WETLAND IDENTIFICATION
AND DELINEATION MANUAL
VOLUME I
RATIONALE, WETLAND PARAMETERS,
AND OVERVIEW OF JURISDICTIONAL APPROACH
by
William S. Sipple
Office of Wetlands Protection
Office of Water
U.S. Environmental Protection Agency
Washington, D.C. 20460
U.S. Environmental Protection Agenoy
Library, Room 2404 PM-211-A
401 M Street, S.».
Washington, DO 20400
April, 1987
Interim Final

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PREFACE
According to Corps of Engineers and Environmental Protection Agency
(EPA) regulations (33 CFR Section 328.3 and 40 CFR Section 230.3,
respectively), wetlands are "... areas that are inundated or saturated
with surface or ground water at a frequency and'duration sufficient to
support, and that under normal circumstances do support, a prevalence
of vegetation typically adapted for life in saturated soil conditions.
Wetlands generally include swamps, marshes, bogs and similar areas."
Although this definition has been in effect since 1977, the development
of formal guidance for Implementing it has been slow, despite the fact
that such guidance could help assure regional and national consistency
in making wetland jurisdictional determinations. Moreover, a consistent,
repeatable operational methodology for determining the presence and
boundaries of wetlands as defined under the federal regulations cited
above would alleviate some concerns of the regulated public and various
private Interest groups; it would also substantially reduce interagency
disputes over wetland jurisdictional determinations. Therefore, this
Wetland Identification and Delineation Manual was developed to address
the need for operational jurisdictional guidance.
The basic rationale behind EPA's wetland jurisdictional approach was
initially conceived in 1980 with the issuance of interim guidance for
identifying wetlands under the 404 program (Environmental Protection
Agency, 1980). In 1983 the rationale was expanded and a draft juris-
dictional approach was developed consistent with the revised rationale.
EPA distributed the 1983 draft rationale and approach to about forty
potential peer reviewers. Because the responses were, for the most part,
favorable, further revisions were made and a second draft was circulated
to about sixty potential peer reviewers in 1984. Individuals receiving
the drafts for review were associated with federal, state, and regional
governmental agencies, academic institutions, consulting firms, and
private environmental organizations; they represented a wide range
of wetland technical expertise. The 1984 draft also went through EPA
regional review, as well as formal interagency review by the U.S. Fish

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and Wildlife Service, Corps of Engineers, National Marine Fisheries
Service, and Soil Conservation Service. Based upon the 1984 peer review
comments, the comments from the federal agencies, and EPA field testing
over the last few years in bottomland hardwoods, pocosins, and East
Coast marshes and swamps, the document was further developed into this
2-volume Wetland Identification and Delineation Manual. Volume I presents
EPA's rationale on wetland jurisdiction, elaborates on the three wetland
parameters generally considered when making wetland jurisdictional
determinations, and presents an overview of the jurisdictional approaches
developed by EPA in Volume II, the Field Methodology. Thus, it lays the
foundation for the "simple" and "detailed" jurisdictional approaches
presented 1n Volume II.
This Wetland Identification and Delineation Manual has been approved
by EPA as an interim final document to be field tested by EPA regional and
headquarters' personnel for a one year period. During this same review
period, the Corps of Engineers has agreed to conduct field review of its
wetland delineation manual (Environmental Laboratory, 1987). After the
respective reviews, both agencies have agreed to meet, consider the
comments received, and attempt to merge the two documents into one 404
wetland jurisdictional methodology for use by both agencies.
The author truly appreciates the efforts of the many peer reviewers
who commented on one or both of the drafts that preceded this interim
final document, including Greg Auble, Barbara Bedford, Virginia Carter,
Harold Cassell, Lew Cowardin, Bill Davis, Dave Davis, Doug Davis, Frank
Dawson, Mike Gantt, Mike Gilbert, Frank Golet, Dave Hardin, Robin Hart,
John Hefner, Wayne Klockner, Bill Kruczynski, Lyndon Lee, Dick Macomber,
Ken Metsler, Jofin Organ, Greg Peck, Don Reed, Charlie Rhodes, Charlie
Roman, Dana Sanders, Bill Sanville, Hank Sather, Jim Schmid, Joe Shisler,
Pat Stuber, Carl Thomas, Doug Thompson, Ralph Tiner, Fred Weinmann, and
Bill Wilen. Their many constructive comments and recommendations have
been very helpful in refining this document. The author also appreciates
the help of EPA's Regional Bottomland Hardwood Wetland Delineation Review
Team (Tom Glatzel, Lyndon Lee, Randy Pomponio, Susan Ray, Charlie Rhodes,

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Bill Sipple, Norm Thomas, and Tom Welborn) in field testing the basic
rationale underlying the Field Methodology at a number of bottomland
hardwood sites in 1986. The vegetation sampling protocol in the Field
Methodology is to a large extent an outgrowth of that effort. Helpful
review and administrative guidance was provided by Suzanne Schwartz,
John Meagher, and Dave Davis of EPA's Office of Wetlands Protection.
Comments and suggestions received during the federal interagency review
were also instrunental in further refining the manual. In fact, in
addressing the soil and hydrology parameters 1n this manual, the author
relied heavily upon materials already developed by the Corps of Engineers
in their wetland delineation manual cited above. Stan Franczak ably
handled the huge typing load associated with the interim final, as well
as the earlier drafts.

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TABLE OF CONTENTS
Pa^e
Section I. Introduction		6
Section II. Rationale				7
Section III. The Three Parameters: Hydrophytic Vegetation, Hydric
Soils, and Wetland Hydrology		8
A.	Hydrophytic Vegetation		8
B.	Hydric Soils		12
C.	Wetland Hydrology		17
Section IV. Overview of Jurisdictional Approach		21
A.	General		21
(
B.	Basic Steps for Jurisdictional Approaches		21
Section V. Literature Cited		27
Appendix A. Glossary		A1

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SECTION I: INTRODUCTION
This volume of the Wetland Identification and Delineation Manual was
developed as a companion document to Volume II, the Field Methodology. It
presents EPA's rationale on wetland jurisdiction (Section II), elaborates
on the three parameters generally considered in making wetland jurisdictional
determinations (Section III), and presents an overview of the jurisdictional
approaches developed by EPA in Volume II, the Field Methodology (Section IV).
Anyone using the Field Methodology, should first become familiar with
Volirne I, since it lays the foundation for the jurisdictional approaches
presented in Volume II. Thus, Volume I should be thought of, in part, as
a prerequisite training document on the use of the Field Methodology. It
is particularly important to thoroughly review the glossary in Appendix A,
since a good understanding of the terms used in the methodology is imperative.
In ut111zing this Field Identification and Delineation Manual, keep 1n
mind that wetland jurisdictional determinations frequently have both technical
and administrative components. Sometimes the latter component will play an
important role in jurisdictional determinations. For example, because of
cyclic hydrologic changes, some isolated wetlands (e.g., prairie potholes)
do not have "fixed" boundaries. What vegetation boundary to choose (e.g.,
that established under high water conditions, low water conditions or average
water conditions) is an agency administrative decision beyond the scope of
this document. A second administrative decision beyond the scope of this
document 1s a determination as to whether or not an isolated wetland meets
the commerce test and is thus a "water of the United States." Therefore,
to the extent practicable, this Wetland Identification and Delineation
Manual emphasizes the technical aspects of jurisdiction.

