardino Mountains
and the suceessional trends which have determined community composition in
elevational zones prior to the influence of photochemical oxidant air pollution.
Emphasis has been placed on information, largely unpublished, which pertains
directly to this mountain range and its vegetation history. Extrapolation of
information from the abundant literature on similar vegetation types in the
forests of the Sierra Nevada has been purposely limited because of the absence
there of the distinct marine influence experienced in the San Bernardino Mountains.
We are indebted to the self-made botanist Samuel B. Parish who lived in San
Bernardino from 1872 until after the turn of the century for many written works
(1894, 1917) on the vegetation of the mountains during that time. John B.
Leiberg (1897-98) surveyed the San Bernardino Mountains to determine the acreage
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A-2.
of merchantable timber and also recorded the condition and species composi-
tion of the forest in several elevational zones on both the northern and
southern slopes of the range. Also, much useful information about the
appearance of the virgin forest, pioneer lumbering, fires, floods, and land
development (1769-1930) are recorded in a very comprehensive history: "Saga
of the San Bernardinos" by La Fuze (1971).
Finally, this section discusses the current knowledge of both the direct and
indirect effects of photochemical oxidant air pollution particularly ozone on
the vegetation of the conifer forest and woodland chaparral zones. Specific
recommendations are made for future research which is necessary to understand
the full impact of oxidant in the ecosystem.
Vegetation Zones and Types
The vegetation of the San Bernardino Mountains is composed about equally of
chaparral and forest types with important minor elements of woodland, sagebrush,
and grassland. Morton (1960) and Minnich (1969) have undertaken major treat-
ments of this vegetation. Horton (1960) recognized six vegetation zones on
the basis of plant physiognomy and environmental conditions (Fig. Al): chamise-
chaparral, woodland-chaparral, desert chaparral, Pinyon-Juniper woodland,
timberland chaparral, and coniferous forest. One or more vegetation types occur
within each zone. Twenty of these types were defined by Horton (1960) on the
basis of field reconnaissance. Minnich (1969), using infrared color imagery
on aerial photographs, mapped 28 vegetation types in the San Bernardino Mountains
(Fig. A2). The relationship between the vegetation types recognized by the two
authors is indicated in Table Al. A brief description, based on Horton (1960),
of each vegetation zone follows.
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A-3.
The Chamise-Chaparral Zone is characterized by a scrub vegetation which varies
in species composition and stand density. Chamise (Adenostoma fasciculatum) is
the most common species herein. This zone is distributed from near sea level
to 3,500 to 5,000 feet on north-facing slopes and to 4,500 to 5,500 feet on
south-facing slopes (Fig. Al). Within this range, annual precipitation varies
from 13 to 35 inches. Fire occurs frequently and has been a primary factor
in the evolution of the vegetation. Five major vegetation types are found in
the chamise-chaparral zone: (1) pure chamise-chaparral, (2) chamise-ceanothus
chaparral, (3) chamise-manzanita chaparral, (4) scrub oak chaparral, and (5)
coastal sagebrush. The important species in each of these types are listed
in table Al. The vegetation of the chamise-chaparral zone has been studied by
a number of investigators. Comprehensive papers include those of Cooper (1922),
Miller, E. H., Jr. (1947), and Navek (1967).
The Woodland-Chaparral Zone is located on the coastal side of the mountains
and to a limited extent in the Mojave River drainages (Fig. Al). It is charac-
terized by chaparral and woodland types dominated by oaks and by localized
stands of big-cone Douglas-fir and knobcone pine. On north-facing slopes, the
zone may begin at elevations of 3,500 to 5,000 feet and extend to 5,000 or
6,500 feet. The lower altitudinal range on south-facing slopes is from 4,500
to 5,500 feet while the upper altitudinal range is from 6,000 to 7,500 feet.
Precipitation ranges from 22 to 45 inches a year. As in the chamise-chaparral
zone, fire is common. Live oak chaparral, live oak woodland, big-cone Douglas
fir forest, knobcone pine forest, and coulter pine forest are the major vegeta-
tion types in the zone (Table Al). Wright (1966, 1968) has examined the
distribution of knobcone pine and coulter pine within the woodland-chaparral zone.
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A-4.
The Desert Chaparral Zone is characterized by open scrub vegetation. Usually
one-half or more of the soil surface is exposed and unprotected by the shrubs.
The zone occurs in the Mojave River drainages and the Cajon Pass area (Fig. Al)
and is generally found at elevations of 3,800 to 7,500 feet. In this range,
precipitation averages 12 to 25 inches annually.
Fire is rare in this zone because of the open cover, but the common species
usually recover following burning in the same manner as the shrubs in the
chamise-chaparral and woodland-chaparral zones. The single vegetation type
in this zone is the desert chaparral (Table AI). Hanes (1971) discusses this
type in his treatment of succession in the chaparral of southern California.
The Pinyon-Juniper Woodland Zone is principally located in Deep Creek and in
the vicinity of Big Bear Lake (Fig. Al). The zone contains woodland and scrub
vegetation in which Great Basin Sagebrush (Artemisia tridentata) is found. The
woodlands are generally open with over half of the soil surface exposed. The
notable exception to this open character is the occasional dense stands of
Juniper (Juniperus occidentalis). This zone ranges in elevation from 3,000
to 9,000 feet with average annual precipitation of 10 to 30 inches. Wildfires
are not common.
Minnich (1969) recognized six vegetation types (Western Juniper-Mountain
Mahogany Woodland, Pinyon Pine Woodland, Pinyon-Juniper Woodland, Great Basin
Sagebrush, Joshua Tree Woodland, and Juniper-Joshua Tree Woodland) in this zone
while Horton (1960) divided the zone into two major types (Pinyon-Juniper
Woodland and Great Basin Sagebrush).
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A-5.
The Timberland Chaparral Zone is characterized by a scrub vegetation usually
under 4 feet in height, and may be open or very dense. Timberland chaparral
occurs throughout the higher mountains (5,000 to 11,000 feet) and shows its
best development in the eastern portion of the San Bernardino Mountains (Fig. Al).
The average annual precipitation varies from 30 to 45 inches most of which
occurs in the form of snow. Summer wildfires are common and are considered
a principle factor in the maintenance of the type. A single major vegetation
type occurs in the zone—timberland chaparral (Table AI).
The Coniferous Forest Zone is found throughout the San Gabriel and San Bernar-
dino Mountains (Fig. Al). It ranges in elevation from 5,000 to 6,500 feet on
north-facing slopes and 6,000 to 7,500 feet on south-facing slopes upwards to
the highest peaks (San Gorgonio, 11,502 feet). These forests vary in both
stature and density according to vegetation types and environmental conditions.
At middle elevations, the stands of ponderosa pine-white fir forest are usually
dense and the height of trees will average 100 feet or more. At higher elevations
a Krummholz type is found where the widely spaced trees are so stunted as to
resemble shrubs. The precipitation is largely in the form of snow and ranges
from 25 to 50 inches a year. Fires are common but the area burned recently is
usually small except where major fires driven by high winds spread from chaparral
areas into the forest.
Several vegetation types are found in the coniferous forest zone. Horton (1960)
recognized seven types (pine forest, ponderosa pine-white fir forest, sugar
pine-white fir forest, grassland, black oak woodland, alpine forest, barren
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A-6.
areas). Minnich (1969) defined eight types in the zone on the basis of
imagery on color infrared aerial photographs. Using this method, he was not
able to distinguish the different coniferous forest types recognized by Horton's
(I960) ground reconnaissance. A comparison of the types recognized by both
Horton (1960) and Minnich (1969) is found in Table AI.
Plant Succession in the San Bernardino Mountains^
Plant succession is the naturally occurring change in vegetation types involving
a series of replacements of one type by another until a steady state is reached.
The vegetation type occurring in the steady state is able to replace itself and
is known as the climax. The climax is in equilibrium with the dominant environ-
mental conditions in an area.
In most cases, the climate of an area is the determining factor in the development
of the climax. However, within a climatic zone other conditions may be more
important in controlling plant succession. The terms climatic climax, edaphic
climax, and fire climax designate climax types controlled by specific factors.
Within a broad regional area, such as the San Bernardino Mountains, several
different climaxes will occur because of the variations in environmental condi-
tions. At some locations, the dominant factor is the climate while at others
the soil or repeated wildfires determine the climax.
As plant succession proceeds in an area, the natural development and replace-
ment of vegetation types may be interrupted by catastrophic events which
destroy or significantly change the existing vegetation. Following a cata-
strophe, plant succession continues but often at a different rate. In order
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A-7.
to understand the changes of vegetation in the San Bernardino Mountains
caused by oxidant air pollution, knowledge of how other catastrophes have
influenced plant succession is necessary.
Wildfire
Fire is a major factor influencing succession in all of the vegetation zones
of the San Bernardino Mountains with the exception of the desert chaparral
and Pinyon-Juniper zone. The adaptations for surviving fire exhibited by a
great number of the species in the chamise-chaparral and woodland-chaparral
zones indicates evolution in an environment where fire was frequent.
Fire in pre-historic times was due to lightning and Indian use and misuse of
fire. Opinion varies as to the degree of burning by Indians prior to the
Spanish settlement of the California coast (Burcham, 1959; Aschmann, 1959).
Regardless of their cause, fires must have burned freely and extensively in
primitive times. During the Spanish period (1769-1822), fire was introduced
as a management tool to improve forage for livestock.
The records of the extent and frequency of fires in the San Bernardino
Mountains prior to 1910 are sketchy (LaFuze, 1971). From 1911 to 1971,
the U.S. Forest Service has kept fire records at the Forest Supervisor's
Office, San Bernardino National Forest, summarized in Figure A3. This map
includes all of those fires which burned in or on the edges of the conifer
zone. For simplification, fires which occurred only in the lower chaparral
zones were omitted. The Cajon Pass area, for example, in the western one-third
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A-8.
of the map, was a complex of overlapping fires whose frequent occurrence there
may be related to the major rail route through the pass.
Fire has had its greatest influence on the conifer zone in the western half of
the mountain region where logging activity was extensive starting in 1852
(Fig. 4). Fires prior to 1910 were frequent, occurring in 1869, 1874, 1879,
1894, 1900, and 1903 in various parts of the forest.
In the eastern half of the mountain region (Fig. 3). fires have been less
frequent and in some cases appear to be caused by lightning. There are
references, however, which suggest that ranchers burned the rangeland annually
to improve the forage for the cattle in this eastern sector from the 1860's to
the early 1900's (Vestal et al., 1904; Horton, 1960).
Fire and Plant Succession
Examinations of the influence of fire on the composition of vegetation types
and plant succession in the chaparral zones indicate the capacity for sprouting
following burning exhibited by many species (Horton and Kraebel, 1955; Hanes,
1971). Burned-over chaparral lands return to a chaparral cover within a few
years after burning as a result of sprouting. Establishment from seeds also
contributes to post-fire vegetation since the seeds of many species are stimu-
lated to germinate by high temperatures (Stone and Juhren, 1951). As long as
fire is a factor in the environment of the chaparral zones, a mosaic of scrub
dominated vegetation types will be encountered.
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A-9.
Chaparral dominated watersheds are subject to severe erosion following burning.
The annual winter floods which follow the summer and fall fires cause severe
damage to urban developments at the base of the mountains, therefore great
effort is being made to control these wildfires in the San Bernardino
Mountains. As fire control becomes more effective and the area burned is
reduced, the fire climaxes can be expected to succeed to climatic and edaphic
climaxes in the chaparral zones. Horton and Kraebel (1955) suggest that
elements of the woodland-chaparral zone, particularly species from the live
oak chaparral and live oak woodland vegetation types, would become dominant
in the absence of fire. Hanes (1971) disagrees because several plots which
have not burned in the last 100 years are still dominated by chamise (Adeno-
stoma fasciculatum). He concludes that a chamise dominated chaparral (pure
chamise-chaparral, chamise-ceanothus chaparral, chamise-manzanita chaparral)
would maintain itself on south-facing slopes and on the desert side of the
mountains in the absence of fire. On north-facing slopes on the ocean side
of the San Bernardino Mountains, scrub oak-chaparral, live oak chaparral,
and live oak woodland would compose the mosaic of climax types if fire were
eliminated.
In the woodland chaparral,•the big-cone Douglas-fir stands are more and more
confined to the steep, easily-eroded draws under the influence of repeated
fires; and the canyon live oak (Quercus chrysolepis), and some shrubs
(Arctostaphylos spp. and Ceanothus leucodermis) occupy the surrounding slopes.
When the oaks and other species sprout after fire, some new seedlings of
big-cone Douglas-fir may become established in the understory. During a long
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A-10.
absence of fire, the firs begin to emerge from the canyon live oak canopy
thereby extending the fir forest out from the refuge of the steep draws
where fire seldom penetrates. The success of the new fir forest depends on
whether the trees have grown large enough to survive the next fire (that is,
with foliage reaching above the oak canopy and with stem bark thick enough to
withstand heat). If fire occurs soon, the new fir seedlings will be destroyed
and the oaks, manzanita, and chamise will sprout anew (Horton, personal
communication).
Occasionally, ponderosa pine will extend down into the upper limits of the
woodland chaparral on relatively gently sloping ridges with deep soil. These
"stringers" of pine forest surrounded by shrubs and canyon live oak are very
vulnerable to fire and suffer from severe competition for soil moisture with
the chaparral species.
Fires have been frequent in the timberland chaparral zone of the San Bernardino
Mountains (Fig. A3). The species in the timberland chaparral adapt to burning
like the chaparral species at lower elevations, but recovery of vegetation
following a fire is slower due to the shorter, copier growing season at the
higher elevations.
Fires in the coniferous forest zone were very frequent and destructive until
the last 20 years (Fig. A3) when more successful fire protection has limited
both frequency and spread. Large fires in this zone have often originated
in adjacent chaparral areas (Fig. A3). Fire control has had a distinct
influence on the structure and composition of forests in the coniferous forest
zone. Periodic ground fires in this area prior to the twentieth century
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A-11.
resulted In a low level of fuel on the forest floor. Seedlings and saplings
of white fir (Abies concolor) and incense cedar (Libocedrus decurrens) were
killed by these fires while pine and oak seedlings survived. A map and other
descriptions in LaFuze (1971) refer to the San Bernardino ''Mountain Pinery"
during the 1850's when loggers were cutting the virgin forest. This suggests
a very large amount of ponderosa and some sugar pines in the virgin forest.
With the reduction in ground fire that came with the establishment of the
National Forests, an accumulation of ground fuel has occurred (Dodge, 1971).
The once open structure of the forests has changed to one composed of flammable
seedlings, saplings, and pole-sized trees reaching from the ground into the
crown canopy. Under these conditions fire can have a much greater impact on
the forest than in previous times. Fire in these forests today is capable of
destroying existing vegetation and initiating a secondary succession in which
timberland chaparral is likely to develop and may retard the succession back
to the conifer types.
Not all vegetation types within the coniferous forest zone are equally susceptible
to destruction by fire. The sugar pine-white fir forests which occur on south-
facing slopes are typically open forests with practically no understory. Fire
spreads very poorly in these forests because the areas between trees and
scattered shrubs are usually bare with surfaces of eroding soil, rock slides,
or rock outcroppings.
In the grassland type, fire is also less common because of the very moist meadow
conditions. Fires do occasionally burn over grassland areas in the late summer
and fall, but do not destroy the type.
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A-12.
Barren areas at high elevations are seldom exposed to fire. Following fires,
the thin lodgepole and limber pine stands of the barren areas are replaced
by timberland chaparral and succession back to former condition is very slow.
In the drier zones on the desert side of the San Bernardino Mountains, fire
is uncommon (Fig. A3) because the wide spacing of plants in this area discourages
its spread. The desert chaparral type includes many species which are capable
of sprouting after a fire, but regrowth of vegetation is very slow. The species
of the Pinyon-Juniper woodland zone are not adapted to withstand burning and
pinyon pine (Pinus monophylla) in particular is nearly always destroyed. How-
ever, fires are not frequent in this zone (Fig. A3).
Man's Activities Influencing Succession in the Conifer Zone
Logging has exerted a heavy influence on the vegetation of the conifer zone
of the San Bernardino Mountains since 1852 when Mormon settlers began to cut
timber in the general vicinity of present-day Crestline (first Seeley Flat).
The progress of early logging, including harvest of big-cone Douglas fir at
lower elevations, from 1830 to 1930 (La Fuze, 1971) is presented in arbitrarily
chosen intervals of 20 years (Fig. A4). During this time span, the timber
harvest proceeded eastward into virgin timber until 1891 when some mills were
re-established in the western areas formerly cutover.
During the first 40-50 years (beginning 1852), many of the larger trees were
left standing because the water or steam-powered sawmills could not accommodate
them and it is probable that the soil and younger trees were not seriously
disturbed by the ox-drawn log wagons.
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A-13.
Timber harvest reached its peak from 1898 to 1912 with the establishment of
the Brookings sawmill and the narrow gauge logging railroad near the present
location of Running Springs (Fig. A4). The Brookings Company clear-cut most
of the 8,000 acres of timber available to them. Trees of all sizes were cut
due to the demand for boxes from the booming citrus packing industry in the
valley below. The snaking of logs to rail cars by cable caused great damage
to seedling trees and to the soil surface. Following a severe 3,500-acre
fire caused by the Brookings locomotive in 1903, the Company was prohibited
from further operation on government land (La Fuze, 1971). Part of this
area was later converted to timberland chaparral (Morton, 1960).
Gold mining and cattle ranching were the primary activities in the Big Bear
Lake vicinity and commercial logging there did not thrive. Some steam engines
at the mines had sawmill attachments and much timber was harvested for mine
construction, houses, and fuel. During the early 1900's, about five sawmills
near Big Bear Lake provided lumber for local construction. The placer mines
and the wastes from deep mines eliminated many trees resulting in the issuance
of citations by forestry officials (La Fuze, 1971).
After 1930, commercial logging in the San Bernardino Mountains was limited and
sporadic. The two most most valuable timber species have always been sugar and
ponderosa pine. White fir, which is difficult to season, and incense cedar, with
a high percentage of dry rot, were rarely used (Parish, 1894).
Today, sanitation salvage logging is practiced whereby only "high risk" trees
weakened by age or by chronic damage from oxidant air pollution are removed
(Hall and Pierce, 1965). These trees are highly susceptible to attack by pine
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A-14.
bark beetles (Dendroctonus spp.) and the practice of removing them is defended
as a method of limiting the population build-up of the beetles through elimi-
nation of their food and lodging.
From 1948 to 1971, 132 contracts were executed, in many cases to remove fire
damaged timber. On most stands, 10 to 15 percent of the stand is removed in
each cut and the same area is recut in 5 to 10 years depending upon the accumu-
lation of trees severely damaged by smog and bark beetle activity.
Figure A5 shows 29 areas on which more than 50,000 board feet was cut between
1948 and 1971. Barton Flats and Holcomb Valley have been cut twice during this
period and one small parcel in the heavily smog-damaged area near Lake Arrowhead
has been cut three times.
Salvage logging is undoubtedly a significant factor influencing succession in
the conifer stand. The selective logging of ponderosa and Jeffrey pines reduces
seed production of these species because the larger trees are removed. After
16 years of observation, Powells and Schubert (1956) reported that the larger,
dominant ponderosa pines produced more than 99 percent of the cones. Further-
more, even the small amount of soil surface disturbance by tractors and skidding
logs provides a mineral soil seedbed favorable to the white fir and incense
cedar, both of which are less important commercially and are more susceptible to
fire. These circumstances coupled with constant air pollution damage and growth
suppression of the more sensitive pines may lead in the ponderosa pine-white
fir and sugar pine-white fir forest types to a higher density of less valuable
and more fire vulnerable timber species such as white fir and incense cedar.
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A-15.
Another impact of logging has been an increase in the rate of fire spread.
Countryman (1955) relates this increase to a change in microclimate resulting
from the logging of closed canopy forests. Rate of fire spread was shown to
increase up to four and one-half times in logged-over forests. If the replace-
ment stock in the understory is white fir or incense cedar as indicated above,
fire mortality greater than for ponderosa or Jeffrey pine would result.
Since 1911, 850 acres were reforested in the San Bernardino National Forest
(not including the San Jacinto Mountain area). The species planted included
Jeffrey, ponderosa, sugar, Coulter, and knobcone pines and the Jeffrey-Coulter
hybrid. Small plots of Sierra redwood are included within the planted areas.
Poor seedling survival has made it necessary to replant and interplant the same
areas. Seedling survival was generally poor, but has improved slightly since
1965 because of improved planting methods and more favorable soil moisture
(file reports, San Bernardino National Forest).
Fires have destroyed several of the better plantations throughout the years.
For example, the Bear fire in 1970 wiped out a successful plantation near
Thomas Hunting Ground.
The areas which are selected for replanting represent the best sites most
favorable for tree growth. This practice results in a very "spotty" pattern
of tree replacement. With generally poor survival, the total effect of
replanting at the current rate is not a major factor affecting succession
in the conifer forest.
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A-16.
In 1890-1910, when the larger virgin timber was gone from the mountains and
the Arrowhead and Big Bear reservoirs were built, the recreational use and
urbanization of the mountains boomed. In 1893, the San Bernardino Forest
Reserve (National Forest) was created and in 1929 the San Gorgonio wilderness
area was set aside. In 1929, 2 million visitors were counted entering the
mountain area, more by far than entered any of the famous national parks.
Today nearly 9 million visitors enter the forest annually.
The distribution of the permanent residents and recreational activity is
indicated in Figure A6a and b. The shape of the four 1970 census tracts (Running
Springs approximated) and data for permanent residents and dwelling units was
obtained from SCRIS Report No. 3 (1971) (Fig. A6a). The projection of popu-
lation and land use in the mountain communities from 1970 to 2020 prepared by
Urbanomics Research Associates (1970) , says "the fact that a high percentage
of the lands in question are designated as National Forests suggests minimal
urban and economic development in these areas in the future." However, the
increasing attraction of the mountains for recreation may well result in the
construction of high rise developments.
Low to high intensity use of public land represented by the wilderness
area, picnic sites, improved campgrounds, and water and snow sports activity in
14 Recreational Information Management areas in 1970 is shown in Figure A6b (File
report, San Bernardino National Forest). Roads alone occupied 336 acres in
the Crestline-Lake Gregory areas in 1961 (Villa-Lovas, 1961).
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A-17.
Man's activities other than logging which alter the physical environment of
the forest include all of the characteristics of urbanization:
1. Disturbance has resulted from the construction of major highways and
streets in a terrace-like configuration in new forest communities.
Normal drainage is disrupted and those trees not removed have their
root systems exposed or buried by cut and fill. Asphalt is often
placed over root systems and winter-salting of major roads causes
salt damage to road side trees. Constant trimming and tree removal
is done in power and telephone line corridors.
2. A vast increase in the number of recreationists using the forest
f
can deplete forest litter and compact the soil with heavy foot traffic.
Ponderosa pine is the species least likely to survive in campgrounds
because of bark beetle attack on larger stressed trees and mechanical
damage to seedlings (Hall and Pierce, 1965; Magill, 1970). The
increase in off-trail motorcycle use, especially impromptu hill
climbing on steep slopes, has produced a labyrinth of erosion scars
where utiderstory vegetation and conifer seedlings have been torn from
the soil.
c 3, The disposal of treated sewage water from mountain communities presents
difficult problems. At present, Lake Arrowhead's effluent is being
sprinkled from settling ponds onto chaparral vegetation in Maloney
Canyon northeast of the Lake where a controlled study of the effects
of irrigation on natural vegetation is in progress (Fig. A6a). Big
Bear Lake communities pump treated sewage water into the "dry" Baldwin
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A-18.
Lake because permission was denied for dumping into Arrastre Creek vhicl
drains north to the Mojave Desert communities (Fig. A6a) . The Crestlij,
Lake Gregory area has many septic tanks and leach lines, but is being
converted to a sewer system.
4. Fire control in the urbanized and heavily used forest has resulted in t|
accumulation of large fuels on the forest floor. If a catastrophic
wildfire should break out of control in the conifer forest, these
additional fuels could produce a hotter fire to kill even the larger
trees (Dodge, 1971).
Influence of Abiotic Agents on Successionin the Conifer Zone
In addition to fire, the three most important abiotic agents influencing tree
growth, survival, and plant succession are drought, winter drying, and
breakage by accumulated snow and ice.
Extended droughts occurred in 1893, 1894, and 1917 (La Fuze, 1971) and during
the late 1950's and early 1960's. Species respond differently to drought
so that changes in stand composition and type distributions are to be expected.
A differential response of seedlings of conifer species to drought in the
ponderosa pine-white fir forest type has been demonstrated and indicates that
prolonged drought would result in a shift toward Jeffrey and ponderosa pine
in this type (Stone, 1957).
Winter desiccation causes injury to many trees in the coniferous forest zone
as a result of an excess of transpiration over water absorption on warm sunny
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A-19.
winter days when soil is cold or frozen. The impact of winter desiccation has
not been studied in the San Bernardino Mountains. However, the extensive areas
over which it occurs suggests that this damage may be significant in the develop-
ment and composition of vegetation types, especially on exposed ridge crests where
heavy accumulations of ice break the tops of the tree causing the crown to be
flat-topped. John Muir commented on this in an 1896 visit there with Pinchot.
Ponderosa pine withstands the rigors of the ridge crest better than other species.
The Effect of Tree Diseases on Succession in the Conifer Zone
The infectious tree diseases of importance in the Pinyon-Juniper and main
conifer zone may be categorized as root rots, stem rots, limb and gall rusts,
needle diseases and both dwarf and true mistletoes.
Root Rots
Armillaria mellea, the oak root fungus, is a very widespread inhabitant of the
roots of many woody plants (Baabe, 1962). It is only occasionally detected as
the cause of death of pines and firs in this area mainly because it becomes lethal
only on trees weakened by some other agent. Proof of its common occurrence was
presented several years ago when the root systems of blown-down Jeffrey pines on
Skyline and Sugar Loaf Ridges south of Big Bear Lake were inspected. Many large
roots were infected; these weakened roots probably brought about the windthrow.
Annosus root disease caused by Fomes annosus is found in discrete infection
centers involving from a few up to 20 trees, most often ponderosa and Jeffrey
pines and occasionally white fir. Small infection centers occur in upper
Barton Flats, eastern Big Bear Valley, and the vicinity of Big Pine Flat
north of Big Bear Lake.
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A-20.
The black stain root disease caused by Verticicladiella wagnerii is a very
serious disease of pinyon pine. Throughout nearly 8,000 acres of the Pinyon-
Juniper forest, this disease has been recognized in small centers ranging from
one-fourth to one acre. It does not attack juniper but it was found on one
occasion on Jeffrey pine. The area of most intense infection is east and
south of Baldwin "dry" Lake.
Stem Rots
Parish (1894) described the common occurrence of pocket dry rot of incense
cedar (Libocedrus^ decurrens) caused by Polyporous amarus. It is still common
today and may seriously limit the longevity of incense cedar. A very extensive
rot column is common in white fir (Abies concolor) but the exact decay organism
is unknown. Polyporous schweinit zii is occasionally observed causing a root
and butt rot of Jeffrey pine.
Rusts
The gall rust caused by Peridermium harknessii is occasionally found on
ponderosa pine near Cedar Springs and Stockton Flat, and on lodgepole pine
(Pinus contorta) at Dollar Lake. The limb rust found primarily on Jeffrey
and ponderosa pine caused by Peridermium stalactiforme occasionally becomes
locally epidemic; for example, in Green Canyon. It is controlled by pruning
and tree removal.
Needle Diseases
The only needle disease of importance is caused by Elytroderma deformans.
It is the major needle disease of ponderosa and Jeffrey pines in western North
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A-21.
America. Its perennial nature and its unique capacity to infect the host
twigs enables it to maintain itself even under adverse environmental conditions.
It reaches epidemic proportions near lakes and stream beds and in moist years.
This disease is found regularly throughout the San Bernardino National Forest.
Currently, intense infection centers are found northeast of Big Bear Lake and
in the upper Barton Flat area.
Mistletoes
These are the most widespread and serious parasites of conifers in the San
Bernardino National Forest. Species of the true mistletoe (Genus: Phorodendron)
infect white fir (_P. bolleanum ssp. pauciflprum) and incense cedar (P_. juniperinum
spp. libocedri). At higher altitudes, white fir is heavily infected; the tops of
older trees in particular are often covered by mistletoe foliage. The trees
weaken and die or are killed by bark beetles. The mistletoe in incense cedar
causes negligible damage to its host.
The greatest timber loss can be attributed to the dwarf misteltoe (Genus:
Arceuthobium) on ponderosa, Jeffrey, Coulter, and knobcone pines (A.
campylopodum). Branch arid trunk swellings and cankers and "brooming" cause
severe damage to the host. Eventually badly infected trees must be removed
by sanitation salvage logging. Jeffrey pine Is more susceptible to the dwarf
mistletoe than is ponderosa pine and areas of severe infection may be found
in the upper Barton Flat and in Holcomb Valley. Coulter pines in the San
Bernardino Mountains suffer heavier infection and mortality than Jeffrey pine.
A., divaricatum is found on Pinyon pine near Horse Springs some 8 miles NE of
Lake Arrowhead and elsewhere in the Pinyon-Juniper zone.
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A-22.
It is evident that some of the tree diseases discussed above have a definite
influence on succession, either directly by killing trees outright (Black stain
root rot of pinyon pine and Fomes annosus root rot of pines and fir) or indirectly
by causing removal of infected trees (dwarf mistletoe and limb rust).
Direct Effects of Oxidant on Important Species. Particularly in the Conifer Zone
Identification of the cause—Conspicuous damage to needles of ponderosa pine
in the conifer zone was noticed in 1953 (Asher, 1956) but similar damage was not
observed in the chaparral zones on any species at that time. This new damage
of unknown cause or origin was at first believed to be related to the black
pine leaf scale [Nuculaspis californica (Coleman)J, but a survey and subsequent
map by Stevens and Hall (1956) showed no coincidence between the occurrence of
heavy scale infestation and the new "needle dieback" of ponderosa pine.
The suggestion that an air pollutant might be the cause of this new disease
(Asher, 1956) led to an investigation, beginning in 1957, for the Kaiser Steel
Corporation to determine if flouride emission from the Kaiser plant at Fontana
was responsible for the damage. Analysis of needle tissue did not indicate
sufficient flouride accumulation to cause injury, but the data gathered from
1957 until about 1961 suggested that damage was related to smog (Kaiser Steel
Corporation file reports, 1956-1961). The investigators noticed the same
symptoms on Coulter, Jeffrey, and sugar pines in the conifer zone and similar
mottle symptoms on wild grape, California sycamore, big leaf maple, and willow
in the drainages.
Parallel observations described the "chlorotic decline" of ponderosa as charac-
terized by a progressive reduction in terminal and diameter growth, loss of all
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A-23.
but the current season's needles, reduction in number and size of the remaining
needles, yellow mottling of the needles, deterioration of the fibrous root
system, and eventual death of the tree (Parmeter, Bega, and Neff, 1962). Exami-
nation of roots, stems, and needles failed to disclose the presence of pathogenic
organisms. An extended period of drought from 1946 to 1960 coincided with
the first observations of the condition. Examination of annual terminal
growth indicated that healthy trees responded to increases in precipitation,
but trees in decline did not. The inception of the decline corresponded
with reports of air pollution injury to grapes in the San Bernardino Valley
not more than 15 air. miles away (Richards, Middleton, and Hewitt, 1958).
In 1960, reciprocal bud and twig grafts were established between healthy
and chlorotic decline trees growing side by side (Parmeter and Miller, 1968).
Four years' observation of these twig grafts led to the conclusion that a
graft transmissible agent, namely a virus, was not present and could be
discounted as a possible cause of the decline disease. Fertilizer was applied
once to decline trees and observations for four growth seasons indicated no
improvement of tree condition (Parmeter and Miller, 1968). Mechanical injury
inflicted upon root systems of healthy trees did not induce chlorotic decline
symptoms nor did removal of all ages of needles over a two year observation
period. However, the needles of ponderosa pine treated with 0.5 ppm ozone in
plastic enclosures for 9 to 18 days under field conditions developed a chlorotic
mottle, terminal dieback, and accelerated abscission similar to needle symptoms
of chlorotic decline (Miller et al., 1963) and the chlorophyll content of
needles treated with ozone for 18 days was generally less than that of ambient
air controls.
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A-24.
A series of studies extending from 1957 to 1966 (Richards et al, 1968)
identified ozone as the cause of the symptom syndrome referred to by Parmeter
as "X-disease" and "chlorotic decline" and the name "ozone needle mottle of
pine" was coined (Richards et al., 1968) to specifically name the causal
agent and permit the inclusion of other pine species exhibiting similar
symptoms.
Studies concentrated mainly in the Crestline-Lake Arrowhead area (Asher, 1956
Hall and Stevens, 1956) indicated the damage, which extended for 12 miles
from west of Crestline to just east of Lake Arrowhead along the undulating
ridge crest, was most severe at Crestline. Evidence of the oxidant or ozone
injury at Running Springs, Camp Angeles and Forest Home areas was also reported
(Kaiser Steel Corp., Edmunds and Richards, 1959).
In the summer of 1969, damage to the ponderosa-Jeffrey pine stands in the San
Bernardino National Forest, excluding the Big Bear Lake area but including
San Jacinto peak and the San Gorgonio Wilderness area, was estimated by use of
special aerial photographic techniques developed by the U.S. Forest Services's
Pacific Southwest Forest and Range Experiment Station. Of the 160,950 acres
of ponderosa-Jeffrey type within the forest boundaries, 46,230 acres had heavy smog
damage; 53,920 moderate damage; and 60,800, light or no damage. An estimated
1,298,000 individual trees were affected: 82% moderately, 15% severely and
3% completely dead (Fig. A7, Wert et al., 1970).
The extent and severity of damage to shrub and tree species in the chamise
chaparral and woodland chaparral is not known. Severe damage to the big-cone
Douglas-fir and slight damage to knobcone pine has been recognized in the
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A-25.
woodland chaparral (Miller and Millecan, 1971), but damage to shrubs such as
ceanothus and manzanita has been ignored or unrecognized.
Measurements of the concentration gradients of total oxidant from the basin at
the city of San Bernardino up to the mountain crest on the south-facing slope
have shown the highest concentrations and longest duration of concentrations
greater than 0.10 ppm to be in the lower woodland chaparral zone (Miller,
McCutchan, and Ryan, 1970).
Incidence of bark beetle infestation
The sometimes sudden death of declining trees prompted field studies to
determine the role of bark beetles in the over-all picture and to compare
some physical and physiological characteristics of healthy and diseased
trees which could relate to increased susceptibility to beetle attack or
greater attraction of beetles. A survey was made in 1966 to determine the
severity of the decline at the time of attack and to establish for future
examination neighbor trees which were also under the influence of air
pollution and which would be adjacent to emerging bark beetle broods from
the killed tree (Stark et al., 1968).
Trees exhibiting advanced chlorotic decline symptoms were more frequently
attacked by the western pine beetle, Dendroctonus brevicomis LeConte, and
the mountain pine beetle, I), ponderosae Hopkins, than those exhibiting less
severe symptoms of decline. There was no apparent relationship of insect
attack or chlorotic decline with crown class, total height, length of live
crown or diameter.
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A- 26.
As a test of the survey results, 100 trees In each of three disease categories
—advanced, intermediate, and healthy—were examined intensively for history
of insect attack. The findings substantiated the survey results: of 60 trees
showing incidence of bark beetle attack, 36 were in the advanced category, 19
in the intermediate, and 5 in the healthy group. These data suggested that
chronic oxidant air pollution injury predisposes sensitive ponderosa pine to
bark beetle attack.
Selected physical and physiological characteristics of healthy and oxidant
inj ured trees
Oleoresin exudation pressure, yield, flow rate and crystallization rate,
sapwood and phloem moisture contents, and phloem thickness were observed (Cobb
et al., 1968). Chronic oxidant injury caused a reduction in oleoresin
exudation pressure and the crystallization rate of oleoresin increased with
disease severity. The moisture content of both sapwood and phloem tissues
showed a decrease from the healthy level in both intermediate- and advanced-
diseased trees. There was also a progressive decrease in phloem thickness
with increase in disease severity.
