United States
Environmental Protection
Agency
Environmental Monitoring
and Assessment Program
Research Triangle Park, NC 27709
Research and Development
EPA/620/SR-94/010 August 1994
EPA Project Summary
Forest Health Monitoring 1992
Annual Statistical Summary
S.A. Alexander
In 1990, the United States Depart-
ment of Agriculture (USDA), Forest Ser-
vice (FS) and the United States Envi-
ronmental Protection Agency (EPA), ini-
tiated a cooperative national program
to monitor the condition of the nation's
forests. This multi-agency effort, within
the framework of the EPA's Environ-
mental Monitoring and Assessment Pro-
gram (EMAP), is called the Forest Health
Monitoring (FHM) program. The FHM
program is jointly managed and largely
funded by the FS and EPA in coopera-
tion with other program participants.
FHM partners provide additional finan-
cial and personnel support and include
participating State Forestry agencies,
United States Department of the Inte-
rior (USDI), Bureau of Land Manage-
ment, the Tennessee Valley Authority
(TVA), and the USDA Soil Conservation
Service (SCS). Other Cooperators in-
clude universities, and three USDI agen-
ciesU.S. Fish and Wildlife Service,
U.S. Geological Survey, and the Na-
tional Park Service. The National Asso-
ciation of State Foresters provides es-
sential program support, guidance, and
assistance.
Data analysis results for the follow-
ing indicators are presented in the re-
port: tree species and stand density
(mensuration), tree crown condition,
tree species diversity, and air pollution
bioindicator plants. The cumulative dis-
tribution function methods used in the
analysis provide a statistical summary
of most measurements. Tabular sum-
maries were also prepared in some
cases. Where possible, indices have
been used in the CDF analysis.
This Project Summary was developed
by EPA's Environmental Monitoring and
Assessment Program, Research Tri-
angle Park, NC, to announce key find-
ings of the research project that is fully
documented in a separate report of the
same title (see Project Report ordering
information at back).
Introduction
On FHM Detection Monitoring plots, a
set of indicators is used to classify forest
health status. These indicators collectively
represent many components of forest
health and are generally responsive to
many types of stresses. The indicators
are measured at various sites which are
selected statistically so that regional for-
est populations are represented.
The Project Report summarizes the data
that were collected as a result of the De-
tection Monitoring activities. Chapter two
of the report provides a brief overview of
forest health monitoring. The remaining
chapters summarize the data for tree spe-
cies and stand density, tree crown condi-
tion, tree species diversity, and air pollu-
tion bioindicator plants. An overview of
indicator development, the plot network,
plot design, and data analysis procedures
are presented in several appendices.
Procedure
In 1992, Detection Monitoring activities
were conducted in twelve eastern states:
Alabama, Connecticut, Delaware, Geor-
gia, Maine, Maryland, Massachusetts, New
Hampshire, New Jersey, Rhode Island,
Vermont, and Virginia (Figure 1). Detec-
tion Monitoring was also conducted in Cali-
fornia and Colorado. Those data will be
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included in the 1993 Annual Statistical
Summary as part of the western data
analysis.
The cumulative distribution function
(CDF) methods used in the analyses pro-
vide a statistical summary of most mea-
surements. Tabular summaries were also
prepared in some cases. Where possible,
indices have been used in the CDF analy-
sis.
Results and Recommendations
Mensuration
Standard Federal Regions 1 and 2
combined have more dead trees (on
a per-area basis) than either Federal
Region 3 or Federal Region 4.
This is apparently due to a noticeably
larger number of dead trees (per area)
across the major forest type group-
ings of spruce-fir forests and maple/
beech/birch forests.
It would be premature to assume that
this reflects significantly increased
mortality and reduced regeneration in
these major forest type groupings
without additional information on
changes over time.
Basal area per hectare shows roughly
the same distribution across all three
Standard Federal Regions.
Crown Assessments
The defoliation of tree crowns was
examined through analysis of 3 eco-
logical groups (species, forest types,
and crown groups) that were found
on 45 or more plots within any of the
four geographical regions (SFRs 1
and 2 combined, 3, 4, and 1-4 com-
bined).
The crown variables dieback and
transparency were aggregated into a
plot-level indicator that evaluated the
defoliation of the outer and inner por-
tions of the tree crowns.
Less than 10 percent of any popula-
tion for any ecological group fell within
the subnominal category, and less
than 3 percent of any subnominal
population proportion was found in
the poor category.
The only ecological groups that de-
serve a cursory investigation due to
the low proportions of populations in
a subnominal or poor condition are
one species (White ash) and two
crown groups (Cedar-Juniper; miscel-
laneous).
No forest types had any significant
proportions of the population in the
subnominal or poor condition.
Figure 1. Sites in which detection monitoring occurred in 1982.
Species Diversity of Trees and
Saplings
Species density was used as a mea-
sure of species diversity of trees and
saplings in Standard Federal Regions
1 and 2 combined, Federal Region 3,
and Federal Region 4. Two species
per unit area was used as a prelimi-
nary subnominal threshold.
Standard Federal Region 4 had a sig-
nificantly higher proportion of plots
with subnominal tree species density
than Federal Region 3. Federal Re-
gions 1 and 2 combined and Federal
Region 3 did not differ significantly for
these proportions.
Standard Federal Regions 1 and 2
combined had a significantly higher
proportion of plots with subnominal
sapling species density than either
Federal Region 3 or Federal Region
4.
Air pollution Bioindicator
Plants
Field crews established biomonitoring
sites, for determining the presence or
absence of ozone injury conditions,
at 39 of the 212 forested plots in New
England.
Based on data from 39 biomonitoring
sites, an estimated 27%+ 13% of the
forested population covered by these
sites showed foliar symptoms indicat-
ing the presence of ozone injury.
Most of the plots rated positive for
ozone injury were located in rural ar-
eas that are known to be contami-
nated by air masses moving into the
region from urban-industrial areas to
the south of New England.
The information in this document has
been funded in part by the U.S. Environ-
mental Protection Agency under Inter-
agency Agreement number DW12935103-
01 with the USDA Forest Service and
Interagency Agreement number DW-
14935509-01 with the USDI Bureau of
Land Management. It has been subject to
the Agency's peer and administrative re-
view, and it has been approved for publi-
cation as an EPA document.
Mention of trade names or commercial
products does not constitute endorsement
or recommendation for use.
The report represents data from one
year of EMAP. Because the probability-
based scientific design used by the EMAP
necessitates multiple years of sampling,
there is uncertainty associated with these
data. This uncertainty will decrease as the
full power of the approach is realized.
Similarly, temporal changes and trends
cannot be reported, as these require mul-
tiple years of observation. Please note
that this report contains data from demon-
stration studies in four Standard Federal
Regions. Appropriate precautions should
be exercised when using this information
for policy, regulatory or legislative pur-
poses.
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Samuel A. Alexander (also the EPA Project Officer, see below) is with the
Environmental Monitoring and Assessment Program, Research Triangle Park,
NC 27709.
The complete report, entitled "Forest Health Monitoring-1992 Annual Statistical
Summary," (Order No. PB94-205416/AS; Cost: $ 19.50; subject to change) will
be available only from:
National Technical Information Service
5285 Port Royal Road
Springfield, VA 22161
Telephone: 703-487-4650
The EPA Project Officer can be contacted at:
Environmental Monitoring and Assessment Program-EMAP Center
U. S. Environmental Protection Agency
Research Triangle Park, NC 27709
United States
Environmental Protection Agency
Center for Environmental Research Information
Cincinnati, OH 45268
Official Business
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EPA/620/SR-94/010
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