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SECTION II: RATIONALE
Although the three parameters mentioned in the Corps-EPA regulatory
definition of wetlands (vegetation, soils and hydrology) are determinative
factors in terms of whether or not a site is a wetland, it does not follow
that all three parameters have to be evaluated or measured in every instance
in order to determine the presence and boundaries of a wetland. Frequently,
vegetation alone, which is a reflection of hydrologic and soil conditions,
will suffice. Specifically, 1n the presence of one or more dominant obligate
wetland species and in the absence of significant hydrologic modifications,
it can be assumed that soils would, with some exceptions (e.g., where
obligate wetland plants have recently become established, but hydric soils
have not yet developed), be hydric. In other words, there is generally no
need to collect data on soils and hydrology in a vegetation unit dominated
by one or more obligate wetland plant species. Likewise, there is generally
<
no need to collect soils and hydrology data for a vegetation unit dominated
by one or more obligate upland species. However, if vegetation alone is
not diagnostic, such as when only facultative species occur, soils and
hydrology must be considered in determining the extent of wetlands and/or
uplands at a site.

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SECTION III: THE THREE WETLAND PARAMETERS: HYOROPHYTIC
VEGETATION, HYDRIC SOILS, AND WETLAND HYDROLOGY
A. Hydrophytic Vegetation
\. Characteristics of Hydrophytic Vegetation
As used in this manual, hydrophyte is a broad term that includes
both aquatic plants and wetland plants. Therefore, hydrophytic vegetation
includes any macroscopic plant life growing in water or on a substrate
that 1s a least periodically deficient of oxygen as a result of excessive
water content. Aquatic habitats are areas, other than wetlands, that
generally have shallow or deep water; the shallow water areas sometimes
support non-emergent macroscopic hydrophytes (e.g., submerged aquatic,
unattached-floating, and attached-floating plant species). "Swamps,
marshes, bogs and similar areas" were mentioned in the Corps-EPA wetland
regulatory definition (33 CFR Section 328.3 and 40 CFR Section 230.3)
as examples of areas commonly considered wetlands and to distinguish
them from other waters of the United States, such as aquatic habitats,
and uplands. The hydrophytes that usually dominate wetlands as defined
in this document are emergent plant species (erect, rooted non-woody
species such as the common cattail, Typha 1 atifolia) or woody species,
such as the bald cypress (Taxodium distlchum). As opposed to submerged
species such as water milfoil (Myriophyllum spicatum), unattached-floating
species such as duckweed (Lemna minor), and attached-floating species such
as water lily (Nympnaea odorata), emergent species may be permanently or
temporarily flooded at their bases, but do not tolerate prolonged inundation
of the entire plants (or if tolerant, do not flower when submerged). Wet-
land hydrophytes are usually also vascular plants. Thus, most wetlands
are dominated by emergent vascular plant species, which may or may not
occur in association with vascular or non-vascular submergent, unattached-
floating, and/or attached-floating plant species. When these non-emergent
macroscopic hydrophytes do occur interspersed with emergent plants in a
vegetation unit, the unit should be considered wetlands if 50% or more
of the total percent area! cover is comprised of emergent species. Small

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areas of bare ground or open water may occur interspersed with wetland
vegetation. Under such circumstances, the bare ground (unless it is an
upland inclusion) and open water should be considered part of the wetland
system.
2.	Prevalent Vegetation
The Corps-EPA regulatory definition of wetlands includes the phrase
"a prevalence of vegetation." As used in this manual, the term prevalence
is considered equivalent to dominance. Thus, the prevalent vegetation is
the dominant vegetation. In an ecological sense, a dominant plant species
is one that by virtue of its size, number, production, or other activities,
exerts a controlling influence on its environment and therefore determines
to a large extent what other kinds of organisms are present in the ecosystem
(Odum, 1971). In this document, however, dominance strictly refers to the
spatial extent of a species because the extent is directly discernible or
measurable in the field. Spatially dominant plant species are character-
istically the most common species (i.e., those having numerous individuals
or a large biomass in comparison to uncommon or rare species). In this
sense, a dominant species is either the predominant species (the only
species dominating a unit) or a codominant species (when two or more
species dominate a unit). In the jurisdictional approaches presented in
this Manual, percent areal cover is the standard measure of spatial
extent, except for trees in which case basal area is used. Note: Because
this Manual relies heavily on vegetation, in its absence (e.g., during
the non-growing season, particularly when dealing with annual species,
or after clearing or filling) historical data (e.g., aerial photographs)
will have to be utilized.
3.	Typically Adapted Plants
The words "typically adapted" are also present in the Corps-EPA wetland
definition. Something that is typical is normal, usual or common in occur-
rence (Environmental Laboratory, 1987). An adaptation is a condition of
showing fitness for a particular environment, as applied to characteristics

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of a structure, function, or entire organism (Mayr, 1970). These character-
istics make the organism more fit (adapted) for reproduction and/or existence
under conditions of its environment. For example, plant species that gain
a competitive advantage 1n saturated soil conditions are typically adapted
fc such conditions. Various morphological, physiological, and reproductive
adaptations for inundation or saturated soil conditions are given in A4b
(page 11).
4. Indicators of Hydrophytic Vegetation
There are a number of indicators of the presence of hydrophytic
vegetation. Some indicators are diagnostic under natural conditions
(i.e., obligate wetland species); others are, for the most part,
diagnostic (I.e., morphological, physiological, and reproductive
adaptations); still others (I.e., facultative species) are Indicative
of hydrophytic vegetation 1n the presence of hydric soils and hydro-
logic Indicators. These Indicators of hydrophytic vegetation are
elaborated below.
a. Obligate wetland species. The U.S. Fish and Wildlife Service
(1986) has prepared a national list and a series of regional
lists of plants that occur in wetlands. Some of the species
on these lists are obligate wetland species which, under natural
conditions, always occur in wetlands. The presence of obligate
wetland species, particularly as dominants, in a vegetation unit
should be considered diagnostic of wetlands as long as the unit
has not been significantly modified hydrologically. Facultative
species may be present as well, but obligate upland species can
not be present.
The U.S. F1sh and Wildlife Service plant lists were developed
1n cooperation with a national panel and regional panels
comprised of personnel from the U.S. Fish and Wildlife Service,
Environmental Protection Agency, Corps of Engineers, and Soil
Conservation Service. There are three points that should be
kept in mind when utilizing the lists.
(1) Because the plant lists were developed for use with the
Classification of Wet 11 ands and Deepwater Habitats of the
United States (Cowardin, et al, 1979), they include
plant species that occur Tn a number of habitat types
that are not considered wetlands under the Corps-EPA
regulatory program. However, most of these areas are at
least potentially other waters of the United States
(e.g., shallow open water, mud flats, and submerged

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aquatic beds)-, which	are frequently dominated by macro-
scopic, non-emergent	species (e.g., the various submerged,
unattached-floating,	and rooted-floating plants) and/or
microscopic algae.
(2)	Because the plant lists include only vascular plants,
alternate taxonomic or ecological reference sources will
have to be utilized for determining the indicator status
of non-vascular plants (e.g., bryophytes). This will
be particularly applicable to bogs and swamps in the
Northeast, Pacific Northwest, Alaska, and Hawaii.
(3)	It has been suggested by some users of the plant lists
that they are too awkward (i.e., they contain too many
species, too many uncommon species, too many unfamiliar
species). This apparently reflects a misunderstanding
of how the lists will likely be used in a jurisdictional
sense. The fact that a field investigator may not know
all the species on a regional list is irrelevant, since
not all the species on a 11st will occur in a generic
wetland type (e.g., a bog) let alone at a given site.
Thus, at any one time, the field investigator will be
dealing with a small subset of the plants on the 11st --
a subset determined by the Investigator at the site,
not the list. The field investigator will then check
the dominants found against their indicator status on
the list and make the jurisdictional decision. If field
Investigators find that their level of unfamiliarity
with the plants at a given site precludes a scientifically
sound and defensible determination, additional expertise
should be sought. Furthermore, because there are many
wetland types in each region and a determination of
all of the dominants for each type has not been made,
potential dominants should not be eliminated by rule
(i.e., a complete list of species that occur in
wetlands will allow for all possibilities).
Plants with adaptations for soil saturation and/or inundation.
(1) Plants with morphological adaptations. Plants manifest a
number of morphological adaptations to inundation and/or
saturated soil conditions such as pneumatophores, buttressed
tijpee trunks, adventitious roots, shallow root systems,
floating stems, floating leaves, polymorphic leaves, multiple
trunks, hypertrophied lenticels, and inflated leaves,
stems or roots. Note: Although a given wetland plant
species may have one or more morphological adaptations,
in other wetland species they may not be as evident or*"
may even be non-existent^