The subsequent effect of chronic photochemical atmospheric oxidant injury on xylat
oleoresin composition, phloem sugars and reserve carbohydrates, and phloem pH
of ponderosa pine was studied (Miller et al., 1968). Oleoresin samples from
healthy and advanced-diseased trees were analyzed for differences in monoterpenes
and resin acids, but no significant differences between healthy and injured
classes were found, nor was there significant difference in quantities of
selected resin acid compounds present in healthy and diseased trees.
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A-27.
Samples for phloem carbohydrates were taken from groups of healthy, intermediate-,
and advanced-diseased trees. There was a reduction generally in the amounts of
sugars and reserve polysaccharides, but only the decrease in reserve poly-
saccharides comparing intermediate- and advanced-diseased trees in the summer
was statistically significant. There was no significant change in phloem pH
due to the disease.
Histological and histochemical appraisal ofozone damage to needle tissue
Chloroplasts aggregated in the peripheral portions of mesophyll cells within
5 days after the start of ozone fumigation (0.45 ppm). Concurrently, the
homogenous distribution of proteins and nucleic acids was disrupted. Acid
phosphatase activity increased within mesophyll cells during ozone exposure.
Mesophyll cell wall destruction occurred after appreciable intracellular
damage. Histological and histochemical changes occurred within 5 to 7 days
while macroscopic symptoms were not visible until two to three weeks after
fumigation (Evans and Miller, 1972a).
Two pine species most sensitive to ozone (ponderosa and Jeffrey) exhibited a
larger number of stomata per cross-sectional area of mesophyll cells while the
number of mesophyll cells per stomata was lower. The number of hypodermal
layers and thickness of epidermal and hypodermal layers was negatively
correlated with ozone sensitivity. In the more ozone tolerant pine species
(Coulter and sugar), initial injury was more closely associated with sub-
stomatal mesophyll cells. Oxone injury occupied a greater length of the entire
needle of the sensitive species as evidenced by the proximity of symptoms to
the needle base (Evans and Miller, 1972b). These results suggest that needles
of ozone sensitive species may be more "ventilated" than those of tolerant
species.
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A-28.
Changes in apparent photosynthesis
Three-year-old ponderosa pines fumigated in controlled environment chambers
with ozone at 0.15, 0.30, or 0.45 ppm had apparent photosynthesis rates reduced
by 10, 70, and 85 percent, respectively, after 30 days exposure. A fumigation
with 0.30 ppm ozone for 33 days reduced the polysaccharides content of both
current and one-year-old needles by 40 percent. Soluble sugar content of
current year, ozone-injured needles increased 16 percent and that of the
one-year-old needles decreased slightly. Higher content of ascorbic acid
in one year old needles did not protect the tissue from ozone injury (Miller
et al., 1969).
Apparent photosynthesis rate of whole plants after ozone injury was determined
in terms of C 0,, uptake which made it possible to compare the apparent photo-
synthetic activity of current-year needles with one year old needles. One
group of seedlings demonstrated that one-year-old foliage was suppressed (77
percent of control), but the current-year foliage was not (113 percent of
control) even though each age of needle had lost about 25 percent of its
chlorophyll (Miller, 1965).
Ozone effects on specific photosynthetic reactions
Both light requiring and dark reaction sequences of photosynthesis were
investigated. The Hill reaction rates of chloroplasts isolated from healthy
and ozone-injured needles were compared at several light intensities. Chloro-
plasts from ozone-injured needles were less capable of Hill reaction activity
at all light intensities in spite of equal chlorophyll concentration. Repeated
comparisons of the chlorophyll a/b ratio of extractions from 0 injured and
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A-29.
healthy plants did not indicate any significant change (Miller, 1965) suggesting
that qualitative or quantitative chlorophyll changes are not the primary
cause of Hill reaction or apparent photosynthesis depression.
The pattern of labeling by C 0_ in the 80 percent ethanol soluble photosynthate
14
of healthy and ozone-injured needles was compared after C 0 fixation for
various lengths of time. No qualitative differences in the pattern of labeling
in the photosynthate were observed following separation by two dimensional
paper chromatography (Miller, 1965).
Relative ozone sensitivity of the important conifer species
Extreme variability of response has been encountered among individuals of a
single species and between fumigations at different times (spring, summer,
fall). Much more replication within experiments and repetition of fumigations
was required than initially anticipated. The goal of fumigation work is to
provide a quantitative, statistically treated estimate of the relative sensi-
tivity of each species compared with ponderosa pine which is included in
every experiment. These data are now being analyzed, but an approximation
of the relative ozone sensitivity of the various species is presented in Table
All (Miller, unpublished).
Effect of oxidant:(ozone) cm the growth of ponderosa pine
Oxidant concentrations with average daily peaks of 0.20 ppm occurred almost
every day from May through September during 1968-1970 at Rim Forest (5,680 feet)
in the San Bernardino National Forest (Miller, 1971). Maximum daily concentra-
tions as high as 0.58 ppm have been recorded repeatedly. In August 1968, groups
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A-30.
of sapling ponderosa pines were enclosed in greenhouses. One house received
activated carbon filtered air, the other unfiltered ambient air. A control
group, not enclosed in a house, was observed simultaneously.
After filtered air treatment for only one year, the symptoms of needle injury
virtually disappeared. Even those trees in an advanced stage of injury were
able to recover in the filtered air environment. These data illustrate the
amount of growth suppression due to photochemical oxidant damage which would
not otherwise be visible (Miller, unpublished). In 1971, those trees in
filtered air which began with only one damaged needle whorl now have four
healthy whorls and the needle length of each new whorl is longer than the
last. Trees receiving the two unfiltered air (ambient smog) treatments have
declined in vigor and most retain only one needle whorl.
In the above experiment ponderosa pine served as an accurate bioindicator of
both improved air quality and of ambient smog after only one year by virtue of
changes in needle symptoms, growth, and retention. This remarkable capability
of pines to serve as an information storage system was also exploited in the
San Bernardino Mountains by Dr. Harold C. Fritts of the Laboratory of Tree Ring
Research, University of Arizona. Figure A8 (Fritts, In Press) shows measurements
of ring width variation as a function of the date of the annual rings. "The
abrupt decline in width at the beginning of the 1950's and 1960's is apparent
in both plots (Fritts, personal communication)." Both of the oxidant-damaged
Jeffrey pines examined were cut in a sanitation salvage logging operation in
1971 in the San Bernardino Mountains. A complete statistical treatment of
these data would separate the anticipated variation due to tree age and annual
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A-31.
precipitation from variation in ring width due to air pollution. This could
provide precise dating of the inception of damage and possibly reconstruct
the responses of the important species in the conifer zone,
Possible Changes in Community Composition Induced by Oxidant Air
Pollution
The complex of variables which interact to influence the individual plant and
subsequently shape the plant community are illustrated in Figure A9, modified
from Billings (1952). It is apparent that both a primary and secondary
influence is exerted by oxidant air pollution in this system. The task of
identifying and quantifying these influences must be performed, if only
provisionally, so that hypotheses for important change can be developed and
tested.
The effect of oxidant air pollution will not be the same in all vegetation
zones in the San Bernardino Mountains. Measurement of oxidant concentration
gradients on the south-facing slopes of the mountains above San Bernardino
(Miller et al., 1970; Edinger et al., 1971) indicated that the chamise-ceanothus,
chamise-manzanita and lower portion of the woodland chaparral zones receive the
longest daily exposure to adverse oxidant concentration and often the highest
daily maximum. However, the greatest visible damage is in the conifer zone.
The timing of severe oxidant exposure both on a daily and seasonal basis is an
important factor determining damage. In the chaparral zones, the daily oxidant
peak occurs during periods of lowest relative humidity, whereas, in the
conifer zone, the peak oxidant occurs later in the day when relative humidity
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A-32.
is increasing (Miller et al., 1970). What influence does humidity have on
stomatal behavior and uptake of pollutant in each vegetation zone?
The Pinyon-Juniper forest and the desert chaparral are more remote and
not as heavily influenced by the marine air mass bearing the oxidant air
pollution. However, the Pinyon-Juniper zone and the chaparral zones cannot
be excluded from consideration because of the wildlife of the conifer zone
which freely use the other zones for feed or cover.
The riverine vegetation, which includes such species as California sycamore,
California bay and Fremont cottonwood, deserves great attention because it is
an area rich in wildlife and it often occupies the mid-to-lower elevation
southern slopes which receive long oxidant exposure.
Even the lodgepole pine (P_. contorta) and limber pine (P_. flexilis) above
8,000 feet cannot be considered exempt from oxidant injury, especially those
on the south-facing slopes of San Gorgonio Peak where the thermal updraft
carries polluted air upward.
At this time, no surveys have been made to identify oxidant damage in the
Pinyon-Juniper, riverine, or alpine zones.
The possible successional trends in the conifer zone have been examined in
relation to site, species composition, ponderosa decline rate, mortality and
silvicultural literature (Miller, 1971). The species composition and age
structure in a heavily damaged 575 acre mixed conifer stand (Table AIII)
show that ponderosa pine is by far the most numerous species in size classes
-------
A-33.
larger than 12 inches dbh (diameter-breast-height). White fir had the greatest
number of survivors in three size classes from seedlings up to poles 11.9 inches
dbh; followed by ponderosa pine, incense cedars, and sugar pine. From 1969 to
1971, the mortality of ponderosa pine was 8.1 percent in a subsample of 160 trees.
In.this group, the number of trees exhibiting no visible injury declined from
27 in 1969 to 11 in 1971.
the 575-acre study area was a relatively smooth, undulating ridge crest over-
looking the polluted air basin to the south and with an abrupt transition to
a north-facing slope dissected by several small intermittent drainages.
Ponderosa pine was most severely damaged by oxidant on the ridge crest where
it was greatest in number, perhaps demonstrating its suitability for this
more severe site. A deterioration at the forest border is suggested, emphasizing
the importance of site as a factor determining succession in the conifer zone.
Hypothesis for Succession in the Conifer Zone
Earlier in this section, it was stated that ponderosa and Jeffrey pines are less
affected by drought and fire than white fir or incense cedar. Sugar pine, a
very desirable species because of apparent oxidant tolerance, is generally
present in such low numbers that it has little potential for natural replacement
of other conifers. Bark beetles, root diseases, dwarf mistletoe, sanitation
salvage logging and urbanization are factors interacting with oxidant air
pollution to deplete the numbers and depress the growth and regenerative capacity
of ponderosa and Jeffrey pine. The growth of white fir and incense cedar is
visibly retarded by oxidant damage and it is probable that other valuable shrubs
and herbs are being eliminated completely from the community (Harvard and
-------
A-34.
Treshow, 1971). Thus, oxidant damage is a potent new selection pressure in
the conifer forest.
Another problem of increasing importance is the large accumulation of heavy
fuels (Dodge, 1971, Dell and Wilson, 1971) in the conifer zone created as a
result of the smog-insect killed trees and of successful fire control policy.
The more abundant white fir and incense cedar regeneration in the understory
is less fire tolerant than are the pines. Catastrophic fires can penetrate
the conifer forest (Bear Fire - 1970) during periods of high winds. The
accumulation of heavy fuel causes a hotter fire which would destroy most of
the seedlings and more of the larger trees. Also, the forest canopy is being
opened up through removal of trees by construction, selective logging and
mortality due to insects and smog, thus increasing rate of fire spread
(Countryman, 1955). Historical records show that bad fire years occur about
every 8 years (Show and Kotok, 1924) . Fire causes the site to become more
xeric and changes the nutrient and water status of the soil. Oxidant air
pollution—the new selective force—retards the regeneration of all vegetation,
both pre- and post-fire. The development of low value timberland chaparral
which occurred after early logging and fires (Horton, 1960) may be repeated in
additional acreages hard-hit by oxidant air pollution and by fire, thus offering
very poor prospects for the future of the conifer forest. The most important
element is time. The multiple effects of air pollution must be understood so
that remedial action can be defined and enacted to save not only the valuable
southern California conifer forests but also those of the western Sierra Nevada.
-------
A-35.
Recommendations for Future Study
1. Reconstruct the history of oxidant air pollution impact on the several
important conifer species and California black oak at selected sites
in the San Bernardino Mountains by the methods of dendrochronology.
Growth ring width variations when standardized for tree age and pre-
cipitation records can show the relative effects of air pollution on
different species, aided by X-ray techniques for measuring wood density.
This would be a powerful tool for predicting future trends. An unpolluted
control area would be included.
2. Carefully define successional trends in the conifer zone by a) estab-
lishing permanent observation plots to describe rate of deterioration
and mortality of both trees and understory vegetation and to observe the
natural replacement of these smog-killed species; and b) determining the
ecological potential of the major species through controlled environment
studies and ordination along gradients of important environmental factors
such as elevation, soil moisture and distance from pollution.
3. Prepare better vegetation type maps with the aid of aerial photography.
4. Investigate the effects of oxidant air pollution on the physiological
potential of the important species with emphasis on the reproductive
stages of the life cycle: flowering, pollen germination, fertilization,
maturation of seeds and fruit.
-------
A-36.
5. Determine if interactions between oxidant air pollution and the major
established plant pathogens (e.g., dwarf mistletoes and root rots)
alters pathogenesis or epidemiology (spread).
6- Define interactions between forest microclimate and oxidant air pollution
which alters rate of pollutant uptake or tree sensitivity (e.g. thinning).
7. Identify the direct and indirect effects of oxidant air pollution on soil
microorganisms (detoxification and nutrient cycling).
8. Sample and evaluate the beneficial or non-beneficial roles of root surface
raicroflora (mycorrhizae) and the effect of oxidant air pollution on these
organisms.
9. Estimate energy flow into a selected type in the conifer zone with and
without oxidant exposure.
10. Investigate the effects of combinations of pollutants on ponderosa pine
based upon preliminary ambient air monitoring for selected pollutants, e.g.
total oxidant, ozone, PAN, SO , NO .
£• 3C
Recommendations assembled from suggestions of:
W. C. Snyder W. W. Wilcox
M. N. Schroth Oen Huisman
D. C. Hildebrand A. H. Gold
R. D. Raabe A. R. Weinhold
of the University of California, Berkeley
-------
Table AI. Vegetation zones, vegetation types, and major species" in. cne sau bex.uai.uxi'iO i^^^a.^^.
Vegetation
zone*
Horton's vegetation
type*
Minnich's vegetation Map
type** symbol
Major species
Chamise-
Chaparral
Woodland-
Chaparral
Pure chamise-
chaparral
Chamis e-ceanothus
chaparral
Chamis e-manzanita
chaparral
Scrub oak
chaparral
Coastal
sagebrush
Live oak
chaparral
Live oak
woodland
Big-cone Douglas
fir forest
none
Soft chaparral
Hard chaparral
Oak chaparral
Coastal sage
scrub
Emergent oak
woodland
Interior oak
woodland
Big-cone Douglas
fir forest
so
CS
Sro
-BS
Adenostoma fasciculatum
Adenostoma fasciculatum. Ceanothus
crassifolius, £. leucodermis, Quercus^
dumosa, Photinia arbutifolia, Rhus ovata.
Adenostoma fasciculatum, Arctostaphylos
glauca. A. glandulosa. Ceanothus
crassifolius. £. leucodermis
Quercus dumosa, (}. wislizenii, Cercocarpa
betuloides, Ceanothus leucodermis, Garrya
yeatchii, Arctos taphylos glandulosa
Artemisia californica, Salvia apiana,
Eriogonum fasciculatum, Encelia farinosa,
Salvia mellifera, Diplacus longiflorus
Quercus wislizenii, Q. chrysolepis.
plus hard"chaparral species
Quercus wislizenii. (}. chrysolepis,
Pseudotsuga macrocarpa, Cercocarpus ledifolius
Pseudotsuga macrocarpa, Quercus chrysolepis
-------
Table AI. (cont.)
Vegetation
zone*
Horton's vegetation
type*
Minnich's vegetation
type**
Map
symbol
Major species
Woodland-
Chaparral
Desert
Chaparral
Pinyon-
Juniper
Woodland
Knobcone pine
forest
none (see
pine forest)
Desert
chaparral
Pinyon-Juniper
woodland
Knobcone pine
forest
Coulter pine
forest
Desert
chaparral
Western Juniper-
mountain mahogany
woodland
Pinyon pine
woodland
Pinyon-Juniper
woodland
GEL. pinus attenuata, Adenostoma fasciculatum,
Arctostaphylos glandulosa, Ceanothus
leucodermis, Pickeringia montana
CE
CP
Pinus coulteri, Quercus wislizenii, (}.
chrysolepis, plus hard chaparral species
Cercocarpus ledifolius, Quercus wislizenii,
2.- dumosa, (£. chrysolepis, Ceanothus
greggii, C. crassifolius, Fremontia
californicus, Garrya veatchii
Juniperus occidentalis, Cercocarpus
ledifolius, Artemisia tridentata,
Chrysothamnus nauseosus
Pinus monophylla, P_. quadrifolia,
Juniperus californica, J_. occidentalis,
Cercocarpus ledifolius, Artemisia
tridentata, Chrysothamnus nauseosus
PJ ginus monophylla, P_. quadrifolia, Juniperus
californica, J^ occidentalis, Cercocarpus
ledifolius, Artemisia ^ridentata,
Chrysothamnus nauseosus, Arctostaphylos
glauca, Quercus dumosa
D
PJT
PJ
-------
Table AI. (cont.)
Vegetation
zone*
Pinyon-
Juniper
Woodland
Timberland
Chaparral
Coniferous
Forest
Horton's vegetation
type*
Great Basin
sagebrush
none
none
Timberland
chaparral
Pine forest
Minnich's vegetation
type**
Great Basin
sagebrush
Joshua Tree
woodland
Juniper-Joshua
Tree woodland
Timberland
chaparral
none (see Coulter
pine forest, dry
Map
symbol
GB
JS
JJ
CT
Major species
Artemisia tridentata, Artemisia arbuscula
nova, Chrysothamnus nauseosus, Colegyne
ramossissitna, Eriogonum spp., Salvia spp.
Yucca occidentalis, Yucca brevifolia,
Chrysothamnus nauseosus
Juniperus occidentalis, Yucca brevifolia,
Artemisia tridentata, Chrysothamnus nauseous
Arctostaphylos oatula, Ceanothus cordulatus,
Castanopsis sempervirens
Pinus ponderosa, Pinus jeffreyi, Pinus
coulteri, Quercus kelloggii
Ponderosa pine-
white fir forest
Sugar pine-
white fir forest
Grassland
forest)
Mixed yellow pine-
white fir forest
none (see pure yellow
pine-white fir forest)
Grassland or
meadow
.M
Pinus ponderosa, Pinus jeffreyi, Abies
concolor, Pinus lambertiana, Libocedrus
decurrens, Quercus kelloggii
Pinus lambertiana, P_, jeffreyi, Abies
concolor, Quercus chrysolepis, plus
timberland chaparral species
Bromus spp., Carex spp., Juncus spp.
-------
Table AI. (cont.)
Vegetation
zone*
Horton's vegetation
type*
Minnich's vegetation
type**
Map
symbol
Major species
Coniferous
Forest
Black oak woodland
Alpine forest
Barren areas
none (see dry forest)
Subalpine forest
Krummholz
Barren
LP
LP.
K
Quercus kelloggii, Quercus chrysolepis,
Pinus ponderosa, Pseudotsuga macrocarpa,
Ceanothus iiitegerrimus
Pinus contorta, P_. flexilus, plus
timberland chaparral species.
Pinus contorta, Pinus flexilus, plus
stunted timberland chaparral species.
none
All Zones
none
none (see Pine
forest, ponderosa
pine-white fir
forest)
none (see Pine
forest, black oak
woodland)
none
Marginal conifer
forest
Pure yellow pine-
white fir forest
Dry forest
Riverine
vegetation
TF A mixture between pure yellow pine-white
fir forest and timberland chaparral species
PF Pinus ponderosa, P_. jeffreyi, P_.
laabertiana, Libocedrus decurrens, Abies
concolor
DF Pinus coulteri, Quercus kelloggii
Platanus racemosa (below 4,000 feet)
Populus trichocarpa (below 4,000 feet),
Alnus rhamnifolia (4,000-7,000 feet),
Salix spp. (above 7,000 feet), Populus
tremuloides (Fish Creek)
-------
Table AI. (cont.).
Vegetation
zone*
Horton's vegetation
type*
Minnich's vegetation Map
type** symbol
Major species
All Zones
Outside of
Above Zone
none
none
Subclimax
vegetation
Open desert
vegetation
Varies with site
* Horton (1960)
** Minnich (1969)
-------
Table All. Approximate ozone sensitivity of important western conifers.
Conifer Zone
Woodland Chaparral Zone
San Bernardino
National Forest
Sierra
Nevada**
San Bernardino
National Forest
Sensitive
Ponderosa Pine
Jeffrey Pine
White Fir
Western
White Pine
Big-cone Douglas fir
Monterey x Knobcone Pine
Moderately
sensitive
Coulter Pine
Incense Cedar
Rocky Mountain
Ponderosa Pine
Red Fir
Knobcone Pine
Tolerant
Sugar Pine
Giant
Sequoia
Miller, unpublished data.
**
Species not native to the San Bernardino National Forest.
-------
Table AIII. The relative numbers per acre of four conifer species in five
size classes on a 575-acre study area severely influenced by oxidant air
*
pollution.
Size
Class
Ponderosa Incense White Sugar
Pine Cedar Fir Pine
Seedlings up to
3.0 ft. tall
Saplings more than
3.1 ft. tall & less
than 3.9 inches dbh
Poles
4.0 to 11.9 inches
dbh
Standard
12.0 to 23.9 inches
dbh
Veteran
24.0 inches dbh
and larger
Totals:
% of Grand Total;
1057 2381 1043 302
33 33 57 10
21 12 38
18
12
1141 2440 1150 320
23 48 23 6
Miller, 1971.
-------
LIST OF FIGURES
Figure Al Vegetative Zones. Horton, 1960.
Figure A2 Vegetative Types. (Minnich et al. 1969). Attached at end of report
Figure A3 Wildfires. 1911-1970.
Figure A4 Logging. 1831-1930.
Figure A5 Sanitation-Salvage Logging. 1950-1971.
Figure A6 Distribution of Permanent Population and Recreational Use. 1970.
Figure A6b Traffic Patterns in Fourteen Recreation Information Management
Districts. 1970.
Figure A7 Smog Impact Area.
Figure A8 Decrease in Ring Width Growth Due to Air Pollution. (Fritts, In Press).
Figure A9 Suggested Interactions of Oxidant in the Forest Environment.
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ID - 148021
RING WIDTHS
1810 1820 1830 1840 1850 1860 1870
ID = 148032
RING WIDTHS
1890 1900 1910 1920 1930 1940 1950 19
1630 1340 1850 1860 1870 I860 1690 1900 1910 1920 1930 1940 1950
Figure A-8 - Decrease in ring width
growth due to air pollution.
(Fritts, In Press)
-------
SUGGESTED INTERACTIONS OF OXIDANT IN THE FOREST ENVIRONMENT
TOPOGRAPHY
Figure A-9
-------
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Asher, J. E. 1956. Observation and theory on "X" disease or needle dieback.
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Cobb, F. W. Jr., D. L. Wood, R. ¥. Stark, and P. R. Miller. 1968. Photochemical
oxidant injury and bark beetle (ColeopterarScolytidae) infestation of
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Dodge, M. 1971. Forest fuel accumulation—a growing problem In manuscript.
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Edinger, J. G., M. H. McCatchan, P. R. Miller, B. C. Ryan, M. J. Schroeder,
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-------
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-------
Section B
EFFECTS OF OXIDANT AIR POLLUTION ON THE FOREST ECOSYSTEM
OF THE SAN BERNARDINO MOUNTAINS
Committee Chairman: J. T. Light, U.S. Forest Service
Researched and Written By:
J. T. Light, U.S. Forest Service} San Bernardino,
Hatch Graham, U.S. Forest Service, Wilbur Mayhew,
University of California, Riverside, Eugene Cardiff,
San Bernardino County Museum, Glenn R. Stewart, Cal
Poly, Pomona, Paul R. Miller, University of California,
Riverside, Murray B. Gardner, University of Southern
California
Principle Contributors:
Assisting in the development of this draft were A. Starker Leopold,
U. C. Berkeley; Michael H. Horn, Cal State Fullerton; Herbert R.
Melchoir, Cal State San Diego; Bruce Browning, California Department
of Fish & Game, Sacramento; Ted Hanes, Cal State Fullerton; Bonnar
Blong, California Department of Fish & Game, Idyllwild; Marvin J.
Whalls, Cal Poly, San Luis Obispo; Richard L. Hubbard, U.S. Forest
Service, PSWF&RES, Fresno; Edward R. Schneegas, U.S. Forest Service,
San Francisco.
-------
EFFECTS OF OXIDANT AIR POLLUTION
ON THE FOREST ECOSYSTEM
OF THE SAN BERNARDINO MOUNTAINS
VERTEBRATE PATHOLOGY
INTRODUCTION
An ecosystem is composed of four main constituents: abiotic substances,
producers, consumers and decomposers (Odum, 1959). This section deals with
consumers: vertebrate organisms which are directly or indirectly dependent
on producers or vegetation for food and cover. Vertebrates in the forest
ecosystem include primary (herbivore) and secondary (carnivore and insectivore)
consumers. Primary consumers are grazers, browsers and seed eaters.
The distribution of vertebrates in the forest ecosystem is governed by the
availability of water and the quantity and quality of the plants in the
system.
Each vertebrate organism occupies a distinct ecologic niche in the forest
ecosystem. Difficult to define, a niche may be described as a place in the
ecosystem in which a particular vertebrate is bound by its structural
adaptations, physiological responses and specific behavior. The specific
role of the niche in the ecosystem is not completely understood.
A general listing of vertebrates and their habitat by vegetative types has
been compiled by the San Bernardino National Forest in a Habitat Management
Plan, Forest Wildlife (Light and Graham, 1968).
-------
B-2.
History of Vertebrates
Man's attitudes toward the environment have effected the status of vertebrates
in the San Bernardino Mountains both directly and indirectly. These attitudes
can be divided into eras of impact which have altered the status of vertebrates
in the study area.
Era of Abundance (1769-1840)
Man's major concern during this period was survival. The abundance of
vertebrates provided the main food supply and depletion of the wildlife
by Indians and outpost missions was minimal.
Era of Exploitation (1840-1900)
Extensive mining of the San Bernardino Mountains during this period
resulted in large-scale slaughter of deer and bighorn sheep for food.
Miners, cattlemen and other residents regularly harvested trout, deer,
bighorn sheep, pigeon, quail and other small animals without restriction.
Concern over the rapid decline of bighorn sheep led to the first hunting
restrictions imposed in 1873, but considerable poaching persisted.
Considered a threat to lives and property, the grizzly bear became
extinct prior to 1921. However, trout were abundant in the Santa Ana
River near the confluence of Bear Creek (LaFuze, 1971) until the early
1900's when natural regeneration diminished because of the damming of
the river and the accumulation of sediment loads deposited in the channel.
Range lands were heavily used by domestic livestock, thus reducing range
carrying capacity and altering the habitat of many species.
-------
B-3.
The Homestead Act resulted in extensive development of valuable wildlife
areas for home tracts and pastures while much land was inundated by
reservoirs. Such misuse persisted until informed citizens instituted
protective legislation for the conservation of wildlife resources.
Era of Preservation and Propagation (1900-1945)
During this period, numerous regulatory agencies were established by
the federal and state government to manage and protect wildlife resources.
Their activities included reduction of cattle on depleted range, protection
of bighorn sheep, imposition of hunting seasons and bag limits, protection
of all scavenger or carrion feeding birds, designation of wildlife refuges
and preserves, and protection from wildfire, insects and disease. Various
species such as trout (1893), black bear (1934), beaver (1940) and upland
game birds were introduced to the San Bernardino Mountains.
Concurrent with these developments, the practices of the logging industry
during this period resulted in the conversion of extensive timber area to
vegetation favoring game population increases (Miller, 1972 ).
As a result of all these measures, wildlife populations increased beyond
all expections. By the early 1940's, populations of game, primarily deer,
had increased beyond range carrying capacity.
Era of Regulated Harvests and Habitat Management (1945-1970)
The increase in game populations during the previous era necessitated a
period of control. Studies (Dasmann, 1963; Lounghurst, 1952; Taber, 1958)
-------
B-4.
indicated that management of deer populations and their habitat was
essential and that habitat conditions produced by the environment played
the major role in game population (Dasmann, 1963). Imbalances resulting
from environmental factors such as temperature and amount and distribution
of rainfall produce marked fluctuations in wildlife populations.
With hunting restricted by fire closures, limited access, private property,
game refuges and firearms closures, habitat management has become the
primary method of wildlife control. Habitat management plans, with
emphasis on increased availability of water and forage, have been developed
by the San Bernardino National Forest Service for the following species:
San Bernardino Deer Herd (Light, 1965)
San Gabriel Deer Herd (Winter and Light, 1965)
Quail (Graham, 1966)
San Gorgonio Bighorn (Light, et al., 1966)
Birds (Graham, 1966)
San Gabriel Bighorn (Light, et al., 1967)
Forest Wildlife (Light and Graham, 1968)
Beaver (Light, 1969)
Fish (Light, 1969)
Coordination of other land uses is now needed if the wildlife resource is
to continue its role in the forest ecosystem.
Era of Environmental Concern (1970- )
Beginning in 1970, national attention was focused on the cumulative effects
of human activity upon the environment. Concern developed for the perservati"11
of our national resources.
-------
B-5.
Nevertheless, current human activities continue to effect the Forest
Ecosystem. Construction of homes and highways is replacing many
important wildlife habitats (Aschmann, 1959). Producer plants and
primary consumers have been and are continuing to be displaced.
Oxidant air pollution emanating from the Los Angeles and San Bernar-
dino basins is having a pathological effect on vertebrates. The users
of the homes and highways further contribute to this air pollution.
Recreational activities such as shooting, motorcycling, and hiking
effect the use of a habitat by both the primary and secondary
vertebrates. Vertebrate habitats in the line of sight zone are
being displaced as if by the bulldozer.
The cumulative effects of human activity in the Forest Ecosystem are
eroding away the habitat of the primary consumer vertebrates such as
the deer and the bighorn; deer now being primarily concentrated in
areas inaccessible or not often frequented by man (Fig. A6b)-
Having put the status of vertebrates in historic perspective, it is now
necessary to isolate the major or critical vertebrate species in the eco-
system in order to consider the possible effects of oxidant air pollution on
the selected vertebrate species.
The current status of vertebrates is shown on the graphic map of the San
Bernardino Mountains (Fig. Bl ) which indicates locations of selected vertebrates,
See the Habitat Management Plan Forest Wildlife (Light and Graham, 1968) for a
complete listing of habitat types and vertebrates.
-------
B-6.
THE VERTEBRATES IN THE ECOSYSTEM
Determining the effects of oxidant air pollution on the vertebrate environment
in the Forest Ecosystem requires a thorough inventory of all vertebrates; a
life history of each vertebrate type; a determination of the dependency of a
vertebrate on a particular community or group of plant communities; and the
isolation of all the possible environmental variables affecting the vertebrates.
Inventory of the vertebrates in the San Bernardino Mountains (Light and
Graham, 1968) has begun. General life history data on the listed vertebrates
is available but not in sufficient detail to relate specifically to the
vegetation communities in the San Bernardino Mountains. The vertebrates studied
for their life histories which occupy vegetation types in the oxidant air
pollution impact zones (P. R. Miller, 1970) are:
Bewick's Wren (Swarth, 1916)
Brown towhee (Davis, 1951)
Scrub & Steller's Jays (Swarth, 1918)
Deer (Taber and Dasmann, 1958)
Wood Rat (Horton, et al., 1944)
Mole (Grinnell and Swarth, 1912)
Chickadee (Grinnell, 1918)
Nuthatches (Korris, 1958)
Chipmunks (Johnson, 1943)
Gnatchatchers (Grinnell, 1926)
Trout (Calhoun, 1966)
Turkey Vulture (Stager, 1964)
-------
B-7.
Studies of other species may have been made, but an extensive review of
literature will be required to extract them.
The larger mammals and birds of interest to man such as deer, bighorn, gray-
squirrel, quail, and pigeon have received extensive study in northern California,
but not in the San Bernardino Mountains. Inventories (Light and Graham, 1958)
have been made of the above species in the San Bernardino Mountains using
behavior and physiological studies made in other areas for comparative analysis
in determining habitat management. However, precise physiological (life
history) data must be gathered on these vertebrates if the effect of oxidant air
pollution is to be determined.
Vertebrate - Vegetative Type Dependency
The dependency of vertebrates on plant communities in the forest biome may be
simple or complex. The Vertebrate-Habitat Dependency Matrix (Table Bl)
(Munnich, 1971; Horton, 1960; Light and Graham, 1968) gives a broad example
of the dependency of vertebrates on the various vegetation types which fall
within the zone of heaviest oxidant air pollution impact (Miller et al., 1970).
Vertebrate Food Chains
The quantity of vertebrate mass by vegetation types is indicated on the vertebrate
- habitat dependency matrix. Another step with respect to each vertebrate's
role in a food chain will enable isolation of the ecologically important verte-
brate for study. The matrix then provides a source for developing a vertebrate
food chain or energy flow chart using the Producer and Consumer constituents of
the system.
-------
B-8.
A simplified vertebrate food chain for larger vertebrates in the black oak
woodland vegetative type is:
Consumers:
Secondary: Mountain lion, Man, Audubon's Warbler,
Coyote, Bobcat, Red-tailed Hawk
Primary: Gray Squirrel, Deer, Band-tailed Pigeon
Producer : Black Oak mast
More complex vertebrate food chains were derived from the matrix for the pine
forest, bigcone Douglas fir and chamise chaparral plant communities of the San
Bernardino Mountains and are shown in the Appendix.
From a cursory analysis of the Vertebrate - Habitat Dependency matrix a listing
of important vertebrates with significance for the oxidant air pollution study
has been devised (Appendix B).
VERTEBRATE PATHOLOGY
The pathological effects of oxidant air pollution on vertebrates has received
limited study in the clinical laboratory, but no study of its affects on
vertebrates in the wilds has been made.
Oxidant air pollution effects in this discussion are classified as either
Direct or Indirect. The Direct effects result from exposure of the vertebrate
to ambient air. The Indirect effects result from exposure of both vegetation
and vertebrates to ambient air involving a break down in the food chain of a
group or particular species of vertebrates.
-------
B-9.
Direct Pathology
Clinical laboratory research of mice and rats has revealed that ambient air
depresses running activity (Emik, et al., 1969; Campbell, et al., 1970), causes
an Increased susceptibility to pulmonary infection but not to increased
pulmonary neoplasia (Gardner et al., 1966, 1970) and promotes the development
of a renal (kidney) degenerative disease in male rats (Gardner et al., 1969).
These studies also indicated that neoplasia and renal degenerative diseases
varied significantly when comparing one strain of mice and rats with another.
Such pathological studies have not been performed in the San Bernardino
Mountains.
It has been well documented (Gardner, 1966) that photochemical smog will "exert
an irritant effect upon human respiratory and ocular mucous membranes". The
probability that this could occur with other vertebrates exists. In the San
Gabriel Mountains, bighorn sheep, Ovis canadensis nelsoni, have been found to
be totally or partially blind from what appears to be cataracts (white blotches
in the eyeball). Older bighorn appear to be those effected. This pathological
phenomena has been observed only in bighorn in the Lytle Creek and East Fork
of the San Gabriel River watersheds of the range where heavy oxidant air pollution
occurs.
Air pollution is suspect in causing respiratory ailments in animals. The effect
could be particularly acute in animals already suffering a high incidence of
respiratory ailments (lungwo mi-pneumonia complex is common in bighorn sheep) or
in animals with a high metabolic rate (swallows, swifts, warblers, etc.).
-------
B-10.
Peroxyacetyl nitrate (PAN), a common constituent of smog, causes eye irritation
in humans. This eye irritation could be far more serious to those vertebrates
which depend on their eyesight for survival, such as swallows, eagles and hawks.
Other effects may occur such as interrupted embryo development similar to that
which results from Hypoxia. The function of the olfactory gland in vertebrates
may be impaired by the ambient air causing a decrease in food-gathering ability,
such as in the Turkey vulture (Stager, 1964), Few of the smaller vertebrates
(rodents and lizards live more than three years in the wild which will make it
difficult to demonstrate any pathological effects of oxidant air pollution
(Stewart, 1971).
Indirect Pathology
The effect of air pollution on plant development and succession is extremely
important to wildlife. Plants can be adversely affected in many ways, but in
general, studies indicate that most plants are affected in a quantitative rather
than in a qualitative sense. Growth of truck farm crops such as lettuce and
celery and of citrus trees has been retarded due to photochemical reactions
resulting from oxidant air pollution (Hindawi, 1970; Jacobson et al., 1970).
The probability exists that certain herbs and shrubs in the forest ecosystem
of the San Bernardino Mountains are also effected by oxidant air pollution.
Observations indicate a quantitative reduction in growth of chamise leaves,
Adenostoma fasiculatum, although the nutrient quality of chamise remained the
same (Hanes, 1971).
-------
B-ll.
Deer habitat analysis conducted by the San Bernardino National Forest Service
indicates that deer use fluctuates with the growth trends of important browse.
Any reduction in vegetation growth, either naturally or as a result of ambient
air, would have far reaching and subtle effects on vertebrates dependent on
annual forage production.
Most vertebrate biologists believe that the primary effects of oxidant air
pollution on vertebrates in the San Bernardino Mountains will prove to be
exerted indirectly through changes in the vegetation. From an analysis of
the vertebrate food chain models of most vegetative types the herbivore
vertebrates, including the rodents and ungulates, appear to provide a signi-
ficant research link. The survival of this group is dependent on the
quantitative production of forage plants. The productivity trends of the
herbivores will similarly effect the productivity trends of omnivore and
carnivore vertebrates who prey on the herbivores.
The probable effects of oxidant air pollution on the aquatic environment would
be of an indirect nature. Limited studies have been made of the effect ambient
air would have on vertebrates in this environment (Holeton, 1971; Whitworth,
1970). Direct pathologic effects may result from the ingesting of suspended
particulate matter arriving in the aquatic environment from the atmosphere
through precipitation (Whitworth, 1970). Indirect pathological effects on
coldwater fish, which predominate in the San Bernardino Mountains, may result
from the loss of vegetation, thereby causing an increase in water temperatures,
a reduction in dissolved oxygen, an increase in biological oxygen demand, and a
reduction of desired aquatic insects which serve as food. Research should be
directed toward an entire aquatic ecosystem located in the ambient air impact
zones as described by P. R. Miller (1970).
-------
B-12.
SUMMARY & RECOMMENDATIONS
An inventory of animals existing in the San Bernardino Mountain area has been
made and their habitat relationships to plant communities is fairly well known.
However, the details of each species' ecologic niche and their dependency on
certain vegetation is only partially understood. The role of each species in
the ecosystem is only basically known (Primary consumer, secondary consumer).
Food habits are known in detail for only a few species.
Present knowledge of the physical effects of oxidant air pollution on the
animals themselves can be derived only sketchily from limited research on
laboratory animals. Nothing is known about the multitude of possible effects
from injury by oxidant air pollution to green plants (producers) and the
habitat changes that may then gradually occur. It is easy to speculate
about changes in quality of forage for ruminants; quantity of food for
seedeaters; plant succession and food availability for animals with specific
food requirements; insect abundance; litter accumulation for shelter of small
mammals and reptiles; and microclimatic changes. Hard facts, obtained by
well-directed, intensive research, are badly needed to measure the magnitude
of the environmental change, both existing and potential.
More precise information on all variables effecting important systems of
vertebrates is needed. Most vertebrate biologists agree that precise inventories
of all vertebrates need to be made in the oxidant air pollution impact areas
(Miller, 1970). Once this is accomplished, the effects of oxidant air pollution
on vertebrates can then be measured. Most contributors expressed the need to
establish a baseline (or control) forest ecosystem not influenced by oxidant
air pollution in order to compare the effects of ambient air on the vertebrates.
-------
B-13.
LITERATURE CITED
Arbib, R. S., et. al. American Birds incorporating Audubon Field Notes
Notes. N.A.S. Vols. 1-25.
Aschmann, H. 1959. The Evolution of a Wild Landscape and its Persistence in
Southern California. A. A. G., Vol. 49, No. 3, Part 2.
Buie, E. E. 1958. Best of Buie, "Bear May Still be in Those Hills". Sun
Telegram.
Campbell, K. I., Emik, L. 0., Clark, G. L., Plata, R. L. 1970. Inhalation
Toxicity of Peroxyacetyl Nitrate. A.M.A., Arch. Environ. Health. Vol. 20,
pp. 22.
Dasmann, W. P. and Dasmann, R. F. 1963. Abundance and Scarcity in California
Deer. CDF&G, California Fish & Game, Vol. 49, No. 1.
Emik, L. 0., and Plata, R. L. 1969. Depression of Running Activity in Mice
by Exposure to Polluted Air. A.M.A., Arch, of Environ. Health, Vol. 18,
pp. 574.
Gardner, M. B. 1966. Biological Effects of Urban Air Pollution. Arch, of
Environ. Health, Vol. 12, pp. 305-313.
Gardner, M. B., Loosli, C. G., and Hanes, B. 1969. Histopathologic Findings
in Rats Exposed to Ambient and Filtered Air. Arch, of Environ. Health,
Vol. 19.
Gardner, M. B., Loosli, C. G., Hanes, B., and Blackmore, W. 1970. Pulmonary
Changes in 7000 Mice Following Prolonged Exposure to Ambient and
Filtered Los Angeles Air. A.M.A., Arch, of Environ. Health, Vol. 20.
Graham, H. 1965. A Quail Habitat Management Plan. U.S. Forest Service,
San Bernardino.
Graham, H. 1967. A Bird Habitat Management Plan. U.S. Forest Service, San
Bernardino.
Hanes, T. 1971. Personal Communication. Calif. State College at Fullerton.
Hindawi, I. J. 1970. Air Pollution Injury to Vegetation. National Air
Pollution Control Administration Publication No. AP-71.
Jacobson, J. S. and Hill, A. C. 1970. Recognition of Air Pollution Injury to
Vegetation - A Pictorial Atlas. Informative Report #1, TR-7 Agric.
Committee, Air Pollution Control Assoc.
LaFuze, P. B. 1971. Saga of the San Bernardinos. Vol. I and II, San
Bernardino County Museum Assoc.
-------
B-14.
Light, J. T. 1965. Habitat Management Plan. San Bernardino Deer Herd Unit.
U.S. Forest Service.
Light, J. T., Zrelak, T., and Graham, H. 1966. Habitat Management Plan, San
Gorgonio Bighorn, U.S. Forest Service.
Light, J. T., Winter, F., and Graham, H. 1967. Habitat Management Plan. San
Gabriel Bighorn, U.S. Forest Service.
Light, J. T. 1968. Habitat Management Plan, Forest Wildlife. San Bernardino
National Forest, mimeo, 37 pp. and Appendix.
Light, J. T. 1967. Habitat Mangment Plan. Forest Fishery of San Bernardino
National Forest, Unpublished.
Light, J. T. 1969. Habitat Management Plan, Beaver. U.S. Forest Service.
Longhurst, W. M., Leopold, A. S., and Dasmann. 1952. A survey of California
Deer Herds Their Ranges and Management Problems. CDF&G, Game Bulletin
No. 6.
Miller, P. R., McCutchen, M. H. and Ryan, B. C. 1970. Influence of Climate
and Topography on Oxidant Air Pollution Concentrations that Damage
Conifer Forests in Southern California. Presentation to VII International
Symposium of Forest Experts on Fume Damage, Essen, W. Germany.
Odum, E. P. 1959. Fundamentals of Ecology. W. B. Saunders Company, Philadelphia
and London.
Stager, K. E. 1964. The Role of Olfaction in Food Location by the Turkey
Vulture. Contributions of Science, L. A. Museum, No. 81:1-63.
Stewart, G. R. 1971. Personal Communication.
Taber, R. D. and Dasmann, R. F. 1958. The Black-tailed Deer of the Chaparral.
CDF&G, Game Bulletin, No. 8.
Winter, F. and Light, J. T. 1965. Habitat Management Plan. San Gabriel Deer
Herd Unit, U.S. Forest Service.
-------
Til
ol
K«,<.,,« v,,;t,^t^
MAMMALS
vrnnr-PMi - MAIMTAT ntPitwiscv MATRIX
--- — ...... -•—- . .........................
cra sa en- fit Ji a ffa s. a a .'!•.
Mule,
Shrew, Dusty
Hyolts. rrinqcd
Myotis, DWernla
Bat, Hoar>
Bit, Western Red
Bat, Lurap-nMed
Bat. PallV
Ground Squirrel,
California
Ground Snulrreu
GoldmantloJ
Chipmunk, Lodiienolp
Chipmunk, Merrlam
Gopher, Dntta roeket
House, Little pocket
House, White-eared
pocket
House, San Diego
pocket
House, California
pocket
Kangaroo Rat, Pacific
Mouse, Western Harvest
Mouse, Canyon
Mouse, Brush ,
Hoodrat, Dusky-footod
Meadow Mouse, California
Jack Rabbit, Black-tailed
Cottontail, Audubon
Rabbit, Brash
Gray Squirrel
flying Squirrel,
Beaver, Golden
Raccoon
Ringtail ed Cat
Weasel, Long-tailed
Skunks
1
5
3
I
S
3
*
Northern
uouyci ^
Fox, Gray 111
Coyote 1 ' ' '
Bobcat ' z
Bear. Black
Hon. Mountain « J
Deer. Mule 1131
Bighorn sheep __ — „ „_
Total" Mass 8 i5 10 16 2«
REPTILES t AHPHIB1AHS
lizards
Western Fence Lizard 1 111
Saqebrush Lizard
Side-blotchffd Lizard 1
Granite night Lizard
Western Skink
Gilbert's Skink
Western WhtnUll
foothill Alligator Lizard '
California leqlcss Li/ard
Snakes
SyBber snake
Rinqnecked snak»
Yellow-bellied racer
California Kinq snake
Mtn. Kinq snake
Striped whipsnake '
Common whiosnake 23 j
Gopher Snake 11111
Pacific Barter 3
Rattlesnake 1111
Western Garter
Amphibians
tschscTioFtz'5 SaleMnder
S, California Salairiaider
W. Spade Foot
Western Toad
Pacific Tree Fron
Canyon Tree Froq
ReJ-leqqed Frog
YelloM-leqqed Froq
Bull Froi
Total" ''Mass C t. .iynn-,
£•
-------
TABLE Bl (cont'd) -.
» , * TF £L
Audubon's Warbler 2
!!lack-(.hinnf(1 Sparrow 23 3
i!lack-thro?ted fir.-/ Warbler 3 . , - ,
Rim-bird, Western ' ,
Bush-tit. Common 32 - - ,
Clilckadcc, fountain 1 132
Creeper, Brown _ „
Crossbill, Red it-
Dipper 3
Dove, Mourning 2 1 » • 1
Eagle, no i den 3 3 '
Finch, Cossln's ,
Finch, House 3 3 3 3 2 3
Finch, Purple 3
Flicker, P.edshafted 5 1
Flycatcher, Ash-throated 23 3 2 *
Flycatcher, Dusky J 7 ?
Flycatcher, Olive-sided ' 3
Flycatcher, Western ^
Gnatcatchtr, Bluc-ciray 123 £ .
Goldfinch, Lawrence's 23 £
Goldfinch, Lesser 232 \
Hawk, Cocn?r's 33 1 » i i i
Hawk, Red-tailed 1 3 \ i \ \
Hav;k, Sparrow 22 1 * »
Hummingbird, Calliope 7
Himwingb'.rd, Anna's 3323 z ,
Jay, Scrub 23323 1 *
Jsy, Stellar's 3 3 3
Junco, Oregon ;*
Kinglet, Ruby-crowned »
Kinglet, Golden-crowned ' 71
La?u)1 Bunting 23 i
Martin, Furole 3 , , • ,
Nutcracker, Clark's ' z '
3 222
Nuthatch, Piqmy
3
Nuthatch, Red-breasted '
Nuthatch, White-bressted ' 3 3 3 i •
Orange-crowned Viarbler f "• •
Owl, Great-horned 33 Z t
Owl, Lontj-eared 32 J
Owl, Pigmy 3 2 2 1 j
Owl, Saw-whet 13
Owl, Screech 3 2 3
Owl, Flamulated • • ? r
Owl, Spotted 2 ,3 I J
Phoebe, Block ,
Pigeon, Bandtailed 1 3 -^ Z
Poorwlll 132
Ouail, California 3
Quail, Mountain 3 » t
Roadrunner 3 ' .
Robin 33 3
Saosucker, WilUanison's ' 31 '
.Saosucker, Yellow-bellied 3 3 I
Solitaire, Townsend's . 3 ™ .'
Solitary 71reo 3 , 3 , j
Sparrow, Lark 1 I
Soarrow, Rufous-crowned 32 J
Sparrow, Sage (Bell) 33. I
Swallow, Violet-green "I 3 • •> j
Thrasher, California 3311 ,
TUmouse, Plain 133 H ,
Towhee, Brown 312 1 (
Towhee, Green-tailed 3 3 •,
Towhee, Rufous-s-'ded 132321 3 !:
Herbllnq Vireo 3 0,
Western Tan^qer 3 33,
Wilson'^ Warbler • 3 ^
Woodpecker, Acorn 3 32 I
Hnodnecker, Downy 3 .
Wcodnecker, Hairy 1 '33 2 g
Woi.dneckcr, Nuttall'i ? 3 1 3 0
WoodDCCher. White-headed 123 I
Wren, BpwitVs 3321 3 ,
Wren, ilousf 123 . 3 n
Hrenti t 23 2 1 - |
Yellow Warbler _ __ _ JL
Total1'1 Mass 36 55 2?. 19 35 36 22 1 0 40 15 <<2 27 26 103 1.6 U
I - (tight !i Graham, 1%'!) 1-raro, ?~fairiy cornraon, S-atn/ndant
II - (Minnlch, I-I/1 dnd Hnrton, WO)
T', -I,,..•.(!•'! ?,.,',!• f.cruh r.i>r--('.M)'Hcr I-in" iwiUnAnt (l-f(1v«l»-|i,p
( '•,« (t,-.-.'ri.)l Cf i,, f. •,;. ,.i,.- ('in.' |-'i!->1i..-:iit (P;.f,r.v,..!,mrt
r.i Hied l.h'- rr^l IiF-lirv ,' '.vir,' I I'-Siih-." !i>i •.'• *••! M
'•,i ',• . i •. ' •: f/.H!),,rr,i' U-t'.;ici ..' '...illir I nn-.i
'•' ->.\ '., -, !<]•• ••<•: li:"r-"-nl ;-f..-r.ii,. ii,. Wiii.' II- i DI'I- >
'.i -. -.'.ir./..r, rv.k Ci -'f1.i. ' ••!, i : i •..ifi'ii-i ,<1
!H • I:M ' "..•.
! ; I-' ,-Mv.',-.--. l-iii-.-'-i'.iyo"'. ^-'"r..! »'i:(-. ' •• i> f. l-rnrc
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Appendix Section B
Appendix: VEGETATION TYPE TABLES
Listing of Key Wildlife Plants: Their
Wildlife Values* and Management
CHAM1SE-CHAPARRAL ZONE
Pure Chamise Chaparral Type
Chamise-Ceanothus Chaparral Type
Chamise-Manzanita Chaparral Type
Scrub Oak Chaparral Type
Coastal Sagebrush Type
WOODLAND-CHAPARRAL ZONE
Live Oak Chaparral Type
Live Oak Woodland Type
Bigcone Douglas fir Forest Type
Knobcone Pine Forest Type
DESERT CHAPARRAL ZONE
Desert Chaparral Type
PINYON-JUNIPER WOODLAND ZONE
Pinyon-Juniper Woodland Type
Great Basin Sagebrush Type
TIMBERLAND CHAPARRAL ZONE
Timberland Chaparral Type
CONIFEROUS FOREST ZONE
Pine Forest Type
Ponderosa Pine - White Fir Forest Type
Sugar Pine - White Fir Forest Type
Grassland Type
Black Oak Woodland Type
Alpine Forest Type
Barren Areas
RIPARIAN WOODLAND TYPE
OTHER IMPORTANT WILDLIFE PLANTS
* Protein values given in the following tables indicate the range which
starts high in the spring and drops to the low in winter.
-------
FURE-CHAMISE CKAFAB&AL TYPE
Location:
Principally found in areas of low
rainfall such as foothills on
coastal side of mountains, Cajon
Pass and H.Fk. of Mojave River.
From low levels to 5,500 feet on
south-facing slopes.
Climate:
Rainfall: 13 to 25 Inches
Growing season: 8 to 12 months
Mean sunnier max; 82°-94°
Mean winter oin; 29°-45°
Other Classifications:
Chaparral (ttunz)
Transition and Mountain Climatic Zone
Lower and Upper Sonoran Life Zones
WILDLIFE VALVES
DOMINANT SPECIES:
rase leal atum
(In this type chamise conprtses 75% or
more of the composition of the stand.
From Sen Gorgoaio Pass south, red-
shank (AdenostPma sparsifglliiml may
replace chamise in this rvpe,)
Food
Seeds - important food of Lawrence goldfinch (5-10% of diet)
Flowers - woodrat
Browse - poor producer of vital protein (4 to 14%) but relatively good source of
maintenance energy for browsers-rates fair to good as feed for deer.
Cover
Good except for roosting
Areas of this type are more productive when opened up and
interspersed with perennial grasses which provide the
protein lacking in chamise. Islands should be left if
better cover species are not available. Because of the
arid location water is often needed.
OTHER SPECIES IN TYPE:
WHITE SAG!
Salvia ag
CALIFORNIA SCRUB OAK
Quercus dimc-ss
BIGBEKRY MASZASIIA
Arctostapnylos glauca
EASTWOOD MANZAXiTA
ArctDstaphylgs glandulosa
These species occur scattered and together make tip less than 25% of this type.
this type their primary value is that they add variety.
Food
Seeds - berries and acorns
Cover
Fair to good
Leave for cover in small islands. Since all these except
Sage are "hard" species and chamise is relatively soft;
this type can be converted economically with a double-disc
treatmemt of the chaoise while skipping the other species.
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CHAMISE-CEANOTHU S
CHAPARRAL TYPE
Location:
Host widespread type on the coastal
side df the mountains; however not
found in Cajon or Lone Pine Creeks
or in the desert drainages; rarely
over 4,000 feet. Generally indicates
better site than Pure Chamise Chapar-
ral type.
Climate:
Rainfall: 13 to 35 inches
Growing season: 8 months
Mean Summer max: 82°-94°
Mean Winter mini 29°-45°
Other Classifications:
Chaparral (Munz)
Transition Climatic fcone
Upper Sonoran Life Zone
WILDLIFE VALUES
MANAGEMENT
DOMINANT SPECIES:
CHAMISE
Adenostoma fasciculatum
Seeds - important to Lawrence goldfinch (5-10% of diet)
Flowers - tfoodrats
Browse - poor producer of vital protein (4 to 14%) although it provides minimum
energy requirements for deer.
Chamise is less valuable than Ceanothus i*ich is co-
dominant in this type. This type represents s good site
for conversions, stoniness and slope permitting.
t 40%
HOARYLEAF CEANOTHUS
Ceanothus crassifolius
In some places replaced by:
CHAPARRAL WHITETHORN
Ce anothus leueodermis
Food
Seeds - in diet of quail, woodrats, ground squirrels
Browse - important to cottontails; fair to good protein supply {11-15%) and pre-
ferred by deer; rated good to excellent,
Cover
Excellent, especially the thonyC_. Leucodermts
Ceanothus is more desirable than chamise. In conversion
projects and wildlife feed openings, the Ceanothus should
be selected for the islands to be retained.
OTHER SPECIES US TYPE:
CALIFORNIA SCRUB OAK
Quercus dumosa
t 201
Food
Acorns - highly valued for many species of mammals and birds. Significant in diet
of bandtailed pigeon (10-25% of diet), quail (5-10% fragments), redshafted flicker
(5-10%), jays (25-50%), rufous-sided townee (5-10%), plain titmouse <5-10%),
California thrasher (2-5%), raccoon (5-10%), pocketgopher (10-25%), mule deer
(10-25% in winter). Acorns are low in protein but high in fats and carbohydrates
and good energy producers.
Browse - Protein levels 16 to 237. in spring, drops to 8% In mature foliage. Accounts
for 10-25% of diet of mule deer in some localities, up to 50% in spring.
Cover
Excellent for most species.
In this type, scrub oak is a valuable shrub to retain
for its high wildlife values.
TOTON (Christmasberry)
Photlnla arbuetfolia
Beyrigs - taken by many birds in small amounts: Wrenti
tailed pigeon, redbreasted sapsucker, California thrash
Browse - little used when mature
jver
Larger specimens (8-10*) provide good roosting cover
WrentiC (2-5% of diet) also band-
ter.
Occasional specimen shrubs should be retained.
Pood
Fruit
EUGARBUSH
Tthus ovata
?d
Fruit - taken by many birds and small :
of diet), mountain quail (2-5%)
Retain occasional specimen shrubs.
als, especially bandtailed pigeon (2-5%
Cover
Excellent
-------
CHAHXSE-MARZANITA
CHAPARRAL TYPE
LOGation:
Less extensive than Pure-Chemise or
Chamlse-Ceanothus Chaparral but of
widespread occurrence above 2,500
feet. 'Density of macusanita varies
from heavy to scattered. Bigberry
manzanita is usually at lower eleva-
tions and at Cajora Pass (more arid
sites). Eastwood manzanita is mostly
on the coastal slopes above A,000 feet.
Climate;
Rainfall: 13 to 35 inches
Growing season; 8 months
Mean summer max: 82°-9A°
Mean winter min: 29°-4S°
Other Classifications:
Chaparral Ofunz)
Transition and Mountain Climatic Zone
Upper Soncran Life Zone
SPECIES
WILDLIFE VALUES
MANAGEMENT
DOMINANT SPECIES;
Food
Seeds - important food of Lawrence goldfinch (5-10% of diet)
- voodrats
CHAMISE
Adenostoma fasciculate
jj
Browse - poor producer of vital protein (4-15%) but relatively good source of main
tenance energy for deer-rates fair to good for feed,
Cover
Good loafing and escape; poor roosting.
Where slope and soil conditions permit conversion, perennial
grass will normally be sore productive than this type for
most wildlife. A few islands should be retained for variety
and cover.
BIGBERRY MANZANITA
Arctostaohyiog glanca
EASTWOOD MANZAHITA
Arc tos taphy1os glandulgsa
Food
Berries - taken by many birds and mammals, California skunk (2-5%), and jays,
mockingbirds, raccoons, ground squirrels, black bear, coyotes, etc.
Browse - although taken some by deer, manzanita is A poor source of protein
(.57, or less) and has feu redeeming characteristics for forage; rated poor.
Cover
Often forms tall, impenetrable thickets - excellent for escape.
Hay be used for islands for escape cover and for the berries
07&ER ASSOCIATED^ SPECIES:
HOARYLEAP CEAHOTHUS
Ceanothus crassifolius
Usually associated with bigberry manzanita
CHAPARRAL WHITETHORN
May be associated with either species of
manzanita
Food
Seeds - in diet of quail, woodrata, ground squirrels.
Browse - important in diet of cottontail, fair to good protein supply (11-15%)
and preferred by deer; rated good to excellent.
Cover
Excellent
Preferred "leave" species for islands in conversion in this
type.
-------
SCRUB-OAK
CHAPARRAL TYPE
Location:
On north-facing slopes mostly above
4,000 feet to 5,500 feet
Climate:
Rainfall: 20 to 35 inches
Growing season: 8 months
Mean sunnier max: 82°-90°
Meic winter mln: 29°-40°
Other Classifications:
Chaparral
-------
EASTWOOD MABZAHITA
AgctoBtaphyloa glandulosa
Least valuable of the conmon species of this type.
Select wanzanita patches f?r wllctlife feed openings and
browseways in this type.
SCRUB-OAK CHAPARRAL TYPE
-------
COASTAL SAGEBRUSH TYPE
Location:
Generally below 3,000 feet on
elopes facing prevailing westerly -
in the "fog belt;" Canyon mouths.
Climate:
Rainfall: 10 to 20 inches
Growing season: 8 to 12 months
Mean sunmer max: 68°-90°
Mean winter min: 57°-48°
Other Classifications:
Coastal Sag* Scrub (Munz)
Intermediate Valley Climatic Zone
Sonoran Life Zone
Lower
WILDLIFE VALUES
DOMINANT SPECIES:
WHITE SAGE
Salvia apiana
Food
Seeds - birds, esp. Lesser goldfinch
Flowers - bees, hummingbirds, esp. Costa
Browse - lov value
Cover
Loafing cover for small birds and raamnals
Consider conversioi
on suitable soils.
in dense areas above 15 inches rainfall
Food
Browse - poor
Cover
Loafing cover for small birds and mat
CALIFORNIA SAGEBRUSH
ATternesia californica
CALIFORNIA BUCKWHEAT
ErioEonum faselculatm
Food
S_ee_ds_ * good, esp. for birds and small mammals; key food for Bell sparrow (10-25% of
diet).
Flowers - 1-51 of diet of jackrabbits, ground squirrels
Cover
Little value
Leave patches of buckwheat when planning conversion.
IWCIENSO
Sncelia farinosa
(Primarily from Flunge Creek east)
Seeds - sunflower-ltke widely used by upland game birds, and esp. American goldfinch.
house sparrow and whitecrown sparrow
Browse • poor
Cover
Little valus
Leave occasional patches or individual specimens.
OTHER INDICATOR SPECIES:
Seeds - goldfinches, other birds
Flowers - huscicebirds, esp. Costa
Browse - little value
Consider conversion of dense areas to provide interspersion
of perennial grasses and forbs.
SLACK SAGE
Salvia me.
-------
MONKEY FLOWER
longiflorus
- most favored native food of Allen hummingbird - also preferred by Anna
Cover
Slight value
Leave for value to hummingbirds and scenic beauty.
The Following Usually Occur in This_Type .
IndiyIduals^ Widely Spaced;
SUGASBTJSH
Rhua ovata
Food
Fruit - taken by many birds and small
diet}, mountain quail (2-5%)
Cover
Excellent
Is, esp. bandtailed pigeon (2-5% cf
Leave for cover in conversion projects.
CALIFORNIA SCRUB OAK
Quercus dumosa
Acorns - highly valued for many species for mammals and birds. Significant in
diet of bandtailed pigeon (10-25% of diet), quail (5-10% fragments), redshafted
flicker (5-10%), jays (25-50%), plain titmouse (5-1.0%), California thrasher (2-57«},
raccoon (5-10%), pocketgopher (10-25%), mule deer (10-25% in winter). Acorns are
low in protein but high in fats and carbohydrates and good energy producers.
Cover
Excellent for most species
Leave for cover in conversion projects.
HOLLYLEAF CHERRY
Prunus ilicifglia
Fruit _and_jeeds - Scrub Jay, pbainopepla, raccoon, chipmunk and woodrats take the
fruit and/or its large seed,
Browse - preferred by mule deer. Has high (20%) protein levels in spring (April;
declining (11Z) by fall (Oct)
Cover
The dense, prickly foliage is excellent cover.
Leave for browse and cover in conversion projects.
MOUNTAIN MAHOGANY
Cercocarpus betulaides
Food
Seeds - taken by some birds
Bro-vse - highly esteemed as forage. Protein levels range from a low of 7% in
January to 157. in April and about 9% in fall. Highly palatable; rated excellent
for deer (2-5%), good for bighorn.
Leave for cover in conversion projects.
COASTAL SAGEBRUSH TYPE
-------
LIVE-OAK
CHAPARRAL TYPE
Location;
On north-facing slopes from 3,500 to
6,500 feet; south-*facing slopes from
A,500 to 7,500. Mostly on the coastal
slopes and to a limited extent in the
Mojave River drainages.
Climate-.
Rainfall: 22 to 45 inches
Growing season: 6 to 9 months
Mean summer max: 8l°-93°
Mean winter rain: 26°-40°
Other Classifications:
Chaparral (Munz)
Mountain Climatic Zone
Upper Sonoran and Transition Zone
WILDLIFE VALUES
SPECIES:
INTERIOR LIVE OAK
Quercus wislizenii
Food
Acorns - highly valued for many species of mammals and birds. Significant in diet of
bandtailed pigeon (10-25% of diet), quail (5-10% fragments), redshafted flicker (5-10%),
jays (25-50%), rufous-sided townee (5-10/0, plain titmouse (5-10%), California thrasher
(2-5%), raccoon (5-10%), pocketgopher (10-257=), mule deer (10-25% in winter). Acorns
are low in protein but high in fats and carbohydrates and good energy producers.
Browse - Protein level 16 to 237. in spring, drops to 87. in mature foliage. Accounts
for 10-25% of diet of mule deer in some localities, up to 507. in spring.
Cover
Excellent for most species.
land permitting access to adjoining types; typically scrub
oak chaparral on coastal slopes and desert chaparral on
interior. Not usually considered good chance for conversioi
In fuelbreaks situations, consider thinning and pruning.
CANYON LIVE OAK
Quercus chrysolepls
Occurs scatceringly throughout
type except on drier slopes
Food
Acorns - approximately same as above.
Browse - low in palatability; crude protein 5 to 11%; rated fair to poor; usually
unavailable.
Cover
Excellent for roosting.
Save for roosting trees.
Similar to interior live oak described above.
When favoring woodland development, remove this species in
favor of Interior or Canyon Live Oak in fuelbreak thinning.
CALIFORNIA SCRUB OAK
Occurs at lower limits of this
type where it merges with other
types
These preferred browse species are a valuable supplement to the live oaks in this type.
Retain where possible in development projects.
CHAPARRAL WHITETHORN
Ceanotfaua leucpdermjls
MOUNTAIH MAHOGANY
Cercocarpus betuloides
These species add little to the wildlife values in this type.
Where projects require fuel reduction, select these species
EASTWOOD MANZANITA
Arctostanhvlos elandulosa
BIGBERRY MAHZANITA
A. ftlauca
-------
LIVE-OAK WOODLAND TYPE
Location:
Host frequently found on north-facing
slopes 3,500 to 6,500 feet but less
common than Live Oak Chaparral type.
Climate:
Rainfall; 22 to !>5 inches
Growing season: 6 to 9 months
Mean summer max: 810-93°
Mean winter aim 260-iO'!
Other Classifications:
Foothill-Woodland (Muni)
Mountain Climatic Zone
Upper Sonoran to Transitio
[Life Zone
MANAGEMENT
WILDLIFE VALUES
DOMINANT SPECIES:
CANYON LIVE OAK
Quercus chrvsolepis
Food
Acorns - highly valued for many species of mammals and birds. Significant in diet of
bandtailed pigeon (10-25% of diet), quail (5-10% fragments), redshafted flicker
(5-10%), jays (25-507.), rufous-sided Towhee (5-107.), thrasher (2-57.), raccoon (5-102.),
pocketgopher (10-25%), mule deer (10-25% in winter). Acorns are low in protein but
high in fats and carbohydrates and good energy producers.
Browse - Protein levels 16 to 237= in spring, drops to 8% in mature foliage. Accounts
for 10-25% of diet of mule deer in some localities, up to 507. in spring.
Cover
Excellent for roosting.
This type is usually an intermediate stage in the succession
to a bigcone douglas-fir Forest Type, There is little habi-
tat management directed toward this type.
BIGCOHE DOUGLAS-FIR
Fseudotsuga macrocarpa
Scattered trees frequently occu
among the oaks
Food
Seeds - valued by many birds and mammals especially rodents.
Foliage - taken sparingly by several forms.
Cover
Roosting - used by many birds and squirrels.
Nesting - important to nuthatches, creepers, woodpecker and other cavity nesters.
Retain a few selected snags for nesting.
-------
B1GCONE DOCGLA5-7I3
FOREST TVP£
Lgcation:
Usually north-facing slopes. >test
extensive in Eastern San Gabriel
Mountains.
Climate:
Rainfall: 22 to 45 inches
Growing season: 6 to 9 months
Mean Summer max: 81°-93°
Mean Winter min: 26°-40°
Other Classifications:
Chas-firral -T (Munz)
Yel'.cv Pine Forest (Munz)
Mount sir. Climatic Zone
U^cer Sot^ren Life Zone
WILDLIFE VALUES
Where terrain penults removal to manage for healthy forest,
decadent species may be reooved to increase vigor of residual
stand. Retain a few selected snags for cavity nests or
sentinel posts.
This type is most valuable for insectivorous birds and for
squirrels. It is not extensive and usually is not a habitat
which benefits by cultural treatment.
DOMINANT SPECIES:
BIGC03E DOUGLAS-FIR
Pseudotsuga nacrocarps
Food
Seeds - valued by many birds and mammals especially rodents.
Foliage - taken sparingly by several forms.
Cover
Roosting - used by many birds and squirrels.
Resting " important to mithatces, creepers, woodpecker and other cavity nesters.
Food
Acorns - highly valued for many species of oaiamals and birds. Significant In diet of
bandtailed pigeon (10-25% of diet), quail (5-10% fragements), redshafted flicker
(5-10%), jays (25-20%). rufous-side towhee (3-10%), plain titmouse (5-10%), California
thrasher (2-5%), raccoon (5-10%), pocketgopher (10-25%), mule deer (10-25% in winter).
Acorns are low in protein but high in fats and carbohydrates and good energy producers.
Browse - Protein levels 16 to 23% in spring, drops to 87= in mature foliage. Accounts
for 10-25% of diet o£ mule deer in some localities, up to 50% in spring,
Cover
Excellent for roosting.
Retain for acom production sinor browse value, cover, etc.
-------
KNOBCONE-PINE
FOREST TYPE
Locat.ion:
Restricted to small areas of poor
site in City, Plunge and Keller
Creeks. Below 5,000 feet.
Climate:
Rainfall: 13 to 35 inches
Crowing season: 8 months
Mean Simmer max: 82°-94°
Mean Winter min: 29°-45°
Other Classifications:
Chaparral (Mtinz)
Transition or Mountain Climatic Zone
Upper Sonaran Life Zone
WILDLIFE VALUES
MANAGEMENT
DOMISAXT SPECIES:
Food
Seeds - seldom available in thia closed cone species
Browse - little value
Cover
Provides good cover for most species
Retain for cover. Site is usually not good enough for
conversion.
Plnus attenuata
OTHER ASSOCIATED SPECIES:
EASTWOOD MflHZANITA
Arctostaphylog glandulps
Food
Berries - taken by many birds and mammals, California skunk (2-5%), and jays,
mockingbirds, raccoons, ground squirrels, black bear, coyotes, etc.
Browse - although taken some by deer, manzanita is a poor source of protein (67. or
less) and has few redeeming characteristic for forage; rated poor.
Cover
Often forms tall, impenetrable thickets - excellent foe escape.
Retain for berries and cover in this type except in fuel-
break or browseway locations.
CHAMISE
Adenostoma fasctculatuia
Food
Seeds - important to Lawrence goldfinch (5-10% of diet)
Flowers - Woodrats
Browse - poor producer of vital protein (4 to 14X) although it provides minimum
energy requirements for deer.
Select browseway routes for fuelbreaks througl
when the choice presents itself.
CHAPARRAL WHITETHORN
Ceanpthus leucoderBtis
Food
Seeds - in diet of quail, woodrats, ground squirrels
Browse - important to cottontails; fair to good protein supply
preferred by deer; rated good to excellent.
Cover
Excellent, especially the thorny C. leucodermis
Retain for browse in this type.
CHAPARRAL-PEA
Pickeringla montana
Food
Seeds - valued by quail whan within their range, ground squirrels, kangaroo rats
Browse - taken by deer, especially after burns; notably high protein levels in
April and May (.197,) drops to 6 to 8% in winter; rated'good to excellent.
Select for browaaways to develop sprouts or for pollarding
studies.
-------
DESERT CHAPARRAL TYPE
i-ocatlon:
Mcjave River drainages, Cajou Pass
area, north and east slopes of San
Jacintc and Santa Rosa Mountains:
3.80C tc 7,500 feet; this type is
open grown vith numerous sub-shrubs
and auch exposed soil.
Climate:
Rainfall: 12 to 25 inches
Growing season: 5 to 8 months
Mean Summer max: 88°-95°
Mean Winter min.: 20°-30°
Other Classi ftcations:
Pinyon-Juniper Woodland (Munz)
Climatic Zone
Upper Sonaran Zone
WILDLIFE VALUES
30MINAST SPECIES:
DESERT MAHOGANY
Cercocarpus Iedifpli.u8
Also found in other types up
to 10,500
Food
Seeds - taken by sorae birds
Browse - highly esteemed as forage. Protein levels range from a low of 7% in January
to 15% in April and about 91 in fall. Highly palatable; rated excellent for deer
(2-57;), good for bighorn.