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(2)	Plants with physiological adaptations. Although they are
not as useful because they cannot be observed in the field,
. known physiological adaptations, such as the accumulation
of malate in the swamp tupelo (Nyssa sylvatica var. biflora)
and increased levels of nitrate reductase in the eastern
larch (Larix laricina), are associated with inundation and/or
soil saturation.
(3)	Plants with reproductive adaptations. Many wetland plants
have reproductive strategies that allow them to exist and
reproduce under inundated or saturated soil conditions.
Some can germinate under low oxygen concentrations; other
have flood-tolerant seedlings. Many species also manifest
prolonged seed viability, remaining dormant until soil moisture
conditions are right for germination.
c. Facultative species. Any combination of the three categories of
facultative species (i.e., facultative wetland, straight facultative,
and/or facultative upland) should be considered indicative of
hydrophytlc vegetation if the vegetation unit in which they occur
has hydrlc soils and one or more hydrologic indicators are at
least periodically present during the growing season. In addition,
obligate upland species must either be absent or present only on
microsites and/or larger similar inclusions. In other words,
facultative species, even as dominants, are not in themselves
diagnostic of wetlands or uplands. However, an examination of
the soils and hydrology should give an Indication as to whether
the facultative species are, in fact, occurring under conditions
that would require them to be adapted for life in saturated soils.
Note: This latter statement may not be applicable to existing
wetlands that have been hydro!oglcally disturbed (e.g., ditched).
Because of the inherent difficulty in establishing how much the
water table in the disturbed wetland would have to drop to no
longer be a wetland hydrologlcally, it may be more appropriate to
judge the significance of the hydrologic impact on the vegetation
by evaluating the nature and direction of secondary plant succession
to determine whether the site still functions, or has the potential
to function, as a wetland.
B. Hydric Soils
1. Definition
A hydric soil is a soil that is saturated, flooded, or ponded long
enough during the growing season to develop anaerobic conditions in the
upper part (Soil Conservation Service, 1987). Such soils usually support
hydrophytlc plants.

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2. Criteria for Hydric Soils
Consistent with the above definition, the Soil Conservation Service
(1987) in cooperation with the National Technical Committee for Hydric
Soils developed the following hydric soil criteria.
a.	All Histosols except Folists, or
b.	Soils in Aquic suborders, Aquic subgroups, Albolls suborder,
Salorthids great group, or Pell great groups of Vertisols that
are:*
(1)	Somewhat poorly drained and have water table less than
15 centimeters (0.5 foot) from the surface for a
significant period (usually a week or more) during
the growing season, or
(2)	poorly drained or very poorly drained and have either:
(a)	water table at ]ess than 30 centimeters (1.0
foot) from the surface for a significant period
(usually a week or more) during the growing
season 1f permeability is equal to or greater
than 15 centimeters/hour (6.0 inches/hour) in
all layers within 50 centimeters (20 inches), or
(b)	water table at less than 45 centimeters (1.5
feet) from the surface for a significant period
(usually a week or more) during the growing season
if permeability is less than 15 centimeters/hour
(6.0 inches/hour) in any layer within 50 centi-
meters (20 inches), or
c.	Soils that are ponded for long duration or very long duration
during the growing season, or
d.	Soils that are frequently flooded for long duration or very long
duration during the growing season.
* For an elaboration of these terms, see Soil Taxonomy (Soil Survey Staff,
1975) or Keys to Soil Taxonomy (Department of Agriculture, 1985).

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3.	Classification of Hydric Soils
Under the current soil classification system published in Soil Taxonomy
(Soil Survey Staff, 1975), there are two broad categories of hydric soils:
Organic soils (Hlstosols) and mineral soils. All organic soils are hydric
except for the Folists, which occur mostly in very humid climates from the
Tropics to high latitudes. In the United States, Folists are found mainly
1n Hawaii and Alaska (Soil Survey Staff, 1975). Folists are more or less
freely drained Hlstosols that consist primarily of plant litter that has
accumulated over bedrock. Those Hlstosols that are hydric are commonly
known as peats and mucks. Mineral soils, on the other hand, consist pre-
dominantly of mineral matter, and contain less than 20% organic matter
by weight (Buckman and Brady, 1969). Mineral soils that are hydric are
saturated long enough to significantly affect various physical and chemical
soil properties. They are usually either gray, mottled immediately below,
the surface horizon, or have thick, dark-colored surface layers overlying
gray or mottled subsurface horizons (Environmental Laboratory, 1987).
4.	Indicators of Hydric Soils
Indicators of hydric soils can be placed into two categories: Soil
series and phases on the national and state hydric soils lists and field
indicators of hydric soils. These indicators are elaborated below.
a. Soil series and phases considered hydric. The Soil Conservation
Service (1987) has developed national and state lists of hydric
soils in conjunction with the National Technical Committee for
Hydric Soils. In practice. It is always best to verify in the
field that the soil series or phase listed as hydric has been
correctly mapped and that the area in question is not an inclusion
of another series or phase that is not hydric. Note: Some mapping
units (e.g., tidal marsh) may be hydric but will not be on the list
of hydric soils because they do not yet have series names for the
area in question. In addition, a hydric soil that has been drained
to the extent that it no longer meets the hydric soil criteria in
B2 (page 13) is no longer considered hydric.

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b. Field evidence of hydric soils,
(1)	Organic soils (Histosols). Histosols are organic soils
(mostly peats and mucks) that have organic materials in more
than half (by volume) the upper 80 centimeters {32 inches),
unless the depth to rock or to fragmental materials in less
than 80 centimeters, or the bulk density is very low (Soil
Survey Staff, 1975). A more detailed definition can be found
in Soil Taxonomy (Soil Survey Staff, 1975). Except for Folists,
all organic soils are hydric.
(2)	Histic epipedons. A histic epipedon is an 8-16 inch (20-40
centimeter) soil layer at or near the surface that is saturated
for 30 consecutive days or more during the growing season in
most years and contains a minimum of 20% organic matter when
no clay is present or a minimum of 30% organic matter when
60% or greater clay is present (Environmental Laboratory,
1987). In general, a histic epipedon is a thin horizon of
peat or muck if the sod has not been plowed (Soil Survey
Staff, 1975).
(3)	Mineral soils with mottling and/or gleying. Soil colors can
be very useful indicators of hydric mineral soils. Because
of the anaerobic conditions associated with waterlogging,
soils generally become chemically reduced and gleyed. With
chemical reduction, elements such as iron and manganese change
from the oxidized (ferric and manganic) state to the reduced
(ferrous and manganous) state. Such changes are manifested
in bluish, greenish or grayish colors characteristic of gleying.
Gleyed soil conditions can be determined by comparing a soil
sample with the gley chart in Munsel Soil Color Charts
(Kollmorgen Corporation, 1975)"^ fTTeymg can occur in both
mottled and unmottled soils.
Mineral soils that are periodically saturated for long
periods during the growing season also are usually hydric.
Under such alternating saturated and unsaturated conditions,
mottles coiranonly develop. Mottles are spots or blotches of
different color or shades of color interspersed with the
dominant color (Buckman and Brady, 1969). The dominant color
is called the soil matrix. Although the soil matrix is usually
greater than 50% of a given soil layer, the term soil matrix
can refer to a soil layer that has no mottles at all. When
the soil matrix in a mottled soil is gleyed, it is considered
a hydric soil. When the matrix is not gleyed, it is still
considered hydric if it has a chroma of _< 2. Likewise, an
unmottled gleyed soil is considered hydric, as are unmottled
soils that are not gleyed, but have a chroma of £ 1. Soil
chroma should be determined using the Munsel Soil Color Charts
(Kollmorgen Corporation, 1975). Note: Because soil color is
generally not a good indicator in sandy soils (e.g., barrier
islands), other indicators of hydric soils may have to be used.

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(4)	Aquic or peraquic moisture regime. The aquic moisture regime
is a reducing regime that is virtually free of dissolved
oxygen because the soil is saturated by ground water or by
water of the capillary fringe (Soil Survey Staff, 1975). The
soil is considered saturated if water stands in an unlined
borehole at shallow enough depths that the capillary fringe
reaches the soil surface except in non-capillary pores.
Because dissolved oxygen is removed from ground water by
microorganism, root, and soil faunal respiration, it is
implicit in the concept of aquic moisture regime that the
soil temperature is above biologic zero (5 degrees centigrade)
at some time while the soil or soil horizon is saturated
(Soil Survey Staff, 1975).
There are also soils (e.g., saltmarsh soils) in which
the ground water is always at or very close to the surface.
The moisture regimes for these soils is termed peraquic
(Soil Survey Staff, 1975). Although soils with peraquic
moisture regimes would always be hydrlc under natural
conditions, those with aquic moisture regimes would be
hydrlc only 1f they meet the hydrlc soil criteria specified
B2 (page 13).
(5)	Su1f1d1c materials. Sulfldic materials accumulate 1n soils
that are permanently saturated, generally with brackish
water. Under saturated conditions, the sulfates in water
are biologically reduced to sulfides as the soil materials
accumulate (Soil Survey Staff, 1975). The presence of
sulfidic materials is generally evidenced by the smell of
hydrogen sulfide, which has a rotten egg odor.
(6)	Iron and manganese concretions. Concretions are local con-
centratlons of chemical compounds (e.g., iron oxide) in
the form of a grain or nodule of varying size, shape,
hardness, and color (Buckman and Brady, 1969). Iron and
manganese concretions are usually black or dark brown and
occur as small aggregates near the soil surface. Iron and
manganese concretions greater than 2 millimeters (0.08
inches) in diameter that occur within 7.5 centimeters (3.0
inches) of the soil surface are evidence that the soil is
saturated for long periods near the surface (Environmental
Laboratory, 1987).
(7)	Anaerobic soil conditions. Most wetlands manifest at least
periodic soil saturation (waterlogging). When saturation
is long enough, an anaerobic environment develops, which
can result in a highly reduced soil. Under these conditions,
ferric iron, the oxidized form of oxygen, is converted to the
reduced form, ferrous iron. The presence of reduced iron
in the soil can be detected by the use of a colorimetric
field test kit.

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(8) Other organic materials. In sandy soils (e.g., on barrier
islands), organic materials in the soil profile under the
conditions described below are considered evidence of hydric
soils (Environmental Laboratory, 1987).
(a)	High organic matter in the surface horizon. Because
prolonged inundation and soil saturation result in
anaerobic conditions, organic matter tends to accumulate
above or in the surface horizon of sandy soils. The
mineral surface layer generally appears darker than
the mineral material immediately below it due to
organic matter interspersed among or adhearing to
sand particles particles. Note: Because organic
matter also accumulates on upland soils, in some
instances it may be difficult to distinguish aTurface
organic layer associated with a wetland site from
litter and duff associated with an upland site unless
the species composition of the organic materials is"
determined
(b)	Organic pans. As organic matter moves downward through
sandy soils, it tends to accumulate and become slightly
cemented with aluminum at a point in the soil profile
representing the most commonly occurring depth to the
water table. This thin layer of hardened organic matter
is called an organic pan or spodic horizon.
(c)	Dark vertical streaking in subsurface horizons. This is
the result of the downward movement of organic materials
from the soil surface. When the soil from a vertical
streak is rubbed between the fingers, a dark stain will
result.
C. Wetland Hydrology
1. Characteristics of Wetland Hydrology
Wetland hydrology is the sum total of wetness characteristies in
areas that are inundated or have saturated soils for a sufficient duration
to support hydrophytic vegetation (Environmental Laboratory, 1987). This
inundation or saturation can come from many sources, such as direct precipi-
tation, surface runoff, ground water, tidal influence, and overland flooding.
Thus, if there is anything that all wetlands have in common, they are at
least periodically wet (Cowardin, et aj[, 1979).

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2. Hydro!ogic Indicators
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Although the hydrology parameter may at times be quite evident and
dramatic in the field (e.g., overbank flooding), more often than not this
parameter and its various indicators are usually very difficult to observe.
Furthermore, as opposed to the vegetation and soil parameters, which are
relatively stable, the hydrology parameter exhibits substantial spatial and
temporal variation, making it generally impracticable for delineating
wetland boundaries. Rather, hydrologic indicators are most useful in
confirming that a site with hydrophytlc vegetation and hydrlc soils still
exhibits hydrologic conditions typically associated with such vegetation
and soils (I.e., that the vegetation unit has not been significantly
hydrologically modified to the extent that it supports only remnant,
generally stressed and/or dying, hydrophytlc vegetation and drained hydric
soils). In other words, whereas hydrologic Indicators can sometimes be
diagnostic of the presence of wetlands, they are generally either opera-
tionally Impracticable (in the case of recorded data) or technically
inaccurate (in the case of field indicators) for delineating wetland
boundaries. In the former case, surveying the wetland boundary 1s generally
too time consuming (even if a given elevation corresponds with the "wetland
hydrologic boundary," which 1s unlikely); in the latter case, it should be
obvious that indicators of flooding frequently extend well beyond the
wetland boundary. Consequently, in the jurisdictional approaches presented
1n this Manual, hydrophytlc plants and hydric soils are used to spatially
bound wetlands. Note: In some instances, however, the successional responses
of the vegetation at a known wetland site that has been hydrologically
modified (e.g., ditched) may be more useful than a documented hydrologic
change, such_as an arbitrarily established drop in water table, 1n determining
whether the site Is still a wetland.
Hydrologic indicators associated with wetlands fall under two categories:
Recorded data and field data. These indicators are elaborated below.
a. Recorded data. Recorded data can be obtained from tide gauges,
stream gauges, flood predictions, historical data (e.g., aerial
photographs and soil surveys), etc. The U.S. Geological Survey
and the Corps of Engineers are two good sources of recorded
hydrologic data.