Because of the comparatively low rainfall, this type is
open grown with low density. It is very slow to recover
after damage by fire, drought or heavy grazing. Major
management should be directed toward protection of the
valuable forage species where present and available.
On depleted areas consider reseeding key species such as
Desert Mahogany and flannelbush. Where plants have become
unavailable because o£ height, considerable pollarding
projects (top pruning) and moderate grazing with livestock.
CALIFORNIA SCRUB OAK
Quercus dumosa
CANYON LIVE OAK
P.. chrvsolepis
Acorns - highly valued for many species of mammals and birds. Significant in diet of
bandtailed pigeon (10-25% of diet), quail (5-10% fragments), redshafted flicker
(5-107,), jays (25-507.), rufous-sided townee (S-10%), plain titmouse (3-10%), California
thrasher (2-57,), raccoon (5-10%), pocketgopher (10-25%), mule deer (10-257. in winter).
Acorns are low in protein but high in fats and carbohydrates and good energy producers,
Browse - Protein levels 16 to 23% in spring, drops to 8% in fall with mature foliage.
Accounts for 10-257= of diet of mule deer in some localities, up to 50% in spring.
Cover
Excellent for raost species.
DESERT CEANOTHUS
Ceanothus greggil
Food
Seeds - used by quail, woodrats, ground squirrels.
Browse - used by jackrabbits, deer, but less valuable than other d
Cover
Fair
leanothus; rated fair
FLANNEL BUSH
Fremontia callfqrnica
Pood
Seed's - rodents
Browse. - taken with apparent relish by all classes of hoofed browsers; rated excellent
for deer.
VEATCH SILKTASSEL
Carrya veatehli
shed by birds especially robins, waxwings, etc.
Browse - fair to good for deer. Protein level is from 5 to 127..
Cover
Good tc fair for loafing and escape.
See above
-------
PINYON-JUNIPER
WOODLAND TYPE
Location:
Principally in Deep Creek, in the
vicinity of Big Bear Lake, on the
north slopes of Santa Rosa Peak and
Martinez Mountain; also occurs in
Cajon Creek; at elevations between
3,000 to 9,000 feet.
CIli
Rainfallr 10 to 30 inches
Growing season: 5 to 8 months
Mean Summer max: &8°-95°
Mean Wtnter win: 20°-30°
Other Classi Cications:
Ptnyon-Juniper Woodland (Munz)
High Desert Climatic Zone
Upper Sonoran Life Zone
WILDLIFE VALUES
MANAGEMENT
DOMIKAHT SPECIES:
SINGLSLEAF PINYON
PInus monophylj.a
FOURLEAF PIN70K
Pinus
-------
GREAT BASE." SAGEBRUSH TYPE
Location:
Most commonly on gentle slopes a
valley floors on desert slopes;
3,000 to 7,000 feet.
Glim
Rainfall: 10 to 30 inches
Growing season: 5 to 8 months
Mean Summer max: 88°-95°
Mean Winter min: 20°-30°
01her_ C lass i £ ica t ions:
Sagebrush Scrub (ttunz>
Kigh Desert Climatic Zone
Upper Sonoran Life Zone
WILDLIFE VALUES
MANAGEMENT
DOHINAST SPECIES:
BASIN* (BIG) SAGEBRUSH
Arternesia tridentata
BLACK SAGEBRUSH
Artemesia arbviscula nova
Food
Seeds - used by a few species of birds and mammals.
Browse - a staple for wintering deer on desert slopes, but must be taken with other
species to be digestible. Black sagebrush may be more palatable than Basin.
Cover
Important to some species of birds in foraging.
Sagebrush on gentle slopes and valley floors is often evi-
dence of past heavy grazing on native perennials and
subsequent encroachment by the sagebrush. When residual
grasses constitute 6 to 8% of ground cover, consider release
spraying sagebrush with 2 Lbs. 2, 4-D per acre. If perennials
are depleted, spray should be followed by reseeding with
wheatgrasses.
There is sufficient sagebrush in other areas to provide any
needs not now recognized.
OTHER ASSOCIATED SPECIES:
Food
Slightly used by :
: birds and by rabbits. Poor browse for deer.
Should be included for spraying to release •
grasses.
ore valuable
RAB3IT3RVSH
ChrV5 a thammis spp.
3CCKHHEATS
SAGES
Salvia sgjp.
S.LACKBRUSH
Coleogyne ramossissima
Generally low value in this type except ss cover for birds which use grasses and forbs
in this type for food.
Same as above.
-------
TIX3=3LAM> CKAPARRAI. IYPE
Lofiattop:
Throughout the higher mountains;
best developed in eastern San
Bernardino Mountains; 5,000 to
11,000 feet.
Rainfall: 30 Co 45 inches
Growing season: 2 to 7 months
Mean Sunnier max: 65°-80°
Mean Winter min: 7 -34°
Other Classifications;
Yellow Pine Forest fMunz) and Subalpine Fores
Mountain Climatic Zone
Transition and Boreal Life Zone
WILDLIFE VALUES
MANAGEMENT
DOMINANT SPECIES:
MOUNTAIN WHITETHORN
Ceanothua cordulatus
Food
Seeds - mountain quail, chipmunks take some.
Browse - fair to good protein levels (6 to 15%); preferred by deer (33% of diet in
some localities); rated good to excellent.
Cover
Excellent for escape, nesting cover.
This type provides good wildlife feed and cover at the
higher elevations where it is open grown with only about
505; cover density. At the lover fS-6,0001) elevations it
forms solid brushfields which could be improved by browse-
ways, openings and accessways. In the denser stands it is
usable mainly by nesting songbirds.
PARRY MANZANITA
Arctostaphylos oarryana var.
pinetorum
Food
Berries - taken by many birds and mammals, especially fox sparrow (10-25% of diet),
black bears, etc.
Browse - rated poor.
Cover
Excellent; provides nesting cover for fox sparrow, green-tailed townee and others.
Food
Nuts - taken by chipmunks (2-5%) in small
Browse - poor to useless.
Cover
Fair
lounts by other rodents and birds.
BUSH CHINQUAPIN
Castanopsis semperyirens
DEER BRUSH
Ceanothus integerrJams
Food
Seeds - mountain quail, chipmunks and rodents take some.
Browse - one of the most valued summer browse feeds in California; well-balanced
amounts of crude protein, fat, mineral matter and nitrogen-free extract; protein
levels have been measured as high as 27% in spring; a higher nutritive value than
most grasses.
Cover
Good
Deerbrush should be encouraged where found. When clearing
for plantations, Leave as much as possible. It will divert
deer from the seedlings.
After 10 to 15 years of age, deerbrush may be out-of-reach
or decadent. Pollarding may induce sprouting and increased
vigor.
-------
PINE FOREST TYPE
Location:
Rather extensive in the San Bernardino
and San Jacinto Mountains between
5,000 and 8,000 feet; also in San
Gabriels and Santa Rosa to limited
extent.
Climate:
Rainfall: 25 to 50 inches
Growing season: 4 to 7 months
Mean Summer max: 80°-93°
Mean Winter min: 22°-34°
OthejrClassifications:
Yellow Fine Forest (Munz)
Mountain Climatic Zone
Transition Life Zone
SPECIES
WILDLIFE VALUES
DOMINANT SPECIES; COULTER PINE
Pinna coulteri
Generally at lower levels; common
in headwaters Deep Creek and Mojave
River, Western slopes of San Jacinto.
PONDEROSA FINE
Pinus ponderosa
Mostly below 6,000 feet.
JEFFREY PINE
Plnus Jeffrey-t
Mostly above 6,000 feet.
Food
Pines rank near the very top in importance to wildlife. They are included in the
diet of more species than any other genus save oak.
Seeds - notably valuable to Clark nutcracker (74% of diet), red crossbill (66%),
pygmy nuthatch (25-50%), redbreasted nuthatch (25-507.), chipmunks (25-50%),
bandtailed pigeon (10-25%), evening grosbeak (10-25%), hermit warbler (10-257.),
rosy finch (5-10%), pinesiskin (5-10%), Lewis woodpecker (5-10%), antelope ground
squirrel (5-10%), whitefooted mouse (5-10%) and many others to a lesser degree.
Seeds, bark, foliage - taken by beaver (5-107.), gray squirrel (25-50%), and locally
by deer in varying amounts.
Cover
Vital for nesting for several species such as nuthatches, brown creeper, woodpeckers,
eagles, bandtailed pigeons, flying and gray squirrels and many others.
Manage in accordance with Timber Management Flan for
Southern California Forests and San Bernardino Working
Circle to promote a healthy vigorous forest for its recre-
ation and watershed values.
When seeding skidtrails and landings, consider wildlife
enhancement in seedmix.
Judiciously select snags to be retained for cavity nesters
and for nests and sentinel posts for hawks, owls, eagles.
CALIFORNIA BLACK OAK
Ojiercys kelloeeli
Food
Acorns - probably at the top of the wildlife food list nation-wide. Their greatest
value is in the critical winter season when other foods are scarce. In this area
they are of particular value to bandtailed pigeon {25-50% of diet), scrub jay
(25-50%) Steller jay (25-50%), gray squirrel (25-50%), whitebreasted nuthatch (10-25%),
varied thrush (10-25%), Lewis woodpecker (10-25%), acorn woodpecker (10-25%), flying
squirrel (10-25%), beechey ground squirrel (10-25%), mule deer (10-25%) and at least
ten other species.
Browse - black oak sprouts, leafage and twigs are used extensively when within reach
by deer, rated good to excellent.
Cover
Often used as den trees and nesting by birds and squirrels.
Black oak should be retained as a valuable component of the
recreation forest for its beauty, variety and contrast, its
wildlife values and watershed values.
Removal of decadent trees is justified to reduce over-
stocking and promote more vigorous, healthy young growth.
Care should be taken to retain den trees.
-------
PONDEROSA PINE-
WKITT FIR FOREST TYPE
Location:
On gentle to ^oderace slopes with
deep soils at altitudes of 5,000
to 8,000 feet. Occ-urs in small
stands throughout the coniferous
forests but is :aost extensive in
headwaters of Santa Ana River and
Deep Creek and in Black Mountain
Scenic Area.
Climate:
Rainfall: 25 to 50 inches
Growing season: 4 to 6 months
Mean Summer max: 80°-93°
Mean Winter min: 22°-34°
Yellow Pine Torest (Wunz)
Mountain Climatic Zone
Transition and Boreal Life Zone
WILDLIFE VALUES
MANAGEMENT
DQMIKAKT SPECIES:
PONDEROSA PINE
Finns ponderos,
JEFFREY PINE
Pinus jeffreyj
Food1 ' 'Ir'" "J J" ^ :'"""
Pine rank near the very top in Importance to wildlife. They are Included in the
diet of more species than any other genus save oak.
Seeds - notably valuable to CLark nutcracker (74% of diet), red crossbill (667.),
pygmy nuthatch (25-507.), rcdbreasted nuthatch (25-50%), chipmunks (25-50%), band-
tailed pigeon (10-251), evening grosbeak (10-25%), hermit warbler (10-25%), rosy
finch (5-10%), pinesiskin (5-10%), Lewis woodpecker (5-10%), antelope ground
squirrel (5-10%), white-footed mouse (5-10%) and many others to a lesser degree.
Seeds, bark, foiiaae - taken by beaver (5-10%), gray squirrel (25-50%), and locally
by deer in varying amounts.
Cover
Vital for nesting for several Species such as nuthatches, brown creeper, woodpeckers,
eagles, bandfcailed pigeons, flying and gray squirrels and many others.
Manage in accordance with Timber Management Plan for Souther
California Forests and San Bernardino Working Circle to
promote s healthy vigorous forest for its recreation and
watershed values.
When seeding skidtrails and landings, consider wildlife
enhancement in seed mix.
Judiciously select snags to be retained for cavity neeters
and for nests and sentinel posts for hawks, owls, eagles.
WHITE FIR
Abies concoloT
Food
Seeds - taken by many birds and squirrels including CLark nutcracker (2-5%),
chipmunks (2-5%). red crossbill, pygmy nuthatch, whitefooted mouses and others.
Twigs and needles - palatability and preference appears to vary greatly between
individual plants. Ycung fir trees are not infrequently "browsed heavily by deer.
OTHER ASSOCIATES SrECEES:
SUGAR PIKE
Pinus 1ambertiana
INCENSE CEDAR
Libocedrus decurretia
See pines above. Sugar pine is especially valuable for its large seeds and as a perch
because of its height.
Food
Incense Cedar is only of minor value as wildlife food.
Cover
The dense protective shelter of cedar is especially valuable in winter.
CALIFORNIA BLACK OAK
Quercus kellogBii
Acorns - probably at the tope of the wildlife food list nation-wide. Their greatest
value is in the critical winter season when other foods are scare. In this area they
are of particular value to bandtailed pigeon (25-5070 of diet, scrub jay (25-50%),
steller jay (25-50%), gray squirrel (25-50%), whitebreasted nuthatch (10-25%), varied
thrush (10-25%), Lewis woodpecker (10-25%), acorn woodpecker (10-25%), flying
squirrel (10-257O, beachey ground squirrel (10-25%), mule deer (10-25%) and at least
ten other species.
Browse - black oak sprouts, leafage and twigs are used extensively when within reach
by deer, rated good to excellent. Cared leaves are used by deer when softened by
rains.
Cover *
Often used as den trees and nesting by birds and squirrels.
Black oak should be retained as a valuable component of the
recreation forest for its beauty, variety and contrast, its
wildlife values and watershed values.
Removal of decadent trees is justified to reduce over-
stocking and promote more vigorous, healthy young growth.
Care should be taken to retain den trees.
-------
SUGAR PINE-
WHITE FIR FOREST TYPE
Location:
Widespread in San Gabriels, in Mill
Creek and Santa Ana River In San
Bernardinos and to limited extent in
San Jaeintos mostly on south facing
steep slopes with active creep;
altitudes 5,000 to 8,000 feet.
Climate:
Rainfall; 25 to 50 inches
Growing season: 4 to 6 months
Mean Summer max: 80°-93°
Mean Winter rain: 22°-34°
Other Classifications:
Yellow Pine Forest (Munz)
Mountain Climatic Zone
Transition and Boreal Life Zone
WILDLIFE VALUES
DOMtSAST SP-CIE5:
SUGAR PINE
Piuus 1ambertiana
JEFFREY PINE
Finus Jeffrey!
Pines rank near the very top in importance to wildlife. They are included in the diet
of more species than any other genus save oak,
Seeds - notably valuable to Clark nutcracker (74% of diet), red crossbill (66%), pygmy
nuthatch (25-50%), redbreasted nuthatch (25-50%), chipmunks (25-50%), bandtailed pigeon
(10-25%), evening grosbeak (10-25%), hermit warbler (10-25%), rosy finch (5-10%),
pinesiskin (5-10%), Lewis woodpecker (5-10%), antelope ground squirrel (5-10%), white-
footed mouse (5-10%), and many others to a lesser degree,
Seeds, bark, foliage - taken by beaver (5-10%), gray squirrel (25-50%), and locally by
deer in varying amounts.
Cover
Vital for nesting for several species such as nuthatches, brown creeper, woodpeckers,
eagles, bandtailed pigeons, flying and gray squirrels and many others.
Management in accordance with Timber Management Plaa fcr
Southern California Forests and San Bernardino Working Circle
to promote a healthy vigorous forest for its recreation and
watershed values where slopes permit.
When seeding skidtrails and landings, consider wildlife
enhancement in seed mix.
Judiciously select snags to be reatined for cavity ntsttrs
and for nests and sentinel posts for hawks, owls, eagles.
MHITE FIR
Abies coi
Food
Seeds - taken by many birds and squirrels including Clark nutcracker (2-5%), chipmunks
(2-5%), red crossbill, pygmy nuthatch, whitefoot mice and others,
Twjgs and needles - palatable and preference appears to vary greatly between individual
plants. Young fir trees are not infrequently browsed heavily by deer.
ASSOCIATED SPECIES:
CANYON LIVE OAK
Quercus chrysolepis
Food
Acorns - highly valued for many species of maiimals and birds. Significant in diet of
bandtailed pigeon (10-257. of diet), quail (5-10% fragments), redshafted flicker (5-10%),
jays (25-507.), rufous-sided towhee (5-107.), plain titmouse (5-10%), California thrasher
(2-5%), raccoon (5-10%), pocketgopher (10-25%), raule deer (10-25% in winter). Acorns
are low in protein but high in fats and carbohydrates and good energy producers.
Browse - Protein levels 16 to 23% in spring, drops to 8% in mature foliage. Accounts
for 10-25% of diet of mule deer in some localities, up to 50% in spring.
Cover
Excellent for roosting.
Leave for .mast, cover and variety.
Tis&erland chaparral species are often
associated with this type. There is
little herbaceous understory.
-------
GRASSLAND TYPE
On alluvial soils in the Forest Zone.
Nowhere extensive. Both dry grass-
lands and wet grasslands occur. In-
troduced grasslands now total over
5,000 acres through type conversion
efforts
Climate:
Rainfall! 25 to 50 inches
Crowing season: 4 to 7 months
Mean Simmer max: 80°-93°
Mean Winter mint 22°-34°
Other Class1fications:
Yellow Pin* Forest (Mwn
Mountain Climatic Zone
Transition Life Zone
SPECIES
WILDLIFE VALUES
DOMINANT SPECJES:
DRY GRASSLANDS
These areas contain many species
of annual grasses and forts,
Broraus - Species are typical, ^inch-
grasses and perennial forbs are
also found.
Grass seeds are valuable to birds and small mammals. Their leaves and stems are used by
rabbits, deer and other herbivores, and in addition the plants provide protective cover
to many small and medium-sized animals.
Individual grasses and forbs of specific value are listed in the R5 Range Analysis Field
Guide.
Maintain and where possible enhance by addition of peren-
nials, legumes, etc.
Achens of sedge are eaten by many species of wildlife. Rush is less valuable.
Maintain wet meadow types and enhance by addition of
legumes.
WET GRASSLANDS
Predominantly sedges. Cares sp
and Rushes, Ju-ncus sp.
-------
BLACK-OAK
WOODLAND TYPE
Location:
Common from 5,000 to 7,000 feet
usually on flat or rolling sites
with deep soil
Climate:
Rainfall: 25 to 50 inches
Growing season: 4 to 7 months
Mean Summer max: 80°-93°
Kean Winter min: 22°-34°
Other Classifications:
Yellow Pine Forest (Munz)
Mountain Climatic Zone
Transition Life Zone
MANAGEMENT
WILDLIFE VALUES
DOMINANT SPECIES:
CALIFORNIA BLACK OAK
Quercus kelloemii
Food
Acorns. - probably at the top of the wildlife food list nation-wide. Their greatest
value is in the critical winter season when other foods are scarce. In this area
they are of particular value to bandtailed pigeon (25-507e of diet), scrub jay (25-50%),
gray squirrel (25-50%), Steller jay (25-50%), whitebreasted nuthatch (10»25%), varied
thrush (10-257,), Lewis woodpecker (10-25%), acorn woodpecker (10-25%), flying squirrel
(10-25%), mule deer (10-25%), and at least ten other species.
Browse - black oak sprouts, leafage and twigs are used extensively when within reach
by deer-rated good to excellent.
Cover
Often used as den trees and nesting by birds and squirrels.
A large part of the black oak woodland type was formed as a
result of early day logging of the conifers. The mature
conifers were removed, and subsequent burning destroyed young
trees. The California black oak, which sprouts vigorously
from the burned stump, then became the dominant species
wherever it was common in the original forest. In recent
years under more intensive fire protection, ponderosa pine
is becoming more abundant in the woodland stands.
Manage to increase variety of species in stand.
CANYON LIVE OAK
Quercus chrysglepig
Food
Acorns - as above
Browse - low in palatability; crude protein 5 to 11%; rated fair to poor; usually
unavailable.
Cover
Excellent for roosting.
Save for roosting trees.
PONDEROSA PINE
Fifiua ponderosa
Food
Pines rank near the very top in importance to wildlife. They are included in the diet
of more species than any other genus save oak.
Seeds - notably valuable to Clark nutcracker (747, of diet), red crossbill (6670, pygmy
nuthatch (25-50%), red-breasted nuthatch (25-50%), chipmunks (25-50%), bandtailed
pigeon (10-25%), evening grosbeak (10-25%), hermit warbler (10-25%), rosy finch (5-10%)
pinesiskiit (5-10%), Lewis woodpecker (5-10%), antelope ground squirrel (5-101), white-
footed jjsouse (5-10%) and many others to a lesser degree.
Seeds, barfa. foliage - taken by beaver (5-10%), gray Squirrel (25-50%), and locally by
deer in varying amounts,
Cover
Vital for nesting for several species such as nuthatches, brown creeper, woodpeckers,
eagles, bandtailed pigeons, flying and gray squirrels and many others.
Maintain to increase variety.
BIGCONE DOUGLAS-FIR
Pseudotsufta macrocarpa
Food
Seeds - valued by many birds and mammals especially rodents.
Foliage - taken sparingly by several forms.
Cover
Roosting - used by many birds and squirrels.
Nesting - important to nuthatches, creepers, woodpeckers and Other cavity nesters.
riety.
DEERBRUSH
Ceanothus Integerrimtis
Food
Seeds - mountain quail, chipmunks, and rodents take some.
Browse - one of the most valued summer browse feeds in California; well-balanced
amounts of crude protein, fat, mineral matter and nitrogen-free extract; protein
levels have been measured as high as 277., a higher nutritive value than most grasses.
Cover
Good
Deer brush sould be encouraged where found. When clearing
for plantations, leave as much as possible. It will divert
deer for seedlings.
After 10 to 15 years of age, deer brush may be out-of-reach
or decadent. Pollarding may induce sprouting and increased
vigor.
-------
ALPINE FORBSt TYPE
on:
ibove 8,000 feet on the high
ins of the San Bernardino, San
I, San Jacinto and Santa Rosa
Rainfall (Snow): 25-50 inches
Growing Season: 7 Co IA weeks
Mean Summer max: 65°
Mean Winter rain: 5°
Other Classifications:
Lodgepole Forest and Subalpine Forest (Munz)
Mountain Climatic Zone
Boreal Life Zone
WILDLIFE VALUES
DOMINANT SPECIES:
LODGEPOLE PINE
Firms contorta
Food
Pines rank near the very top in importance to wildlife. They are included in the diet
of more species than any other genus save oak.
Seeds - notably valuable to Clark nutcracker (74% of diet), red crossbill (66%), pygmy
nuthatch (25-50%), red-breasted nuthatch (25-50%), chipmunks (25-50%), bandtailed
pigeon (10-25%), evening grosbeak (10-25%), hermit warbler (10-25%), rosy finch (5-10%),
pinesiskin (5-10%), Lewis woodpecker (5-10%), antelope ground squirrel (5-10%), white-
footed mouse (5-10%) and many others to a lesser degree.
Seeds, bark, foliage - taken by beaver (5-10%), gray squirrel (25-50%), and locally by
deer in varying amounts.
Cover
Vital for nesting for several species such as nuthatches, brown creeper, woodpeckers,
eagles, bandtailed pigeons, flying and gray squirrels and many others.
Because cover is scarce, existing vegetation is encouraged
LIMBER PIKE
Finus flesills
Pines rank near the very top in importance to wildlife. They are included in the diet
of more species than any other genus save oak.
Seeds - notably valuable to Clark nutcracker (747. af diet), red crossbill (6&%), pygmy
nuthatch (25-50%), red-breasted nuthatch (25-50%), chipmunks (25-50%), bandtailed
pigeon (10-25%), evening grosbeak (10-25%), hermit warbler (10-25%), rosy finch (5-10%),
pinesiskin (5-10%), Lewis woodpecker (5-10%), antelope ground squirrel (5-10%), white-
footed mouse (5-10%), and many others to a lesser degree.
geeds, bark. foItggji - taken by beaver (5-10%) , gray squirrel (25-507=), and locally by
deer in varying amounts.
Cover
Stunted, shrubllke (Krummholz) pines provide excellent cover. The more erec
are used by cavity-nesters.
In some areas grass would be a valuable addition to the
flora. Consider small plots in bighorn range.
spec linens
OTHER SPECIES:
See Timberland Chaparral Type
Timberland chaparral species occur as
isolated individuals throughout this
type.
-------
BARREN AREAS
LOGatton:
Principally occur on the highest
peaks usually above 7,000. Above
10,000 are vldeapread and occupy
moderate as well as precipitous
slopes. Rocky cliffs are a type
of barren area important to several
species of wildlife.
Climate:
Alpine Fell-field (Mim2>
Mountain Climatic Zone
Boreal Life Zone
WILDLIFE VALUES
By definition, barren areas have less
than 51 of the surface covered by vege-
tation. Several palatable forbs and a
few grasses are found in the higher areas
and are reported in San Gorgonio Bighorn
Habitat Management Plan and San Gabriel
Bighorn Habitat Management Plan.
Cover
Rocky cliffs and precipitous terrain in barren areas afford excellent "cover" for
species nimble enough to negotiate the area. They afford vantage points to observe
the approach of enemies. The bighorn is seldom found far from this type. Some
species of birds will nest nowhere else.
With bighorn, food IB often limiting adjacent to the barren
cover areas. Grass should be planted where soil and slope
afford an opportunity for success.
-------
RIPARIAN WOODLAND TYPE
Lgc at ion:
In narrow belts along permanently
flowing streams in all zones. Also
in other canyons where groundwater is
near the surface; at springs and seeps.
Climate:
In all conditions where abundant
moisture is present.
Other Classific.atig.ps;
Al1 zones and types.
WILDLIFE VALUES
MANAGEMENT
DOMINANT SPECIES;
Below 7,000 feet:
WHITE ALDER
Alnus rhombifolia
Food
Seeds - taken by a few birds, notably goldfinch (2-5% of diet) and pinesiskin (2-5%).
jBrowse - taken fairly often, probably for moisture and roughage; low value - rated
fair to useless for deer.
Bark - taken in limited amounts by beaver.
Cover
Dense stands provide effective escape cover and shelter.
Generally maintain cover along flowing streams for shado,
and water temperature control and cover. In very dense
situations, thinning for water-yield may be justified but
wildlife values muse be fully considered.
FREMONT COTTONWOOD
Polulus fremontti
BLACK COTTONWOOL
Fopulus trichocarpa
3oa
Bugsj catkinS) seeds - taken by quail (locally up to 10%), other birds.
Bark - highly preferred by beaver (up to 50% of diet in some locales), also used by
cottontails, squirrels and meadow mouse,
Browse - used frequently by deer but rated fair to poor as feed.
jver
Fair, commonly used by cavity nesting birds.
CALIFORNIA SYCAMORE
Platanus racemosa
Food
Sycamore is generally of little value; the pendant seed balls are utilized by only a
few species, the purple finch being the only bird using the seed in measurable amounts
(2-5%). Beaver may take a bite in passing.
Cover
May be valuable as a perch for insectivorous birds and for nesting.
Leave specimen trees for their beauty.
OTHER SPECIES:
The following occur only in the
chaparral zones of the coastal slopes.
COAST LIVE OAK
Quercus agrifolla
Food
Acorns - highly valued for many species of mammals and birds. Significant in diet of
bandtailed pigeon (10-25% of diet), quail (5-10% fragments), redshafted flicker (5-10%),
jays (25-50%), rufous-sided towhee (5-10%), plain titmouse (5-10%), California thrasher
(2-5%), raccoon (5-10%), pocketgopher (10-25%), mule deer (LO-25% in winter). Acorns
are low in protein but high in fats and carbohydrates and good energy producers.
Browse - Protein levels 16 to 23% in spring, drops to 8% in mature foliage. Accounts
for 10-25% of diet of mule deer in some localities, up to 50% in spring.
Cover
Excellent for most species.
Leave for food value.
BIGLEAF MAPLE
Acer macrophvlIurn
Food
Seeds, buds and flowers - taken by evening grosbeak, nuthatches, purple finch, sap-
suckers (sap), flying squirrel, gray squirrel, chipmunk, white-footed mouse, woodrat.
^rovsa^and barlt - Used by beaver and deer. Leafage is usually out of reach of deer
but sprouts arc cropped with relish; rated fair to poor.
Cover
Leave for food and
Fair to good; birds use the seed stalks in nest buildings.
-------
CALIFORNIA LAUREL (BAY)
Umbellularia callforntca
Food
Bgrri.ea - little used
Browse - seldom used especially when mature. However sprouts, which occur after
a fire or cutting, are often heavily browsed by deer. Some individual plants may
be killed by close cropping. After reaching maturity, their palatability appar-
ently decreases markedly; rated good to fair for deer.
Cover
Good
Leave for cover.
DOMINANT SPECIES;
Above 7,000 feet
The principal riparian dominants at
higher elevations are the several
species of:
Food
WILLOW
Salix lagiandra
1: I- 23E- Abramsii
JJ. caudate var. Bryantiai
S. melanopsis
S. «. var. BolaBderiana
£• lutea Vfflf- Wataonii
S. lemapnii
uleriana
foliage - important to many birds arid mammals including Fine grosbeak
^^^
(5*10% of diet), cottontail rabbit, meadow mouse,; perhaps more important, willows are
resting. places and cover for many forms of terrestrial insects and thus attract many
species of insectivorous birds such as warblers, vireos, chickadees, tit-mice and
others .
Bark - heavily used by the beaver. It is their principal food species on this
forest, wherever it is present in their range.
Srovse - Willow browse is of relatively good nutritional balance, crude protein
levels vary from 7 to 187, with bare twigs of winter dropping to i-5'i. Rating year-
long: fair.
Cover
Excellent in summer.
Willows normally should be left for food and cover. However
in some instances unbroken, dense decadent stands develop
where thinning, topping and opeaiag-up would benefit wild-
life as well as other values.
RIPARIAN WOODLAND TYPE
-------
OTHER IMPORTANT
WILDLIFE PLANTS
Location:
The plants on this list are not con-
fined to a single vegetation type but
are relatively common and have impor-
tance to wildlife. This list is not
intended to be all-inclusive.
Climate:
0ther Classifications:
WILDLIFE VALUES
CALIFORNIA COFFEEBERRY
HOLLYLEAF REDBERRY
Rhamnus crocea var. ilicifolia
Food
Berries - provides 5-10% of diet of Mockingbird, Phainopepla, Swainson thrush; also
used by bandtailed pigeon, California thrasher, Sapsucker, raccoon and robin, hermit
thrush, varied thrush, bear, ringtailed cat, beechey ground squirrel and woodrat.
Browse - taken by deer and bighorn; crude protein ranges from 7.5 to 19%; browse rated
good to poor for deer--coffeeberry is preferred over redberry.
Cover
Fair to good.
The buckthorns seldom form dense stands. Their presence
adds variety of food and cover type and usually are good
candidates for "leave" shrubs in brush conversions.
POISON-OAK
Rhus diversiloba
SQUAWSUSH
Rhus trilobate
Berries * Sumac berries are taken by a large number of birds; they are significant in
the diet of the wrentit (10-25X) and the pocket mouse (10-257,) and important (5-iOX)
for red-shafted flicker, aapsuckers, California thrasher, hermit and Swainson thrushes
and downy and nuttall woodpecker.
Browse - poison-oak rates higher.than grass in crude protein content. In its early
growth stage it has been found as high as 357=; it drops to 8% in the mature leaf.
Squavbush is less palatable. Poison-oak rates good for deer; squawbush fair to poor.
Cover
Fair to excellent.
The sumacs occasionally occur in very dense patches which
afford excellent cover. However poison oak's anti-social
qualities make it hard to recommend for a "leave" plant in
areas of public use. Nevertheless, it has redeeming
features for wildlife. .-.
OTHER SPECIES:
GOOSEBERRY AND CURRANT
Food
Berries - taken by many birds, small mammals, coyotes.
Browse - rated fair to poor for deer although taken fairly heavily after frosts hav
turned the leaves.
Cover
Spiny species excellent; other good to fair.
Useful for variety - especially in Timber Chaparral type.
Sambucus caerulea
Food
Berries - especially important source of summer food for sany kinds of songbirds.
Robins and others eagerly consume the berries even before they ripen. Elderberries
are of high value to phainopepla (up to 50% of diet), blackheadtd grosbeak (5-10%),
Steller jay (5-10%), Suainson thrush (5-10%), many others.
Browse - taken eagerly by deer in late summer and fall especially after frosts have
blackened ehe leaves. Rated good to poor.
Cover
Encourage for its high value for songbirds.
-------
SERVICEBERRY
flaeian.chi.er
Berries - sought by thrushes and many songbirds during early summer. Squirrels,
chipmunks and even bears relish the fruit; frequented by green-tailed towhee
north of Onyx Summit.
Browse - sought by most grazing animals; protein Levels above 107. through Che
summer, lower in winter. Rated good to fair for deer.
Cover
Fair
Serviceberry is a sprouter and should respond well to
pollarding.
FOCRWING SALTBUSH
Atriplex canescens
Food
Seeds - valuable for quail, kangaroo rats, pocket mice, horned lark.
Browse - highly palatable and nutritious. Good deer winter food; taken heavily by
jackrabbits. Rated good to fair for deer.
Cover
Good to excellent.
Highly adaptable to different sites. One of the beet
species for browse plantings, although may need protection
from rodents and rabbits when seedling.
OTHER IMPORTANT WILDLIFE PLANTS
-------
Section C
The Impact of Photochemical Air Pollution on the
Mixed-Conifer Forest Ecosystem—Arthropods
Researched and Written By:
David L. Wood
Professor of Entomology and Entomologist in
Experiment Station Department of Entomology
and Parasitology, University of California,
Berkeley
Principle Contributors:
William D. Bedard, Pacific Southwest Forest & Range Experiment Station
Donald L. Dahlsten, University of California, Berkeley
Clarence J. DeMars, Pacific Southwest Forest & Range Experiment Station
Bland E. Ewing, University of California, Berkeley
Don C. Erman, University of California, Berkeley
Richard C. Garcia, University of California, Berkeley
Thomas Koerber, Pacific Southwest Forest & Range Experiment Station
Peter A. Rauch, University of California, Berkeley
Evert I. Schlinger, University of California, Berkeley
-------
The Impact of Photochemical Air Pollution on the
Mixed-Conifer Forest Ecosystem—Arthropods
The mixed conifer forest of the Westside of the Sierra Nevada
Mountains has served man as a renewable source of timber, water, forage
and wildlife. Demand for these resources and the development of new
uses, i.e., for homesites and many forms of recreation, is increasing
as populations and their mobility increase. Furthermore, timber harvest
is predicted to decline 20% by the end of the century (Oswald, 1970).
Man's activities, such as logging, both fire prevention and fire
initiation, road and dam construction, clearing for transmission lines,
home building, inundation and stream diversions, surface mining, appli-
cation of pesticides and photochemical air pollution, have seriously
disrupted these forest ecosystems. Extreme site deterioration has often
resulted from mining, burning and logging. In these instances, bare soil
of the lower horizons is all that remains where trees once stood. However,
less extreme site deterioration is more common, resulting in the replace-
ment of forests with brush species.
Animals have played an influential and selective role in determining
the succession of vegetation following these disruptions. They assist
in the incorporation of organic matter into the soil and in the release
to the soil of minerals tied up in plant residues. As primary and
secondary consumers, pollinators, and disease vectors they assist one
species to displace another. Soil components, such as arthropods,
pathogens, moisture, structure and chemistry, in turn influence the
capacities of plants to tolerate animal damage. Also, during vegetation
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succession there is a concomitant succession of arthropods in both existing
and newly created aquatic habitats.
Our approach will be to focus on the web of relations among arthropods
exposed to high, moderate and low levels of photochemical air pollutants in
an attempt to determine how these pollutants nfluence the capacities of
plants to tolerate animal damage. Also, during vegetation succession there
is a concomitant succession of arthropods in both existing and newly created
aquatic habitats.
Our approach will be to focus on the web of relations among arthropods
exposed -to high, moderate and low levels of photochemical air pollutants in
an attempt to determine how these pollutants influence populations of arthro-
pods that are 1) known or suspected to play crucial roles in changing age
structure and species composition of vegetation; 2) occupy aquatic habitats,
and 3) inhabit the soil.
Because of the enormous number and diversity of this group of organisms
their study in relation to air pollution is virtually unlimited. Therefore,
we propose that efforts be directed to at least the above major habitats in
the mixed-conifer ecosystem. The literature review is therefore limited to
only a few key references for each study viewed as most promising in revealing
the various impacts of photochemical pollutants on this ecosystem. Of course,
these studies must be integrated with the other components in order to qualify
as ecosystem research.