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b. Field data.
(1)	Visual observation of inundation. An obvious hydrologic
indicator is inundation (flooding or ponding). Although
visual evidence of inundation is most commonly obtained
for wetlands along estuaries, rivers, streams, and lakes,
inundation can sometimes be observed in wetlands occurring
at other geomorphological settings as well, including isolated
depressional wetlands.
(2)	Visual observation of soil saturation. Evidence of soil
saturation can be obtained from examining a soil pit after
sufficient time has passed to allow water to drain into the
hole. The amount of time required will depend upon the
texture of the soil. For example, water will drain more
slowly into a soil pit dug in a clayey soil as opposed to a
sandy one. In some heavy clay soils, however, water may not
rapidly move into the hole even when the soil is saturated.
Under these circumstances, it may be necessary to examine
the sides of the soil pit for seepage. Note: The depth to
saturated soil will always be somewhat higher in the soil
profile than the standing water due to the upward movement
of water in the capillary zone.
For soil saturation to have a significant impact on the
plants in a vegetation unit, it must occur within the major
portion of the root zone (Environmental Laboratory, 1987).
For most species occurring in wetlands, particularly herbaceous
plants, the majority of the roots and rhizomes generally
occur within the upper 30 centimeters (12 inches) of soil.
Note: When examining for this indicator in the field, both
antecedent weather conditions (e.g., the significance recent
storms and long-term droughts) and the time of the year
should be taken into consideration.
(3)	Sediment deposits. Tidal flooding in estuaries and flooding
along non-tidal rivers, streams, and lakes frequently results
in the deposition of inorganic or organic sediments on live
vegetation, debris, and stationary man-made structures. This
is frequently manifested as a fine layer of silt. Silt is also
sometimes evident at the soil surface on small debris.
(4)	Drift lines. Like watermarks and sediment deposits, drift lines
are commonly found along rivers, streams and lakes. Debris (e.g.,
plant parts, sediment, and assorted litter) is frequently left
stranded in plants, on man-made structures, and at other obstruc-
tions as the flood-waters recede.
(5)	Surface scouring. Surface scouring occurs along floodplains where
overbank flooding erodes sediments (e.g., at the bases of trees).
The absence of leaf litter from the soil surface is also sometimes
an indication of surface scouring.

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(6)	Wetland drainage patterns. Many wetlands (e.g., tidal marshes
and floodplain wetlands) have characteristic meandering or braided
drainage patterns that are readily recognized in the field or on
aerial photographs and occasionally on togographic maps.
(7)	Morphological plant adaptations. Many plants have developed
morphological adaptations in response to Inundation and/or soil
saturation (see A4b, page 11). As long as there 1s no evidence
of significant hydrological modifications, these adaptations
can be used as hydrologic indicators.

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-BI-
SECTION IV: OVERVIEW OF JURISDICTIONAL APPROACHES
A.	General
Prior to making a jurisdictional determination, it is generally necessary
to gather preliminary data and scope out the delineation effort. This will
allow the field investigator to decide whether the simple or detailed juris-
dictional approach presented in Volume II is applicable to the project or site
in question. The simple jurisdictional approach is for routine situations
wherein a field investigator needs only to traverse the majority of the site
and record data from ocular Inspection. The detailed jurisdictional approach
is generally for large and/or controversial sites or projects; it entails
establishing transects and sample plots. In addition to traversing the
majority of the site (simple approach) and establishing transects and sample
plots (detailed approach), both of these jurisdictional approaches, involve a
number of specific steps. Four of these steps, which are basic to both
approaches, are elaborated below. The entire sequence of steps, including
the sampling protocols, are presented in Volume 11.
There are a number of ways to effectively sample vegetation. Many
procedures will produce essentially the same results and some procedures may
be appropriate for certain vegetation types but not for others. The procedure
presented in Volume II has been effective in the field, but may have to be
adjusted in some instances because of site conditions and the nature of the
vegetation. Other information on vegetation sampling is included in books
by Barbour, Burk and Pitts (1987), Cain and Castro (1959), Curtis (1971),
Daubenmire (1968), Greig-Smith (1983), Mueller-Dombois and Ellenberg (1974),
Oosting (1956), and Smith (1974).
B.	Basic Steps for Jurisdictional Approaches
1. Horizontal stratification of the site into vegetation units.
Vegetation units (i.e., patches, groupings, or zones of plants that
are evident in overall plant cover and which appear distinct from other
such units) should be distinguished in the field based upon an examination

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of vegetation structure and floristic composition. Vegetation units can
also be determined through analysis of "vegetation signatures" on aerial
photographs as long as a representative number of units are verified by
field checking. Once this step is complete, a field investigator should
h;>v
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-23-
The approach taken in this Manual for determining the dominant species
in a vegetation unit is an inductive one in which the dominant plants are
determined after the data are collected, as opposed to collecting data
on only what are considered the dominant plants based upon some a priori
threshold. Although vegetation sampling protocols for the simple and
detailed approaches vary somewhat, the basic procedure for determining
the dominant plants in a vertical stratum can best be explained using the
herbaceous stratum of a forested site as an example. Under the detailed
approach, this first entails quantifying the average percent areal cover
of each herbaceous species. Next, the herbaceous species are ranked
according to their average percent areal cover; then the average percent
areal cover values for all the herbaceous species are summed. Lastly, the
average percent areal cover values of the ranked herbaceous species are
cumulatively summed until 50% of the total average percent areal cover
values for all herbaceous species is reached or initially exceeded. Any
herbaceous species contributing to this 50% threshold are considered
dominants. An essentially similar procedure is applied to any shrubs,
woody vines, saplings and trees at the forested site. A more detailed
explanation of this procedure is given in Volume II. Note: The 50% rule
used 1n this Manual is for determining the dominant species in a vegetation
unit. It should not be confused with two other 50% rules that have been
suggested for determining what constitutes a "prevalence of vegetation
typically adapted for life in saturated soil conditions" and "hydrophytic
vegetation." Under the 50% rule for determining a "prevalence of vegetation
typically adapted for life in saturated soil conditions," wetland plants
must comprise at least 50% of the dominant species within the "plant
corranunlty" at the site in question. Under the 50% rule for determining
"hydrophytic vegetation," greater than 50% of the dominant plant species
in a vegetation unit must be obligate wetland species, facultative wetland
species, or straight facultative species.
3. Determination of the indicator status of the dominant species in the
vegetation unit using the U.S. Fish and Wildlife Service's national
or appropriate regional list of plants that occur in wetlands.
Species on the lists are classified either as obligate wetland species
or one of the three categories of facultative species (facultative wetland,

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-24-
stralght facultative, and facultative upland). Unless there is a good
technical reason to believe otherwise for a given species, any vascular plant
species not on the lists should be considered an obligate upland species.
However, because the national and regional lists are based upon the National
List of Scientific Plant Names (Soil Conservation-Service, 1982), the
scientific names of some species listed may not be readily recognized by a
field investigator (i.e., the Investigator may be more familiar with a
more commonly used taxonomlc synonym). It is particularly important for
the field Investigator to be aware of this since a species may appear to
be not on the 11st and therefore be considered an obligate upland species
by the investigator, whereas 1t may really be on the 11st under its currently
accepted scientific name. A brief check of the synonyms listed in Volume II
of the National List of Scientific Plant Names should prevent this problem.
t
4. Decision on which vegetation units at the site are wetlands and
delineation of the wetland boundaries.
The geographical extent of wetlands at a site will coincide with
the spatial distribution of the wetland vegetation units. Two tools (a
Jurisdictional Decision Flow Chart and a Jurisdictional Decision Diagnostic
Key) presented 1n Volume II will expedite and conceptually guide decisions
about jurisdiction for sample plots and vegetation units once the field
data have been collected. Two approaches were developed to allow user
flexibility, since some field investigators may feel more Comfortable
using one over the the other; however, they closely track each other and
will lead to the same jurisdictional decisions. For example, the flow
chart and key both indicate that the presence of dominant obligate plant
species, whether obligate wetland or obligate upland, 1s generally diagnostic
in itself. Specifically, if one or more dominant plant species in a vegeta-
tion unit Is an obligate wetland species, the vegetation unit (and the site
if it 1s a monotypic site) is a wetland and there is no need to consider
soils and hydrology, other than to verify that there have been no significant
hydrologic modifications. Likewise, the presence of one or more dominant
obligate upland plant species is conclusive evidence of the presence of
uplands. On the other hand, by definition, the presence of one or more

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-25-
dominant facultative species in a vegetation unit, even the presence of
all facultative wetland dominants, is not truly diagnostic despite the
fact the latter situation in particular would strongly suggest that the
unit is a wetland. Therefore, if only facultative species dominate a
vegetation unit, the flow chart and key direct investigators to the soil
and hydrologic parameters to help determine whether the vegetation unit is
wetland.
In some instances a mix of dominant obligate wetland species and
dominant obligate upland species will occur in the same vegetation unit.
These exceptions are reflected in the flow chart and key. They are either
a consequence of (1) relatively dry microsites and/or larger similar
inclusions (which support the upland species), (2) relative wet microsites
and/or larger similar inclusions (which support the wetland species), or
(3) plant succession resulting from natural or man-induced disturbances
(e.g., the landward edge of a tidal marsh that is encroaching on an
adjacent upland forest due to sea level and a site that has been drained
but at which wetland plant species still persist but upland species are
invading, respectively). When a mix of dominant obligate wetland species
and dominant obligate upland species occurs, it is necessary to check to
see if the site has been appropriately horizonally stratified and to
adjust accordingly. If the obligate upland plants occur on dry microsites
or similar larger inclusions, it is necessary to either show these local
areas as individual upland units or consider the site to be wetlands but
acknowledge the presence of local upland areas in a written description
of the site. (A comparable procedure should be used for local low areas
in an otherwise upland site.) As long as there are definable vegetation
units, howevef*, they should be handled individually. The minimum size
treatable (I.e., the minimal mapping unit) will depend upon site
conditions (e.g., size and access), plant physiognomy, and the tools
available (e.g., type and quality of aerial photographs). Nevertheless,
every attempt should be made to separately treat small units (i.e., to
finely horizontally stratify) in order to segregate any discrete upland
units in a wetland matrix (or vice versa) that could otherwise bias a
jurisdictional determination.

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If there is a rather uniform intermixed distribution of dominant
obligate wetland species and dominant obligate upland species (the
various subcategories of facultative species may be present too), then
the unit is probably a naturally or unnaturally disturbed one where
successional changes are occurring. Under these "circumstances, either
a 50% rule will have to be applied to the obligate species, or as an
alternative for forested sites, tree vigor and reproduction (e.g., seedlings
and saplings) may give a good indication of the direction of vegetation
change at the unit or site. In some instances, the vegetation may be so
heterogeneous that nothing appears to dominate. A situation in which no
species is dominant will seldom occur, however, if the site has been
appropriately horizontally stratified. Nevertheless, this situation is
addressed in both the flow chart and the key.

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SECTION V: LITERATURE CITED
American Society of Agricultural Engineers. 1967. Glossary of soil and
and water terms. Special Publication SP-04-67. 45 pp.
Avery, E.T. 1967. Forest measurements. McGraw-Hill Book Company, N.Y.
Barbour, M.G., J.H. Burk and W.D. Pitts. 1987. Terrestrial plant ecology.
The Benjamin/Cummlngs Publishing Company, Inc., Menlo Park, California.
634 pp.
Buckman, H.O. and N.C. Brady. 1969. The nature and properties of soils.
The Macmillan Company, Ontario, Canada.
Cain, S.A. and 6.M. de Oliveira Castro, 1959. Manual of vegetation analysis.
Harper & Row, N.Y. 325 pp,
Cowardln, L.M., V. Carter, F.C. Golet and E.T. LaRoe. 1979. Classification
of wetlands and deepwater habitats of the United States. FWS/OBS-79-31.
103 pp.
<
Curtis, J.T. 1971. The vegetation of Wisconsin. The Univ. of Wisconsin Press.
657 pp.
Daubenmire, R.F. 1968. Plant communities. Harper & Row, N.Y. 300 pp.
Department of Agriculture. 1985. Keys to soil taxonomy. Soil Management
Support Services Technical Monograph No. 6. 244 pp.
Qilworth, J.R. and J.F. Bell. 1976. Variable plot sampling—variable plot
and three-p. Q.S.U. Book Stores, Inc., CorvalUs, Oregon.
Environmental Laboratory, 1987. Corps of Engineers Wetlands Delineation Manual.
Technical Report, Y-87-1. U.S. Army Engineers Waterways Experiment
Station, Vicksburg, Mississippi.
Environmental Protection Agency. 1980. Environmental Protection Agency
rationale for identifying wetlands. 5 pp.
Greig-Smith, P. 1983. Quantitative plant ecology. The Univ. of California
Press.
Kollmorgen Corporation. 1975. Munsel soil color charts. Baltimore, Maryland.
Kuchler, A.W. 1967. Vegetation mapping. The Ronald Press Company, N.Y. 472 pp.
Mayr, E. 1970. Populations, species and evolution. Harvard Univ. Press.
453 pp.
Mueller-Dombols, D. and H. Ellenberg. 1974. Aims and methods of vegetation
ecology. John Wiley & Sons, N.Y. 547 pp.

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Odum, E.P. 1971. Fundamentals of ecology. W.B. Saunders Company,
Philadelphia, Pennsylvania. 574 pp.
Oosting, H.J. 1956. A study of plant communities. W.H. Freeman & Company,
San Francisco. 440 pp.
Slpple, W.S. 1985. Peat analysis for coastal wetland enforcement cases.
Wetlands 5:147-154.
Smith, R.L. 1974. Ecology and field biology. Harper & Row, N.Y. 850 pp.
Soil Conservation Service. 1982. National List of scientific plant names.
Vol. I. List of plant names. Vol. II. Synonomy. SCS-TP-159.
Soil Conservation Service. 1987. Hydrlc soils of the United States. In
cooperation with the National Technical Committee for Hydrlc Soils.
Soil Survey Staff. 1975. Soil Taxonomy. Agricultural Handbook No. 436,
Soil Conservation Service, U.S. Department of Agriculture. 754 pp.
U.S. F1sh & Wildlife Service. 1986. Wetland plants of the United States
of America 1986. In cooperation with the National Wetland Plant
List Review Panel.