See page C-26 for a first approximation of the photochemical air pollution
and consumer subsystem.
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I. Terrestrial Habitats
A. The Role of the Western Pine Beetle in the Succession of the
Mixed-Conifer Ecosystem Exposed to Photochemical Air Pollutants.
The western pine beetle (Dendroctonus brevicomis) plays a significant
role in the succession of coniferous ecosystems in western North America.
In the interior ponderosa pine of the forests in the north plateau sub-
region, mature and overmature stands are killed by this bark beetle in
patterns that favor both the younger and thriftier age-groups of ponderosa
pine (Keen, 1950). The role of this primary tree killer in westside
mixed-conifer forests is not so clearly understood. However, during dry
climate cycles up to 90% of some stands are killed (Keen, 1950).
Man's activities have created conditions which favor this insect as
an important agent in changing the course of plant succession. Trees
injured directly through logging and construction activity and indirectly
through changes in drainage patterns become more susceptible to infesta-
tation (Miller and Keen, 1960). Thus, attraction centers are created,
which increases the risk of attack on nearby uninjured trees (Hall and
Pierce, 1965). Certain root pathogens (Fomes annosus and Verticicladiella
wagenerii) predispose ponderosa pine to attack by this bark beetle (Cobb
et al., 1971). The incidence of these root diseases in second-growth
stands has probably been favored by logging activity. Ponderosa pines
exhibiting advanced symptoms of photochemical air pollution injury are
killed by I), brevicomis and £. ponderosae at a much greater rate than are
healthy trees (Stark et al., 1968). (See Appendix—"History of Tree Losses
in the Vicinity of Lake Arrowhead, San Bernardino County, California 1922-71")
Even-aged stands, resulting from logging activity at the turn of the century
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as well as those stands created by fire, are particularly susceptible to
the western pine beetle (Miller and Keen, 1960). A light selection cut
has been found to reduce mortality from I), brevicomis in eastside (Wickman
and Eaton, 1962) and in Southern California (Hall and Pierce, 1965) forests.
Techniques are now available to estimate the total population of
the western pine beetle and 80 species of parasites, predators and other
associated insects (Dahlsten, 1970; Otvos, 1970; Demars, et al., 1970).
This includes tree sampling methods (DeMars, 1970; Berryman, 1970) which
provide estimates of population variability between trees, and aerial
photographic techniques (Caylor and Thorley, 1970) which provide estimates
of the total number of infested trees over large areas. Using life tables
(DeMars et al., 1970) it should be possible to detect differences in
abundance and structure of populations in areas variously exposed to
pollutants. A highly detailed and structured data bank exists on western
pine beetle populations at Blodgett Forest for the last decade (Stark and
Dahlsten, 1970; Dahlsten, 1971) and at Bass Lake (Bedard and Wood, 1970)
and McCloud Flats (Gustafson et al., 1971) for two years. Computer
programs are being prepared which will allow these data to be ordered in
a variety of ways so that they can be analyzed and used to produce dynamic
models of processes that determine abundance. This background, together
with inputs developed from other studies in recent years, notably from
plant pathology, physiology, soils, and vegetation, enables us to assess
when and how photochemical pollutants influence the abundance of western
pine beetle and its associated species, and, in turn, plant succession
in the mixed-conifer ecosystem.
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Similar studies of the mountain pine beetle, Dendroctonus ponderosae,
which is also exploiting pollutant-injured ponderosa pine, could be undertaken.
B. Detection and Quantification of Vegetational Changes Resulting
from Bark Beetle Activity Induced by Photochemical Pollutants.
The determination of the amount and distribution of producer and
consumer biomass, and the rates at which various processes affect their
accumulation and utilization, are important aspects in the ecosystem
description and analysis. The measurement methods used must recognize
and utilize the stand structure and composition in a multi-stage sample
framework (Langley, 1969). Aerial photography is the most effective way
to gain the maximum information from any measurement made on the ground.
Photographs allow identification of bark beetle activity (Caylor and
Thorley, 1970; Heller, 1968, 1970) and conifer root diseases (Hadfield,
1970). There is a need to provide this support service to those
researchers in all groups who require remote sensing information. This
project requires a photography and mapping unit which can consistently
and accurately provide:
1. Information about broad classes of vegetation and changes in
vegetation for the entire area.
2. Large scale photo support for ground plots established by
plant ecologists, soil scientists, entomologists, pathologists,
mammologists, ornithologists and others.
3. Up-dated maps.
4. Tables measuring tree mortality and tree establishment trends.
5. Probabilities for sampling frames of photo-detectable charac-
teristics.
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C. The Impact of Photochemical Air Pollutants on Soil Arthropods.
In recent years, the importance of soil animals has received increasing
attention (Wallwork, 1970). They are significant in a number of areas
including the dynamic processes of soil formation, soil fertility as well
as nutrient and mineral cycling (Edwards et al., 1970). In addition, the
influence of soil animals on pesticide degradation and movement in the soil,
as well as on other human waste products, is under investigation (Lechten-
stein, 1970; Dunger, 1968).
With the acknowledged importance of soil animals from a number of
standpoints, the disruptive effects on the soil community resulting from
man's activities should be considered carefully. Some of these influences
have been investigated, including pesticides (Davis, 1968; Barrett, 1968;
Edwards, 1970), fertilization (Rapapat, 1964), radiation (Edwards, 1970),
fire (Buffington, 1967), and agricultural practices (Oliver, 1966).
Despite recent interest in these areas, more detailed, long-term investi-
gations are needed, especially in the forest environment where soil
formation and fertility are largely dependent on natural processes. The
effects of logging, silvicultural practices, road construction and urban
encroachment, and, in particular of smog, are becoming increasingly
important, especially with the mounting pressure on montane recreational
areas (Huhta, 1967; Moritz, 1965). Recent work (Wenz and Dahlsten,
unpubJ.) indicates that the effect of fire on soil microarthropods can
be significant from the standpoint of community simplification. This
may be of particular interest with the use of controlled burning as a
management tool.
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The effect of changes on stand structure and composition caused by
photochemical pollutants offers an excellent opportunity to study the
concurrent effect on soil microarthropods. Studies already underway
(Wenz and Dahlsten, unpubl.) permit comparisons with natural, undisturbed
areas. Characteristics of such disturbances can be obtained, i.e.,
simplification of both numbers of species and number of individuals of
each species, rate of recovery, effects on predator-prey systems and
trophic level relationships. The pattern of succession, accompanying
and affecting changes in the stand following damage by photochemical
air pollutants, can be studied, as soil organisms may be important in
vegetational succession (Shine, 1971). Studies of forested areas under-
going the rapid changes exhibited in the San Bernardino Mountains should
be especially productive.
D. The Impact of Photochemical Air Pollutants on Sucking Insects.
Sucking insects are a widespread and common group of insects in
montane forests. Seldom, however, are they of any concern because of
their associated natural enemy complex which regulates their population
at levels below that which will cause economic concern (Huffaker et al.,
1971) .
These insects are seldom pests when they do occur in large numbers,
but they usually indicate an environmental disruption (Dahlsten et al.,
1969). Recent trends in land development of montane areas as well as
increased recreation activities in forested areas increases the need for
the development of indicators of any adverse impacts from such activities,
The incidence of Phenacaspis pinifoliae, the pine needle scale, as well
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as that of other scales and aphids, provides one of the potentially good
indicators for monitoring these impacts.
Personal observation, along with that of others (Buttrick, 1912),
indicates that pine needle scale survives better on trees which are under
physiological stress. Therefore, the environmental impact of such factors
as photochemical air pollutants, soil compaction, overwater or changes of
water table relationships, may all influence scale populations which in
turn may be a measure of disruption. Matsucoccus aclyptus is presently
in outbreak phase on pinyon pine only in Southern California which may
be a symptom of photochemical air pollution injury to the tree or a direct
affect on the parasitoid complex (Legner, unpublished data; U. C., Riverside,
Dept. of Biological Control, Exp't. Station Project 2729).
Currently, at South Lake Tahoe, investigators are studying a pine
needle scale infestation which has resulted from thermal fogging of insec-
ticides for mosquito control (Dahlsten et al., 1969). Luck (unpublished)
has shown that the insecticide residue on the foliage is sufficient to
cause mortality of the scale parasites. Preliminary information suggests
that the tree's physiological state has an effect on the density of scale.
Over-mature trees were more heavily colonized by scales. The aphid,
Schizolacnus pini-radiatae, was also present in higher numbers immediately
following the cessation of fogging, while in untreated areas such
increases were not observed.
Both the scale and the aphid have a moderately wide host range
(Terry, 1936; Palmer, 1952). The scale very seldom, if ever, causes tree
mortality under forest conditions (McDaniel, 1929) and is noted for its
large natural enemy complex (Thompson, 1946). The scale is not a vagile
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animal. Population movements are restricted to the area around the
population (Brown, 1958) and hence there would not be a tendency to
migrate out of the area in which the disruption was occurring. The
scale has only one generation per year and would therefore be most
effective as a monitor of chronic effects of photochemical smog.
Because the aphid produces many generations per year it could be an
excellent monitor of acute effects that may be expressed by diurnal and
seasonal variation in exposure to photochemical oxidants.
With the increased impact of man on the forest ecosystem through
recreational activity and increasing technology, it is vital that we
develop the capability of predicting potentially serious and irrever-
sible environmental damage. The sucking insects appear to have great
potential in developing such a capability.
E. The Impact of Photochemical Air Pollutants on Insects that
Influence Tree Growth.
Phytophagous insects exert a powerful influence on the growth rate
of host plants. Since they feed selectively on only one or a few species,
they in turn influence their competitive ability. Those insects which
affect commercially important tree species of the mixed-conifer forest have
received the most attention.
The pine reproduction weevil, Cylindrocopturus eatoni, kills young
ponderosa and Jeffrey pines (Eaton, 1942; Stevens, 1965) while the
Yosemite bark weevil, Pissodes yosemite, kills ponderosa, Jeffrey, and sugar
pine (Stevens, 1966). Thus, the age and species composition of young
forests can be greatly influenced by these insects. A consequence of such
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mortality is a change in the growth rate of the non-host species and
remaining individuals of the host species.
Other insects directly affect the growth rate of young trees by
killing the growing terminal, as does the ponderosa pine tip moth,
Rhyacionia zozana (Stevens, 1966), or by consuming the foliage, as does
the pine needle sheath miner, Zellera haimbachi (Stevens, 1959). Defoli-
ating insects such as the Douglas fir tussock moth Hemerocampa
pseudotsugata not only reduce the growth rate but can kill large trees
(Wickman, 1958). Sawflies are another widespread class of defoliators
which potentially affect the competitive ability of their hosts (Struble,
1957; Dahlsten, 1961). Neodiprion abietis (complex), N. fulviceps
(complex) and Zadiprion rhoweri which attack white fir, hard pines, and
pinyon pine, respectively, are important species in Southern California
forests.
Non-commercial plants such as oak, manzanita, and bittercherry also
support an assemblage of insects which may kill them or affect their growth
rate. The western forest tent caterpillar, Malacosoma californicum
(Stelzer, 1971), and the ceanothus silk moth, Hyalophora euryalis (Essig,
1926), are known to feed on a variety of brush plants. During the summer
of 1971 there was a spectacular outbreak of the California tortoise shell,
Nymphalis californica, which caused extensive defoliation of Ceanothus spp.
in northern California. Until very recently, these plants were classed as
woody weeds and any attention devoted to them was directed at killing them
so that they could be replaced by desirable species of trees (Bently, 1967)
Undoubtedly, photochemical pollutants will influence differentially these
brush species and their insectan herbivores.
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F. The Impact of Photochemical Air Pollutants on Arthropods
Important to the Reproductive Biology of Vegetation in the
Mixed-Conifer Ecosystem.
Plant pathogens, vertebrates and invertebrates are all major factors
in the reproductive biology system of plants. However, this outline
refers specifically to arthropod consumers. Nectar and pollen gatherers
are considered as consumers.
Recent studies in pollination biology (Levin, 1970; Levin and Anderson,
1970; Marshall and Jain, 1970) and in seed-consumer ecology (Janzen, 1969)
have indicated that arthropod interaction with plant reproductive biology
can exert very strong selective pressure on plant survival and distribution
patterns. Arthropods play no apparent role as pollinators of the conifer
and Fagaceae components of the mixed-conifer ecosystem. However, they are
critical to the pollination biology of other major plant species especially
in the Rhamnaceae (Ceanothus), and Ericaeceae (Arctostaphylos). Pollen and
nectar production of numerous other plant species, especially the abundant
annual ground forms, play an important if not critical role as a food
source for many arthropod groups (Arthur, 1962; Leius, 1963, 1967; Syme,
1966; Thorpe, 1938, 1939). For example, forest pest arthropods are para-
sitized or preyed upon by syrphids, clerids, tachinids, and ichneumonids,
among others. These groups, along with such pest groups as the lepidopteran
defoliators, require rich sources of amino acids and carbohydrate for
reproduction and energy. They obtain these from the abundant flowering
plants associated with the forest ecosystem. Simultaneously, they serve
the reproductive biology of the plants by acting as pollinating agents.
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Studies of seed- and fruit-consumers apply to all plant species.
Many studies have described the presence and abundance of seed- and
fruit-consumer of conifers and other plants (Keen, 1958; Gashwiler, 1970;
Janzen, 1969; Powells and Schubert, 1956). Generally these studies
conclude that a very large proportion (50-100%) of the seed crop is
selectively destroyed with such consistency that the structure of the
system is directly affected.
Studies on pollination, pollen and nectar production and consumption,
and seed- and fruit-consumers could be designed to elucidate mechanisms
and interactions most sensitive to perturbations caused by photochemical
pollutants. The distribution and abundance of consumers interacting
with plant reproduction systems can be identified and their effects
analyzed. For example, the impact of decreased growth rate of ponderosa
pine caused by photochemical pollutants on the abundance and species
composition of the insects associated with the cones and seeds could be
readily determined. Our knowledge of the biology and key interactions
with Ponderosa pine of such insects as Conophthorus ponderosae (Coleoptera:
Scolytidae) and Laspyrezia miscitata (Lepidoptera: Olethreutidae) is
advanced.
G. The Impact of Photochemical Pollutants on Spider-Prey Relation-
ships .
Spiders are the only large class of arthropods all of whose species
are uniquely adapted as predators of other arthropods, especially insects.
Through their considerable species diversity and their capabilities to
exploit numerous insect niches, spiders must exert tremendous pressure in
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a myriad of ways upon various arthropods in a mixed-conifer ecosystem.
The presence in this ecosystem of approximately 150 species representing
30 families has been observed only recently (Dahlsten and Schlinger,
unpublished data). Further, spiders occupy all available habitats from
those deep in the soil (e.g., Antrodiaetus) to those at the tops of trees
(e.g., Paraphidippus).
The importance of spiders to forest management practices was
emphasized by Vite" (1953), and Kirchner (1964), who advocated using
spiders to control forest insect pests. Nevertheless, studies necessary
to substantiate the positions suggested by Vite" and Kirchner (loc. cit.)
have not been forthcoming. Even in the large integrated ecological research
program of the "Soiling Project", there is a conspicuous absence of data on
these ubiquitous predators (Ellenberg, 1971).
During the past 15 years, several useful specific studies have been
published concerning spider interactions with litter and soil arthropods
(Huhta, 1965; Martin, 1965; Simon, 1966; Clarke and Grant, 1968; Moulder,
et al., 1970; Coyle, 1971), and several others concerning spider relation-
ships with certain defoliating insects have also appeared (Turnbull, 1956;
Luczak, 1959; Loughton, et al., 1963; Dondale, 1966; Bosworth, et al.,
1971). Similarly, a whole series of useful papers concerning spider-
mosquito relationships has pointed out the potential value of spiders as
biological control agents for this important group (Dabrowsky, 1966-1969).
While the above kinds of studies are quite useful, none attempts to
relate, in more than a limited way, the complex interactions that must exist
between spiders, primary consumers, other secondary consumers, as well as
reducers, to the whole of the ecosystem under study. Since some spiders
are long-lived and often move through different habitats during the same or
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different seasons during their lifetime, we might expect these species to play
an entirely different role as predators than those which build webs or those
which reside in burrows and are quite sedentary.
Spiders often reach extremely high densities, even as high as 50/cu ft
(Schlinger et al., 1960a), and, at these densities, internal spider parasitoids
(Acroceridae) are quite evident (Schlinger, 1960b). The effect of these
parasitoids on spider populations has not been carefully investigated, and
since some of these parasitoids as adults are useful pollinators, i.e.,
Eulonchus spp. (Schlinger, 1960c; Grant and Grant, 1965), certain self-incom-
patible plants may be greatly affected (through the Eulonchus) by a drop in
or the destruction of spider population.
Gertsch (1949) and recently Bristowe (1971) suggest that spiders in
general have little preference for prey. However, considerable specificity
has been noted (Schlinger, unpublished data).
Spider-prey relationships could be elucidated concurrently with the
preceeding studies of soil arthropods, defoliators, sucking insects, and insects
that influence plant reproductive biology. Comparative studies of spiders
in these diverse habitats and in portions of the mixed-conifer ecosystem exposed
to high and low levels of photochemical pollutants offer considerable promise
in locating some of the more subtle but crucial impacts of such pollutants on
this ecosystem.
H. The Impact of Photochemical Pollutants on Insectivorous Birds.
Previous studies in California (Dahlsten and Copper, unpublished) have
shown that hole-nesting birds are an important component of the natural control
complex of several forest insect pests. In addition, the hole-nesting species,
particularly the mountain chickadee, lend themselves to study because they nest
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readily in artificial nesting sites. Nest boxes have been used successfully
in California for six years (Dahlsten and Copper, unpublished).
The effectiveness of birds as predators of specific insect species has
been debated, namely that avian predators are extremely important at low
insect population densities but are not important mortality agents during
insect epidemics. Insectivorous birds have been studied extensively in the
Old World (Bruns, 1960; Poznanin, 1956) but have been ignored, by comparison,
in North America, particularly the hole-nesting species. Studies by Buckner
and Turnock (1965) and Coppel and Sloan (1970) have shown the importance of
birds in the population dynamics of several defoliators in North America.
However, both of these studies concentrated on birds generally, rather than on
a single species, although they included hole-nesting species.
The hole-nesting species receiving the most attention in North America
have been the woodpeckers. Woodpecker predation on bark beetles has been studied
in detail for the spruce beetle, Dendroctonus (Otvos, in Stark and Dahlsten,
1971). Woodpeckers have also been studied in relation to other woodboring
insects (Solomon and Morris, 1970).
Many of the hole-nesting birds appear to be closely associated with
certain insect feeding groups (i.e., sucking insects, defoliators, and bark
beetles). Thus, any change in age structure or species composition of insect
populations caused by the activities of man such as logging, road construction,
insect control, home construction and photochemical air pollution undoubtedly
will in turn affect the populations of their avian predators.
II. Aquatic Habitats.
Studies on forest mountain aquatic ecosystems require as intense a monitoring
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c-16.
program of the extraneous physical and chemical components of the water as
would be required for the atmosphere for the study of terrestrial ecosystems.
The present water quality monitoring stations operated by the United States
Forest Service at a number of locations in the San Bernardino National Forest
would be roughly equivalent to the function of the meteorological and moni-
toring program of the atmosphere to the forest ecosystem as a whole. Data from
these monitoring stations should reflect the trends of nutrient flow from the
surrounding land masses, and therefore be of major importance to a study of
the terrestrial system. Since these nutrients and other physical and chemical
qualities of the water affect the aquatic flora and fauna, the data from the
monitoring systems could be used to study the influences of these components
on aquatic life as well. However, it must be emphasized that the aquatic
systems are as fully complex as terrestrial systems, and therefore the amount
of information obtained reflects only the amount of expertise and time
devoted to the study.
In addition, water quality monitoring systems similar to ones proposed or
in operation in the San Bernardino Mountains should be extended to control
sites (regions of no oxidant injury to terrestrial fauna). This would permit
certain predictions about the amount of nutrient runoff resulting from the
impact of atmospheric pollutants on the Terrestrial system.
The flora and fauna of aquatic systems have been receiving greater atten-
tion during recent years and a number of scientific studies have demonstrated
their usefulness as indicators of water quality (Gaufen, 1957; Hynes, 1960, 1970,
and others). Their role in serving as indicators is of major importance, but
it is also apparent that an understanding of the interactions of this ecosystem
is important in itself in order to interpret the role of aquatic organisms and
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and their interactions to the components of the forest ecosystem.
Initially a survey of the aquatic organisms inhabiting water sources
in the study area would give some information as to the past, as well as the
present, condition of the aquatic systems (Tarzwell and Gaufin, 1953; Gaufin
and Tarzwell, 1956; Tarzwell, 1965; Gallup et al., 1970; Howmiller and Beeton,
1971). Changes in the populations of these organisms or displacement by other
organisms might be reflected by an increase in a particular species. For
example, certain species of insects of public health importance such as
mosquitoes, chironomids, simuliids, etc., are adversely or favorably affected
by direct changes in water quality. Indirectly, certain predatory species,
such as notonectids, dytiscids, Tricoptera, etc., which are important in
regulating these insects, might be adversely affected, resulting in an
increase in the species pestiferous to man.
The direct impact of air oxidant pollutants on aquatic systems has not
been studied extensively. However, an area where the direct impact of oxidants
might be measured and followed is the surface microlayer. As pointed out by
Parker and Barsom (1970) "...this thin horizontal layer may have considerable
ecological importance. Not only is the knowledge of the natural chemical
composition of surface microlayers on lakes, streams, and oceans fragmentary
but the influences of substances introduced by man, such as petroleum, long
chain-alcohols, synthetic pesticides and surface active compounds on the biota
which inhabit the microlayer cannot be estimated. We submit that the interaction
of the microlayer with both the air and subsurface water may be of sufficient
ecological importance as to be a major contributing factor in currently
unexplained problems of air and water pollution."
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-------
C-26
First Approximation: Photochemical Air Pollution and
the Consumer Subsystem— Arthropods
ATMOSPHERIC FACTORS
SECONDARY CONSUMERS
PRIMARY CONSUMERS
J TERTIARY CONSUMERS
CO
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O
•M
•H
i a
cu a
a, a,
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'O
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O
Parasit
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POPULATION DYNAMICS
AQUATIC CONSUMER
COMMUNITY
TERRESTRIAL CONSUMER
COMMUNITY
-------
Appendix Section C
APPENDIX: HISTORY OF TREE LOSSES IN THE VICINITY OF LAKE ARROWHEAD,
SAN BERNARDINO COUNTY, CALIFORNIA, 1922-1971
by
R. L. Dalleske, Consulting Entomologist
R. A. Kimball, Assistant Entomologist
Berkeley, California
December 1971
-------
INTRODUCTION
In order to assess a possible relationship between tree mortality due
to bark beetles and air pollution, an attempt was made to reconstruct the
history of tree losses in the vicinity of Lake Arrowhead, San Bernardino
County, California. The literature used was comprised of reports from the
files and archives of the U.S. Department of Agriculture Forest Service,
Pacific Southwest Forest and Range Experiment Station, Berkeley, California,
and the Region 5 Forest Service administrative office in San Francisco,
California. The agencies responsible for the reports include the U.S. Forest
Service, Bureau of Entomology and Plant Quarantine (BEPQ), California Division
of Forestry, Civilian Conservation Corps (CCC), County of San Bernardino, and
the Zone 5 Flood Control District. Undoubtedly, many old reports are on file
in state and county offices, and on Ranger Districts of the San Bernardino
National Forest, but these were not used in the present report.
The use of infestation record sheets facilitated the summarization of the
loss figures (Table 2, Figure 2).
AREA OF INFESTATION
The area covered by this report includes Township 2 north, Range 2 west,
San Bernardino meridian; T2N, R3¥, S.B.M.; and T2N, R4W, S.B.M. (see map).
The respective names and abbreviations assigned the townships are Green Valley
(GV), Arrowhead (AH), and Crestline (C). Historically, the initial work was
done in the Arrowhead township, but later expanded to include Crestline, and
then Green Valley. While the infested acreage has probably fluctuated widely
over time, the loss figures presented are within one of more of the above
-------
il
townships. Sporadic work was done in the vicinity of Big Bear Lake (T2N, R1E),
but was not included in this report.
INTERPRETATION OF TREE LOSS
The history of tree loss due to bark beetles is presented graphically in
Figure 1, and tabularly in Table 1. Several points should be kept in mind when
interpreting these figures:
1. The figures are for several species of trees. Only in three instances
were the losses broken down by tree species, and even then, included a number
of "unknowns". The four species represented by the figures are Ponderosa pine,
Coulter pine, sugar pine, and Jeffrey pine.
2. More than one infesting insect species is involved. The most commonly-
mentioned species are Dendroctonus brevicomis LeConte, I), monticolae (=ponderosae
Hopkins), I), jeffreyi Hopkins, Ips spp., and Melanophila californica Van Dyke.
3. Some of the figures presented are estimates of trees infested, others
are actual counts, and still others represent only the number of trees treated.
For information regarding figures for specific years, see the appendix which
contains the infestation record sheets.
4. The figures do not include infested trees removed by logging on private
lands, nor do they include trees removed by private property owners who never
reported their losses.
5. No exact figure of the spotting efficiency can be given, but it is assumed
that 10 to 15 percent of the infested trees in a given area were probably missed.
The unsuccessful eradication attempts by the CCC during 1933-34 probably reflect
to a certain degree the fact that not all infested trees can be found, even by
an experienced spotter.
-------
ill
6. Prior to 1940, occasional attempts were made at spotting and treating
trees infested by summer-generation beetles. However, practically all of the
control work was done in the winter or spring on overwintering-brood trees. It
is therefore assumed that many infested trees were never counted, since the
summer generations were largely ignored. With the advent of year-round treat-
ment , summer-brood trees were included in the count.
7. Some years (1928-30 and 1934) show no infested trees. However, this
probably indicates waning interest in control activity due to low beetle
population levels, rather than a lack of infested trees.
8. The figures do not include "pole-sized" trees which were treated.
From the above, it is concluded that the total tree loss figures for each
year are conservative.
HISTORICAL NOTES
The following is a brief chronology of the history of tree losses in the
Arrowhead Lake area:
1922-28.--The BEPQ surveyed the area for the first time in March 1922.
Control work soon followed. Excellent records of trees spotted and treated were
kept by BEPQ personnel. Toward the end of this period, the job was turned over
to private landowners, the county forester, and the U.S. Forest Service. By 1928,
the infestation was declared "under control". (References 1, 12, 14, 15, 16,
17, 23.)
1929-32.—No control activity due to low beetle populations. (Ref. 19.)
1933-34.—An attempt was made by the CCC to eradicate the bark beetle
populations in the area; it failed. Field estimates of the 1931 and 1932 brood
trees were made during the treatment period. (Ref. 2.)
-------
iv
1935-38.—Sporadic control attempts were made by private and government
agencies. The infestation increased sharply, and it became apparent that a
more organized effort at control would have to be made. It should be noted
that the figure for 1939 tree loss (Fig. 1 and Table 1) is a field estimate,
not an actual count. (Ref. 10, 19, 20, 21, 22.)
1939-52.—The Zone Five Flood Control Board issued funds in 1939 to aid in
a cooperative effort with private interests, the U.S. Forest Service, and the
California Division of Forestry, to cope with the increasing beetle populations.
By 1940, the populations were greatly reduced, and the control program became
one of "minimum maintenance". During the period 1947-48, the infestation began
to increase, reaching a peak in 1951. (Ref. 11, 18, 19.)
1953-71.—The infestation has persisted at a much higher average level than
in previous years. Annual maintenance control work has continued. The infes-
tation reached its greatest peak in 1971. (Ref. 3, 4, 5, 6, 7, 8, 9, 24.)
DISCUSSION
Despite the conservative nature of the annual tree loss counts, the overall
trend toward an increase in loss is probably valid. Particularly interesting
is the period from 1951 to the present. If the peak loss years during this time
can be interpreted as "outbreaks" and the years between as "endemic" periods,
it can be seen that both are higher than similar peaks and troughs prior to 1951.
Also, it is during the post=1951 period that smog levels began to increase in
this area.
While it was not possible to do so for the present report, it would be
desirable to inspect the treatment records kept by the various agencies involved
to see if they include the species treated. If this information is not
-------
available for each year, it might still be possible to calculate a correction
factor to estimate the number of infested ponderosa pines.
One of the earliest reports remarked on the presence of bettle-infested
trees on or near construction sites. It would be interesting to see if this
relationship has continued through the years.
Finally, many of the old reports in the archives of the U.S. Forest Service
contain information which might be useful in reconstructing the history of the
Lake Arrowhead area with respect to logging, aforestation, fire, and other
factors leading to vegetational changes which might affect the beetle popula-
tions .
-------
vi
ACKNOWLEDGEMENTS
The personnel of Forest Insect Research, U.S.D.A. Forest Service, Pacific
Southwest Forest and Range Experiment Station, and the personnel of the
Regional Office of Region Five, U.S. Forest Service, were most cooperative in
compiling the information for this report.
-------
vii
TABLE 1.
Annual Loss, 1921-1971
Lake Arrowhead Infestation Area
YEAR LOSS—(sum/ow)* YEAR LOSS—(sum/ow)
1921 76 I960 804
22 40 (13/27) 61 1869
23 1 62 2552
24 207 63 2432
25 364 64 2661
26 172 65 1750
27 48 66 995
1931 12* 67 686
32 15* 68 722
33 280 69 922
35 12 1970 3820
36 142 (82/60) 71 4145 (3224/921)
37 233 (33/200)
38 270
39 2279* (1735/544)
1940 570
41 62
42 32
,, ... * sum = summer generations
45 35
,, ,fi ow = overwintering generation
47 99
48 121
49 154
1950 275
51 1250
52 925
53 1488
54 756
55 615
56 568
57 662
58 772
59 855
*Field estimates, not actual counts.
-------
TABLE 2
INFESTATION RECORDS
AREA: LAKE ARROWHEAD-CKESTLINE
YEAR
GENERATION
Survey or
control work
and group
# trees
found, by
spp.
Total volume
(MBF),
by sup p.
Given
Location
(section, etc)
REFERENCES
REF. NO. &
PAGE NOS.
1921-22
OW
SUR=BEPQ
CON=G&P
PP=20
CP=44
1 12u
PP=43.7
GP=33.33
U=27.0
AH
YES
(SEC'S)
14.pl-5,
1922
1922
SUM
CON=GIP
13 u
2
U=7.58
TT=6.81
AH
YES
(SEC'S)
15.1-6
1923
1922-23 1922-23 1923
OW OW SUM
SUR=BEPQ
CON=G&P NONE NONE
27 u
3
U-26.07
AH
YES
(SEC'S)
15.1-6 23.1 23.1
1924 1925
1923-24 1923-24 1924 1924-25 1924-25 1925 1925-26
OW OW SUM OW OW SUM OW
SUR=BEPQ NONE NONE SUR=BEPQ NONE ?
NONE CON=? 4 4 CON=G&P 6
1 u PP=114
CP=64
JP=2
U=27
U=27
5
NOT PP=79.81
GIVEN CP=69.83
JP=2.3
NOTM YES
GIVEN (SEC'S)
AH
23pl 23.1-2 23.1-2 23.1-2 23.2-7
<
H-
H-
NOTES:
1) 12 additional abandoned trees found; spp. unknown 2) 7 standing and 6 windthrown; spp. unknown; also
used 7 trap trees. 3) does not include several group killings of small trees (15 pi.) 4) no work
performed, but "many" trees infested. 5) 250 trees (spp. unknown) total, but CA. 70 not treated; 27
unknowns treated by LAC during the winter of '24-'25. 6) Survey report referred it,, but not given (23.p7).
-------
INFESTATION RECORDS
AREA: LAKE ARROWHEAD-CRESTLINE
YEAR
GENERATION
Survey or
control work
and group
# trees
found, by
spp.
Total volume
(MBF) ,
by spp.
j Given
Location
(section, etc)
REFERENCES
1926
1925-26 1926
OW SUM
SUR=?
CON=G&P ?
1 1
364 u
NOT
GIVEN
YES—
AH-C
17.1-2
12.3
1.P1-2
1927
1926-27 1926-27 1927
OW OW SUM
CON=G&P
? SUR=G ?
1 2
172 u
3
U=151.42
YES—
MAP
AH-C
12.1-8
16. P2
1928
1927-28 1927-28 1928
OW OW SUM
CON=G&P
? SUR=G ?
2
48 u
4
PP=25.24
CP=3.89
SP=1.79
YES -MAP
AH-C
13.1-3
16. P2
1929
1928-29 1928-29 1929 1929-30
OW OW SUM OW
? NONE NONE NONE
NOTES:
1) Report missing (Funke, 1926). 2) Records vague. 3) 109 trees treated. 4) 18 trees treated.
-------
INFESTATION RECORDS
AREA: LAKE ARROWHEAD-CRESTLINE
YEAR 1930
1929-30 1930
GENERATION OW SUM
Survey or
control work NONE NONE
and group
# trees
found , by
spp.
Total volume
(MBF),
by spp.
Given
Location
(section, etc)
REFERENCES
1931 1932
1930-31 1930-31 1931 1931-32 1931-32 1932
OW OW SUM OW OW SUM
both=
NONE 1 1 CCC 11
12 U
1
U=8.54
1
YES-
MAP
AH-C-GV
2.1-22
1932-33 1932-33
OW OW
both=
CCC 2
15 U 1
U=6.91
1
YES-
MAP
AH-C-GV
2.1-22
1933
1933 1933-34
SUM OW
both=
2 CCC
66 U 3
U=57.89
YES-
MAP
AH-C-GV
2.1-22
NOTES:
1) Figures are for abandoned trees found in fall of 1933-apparently an attempt was made to reconstruct
history of infestation for 1931 & 1932. 2) No record of work for these periods. 3) Includes Miller Canyon.
x
-------
INFESTATION RECORDS
AREA: LAKE ARROWHEAD-CRESTLINE
YEAR
GENERATION
Survey or
control work
and group
# trees
found, by
spp.
Total volume
(MBF),
by spp .
Given
Location
(section, etc)
REFERENCES
1934
1933-34
OW
both=
CCC
214 u
u=207.24
YES
Map
AH-C-GV
2.1-22
1935 1936
? 1935-36 1936
OW SUM
SUR= ?
BEPQ
10-12 82 u
possibly
not not
given given
AH AH
20.pl. 21. p2
1937
1936-37 1937
OW SUM
SUR= SUR=BEPQ
BEPQ CON=?
CON=LAC
60 u 33 u
?2
AH YES-
Map,
SEC'S AH
21.1-3 21. p2
NOTES:
1) "Not more than 10 or 12 of these dead trees were seen in the total distance of 6.5 miles..."
pi. 2) "Figures not available." pi.
-------
INFESTATION RECORDS
AREA: LAKE ARROWHEAD-CRESTLINE
TEAR
JENERATION
Survey or
control work
md group
f trees
iound by
spp.
Total volume
(MBF),
>y spp.
Given
location
[section, etc)
REFERENCES
TOTES :
1938
1937-38 1938
OW SUM
CON=LAC
U=200
not
given
AH
22.4.
1938-39
OW
SUR=BEPQ
U=270
not
given
AH-C-GV
22. pi, 4.
1) Only treated trees 2) gives
4) actual no . trees treated in
1939
1939
SUM
SMR=BEPQ
1735u
5
not
given
MAP
AH-C-GV
10.1-5
ave. DBH 3) estimate
AH-C-GV 5) estimated
1940 1941
1939-40 1940 1940-41 1940-41 1941
OW SUM OW OW SUM
CON=CCC both=
G&P
BEPQ
550pp3 U=570
544u4
not not „
given given
MAP* AH-C-GV
AH-C-GV
11. pp8-9 19.p4-8
*18.p8
of infested trees, but not all in AH-C
loss.
1941-42
OW
both=
G&P
U=62
1
2
AH-C-GV
19.p4-8
-------
INFESTATION RECORDS
AREA: LAKE ARROWHEAD-CRESTLINE
YEAR 1942
1941-42 1942
GENERATION OW SUM
Survey or
control work
and group
# trees
found, by
spp.
Total volume
(MBF),
by spp.
Given
Location
(section, etc)
1943
1942-43 1942-43 1943
OW OW SUM
both=G&P
U=32
1
NONE
GIVEN
2
GV-AH-C
(maps)
1944
1943-44 1943.44 1944
OW OW SUM
both=G&P
u=28
1
NONE
GIVEN
2
GV-AH-C
(maps)
1944-45 1944-45
OW OW
both=G&P
U=41
1
NONE
GIVEN
2
GV-AH-C
(maps)
1945
1945 1945-46
SUM OW
both=G&P
U=35
1
NONE
GIVEN
2
GV-AH-C
(maps)
REFERENCES
19.p4-8
19.4-8
19.p4-8
19.4-8
NOTES:
1) Only treated trees
2) Gives ave. D8H
H-
H-
H-
-------
INFESTATION RECORDS
AREA: LAKE ARROWHEAD-CRESTLINE
YEAR
GENERATION
Survey or
control work
and group
# trees
found , by
spp.
Total volume
(MBF),
by spp.
Given
Location
(section, etc)
REFERENCES
V
1946
1942-43
OW
both=G&P
U=46
1
NONE
GIVEN
2
AH-C-GV
19.4-8
1947
1947-48
OW
both=G&P
U=99
1
NONE
GIVEN
2
AH-C-GV
19.4-8
1948
1948-49
OW
both=G&P
UXL21
1
NONE
GIVEN
2
AH-C-GV
19.p4-8
1949
1949-50
OW
both=G&P
U=154
1
NONE
GIVEN
2
AH-C-GV
19.p4-8
NOTES:
1) Only treated trees
2) Gives ave. DBH
-------
INFESTATION RECORDS
AREA: LAKE ARROWHEAD-CRESTLINE
YEAR
GENERATION
Survey or
control work
and group
# trees
found, by
spp.
Total volume
(MBF),
by spp.
Given
Location
(section, etc)
REFERENCES
1950 1951 1952 1953
195°-51 1951-52 1952-53 1953-54""
ow ow ow
both=G&P both=G&P both=G&P both=P
5
Ca.275U Ca.l250U Ca.925U 1488U
1 3 4
NOT NOT NOT NOT
GIVEN GIVEN GIVEN GIVEN
2 2 2
AH-C-GV AH-C-GV AH-C-GV AH
19.p4-8 19.P4-8 19.p4-8 3.pl2
24.
NOTES:
1) Actually spotted only 210 trees-275 is an estimate. 2) Gives ave DBH 3) 963 trees treated 4) 841
trees treated. 5) 26,740 acres (Swain).
-------
Given
Location
(section,etc)
REFERENCES
INFESTATION RECORDS
AREA: LAKE ARROWHEAD-CRESTLINE
_ —
YEAR
GENERATION
Survey or
control work
and group
#trees
found by
spp.
Total volume
(MBF),
by spp.
1954 1955 1956
1954-55 1955-56 1956-57
OW
both=P both=P both=P
1 1 1
756U 615U 568U
NOT NOT
GIVEN GIVEN
1957
•••
both=P
1
66 2U
AH-C
4.pl2
24.
AH-C
5.11
24.
6.11
24.
7.pl5
24.
NOTES:
1) 26,740 acres (Swain)
-------
INFESTATION RECORDS
AREA: LAKE ARROWHEAD-CRESTLINE
YEAR
Given
Location
(section, etc)
1958
AH-C
1959
1960
AH-C
1961
GENERATION
Survey or
control work
and group
# trees
found, by
spp.
Total volume
(MBF),
by supp.
2
bothXP
772 U
NOT
GIVEN
1959-60
both=P both=P
2 2
855 U 804 U1
NOT
GIVEN
both=P
2
1869 U
REFERENCES
8.pl7.
24.
9.pl9
24.
24.
NOTES:
1) + 130 abandoned.
2) 49273 Acres (Swain)
-------
INFESTATION RECORDS
AREA: LAKE ARROWHEAD-CRESTLINE
YEAR
Given
Location
(section, etc)
1962
AH-C
1963
1964
1965
GENERATION
Survey or
control work
and group
//trees
found , by
spp.
Total volume
(MBF),
by spp.
both=G
&P 1
2552 U
NOT
GIVEN
both=G&P both=G&P both=G
111
2432 U 2661 U 1750 U
REFERENCES
24.
24.
24.
24.
NOTES:
1) 49,273 Acres (Swain)
-------
INFESTATION RECORDS
AREA: LAKE ARROWHEAD-CRESTLINE
YEAR
Given
Location
(section, etc)
1966
AH-C
1967
1968
1969
GENERATION
Survey or
control work
and group
#trees
found, by
spp.
Total volume
(MBF)
by spp.
both=G both=G both=G both=G
1 1 1 1
995 U 686 U 722 U 922 U
NOT
GIVEN
REFERENCES
24.
24.
24.
24.
NOTES:
1) 49273 acres (Swain)
x
H-
-------
INFESTATION RECORDS
AREA: LAKE ARROWHEAD-CRESTLINE
YEAR
Given
Location
(section, etc)
REFERENCES
1970
AH-C
24.
1971
GENERATION
Survey or
control work
and group
# trees
found, by
spp.
Total volume
(MBP),
by spp.
both=G both=G
2 2
3820 U 3224 U 921 U
1
NOT
GIVEN
24. 24.
NOTES:
1) to 9/30/71
2) 49,273 acres (Swain)
-------
xxi
ABBREVIATIONS USED IN APPENDIX
SUE: survey work
CON: control work
Pi private concerns
G: government concerns (federal, state, local)
BEPQ: U.S.D.A. Bureau of Entomology and Plant Quarantine
CCC: Civilian Conservation Corps
LAC: Lake Arrowhead Company
AH: Lake Arrowhead township
C: Crestline township
GV: Green Valley township
SEC's: sections (by number, township and range)
SUM: summer generation
OW: overwintering generation
CP: Coulter pine
JP: Jeffrey pine
PP: ponderosa pine
SP: sugar pine
TT: trap tree
U: unknown species, tree
SPP: species
-------
LITERATURE CITED
Anonymous. "Historical notes and miscellaneous field notes—San Bernardino
National Forest".
Browne, A. C. 1934. "Forest insect control work conducted in Southern
California National Forests by the Civilian Conservation Corps during the
season of 1933".
California Forest Pest Control Action Council. 1954. "Forest Insect Conditions
in California, 1953".
California Forest Pest Control Action Council. 1955. "Forest Insect Conditions
in California, 1954".
California Forest Pest Control Action Council. 1956. "Forest Insect Conditions
in California, 1955".
California Forest Pest Control Action Council. 1957. "Forest Insect Conditions
in California, 1956".
California Forest Pest Control Action Council. 1958. "Forest Insect Conditions
in California, 1957".
California Forest Pest Control Action Council. 1959. "Forest Insect Conditions
in California, 1958".
California Forest Pest Control Action Council. 1960. "Forest Insect Conditions
in California, 1959".
Carlson, S. T. 1939. "1939 Forest insect survey, San Bernardino National
Forest".
Dunston, C. E. 1940. "Annual Report, Calendar year 1939, Region 5".
Funke, F. W. 1927. "San Bernardino Project—Spring control work—1927".
Funke, F. W. 1928. "San Bernardino Project—Spring control work—1928".
Hartman, R. D. 1922. "Arrowhead Lake Project (formerly Little Bear Lake)".
Hartman, R. D. 1922. "Report on the Arrowhead Lake Project for 1922".
Hartman, R. D., et al. "San Bernardino National Forest—control data, 1922-39".
Miller, J. M. 1926. "Memorandum for S. A. Nash-Boulden and County Forester
Tuttle; Insect control—San Bernardino National Forest".
Miller, J. M. 1940. "Forest insect control in the pin areas of the San
Bernardino County Flood Control District, Zone Five".
-------
Moore, A. D. 1953. "A review of insect control in the Arrowhead-Crestline
infestation area, 1921-53".
Patterson, J. E. 1936. "Report of forest insect conditions in the southern
National Forests of the California District—June 1936".
Patterson, J. E. 1937. "Memorandum for Arrowhead Lake Company: Reporting
forest insect conditions in the coniferous forests surrounding Lake
Arrowhead during the year 1937".
Patterson, J. E. 1938. "Report of forest insect conditions in the southern
National Forests of the California District, October-November, 1938".
Person, H. L. 1925. "Arrowhead Lake Project, Spring control work—1925".
Swain, K. 1972. "A broad evaluation of zones of infestation within the San
Bernardino National Forest". (Unpublished).
-------
4OOO
<2 3000
4)
0>
-0
6
CO
CO
o
2000
1000
TOTAL TREE LOSS PER YEAR
LAKE ARROWHEAD INFESTATION AREA
a * Field estimate
PI B» m ra
1940 1945 1950
YEARS
p
1921 1925 1930 1935
Figure 1.
1955
I960 1965
1970
-------
BARK BEETLE INFESTED PONDEROSA PINES — WESTERN SECTION, SAN BERNARDINO N. F.
200O
1800
I6OO
uj 1400
UJ
o:
1200
a
U.J
IOOO
800
6OO
400
200
RROWHI
ARROWHEAD -CR
UJ
UJ
ut
e
o
.UJ.
x
AR
TO777771 OVERWINTERING GENERATIONS
HUH SUMMER GENERATIONS
—CRESTLINE —GREEN VALLEY
SUMMER
936 SUMMER
937 SUMMER
Pi CM —
in r*)
-------
Section D
OXIDANT AIR POLLUTION - METEOROLOGY
by
James G. Edinger
University of California
Los Angeles, California
Committee Chairman: James G. Edinger
University of California
Los Angeles, California
Principal Contributors: Richard Minnich, Geography
University of California
Los Angeles, California
Paul R. Miller
Pacific Southwest Forest
and Range Experiment Station,
U.S. Forest Service
Riverside, California
-------
D-2.
OXIDANT AIR POLLUTION - METEOROLOGY
Introduction
Meteorology is involved in a number of ways in determining the impact of air
pollution on an area. Atmospheric motions determine the dilution of contami-
nants both horizontally and vertically and also prescribe the transport of
contaminants from source areas to receptors. Consequently the exposure of
forest areas in the San Bernardino mountains to oxidant air pollution depends
not only upon the atmospheric conditions in these mountains but upon those
found in the remainder of the South Coast Air Basin as well.
Meteorology has many impacts on forest ecosystems in the area such as
temperatures, humidities, winds, and rainfall. Although the emphasis here
is on the impact of air pollution, these other variables are of importance
also. For example, the pattern of the strong, hot, dry, northeasterly
winds known as "Santa Ana winds" dictates the behavior of the wildfires
that periodically devastate large areas of forest and chaparral; and the
pattern of rainfall (Fig. Dl) influences strongly the distribution of vegeta-
tion (Minnich, 1971).
This report, in presenting what is presently known, divides the material into
three parts: (A) the large-scale meteorological features affecting the
transport and diffusion of air pollution in the South Coast Air Basin, (B)
the small-scale atmospheric phenomena generated by the local terrain
prescribing the details of pollution distribution, and (C) an estimate of the
distribution of oxidant air pollution in the San Bernardino Mountains based
on available oxidant concentration data combined with meteorological inference.
-------
D-3.
The meteorological data were compiled by the network of stations shown in
Figures 2 and 3. These observational sites are operated by the U.S. Forest
Service, the California Division of Forestry, the California Division of
Water Resources, and the Big Bear Fire Department. The oxidant data stem
from field investigations made by the U.S. Forest service and the University
of California.
A. Large-scale meteorological features
The various types of large-scale weather patterns can be separated into three
categories: (a) those producing general on-shore flow, putting the San
Bernardino Mountains downwind of the nearly 100 mile expanse of urban and
industrial sources between these mountains and the coast, (b) those producing
prevailing off-shore flow leaving the mountains upwind of the pollution
sources, and (c) those providing the mountains with polluted currents from
the basin in some sectors and with opposing currents of unpolluted air in
others.
a. On-shore flow
The net daily motion of air across the basin is usually from sea
to land. Particularly in Spring, Summer and Fall, the presence of
the north Pacific semi-permanent anticyclone off the coast of
California provides a northwest flow along the coast. During these
seasons a strong daytime sea-breeze coupled with a weak nocturnal
landbreeze superposed on this northwest flow produce a net on-shore
transport of air. Typically marine air from the coast takes about
one day to reach the San Bernardino Mountains.
Associated with this northwest flow are large-scale subsiding
motions aloft which create the persistent low level temperature
-------
D- 4.
inversion lying immediately above the shallow, cool, moist marine
layer. The primary air pollutants are injected into this marine
layer whereupon the inversion above, devoid of turbulent mixing
motions, inhibits the vertical diffusion of the pollution from
the marine layer. The marine layer typically is a little less
than 1000 ft deep as it crosses the coastline. In the Spring it
tends to be somewhat deeper and in the Pall a little shallower;
however, day to day variations tend to be greater than these
seasonal changes (De*farrai£> et al, 1965).
During the Winter, occasional cyclone passages produce strong
on-shore flow devoid of any low ^Level inversion. With strong
winds across the source area and no inversion to impede the verti-
cal diffusion of the pollution, the air contamination reaching the
San Bernardino Mountains is extremely dilute during these conditions,
b. Off-shore flow
Occasionally the typical weather pattern is interrupted by the
development; of a strong high pressure area in the Great Basin
resulting in a reversal of the general flow. The most striking
example of this phenomenon is the strong "Santa Ana wind". In this
situation the South Coast Mr Basin pollution is swept out to sea -
and the threat of air pollution in the San Bernardino Mountains v
is replaced by another hazard, the threat of wildfires.
-------
D-5.
c. Opposing flows
Depending upon the strength of the high pressure system in the
Great Basin and the pattern and strength of the winds aloft, the
flow of air from the desert, through the passes and over the ridges,
varies from the violent "Santa Ana wind" to a light northerly or
easterly flow. In the latter case, the winds may be sufficiently
vigorous to halt the advance of the polluted up-slope flow in the
passes and on the more exposed slopes. On other occasions, mainly
in summertime, the opposing flows are provided by downdrafts under
thunderstorms which develop in deep moist currents moving into the
mountains from the south and southeast.
B. Small-scale phenomena
The character of the terrain from the coastline inland to the peripheral
mountain ranges prescribes the nature of the small-scale meteorological
factors which perturb the general flow. The differential heating of land and
sea impose the diurnal variation of sea- and land-breeze in the basin, typi-
. cally developing air motions as vigorous as the general flow upon which they
are superposed. The mountain ranges are obstacles to the cool dense marine
air and steer it like a polluted stream into the passes on either side of the
San Bernardino Mountains. At the same time, the heated daytime slopes of the
mountain ranges heat that part of the marine layer coming into contact with
them, thus forming a buoyant layer that ascends the slopes to the ridges and
peaks. This film of heated air rising along the slopes, often referred to
as a thermal chimney, vents polluted air out of the basin.
-------
D-6.
The heated coastal plain and floors of the valleys leading from the coast to
the San Bernardino Mountains systematically raise the temperature of the
marine layer as it moves inland. At some point during this journey the marine
layer becomes sufficiently warm to destroy the inversion; i.e. air in this upper
layer is no longer warmer than the marine layer below. The polluted marine
layer is then free to mix vertically with the pollution-free air above and
this active dilution results in a systematic decrease in pollution concen-
trations as the air travels inland. Typically this final demise of the
inversion occurs in the mountain passes and in the thermal chimney along the
basin-facing slopes. The peripheral ranges, of which the San Bernardino
Mountains are a part, then, typically delineate the inland limit of the
polluted marine layer trapped beneath £he inversion. At and beyond this
limit a rapid decrease in concentrations takes place via vertical diffusion
providing the marked improvement in visibility from the coastal side of the
peripheral ranges to the desert.
At night a weak off-shore flow replaces the more vigorous daytime on-shore
flow in the basin. The mountain slopes and canyons become the site of
drainage winds. Mountain basins such as that at Big Bear impound the chilled
air moving down the slopes to form a strong nocturnal temperature inversion.
In general, then, the nighttime hours are characterized by a retreat of air
from the mountains.
C. Distribution of oxidant in the San Bernardino Mountains
Measurements of the oxidant concentrations in the San Bernardino Mountains
have been made since 1967 (Miller, 1971). These surface observations have
been supplemented by measurements aloft during several intensive field
-------
D- 7.
experiments (Edinger et al, 1970); These studies reveal several important
facets in the distribution of oxidant in the mountains.
At elevations above the top of the inversion (average about 3500 ft) the
exposure to oxidant falls off with distance downwind. The graph in Fig.' D4,
based on October 1967 data, illustrates that both the average daily total
oxidant maximum and the number of hours when total oxidant exceeded 0.10 ppm
decrease with distance downwind from Rim Forest (5,780 ft).
Observations made on the slopes below and upwind of Rim Forest in June
1970 indicate that the maximum concentration actually occurs at about
3500 ft. This is the typical elevation of the top of the temperature
inversion and is the altitude on the mountain slopes where the rapid
vertical diffusion of polluted marine air begins. The concentrations
tend to decrease slightly with distance downslope (upwind) from the
3500 ft contour. Some features of the vertical distribution of pollution
in the marine layer prior to its arrival at the mountains suggest reasons
for this result.
The measurements made by aircraft over the urban source areas upwind of
the mountains indicate that the pollutants are not uniformly distributed
vertically in the layer beneath the inversion. Figures D5 and D6 are
typical examples of soundings of oxidant and temperature from the
surface up through the marine layer, inversion layer and the air above.
-------
D-8.
They illustrate the tendency for a maximum concentration near the base
of the inversion. Frequently this maximum actually occurs in the very
lowest layer of the inversion. Earlier observations (Sdinger, 1963) of
high moisture content in the lowest part of the inversion support the
hypothesis that the uppermost part of the marine layer is a layer of
convective debris that accumulates just below the warm dry inversion
air above. Being warmer than the remainder of the marine layer below,
this debris becomes an extension downward of the inversion. It does
not mix subsequently with the marine layer below and so is not subject
to those reactions with new material introduced at the ground which
consume oxidant. Consequently the photochemical processes which
create the oxidant proceed unopposed in this lowest part of the inversion.
Not infrequently the aircraft soundings also revealed layers of high
oxidant content completely imbedded within the inversion as illustrated
in Figures D7 and D8. Visual and photographic evidence suggests that
these layers of photochemical aerpsol are injected into the inversion
from the polluted thermal chimney moving up the slopes of the San
Gabriel Mountains on the north. Encapsulated in the inversion where
no mixing motions exist to diffuse and disperse them and where no
destructive reactions operate, these layers also achieve high oxidant
concentrations. These layers come into contact with the slopes of the
San Bernardino Mountains near the 3500 ft level. This is the level at which
maximum oxidant concentration is observed.
The basic processes working in concert to produce the vertical profile
-------
n-9.
of oxidant delivered from the source area to the slopes of the San
Bernardino Mountains are summarized in the sketches shown in Fig. D9. On
days when the inversion is weak (i.e. when there is little difference in
temperature from the base to the top of the inversion), it will be destroyed
by convective erosion from below prior to its arrival at the San Bernardino
Mountains. On such days the polluted current will be deep and dilute
upon arrival at the mountains and fairly uniform vertically. On the
majority of days, however, the inversion is strong enough to reach the
slopes of the San Bernardino Mountains intact, although thinned and
weakened substantially by the erosion from below. The final breaking
of the inversion occurs in the thermal chimney. At this point, typically
3500 ft., the pollution encapsulated in the inversion is released into
the upslope flow. This is a possible explanation for the maximum in
concentrations observed at this level.
Fig. DID shows the area between 3000 and 4000 ft. on the basin-facing
slopes of the San Bernardino Mountains where the maximum oxidant concen-
trations are to be expected. This area extends laterally from Cajon Pass
to San Gorgonio Pass. Since Cajon Pass at its summit has an elevation
of 3500 ft., the zone of maximum concentration should terminate near the
summit because at this elevation even the uppermost part of the inversion
is finally affected by surface heating and is destroyed. However, in San
Gorgonio Pass the summit is at approximately 2500 ft; therefore, the polluted
air, with inversion intact, can flow through the pass for some distance
before the inversion is broken. Consequently, the zone of maximum concentra-
tions should extend some distance around the south side of the San Bernardino
Mountains into the desert. Just how far depends upon such variables as the
-------
D-10.
strength of the inversion, the wind speed, and the time of day, in
addition to the height of the top of the inversion.
It is difficult to specify the lateral variation of oxidant concentrations
along this maximum zone. Some variability is expected since the broad
polluted stream from the basin source area is not homogeneous laterally. In
addition, the trajectories from the sources vary from day to day and also
influence the lateral distribution. The scant data taken immediately upwind
of the mountains substantiate this conclusion. Table Dl shows the mean daily
maximum values of oxidant at Riverside and San Bernardino for the years 1968,
*69, and '70. During this period the values at Riverside consistently
exceeded those at San Bernardino by close to 33%. If this is representative
of the lateral distribution of oxidant before it reaches the mountains, a
similar gradient of concentration along the 3500 ft contour can be expected.
As previously indicated, concentrations also decrease with distance downwind
from the 3500 ft contour on the basin-facing slopes. Taking this into account
along with the lateral gradient described earlier, a simplistic typical hori-
zontal distribution of oxidant throughout the mountains can be projected. A
host of local terrain effects distorts this general picture, as do anomalous
local weather events. Summer thunderstorms, in particular, profoundly alter
the pollution distribution in the mountains. Minnich (1967) has made a
study of these storms and the distribution of thundershowers over the range.
Fig. Dll gives a distribution of the rain days resulting from summertime
convection. The locations having the maximum number of rain days are likely
to be the sites experiencing diminished air pollution. The downdrafts
produced by the precipitation oppose the upslope flow which otherwise
-------
D-ll.
delivers pollution from the source areas. Furthermore, the shade
afforded the slopes by the clouds dramatically weakens the heating
responsible for the upslope motion. The difference in the number
of rain days from place to place within the range is seen to be
substantial, varying from 4 per summer season at the west end to
30 near the summit of San Gorgonio Peak.
Another complication affecting the distribution of oxidant on the slopes
is the lateral distribution of oxidant imbedded in the inversion before
it reaches the range. If this source of oxidant, as suggested earlier,
is largely responsible for the maximum concentrations observed at the
3500 ft level on the slopes, the lateral distribution of oxidant within
the inversion could influence the pattern of oxidant across the range
at all levels above 3500 ft. However, until observations concerning
this lateral distribution in the inversion can be made, no positive
conclusions can be drawn.
Other influences are introduced by smaller terrain features within the
mountains such as south-facing vs. north-facing slopes, box-canyons vs.
through-canyons, broad valleys and basins vs. deep narrow canyons. All
these have their own unique influence on the transport and turbulent
diffusion of polluted air passing over and through them. Each location
requires its own special study as regards these micrometeorological
details, a task beyond the scope of this discussion.
With the limited information available, a description of the impact of
air pollution and its geographical distribution throughout the San
-------
- 12.
Bernardino Mountains must be in the broadest of terms. To summarize,
the impact of oxident poJtlutipn depends upon the following factors
related to atmospheric conditions: a) whether the site is facing the
basin (south-facing) or facing the desert (north-facing), b) whether
the basin^facing slopes are above or below 3500 ft, c) the distance
downwind on slopes above 3500 ft when the wind is from the basin, d)
the average wind speed from the basin and e) the frequency of summer
thundershowers at the site.
Among the factors listed above only the effect of the wind speed has
not been discussed. Wind speed influences the reactions between oxidant
and the trees. Assuming that the rate at which the reactions take place
increases with heavier oxidant concentration, the rate at which the
oxidant is delivered (the wind speed) is involved. Thus, the greater
the wind speed the more rapidly oxidant is replenished.
The average wind at a location is affected greatly by the terrain. The
windiest locations are: (a) passes low enough to admit the marine layer
still capped by the inversion, (b) tops of long steep slopes, (c) heads
of canyons on the sunny side of the range, and (d) the crests of steep
low ridges extending out into passes across the general flow.
Since our concern lies with forests susceptible to oxidant damage, the
area of concern is limited, as shown on the map in Fig. D10, to those areas
where pqnderosa and Jeffrey pines are found. These areas all occur above
the 3500 ft. contour which, as discussed above is the site of the maximum
oxidant concentrations.
-------
D-13.
Certain locations in the San Bernardino Mountains have been selected to
identify the places where the greatest impact of oxidarit air pollution on
ponderosa and Jeffrey pine forests may be expected. These maximum impact
areas are: (A) Rim Forest, (B) Camp Angeles, and (C) the upper end of
Mill Creek canyon above 6000 ft. The sites selected where impact should
be minimum are (D) Big Pine Flat and (E) the east end of the Big Bear Basin.
These selections are not all inclusive nor are they absolute, but should
be considered as best estimates subject to revision when more complete
data coverage in the mountains becomes available. Certainly the sparse
data currently at hand suggests great variability from place to place
and from time to time. Consider, for example, the data in Table D2, which
contrasts daily maximum oxidant values at Rim Forest with those at the
east end of Big Bear Lake for August and September 1968. As our simple
criteria would require, the values at Big Bear are much lower than those
at Rim Forest. However, Table D3, indicating the highest daily maximum
values reported at the two stations, shows that for both months the
highest individual readings were reported at the Big Bear station.
Some special array of meteorological and source factors combined to
deliver higher concentrations of oxidant to the more remote location on
these days.
The conclusions reached in this section were constructed on slim data and
therefore must be considered very tentative. Nevertheless, the data
available does permit a few firm conclusions. The San Bernardino Mountains
encounter air with oxidant concentrations exceeding the State ambient
air quality standards every day from May through September. In its 1970
Annual Report the San Bernardino County Air Pollution Control District
-------
D-14.
reported that the standard (0.10 ppm of oxidant) was exceeded in the city
of San Bernardino on 167 days during that year. The analysis above
indicates the concentrations in the San Bernardino Mountains downwind of
the city are even higher. The data also clearly indicates that marked
differences in the impact of air pollution occur within the range; in
particular, marked decreases in the downwind direction above 3500 ft.
More detailed analysis of oxidant distribution in the range requires more
complete networks of data at the surface and aloft, within the mountain
range and upwind. In the last analysis, however, the most telling data
concerning the meteorological details may well be non-meteorological infor-
mation, such as the detailed distribution of oxidant damage to vegetation
throughout the San Bernardino Mountains. The initial efforts in this field
by Miller (1971) and Wert (1969) have already provided important Insights.
-------
D-15.
Acknowledgements
Special thanks are due Paul Miller and Rich Minnich for providing not only
firm facts and figures but some very suggestive observations that otherwise
would remain invisible between the rows and columns of figures.
-------
D-16.
Literature Cited
Minnich, R. A., 1971: An analysis of annual rainfall in the San Bernardino
Mountains, (private communication)
DeMarrais, G. A., G- C. Holzworth, and C. R. Hosier, 1965: Meteorological
summaries pertinent to atmospheric transport and dispersion over southern
California, Tech. Paper No. 54, U.S. Dept. of Commerce, Weather Bureau.
86 pages.
Miller, P. R., 1971: Oxidant^induced community change in a mixed conifer
forest, American Chemical Society Symposium, April.
Edinger, J. G., M. H. McCutchan, P. R. Miller, B- C. Ryan, M. J. Schroeder,
and J. V. Behar, 1970: The relationship of meteorological variables
to the penetration and duration of oxidant air pollution in the eastern
South Coast Air Basin, Project Clean Air, University of California
Research Reports, Vol 4, Research Project S-20.
Edinger, J. G., 1963: Modification of the marine layer over coastal southern
California, J. Appl. Meteor. 2 (6), 706-712,
Minnich, R, A., 1971: Distribution of thundershower days in the San Bernardino
Mountains, Summer 1967, (private communication).
Wert, S. JL., 1969: A system for using remote sensing techniques to detect
and evaluate air pollution effects on forest stands, Proc. of the sixth
international symposium on remote sensing of environment, Vol II pp 1169-
1183. (Willow Run Laboratories, University of Michigan).
-------
Table Dl. Yearly mean of the daily maximum hourly average
Concentration of oxidant for the cities of San
Bernardino and Riverside, (ppm)
1968
1969
1970
San Bernardino
.09
.11
.12
Riverside
.13
.15
.15
-------
Table D2. Average daily maximum oxidant concentration at
Rim Forest^ and Big Bear for August and September
1968,
1968
Aug
Sept
Rim Forest
,21
.17
Big Bear
.12
.08
Table P3. Highest daily maximum oxidant concentration recorded
at Rim Forest and Big Bear for August and September
1968. (ppm)
1968
Aug
Sept
Rim Forest
.32
.31
Big Bear
.37
.33
-------
Figure legends
Fig
Dl Average annual rainfall in San Bernardino Mountains, 1870-1970,
(inches)
D2 Weather stations recording observations at 14:30 (USFS) or 14:00 PST
D3 Weather stations making night wind observations and fire lookout
observations (07:00 PST)
D4 Average daily total oxidant maximum and number of hours when total oxidant
exceeded 0.10 ppm, as a function of distance downwind from Rim Forest,
October, 1967.
D5 Vertical soundings of oxidant and temperature, 16:20 PST, June 20, 1970,
Rialto-Miro airport.
D6 Vertical soundings of oxidant and temperature, 13:44 PST, June 19, 1970,
El Monte.
D7 Vertical soundings of oxidant and temperature, 13:28 PST, June 20, 1970,
Santa Monica.
D8 Vertical soundings of oxidant and temperature, 13:28 PST, June 20, 1970,
Santa Monica.
D9 Schematic vertical cross-sections illustrating meteorological features
that influence the vertical distribution of air pollution in the South
Coast Air Basin.
D10 Map of San Bernardino Mountains. Elevation in thousands of ft mean sea
level given by numbers of contours. Stippled area denotes location of
ponderosa and Jeffrey pines. Hashed area denotes zone of expected
maximum oxidant concentration.
Dll Number of thunderstorm rain days, June 28 - Sept 10, 1967.
-------
15
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AV<3. DAILY MAX. OXIDANT (PPM)
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Figure D-4
-------
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Figure D-5
-------
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OXIDANT
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Figure D-6
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Figure D-7
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Figure D-8
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-------
-------
Section E
GEOLOGY, SOILS AND HYDROLOGY OF THE SAN BERNARDINO MOUNTAINS
L. J. Lund and A. L. Page
Coordinators
Contributors
Willie Z. Brock
Soil Scientist
U. S. Forest Service
144 North Mountain View
San Bernardino, Ca. 92408
W. N. Johnson
Hydrologist
U. S. Forest Service
144 North Mountain View
San Bernardino, Ca. 92408
Lanny J. Lund
Assistant Professor
Department of Soil Science and
Agricultural Engineering
University of California
Riverside, Ca. 92502
Albert L. Page
Associate Professor
Department of Soil Science and
Agricultural Engineering
University of California
Riverside, Ca. 92502
-------
TABLE OF CONTENTS
Page
GEOLOGY 2
SOILS
DRAINAGE BASINS AND RUNOFF 12
EROSION, SEDIMENTATION AND WATER QUALITY 15
-------
E-2
The San Bernardino Mountains are part of the Traverse Range
Province that extends from west to east across parts of Santa Barbara,
Ventura, Los Angeles, San Bernardino, and Riverside Counties, Cali-
fornia (Bailey and Johns, 1954). They are situated between 116 30'
and 117°30' West Longitude and 34°00' and 34°25 ' North Latitude. The
San Bernardino National Forest in this area is bounded on the north by
the Mojave Desert, the east by the Little San Bernardino Mountains, the
south by the Upper Santa Ana Valley and Yucaipa-Beaumont Plains, and on
the west by the San Gabriel Mountains.
The San Bernardino Mountains are characterized by deep, steep-
walled canyons and altitudes ranging from 4,000 to over 11,000 feet
(Figure EH) . A subdued upland surface which is discontinuous is found
in the Lake Arrowhead-Big Bear Lake region and is covered primarily by
conifer forest. San Gorgonio Peak, the highest point in southern
California (altitude 11,502 feet), is located in the eastern end of the
San Bernardino Mountains along with many other prominent peaks and ridges.
GEOLOGY
A generalized geologic map of the San Bernardino Mountains is
shown in Figure E2. This range was formed by uplift along the San
Andreas fault zone on the south and along several steeply dipping
reverse faults on the north.
The area is composed mainly of gneisses, schists, plutonic rocks,
sediments, and recent alluvium, the Cactus granite formation (Miller,
1946), which is mainly a light-colored quartz monzonite of Mesozoic age,
is exposed over a large portion of the mountain area, especially in
-------
E-3
the Lake Arrowhead region. This exposure is found primarily on the
subdued upland surface. Metomorphosed sedimentary rocks of Paleozoic
age are abundant in the area and numerous intrusions of metomorphosed
rocks are found in both the Cactus formation and other plutonic bodies.
Sedimentary rocks of Pliocene and Pleistocene age are .also found in the
area along with Recent alluvium.
The texture of the rocks found in this mountain area vary from
fine textured volcanics to gravels which contain boulders several feet
in diameter. Rocks which have been fractured and broken to a great
extent are found in much of the mountain area, especially near faults
and in fault zones. In some areas only normal jointing and fracturing
are exhibited by the rocks. The presence or absence of fractures and
joints is important to the hydrologic characteristics of the area in
their effect on infiltration and runoff.
SOILS
Soils have formed in the San Bernardino Mountains through the
influence of climate, relief, vegetation, parent materials and time.
The climate varies from semi-arid to humid depending on altitude. The
vegetation varies from chamise chaparral on the foothills to coniferous
forest in the Lake Arrowhead regions. These factors are discussed in
following sections.
As noted in the geology section, parent materials vary from Recent
alluvium to weathering products of Pre-Cambrian rocks. Igneous, sedi-
mentary and metamorphic rocks are present to serve as sources of parent
material as well as alluvium derived from these sources. The types of
-------
E-4
parent material have influenced the texture, depth, and other properties
of the soil found in this area.
Relief has been an important factor in soil formation in this area.
Slopes vary from nearly level to nearly vertical. Soils found on steeply
sloping land are generally shallow due to erosion processes during soil
formation. Deeper soils are found on landscapes that are more stable
such as on the relatively subdued upland surface around Lake Arrowhead.
The effects of climate and vegetation are impared on the parent
materials. As parent materials are exposed to climate and vegetation
for longer periods of time, soil formation processes result in deeper,
finer textured soils. If relief is such that erosion would equal soil
formation, time would have little effect on soil properties.
The various geologic materials in the San Bernardino Mountains
have weathered by physical and chemical processes to form parent
materials. These parent materials have been differentiated into soil
profiles by the processes of additions, removals, transfers and trans-
formations. Differences in the rates of these four processes have
resulted in the formation of different soils.
Soil bodies which are similar in all properties (color, structure,
depth, pH, etc.) except surface texture, are grouped together into a
classification category, soil series. Soil types and soil phases which
are subdivisions of soil series are used as mapping units when mapping
soils within an area of interest.
No general mapping has been done in the San Bernardino Mountains;
however, some mapping has been done by the U. S. Forest Service and the
-------
E-5
Soil Conservation Service in small areas within the San Bernardino
Mountains. The soil series that have been mapped in these areas are
given in Table El along with some of their important properties. Other
soil series which may occur in the Lake Arrowhead region are given in
Table E2. Since little mapping has been done, few series have been
described and correlated for this area. Some of the series names given
in Table Elare those which most nearly represent the observed soil
characteristics.
Most of the soils mapped are coarse textured, well drained and
have a low water holding capacity. These properties are primarily the
result of relief and parent materials. Two soil series which may occur
in the San Bernardino Mountains are Chawanakee and Shaver. These may
represent somewhat a set of end-members of the soils found in this area.
The former is a shallow soil and the latter a deep soil. The official
description of these series is as follows:
Ghawanakee Series
The Ghawanakee series is a member of the loamy, mixed, mesic,
shallow family of Dystric Xerochrepts. Typically, Chawanakee soils
have grayish brown, medium acid, coarse sandy loam A horizons and very
pale brown, medium acid B2 horizons overlying strongly weathered
granitic bedrock.
Typifying Fedon: Chawanakee coarse sandy loain - forested.
(Colors are for dry soil unless otherwise stated.)
01 1-1/2-1/2" -- Grayish brown, dry, loose litter of bear clover,
leaves and twigs with occasional pine needles.
02 1/2-0" -- Very dark grayish brown partly decomposed litter,
weakly matted.