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APPENDIX A
GLOSSARY

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APPENDIX A
GLOSSARY
Adaptation—The condition of showing fitness for a particular environment,
as applied to characteristics of a structure, function, or entire organism
(Mayr, 1970). These characteristics make the organism more fit (adapted)
for reproduction and/or existence under the conditions of its environment.
Plant species that gain a competitive advantage in saturated soil conditions
are typically adapted for such conditions.
Aerobic—A condition in which molecular oxygen is present in the environment.
Anaerobic--A condition in which molecular oxygen is absent from the environment
(Soil Conservation Service, 1987). This commonly occurs in wetlands when
soils are saturated by water.
Aquatic habitats—Habitats, other than wetlands, that generally have shallow
or deep water. The water can be intermittently or permanently present.
Shallow water areas sometimes support non-emergent hydrophytes.
Aquic moisture regime—A reducing regime in which the soil is virtually free
of dissolved oxygen because it is saturated by ground water or by water of
the capillary fringe. Some soils (e.g., salt marshes) are so wet that the
ground water is always at or very close to the soil surface and they are
considered to have a peraquic moisture regime (Soil Survey Staff, 1975).
Basal area—A measure of dominance in forests expressed as the area of a
trunk of a tree at diameter breast height (dbh) or as the total of such
areas for all trees in a given space (Curtis, 1971).
Baseline—A line, generally a highway, unimprove road, or some other evident
feature, from which transects extend into a site for which a wetland juris-
dictional determination is to be made.
Bryophytes—A major taxonomic group of non-vascular plants comprised of
liverworts, horned liverworts, and true mosses.
Capillary zone—The zone of soil essentially saturated with water, in which
pores become_filled as a result of surface tension (American Society of
Agricultural Engineering, 1967).
Chemical reduction—Any process by which one compound or ion acts as an
electron donor. In such cases, the valence state of the electron donor is
decreased (Environmental Laboratory, 1987).
Cover class—As used in this Manual, a category into which plant species
would fit based upon their percent area! cover. The cover classes used
(midpoints in parenthesis) are T=
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A-2
Diameter breast height (dbh)—The diameter of a tree trunk at 1.37 meters
(4.5 feet) above the ground.
Dominant —In a ecological sense, a dominant plant species is one that by
virtue of its size, number, production, or other activities, exerts a
controlling Influence on Its environment and therefore determines to a
largo extent what other kinds of organisms are present in the ecosystem
(Odum, 1971). In this document, however, dominance strictly refers to the
spatial extent of a species because spatial extent 1s directly discernible
or measurable In the field. In this sense, a dominant species 1s either
the predominant species (I.e., the only species dominating a unit) or a
codominant species (I.e., when two or more species dominant a unit). The
measures of spatial extent utilized in this Manual (percent area! cover
and basal area) are defined elsewhere 1n the glossary.
Facultative species—Species that can occur both in wetlands and uplands.
There are three subcategories of facultative species (facultative wetland,
straight facultative, and facultative upland). Under natural conditions,
a facultative wetland species is usually (estimated probability of 67-99%)
found in wetlands, but 1s occasionally found in uplands; a straight facul- *
tatlve species has basically a similar likelihood (estimated probability
of 34-66%) of occurring 1n both wetlands and uplands; a facultative upland
species 1s usually (estimated probability of 67-99%) found in uplands, but
1s occasionally found In wetlands.
Fern allies—A group of non-flower1ng vascular plants comprised of clubmosses
(Lycopodlaceae), small clubmosses (Selaginellaceae), horsetails (Equlsetaceae),
and qulllworts (Isoetaceae).
Flooded—A condition 1n which the soil surface is temporarily covered with
flowing water from any source, such as streams overflowing their banks,
runoff from adjacent or surrounding slopes, inflow from high tides, or any
combination of sources (Soil Conservation Service, 1987).
Flora—A 11st of plant taxa in a geographic area of any size. This could be
a simple list or a more detailed one that includes taxonomic descriptions,
diagnostic keys, distribution data, etc. Compare this term with the term
"vegetation-.0
Fol 1st—A mdj»cor less freely drained Histosol that consists primarily of
plant Utter-that has accumulated over bedrock (Soil Survey Staff, 1975).
Forbs—Broad!eaf herbaceous plants, in contrast to bryophytes, ferns, fern
all1es, and gramlnoids.
Frequently flooded—A class of flooding in which flooding is likely to occur
often under usual weather conditions (more than 50% change of flooding 1n
any year, or more than 50 times in 100 years) (Soil Conservation Service,
1987).
Gramlnoids—Grasses (Gramlneae) and grasslike plants, such as sedges
(Cyperaceae) and rushes (Juncaceae).

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A-3
Growing season—The portion of the year when soil temperatures are above
biologic zero (5 degrees C), as defined in Soil Taxonomy (Soil Survey Staff,
1975). The following growing season months are assumed by the Soil Conser-
vation Service (1987) for each of the soil temperature regimes:
Isohyperthermic: January-December
Hyperthermic:	February-December
Isothermic:	January-December
Thermic:	February-October
Isomesic:	January-December
Mesic:	March-October
Frigid:	May-September
Cryic:	June-August
Pergeiic:	July-August
Habitat—An environment occupied by plants and animals.
Herbaceous plants—Plants without persistent woody stems above the ground.
Herbaceous plants are coiranonly called herbs.
Histic epipedon—An 8-16 inch (20-40 centimeter) soil layer at or near the
surface that is saturated for 30 consecutive days or more during the growing
season in most years and contains a minimum of 20% organic matter when no
clay is present or a minimum of 30% organic matter when 60% or greater
clay is present (Environmental Laboratory, 1987). In general, a thin
horizon of peat or muck if the soil has not been plowed (Soil Survey Staff,
1975).
Histosol--An order in Soil Taxonomy composed of organic soils (mostly peats
and mucks) that have organic materials in well over half the upper 80
centimeters (32 inches) unless the depth to rock or to fragmental materials
is less than 80 centimeters (a rare condition), or the bulk density is
very low (Soil Survey Staff, 1975).
Horizontal stratification—The division of the vegetation at a site into
vegetation units (i.e., various patches, groupings, or zones).
Hydrlc soil—A soil that is saturated, flooded, or ponded long enough during
the growing season to develop anaerobic conditions in the upper part (Soil
Conservation Service, 1987).
Hydrophytes—Large plants (macrophytes), such as aquatic mosses, liverworts,
non-microscopic algae and vascular plants, that grow in permanent water
or on a substrate that is at least periodically inundated and/or saturated
with water.
Hydrophytic vegetation—Macrophytic plant life growing in water or on a
substrate that is at least periodically deficient in oxygen as a result of
excessive water content.
Inundated—A condition in which a soil is periodically or permanently flooded
or ponded by water.

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A-4
Long duration,--A duration class in which inundation for a single event
ranges from 7 days to 1 month (Soil Conservation Service, 1987).
Mineral soil—A soil consisting predominantly of, and having its properties
determined predominantly by, mineral matter. Mineral soils usually contain
less than 20% organic matter by weight (Buckman.and Brady, 1969).
i
honotyplc vegetation—Vegetation that 1s dominated by only one plant species.
Mottling—Spots or blotches of different color or shades of color interspersed
with the dominant color (Buckman and Brady, 1969). The dominant color is
called the soil matrix.
Muck—Highly decomposed organic material 1n which the original plant parts
are not recognizable (Buckman and Brady, 1969).
Obligate upland species—Species that, under natural conditions, always
occur 1n uplands (i.e., greater than 99% of the time). The less than 1%
is to allow for anomalous wetland occurrences (I.e., occurrences that are
the result of man-Induced disturbances and transplants).
Obligate wetland species—Species that, under natural conditions, always
occur In wetlands (I.e., greater than 99% of time). The less than 1% 1s
to allow for anomalous upland occurrences (I.e., occurrences that are the
result of man-induced disturbances and transplants).
Organic pan—A layer (i.e., spodlc horizon), usually occurring at 30-75
centimeters (12-30 inches) below the soil surface in coarse-textured soils,
1n which organic matter and aluminum (with or without Iron) accumulated at
the point where the top of the water table most often occurs (Environmental
Laboratory, 1987).
Peat—The sod layer at and near the surface of a wetland, as well as the
deeper, partially decomposed, vegetation into which the sod eventually
grades (Sipple, 1985).
Percent area! cover—An estimate of the area covered by the foliage of a
plant species projected onto the ground. It is determined independent of
other spe0es, and because of species overlap, the total areal cover for
all specl^wfll frequently exceed 100%, particularly for forested sites.
Periodic—Occurring or recurring at intervals which need not be regular or
predictable. Used here 1n reference to inundation or saturation of a
wetland soil.
Permeability—The quality of the soil that enables water to move downward
through the profile, measured as the number of Inches per hour that water
moves downward through the saturated soil (Soil Conservation Service,
1987).
Physiognomy—A term referring to the overall appearance of the vegetation,
as opposed to Its floristic composition. This 1s the result of the various
life forms (e.g., trees, shrubs, and herbs) and their distribution in each
stratum (Kuchler, 1967).