-------
E-6
A1 0-6" -- Grayish brown (10YR 5/2) coarse sandy loam, very dark
grayish brown (10YR 3/2) moist; moderate medium and fine
granular structure; slightly hard, friable; many fine^small
shrub roots; many small pores; medium acid (pH 5.7); diffuse
smooth boundary. (3 to 6 inches thick)
B2 6-18" -- Very pale brown (10YR 7/3) coarse sandy loam, brown
(10YR 5/3) moist; very weak fine granular structure; hard,
friable, few small shrub roots; some continuous pores;
medium acid (pH 5.7); abrupt irregular boundary. (8 to
30 inches thick)
C 18-32" — Pale brown disintegrated and partly decomposed parent
rock; mineral grains retain original orientation; thin
discontinuous reddish brown (SYR 4/4 and 4/6, dry) clay
films on some mineral grains and partially fills some
spaces between grains, diminishing with depth, disappearing
below 30 inches; grades to unweathered rock at undetermined
depth.
Shaver Series
The Shaver series is a member of a coarse-loamy, mixed, mesic
family of Pachic Ultic Haploxerolls. The soils have dark grayish brown
to grayish brown coarse sandy loam Al horizons, brown coarse sandy loam
AC horizons, pale brown coarse sandy loam upper C horizons which over-
lie strongly weathered acid igneous rock.
Typifying Pedon: Shaver coarse sandy loam - forested
(Colors for dry conditions unless otherwise noted)
Oil -- 3-2" -- Dried litter of white fir and sugar pine needles,
some twigs.
012 -- 2.0" -- Partially decomposed litter; abundant white fungal
mycelia; rests abruptly on:
All — 0.2" -- Dark grayish brown (10YR 4/2) coarse sandy loam,
very dark brown (10YR 2/2) moist; strong fine crumb
structure; soft, very friable; abundant fine roots;
many fine interstitial pores; slightly acid (pH 6.5);
abrupt wavy boundary. (2 to 9 inches thick)
-------
E-7
A12 -- 2-5" -- Grayish brown (10YR 5/2) coarse sandy loam, dark
brown (10YR 3/3) moist; moderate fine crumb structure;
soft, very friable; abundant fine, plentiful medium,
few coarse roots; many fine interstitial pores; slightly
acid (pH 6.3); clear wavy boundary. (3 to 14 inches
thick)
AC -- 5-33" -- Brown (10YR 5/3) coarse sandy loam, dark brown
(10YR 3/3) moist; weak fine crumb structure; soft, very
friable; abundant fine, plentiful medium and coarse
roots, very few large roots; many fine interstitial pores;
slightly acid (pH 6.2); abrupt wavy boundary (12 to 54
inches thick)
Cl — 33-73" -- Pale brown (10YR 6/3) coarse sandy loam, dark brown
(10YR 4/3) moist; massive; slightly hard, very friable,
very slightly sticky; many fine, medium and coarse roots,
very few large roots; common fine and medium tubular
pores, many fine interstitial pores; medium acid (pH 5.9);
abrupt irregular boundary. (7 to 40 inches thick)
C2 -- 73"+ -- Light gray, strongly weathered quartz diorite;
original rock fabric clearly visible in place; easily
excavated and crushes readily to a coarse sand; porous;
occasional large tree roots; many feet to unweathered
rock (R).
A property associated with many southern California soils of
interest to any ecology study is water repellency. Water repellency
will have an effect on infiltration and runoff characteristics of any
soil that is water repellent. The water repellency in some soils is
intensified by heat such as a forest fire, Debano (1969) found the
water repellency in a 2 to 4 inch depth increased in a burned area
compared to an unburned area.
Water repellent soils are present in the San Bernardino Mountains
(Holzhey, 1969). Some areas show seasonal repellency while others are
water repellent year-around. The various degrees of water repellency
appear to be related to vegetation, parent material and topography;
however, no specific relationship has been found.
-------
E-8
DRAINAGE BASINS AND RUNOFF
The creeks and rivers for the San Bernardino Mountains are
indicated in Figure 3. The northern slopes of the study area are
drained by Deep Creek and the West Fork of the Mojave River along
with other minor tributaries and intermittent streams. The creeks
and rivers on the northern slopes drain into the Mojave River. The
combined flow of the West Fork of the Mojave River and Deep Creek dis-
charges an annual average of 84,500 acre feet onto the adjacent valley
floor. All of this runoff, except for flood periods, becomes a recharge
to ground water storage in the Mojave Desert. The geology of the
northern slopes is of principally granitic origin (Figure 2E) . Geologic
parent materials of this nature are generally the least water absorptive
and retentive mantle rock and because of this the northern slopes which
drain into the Mojave River have high winter flood runoff and low summer
delayed runoff. Storm surface runoff occurs in the San Bernardino
Mountains only during a shower of unusual intensity. Due to the
characteristics of the mantle rock this runoff is caused by temporary
ground water storage. Relative to runoff characteristics mantle rock
can be placed in three rather broad categories: (a) least absorptive
and retentive mantle rock having maximum flood runoff and minimum summer
delayed runoff; (b) moderately absorptive and retentive rock having
moderate flood and summer delayed runoff; and (c) most absorptive and
retentive mantle rock having minimum flood runoff and maximum summer
delayed runoff. For the northern slopes draining into the Mojave Desert
about 80%, 5%, and 15% of the mantle rocks fall into the categories of
-------
E-9
least absorptive and retentive, moderately absorptive and retentive,
and most absorptive and retentive, respectively (Troxell, 1954).
The southern slopes of the study area are drained by the Santa
Ana River and its tributaries (Figure E3). The more important creeks
on the southern slopes almost immediately south of Lake Arrowhead
include Plunge Creek, City Creek, Strawberry Creek, Waterman Canyon
Creek, and Warm Creek. Approximately 30% of this region contains mantle
rock with least absorptive and retentive properties, while 60% and 10% of
the mantle rocks in the region can be classified as moderately absorptive
and retentive, and most absorptive and retentive, respectively. The
Santa Ana River and Mill Creek drain the southern slopes southeast of
the study area. Mantle rock for this region can be categorized as
about 20% least absorptive and retentive, 30% moderately absorptive
and retentive, and 50% most absorptive and retentive. The southern
slopes west of the study area are drained principally by Lone Pine
Creek and Lytle Creek. Mantle rock in this region is approximately
80% most absorptive and retentive and 15% moderately absorptive and
retentive. In summary, mantle rock on the northern slopes of the San
Bernardino Mountains provide the least conducive conditions for ground
water runoff and storage, while those to the west of the study area on
the southern slopes provide the conditions conducive to the maximum
ground water runoff and storage.
-------
E-10
EROSION, SEDIMENTATION AND WATER QUALITY
There are very few data available on erosion, sedimentation, and
water quality for the study area. The U. S. Forest Service— are
currently in the early stages of setting up a water quality program for
the San Bernardino National Forest. Parameters to be measured include
flow, temperature, turbidity, dissolved oxygen, phosphates, total
hardness, total dissolved solids, bacteria, sedimentation and erosion.
Acute erosion problems commonly occur following forest fires. An
example of this is the Plunge Creek drainage (Figure E3)which is some-
what similar in geology and soils to the Deep Creek area. Sediment
measurements for the first year after a wildfire showed debris yields
up to 108,500 cubic yards per square mile. Debris gradually decreased
to 3,600 cubic yards per square mile ten years after the burn.—
Removal of vegetation by logging, housing developments, roads, and any
other means may increase stream flow, erosion, and sedimentation.
Drastic reduction in timber stands caused by air pollution would, in
effect, produce results similar to forest fires. Since reductions
caused by air pollution would be gradual, their effects should not be
as acute as those associated with fire.
Changes which may occur in soil properties would be restricted to
the surface horizons. If the canopy were to be reduced by forest
thinning, this would affect both the amounts of organic matter ac-
cumulated in the soil surface and the rate at which it would be
_!/ Private communication, U. S. Forest Service.
-------
E-ll
microbially decomposed. The soil surface would intercept more heat
thereby resulting in a greater degree of decomposition of the organic
materials. Coniferous vegetation produces an acidic environment.
Under conditions where the amounts deposited on soils were reduced
the chemical weathering of the soil materials would be retarded. On
the steep slopes if vegetation were drastically reduced, seasonal
erosion of surface deposited materials would alter the normal soil
forming processes.
-------
E-12
REFERENCES
Bailey, T. L. and R. H. Jahns. 1954. Geology of the Traverse Range
Province, Southern California. In Geology.of Southern California.
Bulletin 170, Vol. 1. Division of Mines, Dept. of Natural Re-
sources, State of Calif. San Francisco, pp. 83-106.
Debano, L. F. 1969. The relationship between heat treatment and water
repellency in soils. In Water Repellent Soils. Proceedings of
the Symposium on Water Repellent Soils. Univ. of Calif., River-
side, pp. 265-279.
Holzhey, C. S. 1969. Water-repellent soils in Southern California.
In Water Repellent Soils. Proceedings of the Symposium on Water
Repellent Soils. Univ. of Calif., Riverside, pp. 31-41.
Miller, W. J. 1946. Crystalline rocks of Southern California. Geol.
Soc. Amer. Bull. 57:457-542.
Troxell, H. C. 1954. Hydrology of the San Bernardino and Eastern San
Gabriel Mountains, California. Hydrologic Investigations Atlas
HA 1. U. S. Geological Survey.
-------
Soil Series
Ahwahnee*
Auberry*
Bancas*
Behemotoch*
Chiquito*
Cieneba*
Godde*
La Posta
Mottsvtlle
Oak Glen
Soboba*
Stoner*
Tollhouse
Slope on
Surface which series Parent
texture occurs material
7=
coarse
sandy loam
coarse
sandy loam
fine
sandy loam
gravelly
loam
very gravelly
sand
rocky sandy
loam
very gravelly
loam
loamy coarse
sand
stony loamy
sand
sandy loam
cobbly
loamy sand
cobbly
loamy sand
cobbly
sandy loam
5-50
15-30
15-50
15-75
20-50
9-50
> 70
5-30
9-15
0-30
2-9
15-30
5-50
decomposed
granodiorite
weathered
granite
weathered
granite
schist
weathered
granodiorite
weathered
granite
weathered
schist
decomposed
granodiorite
granitic
alluvium
granitic
alluvium
granitic
alluvium
weathered
granodiorite
weathered
granodiorite
Natural
drainage
well
well
well
well
excessive
well
well
excessive
excessive
we 111/
excessive
well
well
Runoff
medium
to rapid
medium
to rapid
medium
to rapid
medium to
very rapid
medium
to rapid
medium to
very rapid
very rapid
medium
to rapid
slow
very slow
to medium
slow
medium
to rapid
medium
to rapid
Erosion
hazard
moderate
to high
moderate
to high
high
high to
very high
moderate
moderate
to high
very high
high
slight
slight
slight
moderate
slight
to high
Effective
depth
in.
24-40
40-60
30-40
30-40
20-30
10-20
10-20
20-36
60+
60+
60+
24-48
10-20
Available
water
capacity
medium
to low
medium
medium
low
low
low
very low
low
low
medium
to high
low
medium
low
* Series indicated most nearly corresponds with the observed field characteristics.
I/ Seasonally wet.
-------
Table E2. Soil series which may occur in the San Bernardino Mountains
Soil Series
Bull Trail
Ghawanakee
Coarsegold
Crafton
Grouch
Shaver
Sheephead
Surface
texture
sandy loam
sandy loam
loam
sandy loam
sandy loam
s andy 1 oam
fine sandy
loam
Slope on
which series
occurs
%
9-15
10-30
10-30
20-50
10-30
10-30
10-30
Parent
material
granitic
alluvium
weathered
granite
weathered
mica schist
micaceous
schist
weathered
granite
weathered
granite
micaceous
schist
Natural
drainage
well
well
well
well
well
well
well
Runoff
medium
medium
to rapid
medium
to rapid
medium
to rapid
medium
to rapid
slow to
medium
medium
to rapid
Erosion
hazard
moderate
moderate
to high
moderate
moderate
moderate
moderate
moderate
Effective
depth
in.
60+
10-40
20-40
20-40
24+
60+
10-20
Available
water
capacity
low
low
med ium
to high
medium
well
low
low
-------
Figure Legends
Fig.
El Topographic map of the San Bernardino Mountains.
Contour interval is 500 ft.
E2 Geology map of the San Bernardino Mountains.
E3 Drainage basins in the San Bernardino Mountains
-------
Figure E-l — Topographic map of the
San Bernardino Mountains
Contour interval is 500 ft.
-------
| Qoi
| Ql
I Ot
1 Qc
1
PC
1 Prtilt
1
1 Me
ALLUVIUM
QUATERNARY LAKE DEPOSITS
QUATERNARY. NONMARINE
TERRACE DEPOSITS
PLEISTOCENE NONMARINE
UNDIVIDED PLIOCENE NONMARINE
MIDDLE AND /OR LOWER
PLIOCENE NONMARINE
UNDIVIDED MIOCENE NONMARINE
O
o
N
0
01
LU
5
w
O
N
O'
LJ
<
O.
"
Ei
gr MESOZOIC GRANITIC ROCKS
I fri 1 MESOZOIC BASIC INTRUSIVE ROCKS
| JRv | JURA-TRIAS METAVOLCANIC ROCKS
j m | PRE-CRETACEOUS METAMORPMIC ROCKS
[ mg1 PRE-CRETACCOUS METASEDIMENTARY ROCKS
[ IP | PALEOZOIC MARINE
[ C | UNDIVIDED CARBONIFEROUS MARINE
i 1
PRE-CAMBRIAN METAMORPHIC ROCKS
I PRE-CAMBRIAN IGNEOUS AND
I METAMORPHIC ROCK COMPLEX
Figure E-2 — Geology map of the
San Bernardino Mountains.
-------
Figure E-3 Drainage basin in the San Bernardino Mountains.
-------
Section F
Sociology Committee Report
History and Suggested Protocol
for
Environmental Protection Agency
Study of the Impact of Oxidant Air
Pollution on the Mixed Conifer Forest Ecosystem
Committee Chairman: Edgar W. Butler, Department of Sociology,
University of California, Riverside
Principal Contributors: Sheldon Bockman, Sociology, University
of California, Riverside
John H. Freeman, Sociology, University
of California, Riverside
Charles E. Starnes, Sociology, University
of California, Riverside
Joanne Hancock, Research Assistant
Sociology, University of California, Riverside
David McElroy, Research Assistant, Sociology,
University of California, Riverside
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Section F
I. INTRODUCTION
This section of the report presents results of the search for historical
and demographic data and information on the utilization of the Lake Arrowhead
region by the human population, along with some background material suggesting
possible effects of oxidant air pollution upon the human population. In
addition, a brief description of a frame of reference for future studies of
the effects of oxidant air pollution upon man in the Lake Arrowhead region is
given. Beyond describing the historical background, the human population and
its use of the Lake Arrowhead habitat, and the possible effects of oxidant air
pollution on man, this report briefly suggests a frame of reference for the
long term study of oxidant air pollution and begins to outline methods and
techniques that may be used in areas other than Lake Arrowhead to more effectively
study the impact of air pollution upon man.
A large number of social scientists, in a variety of disciplines, have
expressed interest in future research endeavors to be centered in the Lake
Arrowhead region; the following persons made contributions to the compilation
of data and writing of the Social sciences section contained herein.
Edgar W. Butler, Coordinator, Sociology, U.C.R.
Sheldon Bockman, Sociology, U.C.R.
John F. Freeman, Sociology, U.C.R.
Charles E. Starnes, Sociology, U.C.R.
Joanne Hancock, R.A., Sociology, U.C.R.
David McElroy, R.A., Sociology, U.C.R.
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II. HISTORICAL BACKGROUND ON LAKE ARROWHEAD
The introduction of human society to the San Bernardino Mountains, with the
exception of small, scattered Indian settlements, probably began in the Spring
of 1852 when the first roadway was cleared to the top of the mountains. Amasa
Lyman, Bishop Crosby, and Charles Crisman organized a party of men from the
Mormon fort in San Bernardino to begin work on a steep, narrow roadway which
opened the mountains and valuable timberland to them. The year of 1852 was a
busy one in the mountains, for in the Fall of that year a United States deputy
surveyor climbed to the highest peak and took bearings for the first true
east-and-west map line in Southern California.
Ten years after Mormon settlers from San Bernardino set up several small logging
operations in the mountains, lumbering had become a major enterprise. Most
settlers were content with farming the land in the valley below, but numerous
pioneers established small land holdings in the mountains. However, no large
settlements sprang up in the mountains until the 1920*s. Many species of
wildlife roamed the mountains in considerable numbers, but the human population
settled itself in the logging camps or in the valley below. Gold and other
minerals were discovered in the mountains and many small placer mines and claims
were established with such pictureque names as Sitting Bull, Blowout, Lone Star,
Diablo, and Upset.
Settlement took place in Bear Valley and further west in Grass Valley and Little
Bear Valley. Little Bear Valley is of particular concern to this study because
the Little Bear meadow became the site of Lake Arrowhead. The Talmadge Mill
was located near the site where the Lake Arrowhead "Village" was later established
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The history of Lake Arrowhead as a "lake" began in 1891 when the Arrowhead
Reservoir Company incorporated and built the first passable road into the
mountains, thus making them more accessible. Substantial organized settle-
ment in the mountains began with the building of small, private lodges such
as the "Squirrel Inn" and by 1895 tourists were treking up the Arrowhead toll
road to visit the primitive yet comfortable retreats. The mountains were
"officially" conquered on June 30, 1900 when a Locomobile made a test run
up the narrow winding road to Bear Valley, across the mountains, and down the
Arrowhead toll road. The Arrowhead Reservoir Company had been in operation
for thirteen years when, in 19,04, it let the official contract to build the
cement corewall for the little Bear Valley reservoir. Such a major construc-
tion project was a great undertaking given the primitive roads and the
difficult accessibility to the site.
Accessibility to the mountains was always a problem. Transportation on the
roads was hazardous because of steep grades and switchbacks which often proved
fatal to loggers bringing lumber down from the mountains. Tourists visiting
the mountains with increasing frequency found transportation lacking because
automobiles were not permitted on the toll road. A solution to the transporta-
tion problem was begun when the Pacific Electric Railway laid track from San
Bernardino to the Arrowhead Hot Springs Hotel in Waterman Canyon at the base
of the mountains. In 1908, the Arrowhead Road was given to the County of
San Bernardino and automobilists began to drive cars up the County Road in
Waterman Canyon. Within a year the road was open to automobiles, thus creating
a booming tourist business.
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The permanent residents in the mountains were hearty, rowdy, pioneering
people who sometimes backed up their words with guns and violence. Logging
as a destructive element in the mountains was impeded when the mountains
became a national forest and rangers enforced some order on the mountain
society. In contrast to tough permanent residents, summer tourists who
visited the area were wealthy, upper-class people who could afford to be
dilletante nature lovers. The tourist society was a gay, carefree crowd
given to elegant balls in outdoor pavilions, potato and raarshmallow roasts,
watermelon feasts, and campfire sings. Catering to the tourist trade, like
the logging and mining industries, had become a paying enterprise in the
mountains.
In 1920, the Lake Arrowhead Company purchased the properties of the Arrowhead
Reservoir and Power Company which was centered in Little Bear Valley. A
spokeman for the new company said that the Arrowhead Company planned to create
a lake in the west fork of the Mojave and send water to some of the desert-
side irrigation districts; to raise the Little Bear Dam thirty-one feet. . .
and change its name and that of the lake formed to "Lake Arrowhead". Within
two years the Lake Arrowhead project had been mapped out in minute detail,
planning the development of every foot of the five-mile shoreline. The
directors of the company met with the Rim of the World Association and
attempted to get better roads and stage service to Lake Arrowhead.
In the middle of April, the Arrowhead Lake Company began putting its develop-
ment plans into effect. A large group of men leveled a terrace for the
business section at the west end of the lake near the Little Bear Resort
buildings which were being demolished. In the pine woods across the cove from
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the village, housekeeping cabins were built. At Orchard Bay a pay auto-camp
to hold a thousand cars for fishermen was built. The grand opening of the
first facilities, including a hotel, village stage depot, shops, market, art
shop, drug store, dance pavilion, and a gas station, was set for June.
The opening of the new Lake Arrowhead Company brought dignitaries from all
over Southern California and two hundred and fifty newspapermen and women.
All were impressed with the orderly growth, the unifying architecture, the
combination of the works of Nature with artistic and beautiful works of man.
Transportation was still somewhat of a problem even during the summer. The
Motor Transit Company which offered two round trips a day to Lake Arrowhead
was notorious for lateness, discomfort, speed at viewpoints, overloading, and
danger, since a car tumbled off a soft shoulder at a steep grade. The
Company held a $5,000 contract for delivery of the U.S. mail as well.
Lake Arrowhead became a thriving settlement with 44 resorts, all supplied with
electricity. The services of a doctor, minister and local court judge also
were available. The first permanent social organizations were started—a masonic
lodge and a women's club. In 1923 the Pacific Telephone Company completed a
single line through to Lake Arrowhead, enabling the mountain community to
communicate with the outside world. The Federal government appropriated
$75,000 to the National Forest-Highway program for construction of a good road
to the top of the mountain.
The Lake Arrowhead complex offered additional services to its residents with
the opening of a branch office of the Pacific Southwest Savings and Trust Company.
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Spiritual needs were attended to by Catholic priests who held mass in the
hall across from the Lake Arrowhead Post Office. American Legion members
residing in Lake Arrowhead received a 14 acre government plot on which to
place a building. The North Shore subdivision was being offered, with such
notables as an heiress of the National Biscuit Company purchasing land.
Other retreats were established by movie stars Buster Crabbe, Gene Lockhart,
J. Carrol Nash, and Myrna Loy. The number of permanent year-round residents
was increasing and in 1924 the first school—Lake Arrowhead Elementary School
—was established in a small, wood frame building for the 14 children of
permanent residents. The area became increasingly popular as a resort settle-
ment and there were upwards of 200 resorts there in 1924. With the increased
number of residents and visitors, fires and environmental pollution appeared,
as well as a decline in wildlife.
Growth continued during the next few decades and today the area contains many
large homes, mountain retreats, and a larger resident population and millions of
visitors.
III. THE HUMAN POPULATION AND ITS USE OF THE LAKE ARROWHEAD HABITAT
Currently, the forest region has a human population highly variable in density
and spatial distribution, and the population fluctuates by season, month, day
of the week, and snowfall. Several different and relevant human populations
utilize the Lake Arrowhead region, thus any evaluation of land use requires
information on the following: (1) permanent residents, (2) owners who
intermittently utilize their property as summer and recreational facilities
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for themselves, relatives, and friends, and (3) "visitors"—the transient
population. Population data pertaining to the permanent residents and
intermittent users can be obtained from the United States Census and are
discussed in more detail below. Estimates only are available for the
visitor population.
Assuming that residential growth in the San Bernardino National Forest will be
minimal and that zoning will prohibit multiple family housing units or high-rise
construction in the Lake Arrowhead region, the actual population growth poten-
tial of Lake Arrowhead is severely limited by geographical constraints.
However, recent expansion of one of the major access highways to four lanes
decreased highway congestion and made accessibility easier fbr an increased
number of visitors. Other major routes may be widened thus providing easy
accessibility to Lake Arrowhead for virtually all Southern California residents.
While the permanent population growth may have upper limits, this easy accessi-
bility, coupled with higher per capita incomes, may result in an ever increasing
visitor use of picnic grounds, campgrounds, and other recreational facilities,
leading to increased locally produced air pollution and despoliation of the
environment.
Lake Arrowhead is located in San Bernardino County, one of the eleven counties
constituting Southern California. Southern California is expected to have a
population of eighteen million persons by 1980. Of the 684,072 people enumerated
in San Bernardino County in the 1970 U.S. Census of Population and Housing,
180,000 of them were added during the previous decade. San Bernardino County
contains 20,160 square miles and is highly diverse in its social, economic,
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and topographic composition. The vast majority of the population (all but
138,000) reside in the valley south of the national forest boundary. In
addition to the local resident population, the San Bernardino National Forest
receives an estimated eight million visitors a year.
A precise description, beyond sheer numbers, of the population in the immediate
Lake Arrowhead environments is extremely difficult because each agency defines
boundaries somewhat differently. One boundary, San Bernardino County Planning
District 16, includes the Lake Arrowhead census tract as well as two others.
In 1970, this planning district contained a population of 18,267. The popu-
lation is expected to grow to 25,000 by 1980 and to over -31,000 by 1990. Census
Tract 101—Lake Arrowhead—had a population of 2,343, in 1950; 4,247 by 1960;
and a population of 10,437 in 1970. During the past decade the resident popu-
lation has been increasing at a faster pace than dwelling units, suggesting
that an increasing proportion of people are utilizing their property at Lake
Arrowhead as a full time, permanent place of residence. Enumeration district
data (E.D's 210-223) indicate that the immediate Lake Arrowhead habitat had a
population of 3,031 in 1970. Using a slightly different population base of
2,672 (less two of the above E.D.'s), in 1970 the resident population was 98.4%
white, with a median age of 31.2 years. Almost 63% of the dwelling units were
vacant at the time of the 1970 census, 25.4% were occupied by owners, and
11.8% were occupied by renters. The vacancy rate, of course, reflects the
important recreational facet of the Lake Arrowhead region and part-time use
by people from Los Angeles, Orange, Riverside, San Bernardino Counties and else-
where. Over 90% of the dwellings are single-unit structures. Median value of
owner occupied units at the time of the census was $31,250; median rent was
$131 per month.
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Land use within the immediate vicinity of the Lake is primarily residential
except for the "Village" which contains commercial, shopping, and business
areas, a small lake adjacent to the country club, a riding club, the University
of California Conference Center, and a few public facilities, such as schools.
The Lake Arrowhead population concentration is virtually surrounded by the San
Bernardino National Forest.
Because of the small permanent population living in the mountain region, most
of the oxidant air pollution is not locally produced, but rather comes from
population concentrations and industry in Los Angeles, Orange, and Riverside
Counties, and from the valley population of San Bernardino County. Therefore,
although the population growth in the mountain region is limited by the amount
of land now available for private use, the air pollution supply is virtually
unlimited. As the population of the Los Angeles basin increases and as industry,
automobiles, and other sources of pollution increase, it is expected that the
air pollution problem will become more severe in the Lake Arrowhead region.
One major use of the mountain region, of course, is recreation. People tend to
use recreational facilities without regard to jurisdictional boundaries;
therefore, the Lake Arrowhead recreational area has a potential population
reservoir, throughout Southern California, of eighteen million persons to draw
upon. This vast population reservoir generates recreational demands ranging
from the most urban to the most rustic, including picnic grounds, riding and
hiking trails, scenic drives and parkways, and skiing, fishing, hunting, and
boating areas (SCAG, September, 1970). The region embraces the San Bernardino
National Forest which is the largest national forest in Southern California.
About 3/4's of the acreage of the Lake Arrowhead region is included in the
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National Forest, which drew an estimated 8 million visitors last year. These
visitors included those who stayed one day or less as well as campers and
vacationers who stayed several days.
As indicated on Figure G-l, virtually all of the major recreational facilities
in San Bernardino County (excluding only the Colorado River area and the Prado
Basin) are concentrated in the San Bernardino Forest—Lake Arrowhead vicinity.
Silverwood Lake in the region is in process of being fully developed as a
multiple-purpose recreational center and will very shortly substantially
increase the number of visitors to the region. In addition, Holcomb Valley
is an underdeveloped section with high potential recreation usage.
Precise data on the specific use of main highways are available from the
California State Department of Highways. Utilization of public campsites
and picnic grounds, Natural Preserves, etc., are available from the United
States National Forest Service, San Bernardino, California, and Washington,
D.C. When more time and resources are available these data sources will allow
a determination of the total in-and-out flow of traffic into the region.
Currently, we do not have an estimate of the impact of air pollution of the
human population of the Lake Arrowhead region nor of the effect of air
pollution and the human population on the ecological balance of the Lake
Arrowhead environment.
IV. POSSIBLE EFFECTS OF OXIDANT AIR POLLUTION ON MAN
In this section we discuss the following: (A) the perceptual awareness of
air pollution, (B) the possible impact of air pollution on human behavior, (C) the
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organization of the human population, (D) the organizations that people may
belong to, (E) the economic costs of air pollution, and (F) its health and
mortality implications.
A> Perceptual Awareness. Studying the perceptual awareness of air pollution
assumes that humans are the creators of the condition, the measurers of the
problem, and the sources of the solution. The fact that pollution exists and
is relative to human perception carries with it two important considerations.
The first is to what degree the conditions are tolerable; the second is the
extent that toleration varies by different population segments. Differential
perceptual awareness may lead to varying behavioral and organizational responses
by human beings (Molotch, forthcoming). Perception, or lack thereof, of air
pollution may be considered exclusive of its involuntary effects upon individuals.
In fact, literature suggests that air pollution has its most adverse effects on
older persons, yet it is older persons who are the least perceptive of air
pollution. Only if air pollution is perceived as a problem, will corrective
action be taken, because it is probable that only those persons who perceive
air pollution as a serious problem are likely to attempt to do anything about
it. Further, it is probably only an aware and awakened public that will
support effective control programs.
Previous studies of the perceptual awareness of air pollution have focused
primarily on the following:
(1) Perception of the nature and extent of air pollution as a problem.
(2) Where knowledge about air pollution is obtained.
(3) What are the attitudes about the air pollution problem.
(4) What, if anything, should be done about air pollution.
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(5) What programatic elements persons will accept and support in efforts
by local, state, and federal governments to overcome the air pollution
problem.
(6) How accurately individuals perceive air pollution.
(7) Whether perception of the air pollution problem galvanizes the individual
into behavioral responses.
(8) What are the perceived causes of air pollution.
No data exists that describes the level of awareness of air pollution by the
region's population. Casual discussions with residents and newspaper articles
suggest a polarity of responses. Many residents are highly disturbed by the air
pollution and want to something about it. Other residents deny its very
existence and, obviously, since the problem does not exist for them, nothing
should be done about it from their point of view.
B. Behavior. While knowledge about and perception of air pollution are
important areas of concern, it is conceivable that air pollution may effect
human behavior regardless of whether or not it is perceived. One obvious
response to it if it is perceived is to avoid it by moving to another pollution
free location (Butler, et al, 1972). Air pollution may restrict other behavior
such as the amount of physical exertion that is deemed desirable by authorities
(i.e., in schools physical education may be terminated if air pollution reaches
a specified level, a level which appears to vary by school district in the Los
Angeles basin). Furthermore, air pollution may restrict breathing, result in
eye and nose irritation or make the individual feel so poorly that he does not
want to work or become involved in physical activities.
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Under severe air pollution conditions, visibility may be so markedly reduced
that normal community activities must be halted or altered. Under less severe
conditions, visibility impairment may not even be noted by the individual, but
in fact is reduced to such a degree tfcat automobile accidents are more likely
to occur.
Conversely, some behavior by individuals contributes to the community air pollution
problem as well as to their own specif ic likelihood of being affected, Some
occupations expose people to severe polluted conditions for long periods of
time and then have an unusually high risk factor of morbidity and mortality.
Occupations such as traffic policeman, automobile mechanic, and truck driver
immediately come to mind. In addition, cigaret smoking, use of fireplaces, use
of certain methods of cooking, and of aerosal sprays all contribute to
individualized air pollution.
Our future studies will explore these facets of human behavior, as well as
others, in an attempt to measure the effect of air pollution upon human behavior
in the Lake Arrowhead region.
C. Organization of the Human Population. The environment, technology,
and human population structure (spatial distribution, etc.,) and organization
are related to air pollution. Through its use of the environment and its impact
upon the environment through its technology, the human population is responsible.
for most air pollution and is the only species that can do anything about
overcoming the air pollution problem.
People residing in large population concentrations are ordinarily organized
around urban life forms and use the environment in certain ways which produce
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air pollution. In Southern California this air pollution drifts to the Lake
Arrowhead region, and elsewhere, and is added to locally produced oxidants.
From a broad context, then, the entire metropolitan complex, as well as local,
state, and federal influences, 3.8 important in studying the local air pollution
problem. A study of the political impact and influence which various individuals,
groups, organizations, and industries have upon decision-making at the local,
state, and federal level in regard to air pollution (its control, management,
and effects) is imperative in the study of the organization of the human popu-
lation and its impact upon the environment.
On a more localized scale, a study of the ways in which the problems of air
pollution in recreational areas can erect barriers or precipitate effective
local and extra-local public action is important. The communication and
determinants of public information and consequent attitudes toward various
alternative solutions are substantially a product of the social organization
of the population. The human population's response to air pollution in the
local communities should have an impact upon local communities and their
organizational structure. That is, there could be attempts by local permanent
residents, as well as intermittent residents and visitors, to influence local,
state, and federal officials in the use of social power, management techniques,
etc., in order to overcome air pollution. In this regard, assuming that air
pollution will shortly become a very salient issue to the residents of the Lake
Arrowhead region, organizations will soon be established to combat air pollution.
Some of these organizations may be associated with extra-local organizations
formed to combat air pollution and other environmental hazards on a larger scale.
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Will these organizations have an influence upon regulatory measures designed to
control technology? Will there be effective attempts by individuals and organi-
zations to influence management systems in regard to air pollution? How will
the management systems be brought into being? Who will manage the management
systems? How effectively will they implement controls? All of these aspects
need to be examined at the local level and tied to state and federal social
power sys terns.
D. Organizations. How people behave and how they organize in activities
related to air pollution is the essence of our concern. People may organize,
either in formal or informal groups, to study the problem of air pollution
and the effective means of initiating local and extra-local public action; to
discuss various alternate solutions; to evaluate the monetary, health, and
other costs of air pollution; to influence local, state, and federal officials
in the use of social power in an attempt to overcome air pollution; and to study
the impact of regulatory measures in controlling technology and energy use.
Currently, there are no local organizations in the Lake Arrowhead area concerned
with air pollution in the region. There have been attempts by a few isolated
individuals to combat pollution, but there have been no organized efforts in
the region to influence local, state, and federal officials to overcome air
pollution. Given the heavy damage from air pollution that is expected to become
highly visible over the next few years (e.g., thousands of trees dying), it may
be expected that some local organizations will be formed to combat air pollution.
In addition, it is expected that there will be concern expressed over the
increasing recreational use of the area and the possiblity of undesirable
housing, apartments and condominiums being built, and how various solutions may
be effectively implemented through enforcement of regulatory measures.
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The form that organizations may take are varied, and the impetus for organizations
may be local or extra-local. With the aid of "experts" in air pollution,
organizations may be formed which essentially will utilize local "voluntary"
participation. Discussion groups and educational meetings should be helpful in
allerting local persons to the air pollution problem and the means by which they
can do something about it. Another "community organization" approach is to
focus on conflict rather than on discussion and education. Here organizations
which stress the external nature of the "enemies" from other regions (e.g. the
L. A. Basin) and how local residents may combat them would be the focus.
Hostility toward outsiders, including government and industry, is apparent in
this approach to meeting the problem. In both instances, organizations might
be formed which would act as "watch dogs" over public agencies who are charged
with air pollution control and management responsibilities.
Others, of course, argue that there is more to overcoming the air pollution
problem than organizing or acting as watch dogs. Molitch (forthcoming) argues
that the problem of air pollution is not simply one of obtaining the right kinds
of information and acting upon it, and points out that there are vested interests
in the continuation of air pollution. This perspective asserts that the use,
control, and knowledge of social power is the only way that technology, which
is producing air pollution, can be effectively managed and brought under control.
An organized and mobilized public wielding its power would be a factor to be
reckoned with and would make air pollution more than a symbolic issue. That is,
laws would be enforced and have a real impact upon controlling air pollution.
E. Economic. It must be made explicit in .any discussion of the costs of
air pollution that social values are inherent in the concept of "costs". In
estimating costs, reliable and valid measurements are necessary and these costs
will vary according to the point of view of those who are calculating them.
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Further, trade-offs and alternative control management programs only make sense
when one considers the point of view of those who are making the estimates, and
from what value vantage point they are making the estimates. The "emmitors"
and "receptors" do in fact have different views of the necessity of risks and
how much should be spent to avoid certain levels of risk. Monetary costs in
converting old plant equipment and transportation vehicles to acceptable levels
(by whose standards?) and the building of new plants and vehicles can probably
be estimated fairly accurately. However, social and health costs are virtually
impossible to measure with any precision. For example, in regard to the effects
of air pollution upon health and mortality, how does one measure the cost of a
father or a mother to their children? How much effect does air pollution have
on present and future earnings, on average duration and severity of temporarily
disabling and efficiency-reducing capabilities, on permanent disabilities, on
increased probability of morbidity and mortality from other diseases, and on
absentism at work and at school? Further, how can one estimate air pollutant
costs in its impact on the size, composition, distribution and income of the
population? Finally, what would it cost to find and treat victims and what
costs accrue to those who attempt to avoid air pollution all together (Weisbord,
1961; Butler, et al, 1972)?