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Ponded--A condition in which water stands in a closed depression. The
water is removed only by percolation, evaporation, or transpiration (Soil
Conservation Service, 1987).
Poorly drained—A condition in which water is removed from the soil so
slowly that the soil is saturated periodically durirrg the growing season
or remains wet for long periods (Soil Conservation Service, 1987).
Prevalence--This term is equivalent to dominance. Thus, the prevalent
vegetation is the dominant vegetation.
Quadrats—Samp!ing units or plots that may vary in size, shape, number,
and arrangement, depending upon the nature of the vegetation and the
objectives of the study (Smith, 1974).
Root zone--That part of the soil profile that is or can be occupied by plant
roots and rhizomes. For most plant species occurring in wetlands, particu-
larly herbaceous plants, the majority of the roots and rhizomes generally
occur within the upper 30 centimeters (12 inches) of soil.
Sap!ing—A young tree between 1 and 10 centimeters (0.4 and 4 inches) in
diameter 1.37 meters (4.5 feet) above the ground surface.
Saturated—A condition in which all voids (pores) between soil particles in
the root zone are filled with water to a level at or near the soil surface
(maximum water retention capacity). Saturation may be periodic or permanent.
Seed!1ng--A young tree that is smaller than a sapling and generally less than
1 meter (3.28 feet) high.
Shrub—A woody plant that at maturity is usually less than 6.1 meters (20
feet) tall and generally exhibits several erect, spreading or prostrate
stems and has a bushy appearance (e.g., smooth alder, Alnus serrulata)
(Cowardin, et £l_, 1979).
Soil—A dynamic natural body on the surface of the earth in which plants
grow, composed of mineral and organic materials and living forms. Also
the collection of natural bodies occupying parts of the earth's surface
that support plants and that have properties due to the integrated effect
of climate and living matter acting upon parent material, as conditioned
by relief, over periods of time (Buckman and Brady, 1969).
Soil color—A characteristic of soil that has three variables: chroma,
hue,, and value. The hue notation of a color indicates its relationship to
red, yellow, green, blue, and purple; the value notation indicates its
lightness; and the chroma notation indicates its strength or departure
from a neutral of the same lightness (Kollmorgen Corporation, 1975).
Soil horizon--A layer of soil, approximately parallel to the soil surface,
with distinct characteristics produced by soil-forming processes (Buckman
and Brady, 1969). For example, the A horizon is the upper-most mineral
horizon. It lies at or near the soil surface and is where maximum soil
leaching occurs.

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A-6
Soil matrix—The portion (usually greater than 50%) of a given soil layer
that has the dominant color (Environmental Laboratory, 1987).
Soil phase--A subdivision of a soil series based on features such as slope,
surface texture, stoniness, and thickness (Soil Conservation Service,
1987).
Soil profile—A verticle section of the soil through all the horizons and
extending into the parent material (Buckman and Brady, 1969).
Soil series—A group of soils having horizons similar 1n differentiating
characteristics and arrangements 1n the soil profile, except for texture
of the surface layer (Soil Conservation Service, 1987).
Somewhat poorly drained—A condition in which water 1s removed slowly enough
that the soil Is wet for significant periods during the growing season
(Soil Conservation Service, 1987).
Species area curve—As used in this Manual, the curve on a graph produced
when plotting the cumulative number of plant species found 1n a series of
quadrats against the cumulative number or area of those quadrats. It 1s
used here 1n the detailed jurisdictional approach to determine the number
of quadrats sufficient to adequately survey the herbaceous understory.
Topographic contour—An imaginery line of constant elevation along the
ground (Environmental Laboratory, 1987). A contour line 1s the corres-
ponding line on a topographic map.
Transect—As used in this Manual, a line along which sample plots are
established for collecting vegetation, soil, and hydrology data.
Tree—A woody plant that at maturity is usually 6.1 meters (20 feet) or
more 1n height and generally has a single trunk, unbranched to about three
feet above the ground, and more .or less definite crown (e.g., red maple,
Acer rubrum) (Cowardin, et al_, 1979). As distinguished from a sapling,
a tree is greater than 10 centimeters (4 inches) diameter breast height.
Typical—That which normally, usually or commonly occurs (Environmental
Laboratory* 1987).
Under naturlf conditions—This phrase refers to situations in which plant
species occur 1n the native state at sites "undisturbed" by man as opposed
to those species occurring as transplants or on sites significantly disturbed
by man's activities (e.g., dredging, filling, draining, and impounding).
Under normal circumstances—This phrase was placed in the regulatory deflni-
tlon of wetlands to respond, for example, to those situations in which an
Individual has attempted to eliminate permit requirements by destroying
the wetland vegetation (e.g., a de-vegetated wetland could normally support
wetland vegetation) and those areas that are not wetlands but experience
the abnormal presence of wetland vegetation (e.g., marsh spoil piles

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placed under upland conditions, but temporarily supporting marsh plants
due to remnant plant propagules). Under the former situation, an area
would still remain a part of the overall wetland system protected by the
Section 404 program. Conversely, the abnormal presence of wetland vegetation
in a non-wetland area would not be sufficient to include that area within
the jurisdiction of the Section 404 program. Legal alterations to the
hydrologic regime, as opposed to mere removal of vegetation, may alter
"normal circumstances" if they in fact change the nature of a wetland
area so that it no longer functions as part of waters of the United States.
Up1ands--Areas that, under normal circumstances, support a prevalence of
plants that are not typically adapted for life in saturated soil conditions.
Uplands include all areas, other than aquatic habitats, that are not
wetlands.
Upland-wetland boundary—The line established in jurisdictional determinations
that separate wetland areas from adjacent upland areas.
Vegetation—The plant life as it exists on the ground (i,.e., the mosaic of
plant communities on a landscape) (Kuchler, 1967).
Vegetation signature--A unique spectral reflectance or emission response
transmitted or received by a sensor (e.g., the photographic appearance of
vegetation units on color film).
Vegetation structure—The division of a plant community into strata and the
distribution of the various life forms in each of these strata (Kuchler,
1967).
Vegetation unit--A patch, grouping, or zone of plants evident in overall
plant cover which appears distinct from other such units because of the
vegetation's structure and floristic composition. A given unit is typically
topographically distinct and typically has a rather uniform soil, except
possibly for relatively dry microsites in an otherwise wet area (e.g.,
tree bases, old tree stumps, mosquito ditch spoil piles, and small earth
hummocks) or relatively wet microsites in an otherwise dry area (e.g.,
small depressions).
Very long duration—A duration class in which inundation for a single event
is greater than 1 month (Soil Conservation Service, 1987).
Very poorly drained—A condition in which water is removed from the soil so
slowly that free water remains at or on the surface during most of the
growing season (Soil Conservation Service, 1987).	-
eW'0P
Water table—The zone of saturation at the highest average«d£pth during the
wettest season. It is at least 15 centimeters (6 inches) thick and persists
in the soil for more than a few weeks (Soil Conservation Service, 1987).

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Wetland hydrology—The sum total of wetness characteristics in areas that
are inundated or have saturated soils for a sufficient duration to support
hydrophytic vegetation (Environmental Laboratory, 1987).
Wetland indicator status—The excluslveness or fidelity with which a plant
species occurs in wetlands. The different indicator categories (i.e.,
facultative species, obligate wetland species, and obligate upland species)
are defined elsewhere in this glossary.
Wetlands—Areas that are inundated or saturated by surface or ground water
at a frequency and duration sufficient to support, and that under normal
circumstances do support, a prevalence of vegetation typically adapted for.
life in saturated soil conditions (33 CFR Section 328.3 and 40 CFR Section
230.3).

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