At a somewhat different level, an investigation is needed to evaluate air
pollution effects in high and low pollution areas by measuring the need and
cost of more frequent painting of the exteriors of housing, the time spent in
routine housecleaning, the hours of use of garments between cleanings, the
expenditures on laundering supplies, the frequency of washing cars, and the
willingness of the public to pay for the amelioration of air pollution, and
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finally, the effect of air pollution upon property and rental values. These
factors suggest that air pollution has costs other than those ordinarily antici-
pated (Ridker, 1967).
For this project, our concern would be mainly with the costs that the public
pays in regard to morbidity, mental well-being, perceived costs of air pollution,
and what the public would be "willing to give up" in order to solve the impure
air problem. These facets are discussed at more length below. The questions
are related to "who will pay and how much is it going to cost them?"
F. Health and Mortality. Goldsmith (1968) has pointed out that "a man can
live for five weeks without food, for five days without water, but only five minut
without air". He further suggests that before the effects of air pollution upon
health can be determined, the following requirements must be met: (1) pollution,
or an index of it, must be measured; (2) one or more effects must be measured;
(3) a relationship between the two must be shown—pollution and its effects.
The few studies accomplished to date suggest that premature infants and the
infirm are highly susceptible to air pollution. Most suceptible, however,
are the aged. Goldsmith further lists the effects of air pollution and
argues that they are differentially distributed among the different ages
and medical statuses: (1) acute sickness or death; (2) chronic diseases,
shortening of life, or impairment of growth; (3) alteration of important
physiological functions such as ventilation of the lung, transport of
oxygen by hemoglobin, dark adaptation (ability to adjust eye mechanisms for
vision in partial darkness), or other functions of the nervous system;
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(4) other symptoms, such as sensory irritation, which in the absence of
obvious cause might lead a person to seek medical attention and relief;
(5) discomfort, odor, impairment of visibility, or other effects of air
pollution in sufficient strength to lead individuals to change residence or
place of employment.
In studying the above human responses to air pollution, Goldsmith (1968)
presents a cogent argument for the most sensitive measuring instruments
possible since almost any level of effect upon some individuals will
seriously effect others. There is an additional problem of ferreting out
the characteristics of persons with different thresholds of resistence to
air pollution.
Goldsmith concludes from his review of the literature that individual
pollution, cigaret smoking and the like, is a major causal factor in lung
cancer whereas community-wide air pollution is, to date, only a "suspected"
factor. Sufficient exposure to air pollution appears to be a factor in
chronic bronchitis and emphysema, although probably it is not the only causal
agent. There is some evidence that cigaret smokers are more susceptible than
non-smokers in a common polluted environment. Furthermore, there is evidence
suggesting a link between air pollution and asthmatics. The available studies
are not definitive because few of them have sorted out individual air pollution
from community air pollution. One obvious solution is to study young children.
When this has been done, the studies indicate "a strong case for adverse
effects of air pollution on lower respiratory tract conditions" (Goldsmith,
1968).
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Little data exists which establishes a relation between air pollution and
mental well-being. However, a series of studies conducted in California
during 1956-61 indicate that perception of air pollution is associated with
feelings of overall malaise as well as physical symptoms such as eye irritation,
asthma, nose complaints, headaches, and chest pains. Further, these complaints
were more prevalent during periods of high air pollution counts than during
favorable weather conditions.
No studies to our knowledge have examined the effects of air pollution on
the health of the population in the Lake Arrowhead region. The methodology
to measure most health effects exists and the health of the human population
in the region will be one of particular importance for future investigation
in the Lake Arrowhead habitat.
Research has demonstrated that periods of unusually high air pollution are
associated with small increases in excess mortality—that is, mortality beyond
that ordinarily expected on a normal probability basis. Several problems exist
in measuring air pollution's effect upon mortality in the Lake Arrowhead Region.
First, ordinarily a very large population is necessary so that excess deaths can
be estimated, unless there is a "disaster" such as the ones in Donora, Pennsyl-
vania in 1948, London in 1948 and 1952, New Orleans in 1955, and world-wide in
1962 (Goldsmith, 1968). Second, the intermittent nature of a substantial
proportion of the Lake Arrowhead population precludes precise estimates of the
effect of air pollution in the region upon the mortality rate. The mortality
that does occur will vary substantially by subregion because the population
age structure is highly variable. Research suggests that the most susceptible
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F-21.
to air pollution mortality are the aged, infants, and those with antecedant history
of respiratory and/or heart problems.
V. FUTURE STUDIES FRAME OF REFERENCE
In a broad-based ecosystem approach to the study of the human consequences
of air pollution in the Lake Arrowhead region, the following could be used
as a starting point for the long term research endeavors to be undertaken
by the social science inter-disciplinary team. Four primary elements make up
the approach: (1) Environmental Studies, (2) Technological Inputs, (3)
Human Population Structure, and (4) Organization of the Human Population
(Duncan, 1961). Each of these segments are discussed individually and then
they are briefly incorporated into an overall research scheme.
(1) Environmental Studies. In our terms, environmental studies are all
those endeavors that involve research concerned with vegetation cover, animals
(other than Homo sapiens), soils and hydrology, and air monitoring and meteoro-
logy. We have assumed from previous discussions and proposals from the
committees in each area, or in each particular sub area of investigation, that
particular "models" will be developed, as well as models linking together these
various sub models.
These environmental research endeavors, along with technological background data,
are extremely important to the social scientists in furnishing the necessary
independent variables needed to measure the impact of air pollution upon the
human population and ecosystem. Environmental studies will make available to
the social scientists objective measurements of the products of technology (air
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F_22.
pollution) and objective measures of environmental changes brought about by
technological inputs. Air pollution probably has a direct effect upon individuals,
but we expect that relevant effects for social policy come only when large numbers
of individuals begin to perceive that the environment is drastically changing,
e.g., the trees are dying, and ascribe the cause as air pollution. In short,
environmental studies would give us objective measures of the changing environment.
The social scientists' contribution would be to measure the impact of these
objectively measured inputs of air pollution and environmental changes upon
human beings.
(2) Technological Inputs. The study would use technological data only
in a descriptive sense. Social scientists are interested in the sources of
pollutants, whether industry, automobiles, or any other sources. However,
social scientists will be interested primarily in technology as it produces
air pollutants and whether any environmental changes as measured by the
natural and physical scientists in the region can be attributed to these
by-products of technology. Further, we will be using as key aspects of our
study environmental changes in the Lake Arrowhead region made possible by
changing technology, resulting in construction of freeways, bridges and
transportation networks that make accessibility to the region simpler for
larger proportions of the human population residing in the greater Los Angeles ,
metropolitan basin and elsewhere. 1
(3) Human Population Structure. Social scientists, of course, are ,
concerned with human populations. We expect to be concerned with the demo- j
graphy of the region: migration patterns, fertility, morbidity, and mortality. (
We would be especially interested in describing the population in absolute j
numbers and density, by various sites in the Lake Arrowhead region. Both
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F-23.
number and density are highly variable in this region because of the extensive
recreational land utilization. The permanent, intermittent, and transient
populations need to be considered in any research design in the Lake Arrowhead
region. There are changes in absolute numbers and density of population as
results of the in-and-out-flow of people at various times and seasons. In
addition, measures of morbidity, mental and physical health, and their interaction
with socio-economic status are important. Data from various hospitals, the Kaiser
Medical Plan, and individual medical practitioners would be invaluable.
In all the above population characteristics, measurement of perceptions,
knowledge, attitudes, and behavior occurring across time as the environment
begins to change and possibly deteriorate are especially important.
It is possible, of course, to determine if changing knowledge and attitudes about
air pollution are translated into meaningful attempts to change the technology's
impact upon the environment. Individual behavior such as selling property and
moving away from the region or no longer visiting it on an intermittent basis
are examples of possible behavioral manifestations. Psychological mental stress
that air pollution may or may not have upon the individual and the impact of
pollution upon various value systems that the population may hold in regard
to government, politics, and social problems, would be another focus of
research. What are the political implications if the recreational use of
Lake Arrowhead declines? Social scientists would be concerned primarily with
the extent of knowledge about air pollution, attitudes toward air pollution, and
how air pollution effects behavior of the population living in the area. In
f
addition, they would be concerned with the kind of support the population would
give to abatement or management systems. A human population based model would
incorporate many of the aspects that are included in other models discussed in
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F-24.
this report. A basic assumption is that perception and behavioral manifestations
of air pollution varies by morphological and social characteristics including
age, sex, social class and so forth. Not only does perception vary, interpre-
tation of what can be done about the particular problem varies by morphological
and social characteristics. These notions lead us to the fourth element in our
ecosystem frame of reference.
(4) Organization of the Human Population. When social scientists discuss
the organization of the human population, they are in essence describing behavior
of the human population, in social groupings; that is, where and how they interact
in social groups for some particular purpose. The communication and determinants
of public information and attitudes regarding the existence of the problem and
determinants of attitudes toward various alternative solutions would be examined.
Problems of use-management, land development, commercialization, and historical
patterns of economic exploitation of area resources, and comparative problems
of polluted (e.g. Lake Arrowhead) vs. relatively non-polluted (e.g. Big Bear or
Idyllwild) areas would be of interest to social scientists. What impact has all
of this upon the perception of Lake Arrowhead as a place "to get away from it
all", its perceived "natural beauty", and its healthful living?
\
The population's response to air pollution in the local area in an organizational
sense such as the attempts by local permanent residents, as well as intermittent
residents, to influence local, state, and federal officials in the use of social
power in an attempt to overcome the air pollution problem is directly relevant
here. In this regard, then, the study of the formation of local and extra-local
groups and the process they use to combat air pollution and other environmental
hazards would be mandatory.
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F-25.
Within the same frame of reference, the impact which local, permanent, and
intermittent residents have upon regulatory measures attempting to control
technology needs to be studied. These regulatory measures include varying
energy usage as well as the type of energy usage, family size limitation,
disposal techniques, and economic controls upon various kinds of technologi-
cal inputs to the environment that create pollutants, i.e. automobiles and
factories. Are there any effective attempts by individuals, either permanent,
transient, or intermittent, to influence management systems in regard to air
pollution? This would include how these management systems were brought into
being and how they are implemented. All aspects of local, state and federal
social power systems could be examined. Again, the model, or models, derived
from our analyses would be integrated with the other models developed focusing
on technology and environment to form a larger ecosystem model.
Briefly, the total system views the relationship between the environment and
technology at the beginning of the causal network. Technology's impact upon the
environment has implications for the structure of the human population, including
absolute numbers, density, age structure, migration, fertility, mortality and
morbidity; and for how the population is organized and in what fashion it is
organized in relation to changes in technology and the environment.
If social scientists and their orientations or approaches are to be considered
in this particular research endeavor, they need to have some input on "site"
selection, which should include a representative sample of uninhabited and
habited sites. Habited sites would include those sites which are exposed to
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F-26.
transient use, and would include wilderness areas in which virtually no people
are found as well as picnic grounds and camp sites which have substantial and
continual use by transients; Intermittent-permanent areas, which includes sites
of weekend and/or summer visits by owner-residents and/or renters; and Permanent
residential areas or sites which includes various subareas in which the majority
of people reside the year around. The use of aerial photographs of the region
would be useful here in assessing differential tree damage to selected sample
sites with varying human population usage. The severity of the problem may be
related to the input of sheer numbers of people which may itself result in
differential impact upon the forest, as well as air pollution. Environmental
data on these specific sites allows a linking of actual environmental changes
to the structure and organization of the human population.
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F-27.
LITERATURE CITED
Butler Edgar W. Ronald J. McAllister and Edward J. Kaiser. Air Pollution
and Metropolitan Population Redistribution. In Press.
Duncan Otis Dudley. From Social System to Ecosystem, Sociological Inquiry.
31 (Spring, 1961): 140-149. a !L
Goldsmith, J. R. 1968. Effects of Air Pollution on Human Health, in Mr
Pollution. Arthur C. Stern (ed.). New York: Academic Press.
Molotch, Harvey. Pollution as a Social Problem, Social Problems. Jack D.
Douglas (ed.). New York: Random House. In Press.
Ridker, Ronald G. 1967. Economic Costs of Air Pollution. New York: Frederick
A. Praeger Press.
Southern California Association of Governments (SCAG). Interim Open Space
Element of the Southern California Regional Development Guide. SCAG,
September, 1970. ~"~~
Weisbord, Burton, 1961. Economics of Public Health. College Park: University
of Pennsylvania Press.
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Section G
The Impact of Oxidant Air Pollution on the
Mixed-Conifer Forest Ecosystem—Systems Integration
Researched and Written By:
Bland Ewing, Associate Specialist
Division of Biological Control
University of California
Berkeley, California
and
Peter A. Rauch, Senior EDP Systems Analyst
Division of Entomology and Parasitology
University of California
Berkeley, California
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G-l.
The Impact of Oxidant Air Pollution on the
Mixed-Conifer Forest Ecosystem—Systems Integration
Three inter-related components to the Systems aspect of this study are:
1. Modelling
2. Information System
3. Systems Coordination and Integration
Each component has specific attributes that can be described independently
of the other components.
The components themselves, however, are not independent. Design of any
component will directly affect in significant ways the other components.
It is therefore wise to take a unified approach to development of all
three components. The Systems aspect of the study is built by linking
the components together into a functional unit.
The need for a Systems approach to an ecological study such as the one
proposed for the San Bernardino Mountains can be summarized with the
following observations.
1. Extensive resources must be brought to bear on the problem,
including large-scale funding, and numerous technical and
research personnel.
2. A large, very diverse data base will be generated to study
the problem.
3. The problem is complex (because the system is dynamic and
interactive), multidisciplinary in content, and subject to
redefinition during the course of investigation.
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G-2.
4. Both the data and the personnel must be coordinated for
systematic progress toward solution of the problem.
These observations suggest the first-order constraints and priorities on
the design of the Systems aspect of the study.
Modelling
Preceding sections of this report clearly bring out the great complexity of
the mixed conifer forest, even though relatively little is known about this
ecosystem. Also, the high degree of interdependency cutting across tradi-
tional disciplines is brought out well in the sections on plants and
arthropods, and in the summary.
As a result of the studies on population dynamics of western pine beetle
and large-scale synthetic pheromone field evaluation tests that have been
done at the University of California, Berkeley, and the Pacific Southwest
Forest and Range Experiment Station, U.S. Forest Service, Berkeley over
the last few years, there is detailed information on a small portion of
this mixed conifer forest system. This system includes adult ponderosa
pine, root diseases, and western pine beetle with its parasites, predators,
and other associated insects, all of which form an intricate network of
strong interactions that are generally non-linear, showing thresholds,
saturations, and state-dependent time delays. Important interactions are
discrete and stochastic and many of the processes are sequential in the
sense that past history strongly affects present and future behavior.
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G-3.
There does not seem to be anything unique about the small portion of the
forest that has been studied in detail; thus there is every reason to
believe that the remainder of the forest will be at least as complex and
functionally similar in its interactions.
Flora and fauna of this region have co-evolved over an extended period of
time and in spite of interference by man the system is still reasonably
intact. It appears that interactions between the major conifer species
and between the conifers and other plants, insect pests, disease, soils,
climate, and fire, are such that dense, even-age pure conifer stands are
unstable. The forest breaks up into a mosaic of different species which
shift their position through time. It is only man's short life span that
makes it difficult to appreciate how dynamic the mixed conifer forest is.
It is a system that may change significantly and rapidly under the impact
of oxidant air pollution damage.
It is not clear how one could - or even if one should - try to manage the
stand to compensate for damage caused by air pollution. Such a highly
complex, non-linear system may be quite counter-intuitive in its response
to direct manipulation. The forest is responding to a constantly changing
physical environment: daily and annual cycles, shifting weather patterns,
short- and long-term changes in climate. The system may have multiple
equilibrium points or under varying input no equilibrium at all. It could
turn out that extensive, selective air pollution damage to the forest could
so alter the composition of the forest that it would never return to its
original state even after air pollution levels were reduced.
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G-4.
Different mortality patterns could produce differing attitudes toward the
smog damage. If in an area of fairly uniform conditions the ponderosa
pines declined at approximately the same rate, the trees could decline for
a period of ten or fifteen years without much increase in mortality, and
then having reached their physiological limit at roughly the same time a
large portion of the trees could die over a few-year period. White fir
and incense cedar in the understory of the ponderosa pine forest would be
released and would eventually grow to produce many years later a new forest
of white fir and incense cedar. Another possibility is that the micro-
climate and soil conditions would be sufficiently varied and the genetic
resistance of individual trees would differ enough so that the ponderosa
pine mortality would be widely distributed over time and space. As indi-
vidual trees died this would release fir and cedar in their immediate
vicinity and the stand gradually would be converted from a ponderosa pine
forest to a white fir and incense cedar forest. A third possibility is
that by the time the ponderosa pine was dying from air pollution there
would be sufficient damage to the fir and cedar so they would be stunted
in their growth, and consequently as the ponderosa pines died the forest
would be invaded by brush species. Even though the same number of ponderosa
pine eventually died, people would probably react very differently to each
of these three cases.
It would be very desirable to predict the course of change in the forest
under different patterns and levels of air pollution. What would happen if
the levels of air pollution remained essentially the same into the distant
future or if air pollution was to gradually increase? Would the forest be
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G-5-
eliminated entirely? Far stricter air pollution standards and control
methods are proposed for 1975-76. If these controls were to significantly
drop the levels of oxidant air pollution in the Los Angeles basin, what
effect would this have on the mixed conifer forest? Would the changes
in the forest be significantly different if the reduction was delayed
until 1980 or 1985?
Also it would be desirable to know if there were any practical ways of
manipulating the forest to at least partially compensate for the damage
caused by oxidant air pollution. Any management of the forest to compensate
for air pollution damage would have to involve economic considerations
over an extended period of time. An annual expenditure of a few percent
of the total value of the forest is all that would be practical. This
means that any manipulation of the forest would have to be limited and
selective. To be effective it would have to be well integrated with the
naturally occurring processes in the forest.
Trying to predict long-term changes in the forest resulting from air
pollution damage through direct experimentation will have only limited
value. Forests are simply too extensive in space and time to be a
reasonable object for experimentation. Spatially, forests are functionally
intact ecosystems of tens to hundreds of square miles. Temporarily, the
major tree species of the mixed conifer forest have potential life spans
of 300 to 400 years and generation times of 50 to 100 years. A single tree
is not a forest. Even a square mile of forest in isolation would show
abnormal patterns of reproduction, dispersion, growth and death, interacting
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G-6.
with fire, disease, and insect pests in an atypical manner, thus changing
the dynamics of the system and the successional patterns.
Experimental science is most effective as a multistage process where the
design of each experiment is based upon the information and knowledge
gained from preceding experiments. Unfortunately, it is difficult to see
how one could even carry out a single controlled experiment that would be
extensive enough in space and time to contribute significantly to under-
standing successional processes within the mixed conifer forest. About
the only possible approach to understanding the forest would be to
experiment with many of the components of the forest under a variety of
conditions over a short period of time. The forest is a diverse mosaic of
animals, plants and physical conditions. A wide range of naturally
occurring experiments on various components of the forest is continually
in progress and needs only to be monitored. In addition, these experiments
can be supplemented with artificial field and laboratory studies to
elucidate specific features of the forest system. However, data gathered
in this manner are not in a form suitable for predicting the long range
consequences of oxidant air pollution on the mixed conifer forest. Nor
are the data suitable for exploring various management strategies which
might be used to at least partially compensate for the damaging effects of
air pollution on the forest.
Experimental data must be transformed from an organization describing
changes in the system for many varied conditions over a short period of
time into one showing changes for a particular set of conditions over an
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G-7.
extended period of time. These reorganized data could then be used to
predict the long range changes in the composition of the forest under
different concentrations and distributions of air pollution through time.
Also, one could explore, under different patterns of air pollution, the
consequences of strategies aimed at reducing damage or mortality caused by
disease, bark beetles, mistletoe, and animals that consume cones and seed.
It may be that over an extended period of time, at the present levels of
air pollution, it will be impossible to maintain ponderosa pine, but that
under proper management conditions a forest of white fir, incense cedar
and sugar pine would be stable.
Perhaps it would be well to stress again the impossibility of answering
these questions through direct experiment. It simply is not feasible to
directly explore through experimentation the effects of different manage-
ment strategies or patterns of air pollution over tens to hundreds of square
miles of forest and decades to centuries of time. Complex, non-linear,
multiloop systems with state-dependent time lags are counter-intuitive in
their properties. To successfully control such a system one has to anti-
cipate future states and compensate for conditions in the future rather
than those of the present. Since, in general, different processes have
different delays associated with them, a whole array of future states of
the system must be anticipated to successfully control the system. Trying
to manage a system of this complexity by responding to present and past
states of the system almost certainly will be ineffective and can even
produce changes contrary to those desired. Thus the successful prediction
or management of a. system with such a structure depends on having validated,
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quantitative, predictive mathematical or algorithmic models. The con-
struction of these models from many small, short term, indirect experiments
must be a central activity in any effective study of the dynamics of the
mixed conifer forest.
The formation and transport of oxidant air pollution is an exogenous
variable in this study. There are other extensive studies investigating
these problems from the analytical and algorithmic modelling approach.
Direct effects of oxidant air pollution on the hydrology of the system is
probably negligible. The emphasis in hydrology would be to monitor water
quality and other hydrological aspects to determine whether indirect
effects of air pollution on vegetation would affect the hydrological
system. Until such effects can be demonstrated, modelling of the hydro-
logy of the system must be considered external to this study.
Modelling efforts on systems of the nature and magnitude of the San
Bernardino forest ecosystem, such as the IBP Biome studies, have been
investigating the concepts of productivity, energy transfer and nutrient
cycling. Because of this emphasis their approaches to modelling have been
radically different than those required for this type of study.
The San Bernardino National Forest is no longer based on a timber producing
economy. Its main value is as a recreational and watershed site. For
recreational value, the forest's significant attributes are described by
its structure; species distribution, abundance and diversity, age distribution
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G-9.
of its principal floristic components, wildlife diversity, and the abundance
and quality of its surface water, among others. These attributes combine
to produce the aesthetic qualities required in a recreational forest
setting. They also describe the parameters which must be manipulated by
forest managers. Predictive models of this system would therefore have to
include these attributes into their own structure, for there is no clear
relationship demonstrated between such concepts as productivity and
floristic diversity that would be useful to this problem.
Very little work has been done that considers the forest structure within
the framework of a dynamic model. There is an abundance of literature
that describes static models of such things as species diversity and
distribution. These models give little insight into the underlying
mechanisms that drive the system and are of no use in simulating the
dynamics of a system subjected to different management strategies, or to
such stresses as air pollution.
Analytical models applicable to a system of the structure described here
can be found in the area of mathematics dealing with stochastic processes.
General summaries of the mathematical theory can be found in Karlin, 1966,
and Harris, 1963. Examples of the application of stochastic theory to
biological problems in population ecology are found in Chiang, 1968, and
Reddingius, 1971.
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G-10.
Several computer languages which have recently become available will
facilitate the design and implementation of synchronous and asynchronous
stochastic algorithmic models. These include APL/PLUS as implemented on
UCLA CCN's IBM 360/91 computer, and SIMSCRIPT II.5 as marketed by
Consolidated Analysis Centers, Inc., Los Angeles, Calif.
Information System
Modelling and other analyses performed during this study will, of course,
be driven by real and simulated data. These data will be accumulated from
various sources throughout the study, principally from the field, and
secondarily from literature and simulation studies. Because of the
magnitude and complexity of the study, careful attention must be given to
the problem of data base generation and management. Early planning and
development of an Information System will result in a more fully coordi-
nated study, and will produce long-run economies in people-time and in
data processing.
General observations about data management in this study are:
a. Data are not usually gathered in the order in which they are
to be accessed for analysis.
b. Data describing many parameters of the system must be simul-
taneously accessed during analysis.
c. People are not very adept at performing manually the tasks
implied by a. or b.
d. Data are structurally very diverse.
e. Data are qualitatively very diverse.
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G-ll.
f. There-exists substantial a, posteriori information about the
diverse structural and qualitative attributes of data, and
about the multiple ways in which they will be used.
g. This information can be used to enhance—or even to make
possible—the ability of researchers to "get at" the data.
h. Electronic data processing (EDP) provides the necessary medium
to perform these tasks well.
i. However, it is necessary to effectively interface the tech-
nology of EDP with the user, in this case the ecologists in
the field and other investigators.
In order to accommodate these observations the following structure is
recommended. The Information System should be divided into three well-
integrated subsystems. First, for input, there should be a data capture
(data recording, verification, and editing) subsystem. Second, for mani-
pulating the data, there should be a generalized file management subsystem.
Third, for output, there should be a data interpretation (reduction,
analysis, report generation, and graphics) subsystem. Each of these sub-
systems would operate on different data bases, each usually being generated
from output of the preceding subsystem.
I. The data capture subsystem presents the most difficult problems
regarding human engineering requirements which are very necessary to
consider in this subsystem.
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G-12.
It is at the point of data capture that the greatest opportunities to
generate unrecoverable errors usually occur in ecological studies. There
are numerous reasons that can be suggested to support this contention.
Much sampling in ecological studies is manual in nature. Automated
recording stations and devices, although commonly used for certain appli-
cations, are generally not available; e.g. they do not exist, they cost
too much, the technology is not developed, etc. It is necessary therefore
to design the data capture system to reduce errors generated by common
human problems such as fatigue, fallible memories, boredom with repetitious
tasks, illegible and ambiguous handwriting, and individual competency.
Each, or even several, of these traits may be of minor concern in a study
where the principal investigator is the only participant. Re can generally
decipher his own handwriting. Also, he is probably more aware of the con-
sequences of deviation from the defined tasks since he has a "world view"
of his project.
In a multi-disciplinary project with several to many principal investigators
and technical support personnel this is not true. In this situation each
person's contribution represents only a small part of the overall project.
This does not imply that it is an insignificant part, nor does it imply
that each part is unlinked in a multiplicity of ways to other parts of the
project. The data that are entered into the system, then, must be "available"
to others, i.e. they must be rendered into useful information. Raw data must
therefore be legible, commensurate with other similarly gathered data, of
identifiable origin, and accurately entered into the system.
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G-13.
In addition to the human problems of data transfer, there are other reasons
to make every effort to develop good management techniques for data capture.
It is frequently not possible to "re-capture" data that have been lost,
destroyed or otherwise rendered not usable. One such situation occurs
with destructive sampling where the measurements cannot be taken twice.
Another situation that frequently occurs in ecological fieldwork is the
observation of what may be termed "rare" or "unusual" events, or
"opportunistic" observation. Measurements acquired on such events frequently
provide useful insight into the problems being studied. Suitable ways to
incorporate these observations into the data base should be developed.
Otherwise, they get recorded as miscellaneous notations in the margins of
data recording forms and are left behind during transcription.
Measurements taken on time-dependent parameters cannot usually be repeated
since they are only meaningful in their proper time-frame relationships
to measurements on other parameters.
Even after every reasonable effort is made to prevent accidental loss of
raw data, errors are still going to be introduced into the data base. So,
data verification (against the original copy) and editing (of the errors
uncovered) must be included into the data capture subsystem. The process
of "checking" the digitized data against the original data should be done
by those responsible for having generated the original data. They are
usually the ones most likely to recognize any of a multitude of discre-
pancies that can and usually do occur. This procedure can be optimized to
simplify the process and to reduce the time required to do the checking.
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G-14.
II. The generalized file management subsystem is the least problematic
to acquire or design since two suitable options are already available.
They differ from each other substantially in structure and investment in
resources.
Within government agencies there are (or will be) several file management
systems of particular usefulness to ecological studies of the type proposed.
The USDA Forest Service is currently negotiating the establishment of GIM
(General Information Management system). It may be available by summer,
1973. It is proposed to be available on a nationwide network of Computer
Sciences Corporation of Los Angeles. It will probably be relatively costly
to use but this is far from determined yet.
Another system reputed to be quite useful is RECON, the NASA Information
System. Its. availability is undetermined.
Although systems such as these may be available, the practicality of using
them would involve major considerations of convenience, as well as of costs
and other more technical factors. File management is only one of the three
subsystems needed in the Information System. These file management systems
are not available at all computing facilities. Conversely, other necessary
computational tools (to be used in the data capture and data interpretation
subsystems) may not be available at the installations having file management
systems. Given limited resources, the solution normally involves some sub-
stantial compromise such as abandoning the best of one world and making do
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G-15.
with less. Two such compromises might be to:
A. Physically transport data (on some machine-readable medium such
as magnetic tape) from one installation to the other. This permits the
continued utilization of desired software resources. However, the time
delays can be devastating to productive use of researchers' time. Ideas
will continually be tested against the data base. Efficient interactive
capability between the investigator and the data permits the continuity
of thought processes that must be part of any research program. This is
even more critical when several investigators must participate in a multi-
disciplinary environment. The quality of the communications system can
be the determining factor in the success of a project.
B. Determine whether the "robustness" of a computer center's
resources is sufficient to allow a useful information system to be
developed without the services of a sophisticated file management sub-
system. A measure of such robustness would include considerations of
languages diversity, utility routines scope, communications features, size
and cost of processors and peripheral storage, and other factors. Given a
system robust in other resources, it is possible that more programmer time
can be dedicated to "managing" files to compensate for the lack of a more
automatic system.
Obviously, the turn-around time under the latter compromise should be
shorter (and balanced in other ways, such as in cost) to be competitive
with compromise A-
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G-16.
An effective interactive information system is needed not only for the
investigators but also for the programmers who support the principal
research personnel. Although the principal investigators are able to
distribute their workloads among multiple obligations, such as teaching,
committee meetings, field work, and data interpretation, the programming
staff is generally dedicated solely to design, implementation and execution
of programming support. Effective utilization of programmers' time is
best served by a highly interactive computing environment.
Ecologists have made little use of sophisticated file management systems
in the past. (Indeed, such systems have not been available except during
the past few years, and they are not widely distributed.) There is still
much to be learned about how best to interface them into ecological
studies. A definite need for them is indicated, however.
III. The data interpretation subsystem receives raw data from the
various files created previously and processes them to eventually produce
information that can be interpreted by the researchers. From this process
future emphasis and direction of the study can be planned. This planning
and re-planning permits refinements to be incorporated into the study plan
as more is learned about the system. For, although there is general
agreement that the forest-smog system is degenerating and should be studied,
no one would suggest that we know exactly how the study should proceed.
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G-17.
The tools and techniques used in data analysis will strongly reflect the
experiences and biases of the individual investigators, which are varied
and many. Because systems such as the San Bernardino National Forest are
poorly understood, it is certain that a variety of techniques will be
applied to analyze the behavior of this system. Many of these techniques
are themselves under development, and new ones will undoubtedly be
formulated.
It is therefore reasonable to provide a great degree of flexibility to
design new methods of analysis. This flexibility would be based upon
having a broad spectrum of computing languages and associated resources
available. They would include as a minimum, APL/PLUS, PL/1, FORTRAN and
SIMSCRIPT II.5. An array of languages such as these will allow ideas to
be rapidly implemented in the most natural manner to test the validity of
the method. If proven to be useful, then full-scale implementation for
overall efficiency can be pursued.
Systems Coordination
The necessity to provide a formally recognized mechanism for coordination
and integration of a large multidisciplinary study is obvious. No one
person will be able to assume sole technical direction for the project.
The scope of the project is too br"oa
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G-18.
decision-making committee will assure that serious deficiencies develop
and persist in planning and executing the study.
First, then, it is recommended that a technical decision-making (DM)
committee be an integral part of the study. This committee should have
representatives from each of the major disciplines involved in the study.
The committee would be responsible for on-going evaluation of progress,
and for providing solutions to the many major logistic and technical
problems that will arise during the study. It would also have the res-
ponsibility to propose the direction and priorities for future research.
Since it is to function as a multidisciplinary committee, its members
should be selected for their proven ability to function in this type of
disputatious atmosphere. This technical DM committee will function well
only if it has effective communication lines established within itself,
and with the remainder of the project. Three essential lines can be
considered the minimum configuration.
First, there should be a full-time Field coordinator. This person would
have the responsibility to assure that plans are implemented and carried
on as required, or to determine why they cannot be carried out. The Field
coordinator must be a broadly-trained individual, one who can communicate
effectively, and who is resourceful. This person is possibly the single
most critical participant in the study, since he assumes the responsibility
to determine that a well-planned study is actually being executed.
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G-19.
A second line of communications should be established between the committee
and the Information System. This may be done through an Information System
coordinator, a person with the responsibility to coordinate development
and implementation of the various Information System subsystems. He would
establish priorities for data processing based on information supplied
by the technical DM committee. He would work with the Field coordinator
to determine the characteristics of data capture processes of the various
investigators. This will provide further necessary information to design
and operate a more intelligent Information System. He would keep the
technical DM committee informed about the status of the Information System,
i.e. progress, problems, requirements, etc., associated with proper
functioning of the System. He would work with the Modelling coordinator
(discussed below) to establish System requirements of that effort.
A third line of communications, the Modelling coordinator, would have
primary responsibility to bring together the group of investigators for
the purpose of constructing a model(s) (representation) of the system
under study. Since the model will necessarily be a limited view of the
real system it is most important that the particular view represent the
best information available. Therefore, all principal investigators should
be expected to participate in the formal modelling effort. As indicated
previously, the model will be driven with real and simulated data. Much
of the real data are to be generated during the study. (As indicated in
other parts of this report, there is a paucity of information on many
important components in the system.) Data collection and modelling
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G-20.
efforts must then be run concurrently to assure that the information
needed for the model is indeed the information being gathered in the field.
The Modelling coordinator would have the responsibility to determine that
goals of the study are correctly represented in the modelling effort. He
would develop a framework for the overall modelling strategy and be
responsible for its updating or modifications as necessary.
The two most important points to be derived from the above discussion
about lines of communication are that 1) there do exist several critical
points of coordination, and 2) participation in group interactions is
essential. From this it should be concluded that special effort must be
made to place reliable people in those positions of coordination, and
that all principal investigators should be expected to convene frequently
to contribute their talents to the modelling project. Needless to say,
a substantial travel budget should be established within the Systems
component of the study to be able to bring people together.
One other manpower component must be discussed within the framework of
Systems coordination. This project will need a number of full-time
investigators to support the principal, or as VanDyne, 1972, refers to
them, contractual investigators. On countless projects the graduate
student has traditionally filled this role. He had, by this stage in his
career, developed sufficient tools to be productive. He is generally
highly motivated and has a vested interest in contributing to the success
of a project.
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G-21.
A graduate student does have serious restrictions, however, that can be
disruptive to a large-scale integrated project. His other obligations,
such as classwork, prevent full-time and year-round participation in a
project. Not all project work is suitable for dissertation material,
and various problems of proprietary and originality arise.
The manpower market has traditionally been limited to the graduate student,
The current availability of recent (and not so recent) Ph.D.'s provides
other options with advantages over the use of graduate student manpower.
These include completed training, well-oriented interests, proven skills,
full-time availability to participate, and greater self-direction. It
can be further argued that post-doctoral contributors probably cost very
little more than do graduate students. Double the salary of a graduate
research assistantship, add the costs to the project of cultivating the
talents of the student, plus the relatively high risk of failure on the
student's part to find a dissertation project to his liking and you have
most of the price of a recent Ph.D.
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G-22.
Literature Cited
Abraham, F. F. Computer simulation of diffusion problems using the
continuous system modeling program (CSMP) language. IBM Data
Processing Division 320-3284.
Chiang, Chin Long. 1968. Introduction to stochastic processes in bio-
statistics. John Wiley & Sons.
Harris, T. E. 1963. The theory of branching processes. Gottingen &
Heidelberg, Springer, XIV.
Karlin, Samuel. 1966. A first course in stochastic processes. Academic
Press.
Reddingius, J. 1971. Gambling for existence. Acta Biotheoretica,
Vol. XX. Suppl. I.
VanDyne, George M. 1972. Organization and management of an integrated
ecological research program with special emphasis on systems analysis,
universities, and scientific cooperation, pp. 111-172. In
Mathematical Models in Ecology, J. N. R. Jeffers (ed.), Blackwell
Scientific Publications.
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