Seeing the Forest and the Trees:
Ecological Classification for Conservation
The classification that this publication describes was authored by:
Mark Anderson
Patrick Bourgeron
Mark T. Bryer
Rex Crawford
Lisa Engelking
Don Faber-Langendoen
Mark Gallyoun
Kathleen L. Goodin
Dennis H. Grossman
Sally Landaal
Kenneth J. Metzler
Karen D. Patterson
Milo Pyne
Marion S. Reid
Lesley Sneddon
Alan S. Weakley
and by ecologists in the network of Natural Heritage programs and Conservation Data Centers (see
back cover).
Citation: Maybury, Kathleen P., editor. 1999. Seeing the Forest and the Trees: Ecological Classification for
Conservation. The Nature Conservancy, Arlington, Virginia.
ISBN 0-9624590-2-X
Copyright 1999 The Nature Conservancy
Acknowledgements
Don Faber-Langendoen, Alan Weakley, Marion Reid, and Dennis Grossman, deserve special acknowledgement
for their ideas, careful review, and other contributions to this publication. Thoughtful review and comments
were also provided by Jonathan Adams, Mark Anderson, Mark Bryer, Patrick Comer, Christine A. De Joy, Beth
Duris, Stephanie R. Flack, Kathleen L. Goodin, Sally Landaal, Julie Lundgren, Karen D. Patterson, Milo Pyne,
Carol Reschke, Lesley Sneddon, and Bruce A. Stein. Deborah A. Gries provided research assistance. Jim
Drake, Jonathan L. Haferman, and Stuart Sheppard assisted with maps.
Design and Production: Nicole S. Rousmaniere
Table of
Contents
Preface ............................................................................................................................. 2
Introduction ....................................................................................................................... 3
Why Communities? ............................................................................................................. 4
Why Is a Classification System Important? .............................................................................. 6
What Is the USNVC? .......................................................................................................... 7
What Is the Current Status of the USNVC? ........................................................................... 10
How Is the USNVC Being Used? ........................................................................................ 12
Within the Conservancy ............................................................................................. 12
Beyond the Conservancy ............................................................................................ 19
Summary and Future Challenges ......................................................................................... 23
Appendices: The Nuts and Bolts of the USNVC System ........................................................... 24
Appendix A—Key Attributes ....................................................................................... 24
Appendix B—Structure and Type Definition ................................................................... 26
Appendix C—Partners in Development and Application .................................................. 29
Cited References .............................................................................................................. 36
I
n the early summer of 1991, a biologist invento-
Classifications such as the one developed in North Caro-
rying a pine savanna on the North Carolina
lina have now been compiled, integrated, and expanded
Coastal Plain came across a 3-foot-tall plant he couldn’t
into a system that is applicable across the nation: the U.S.
identify. The puzzling plant species, a member of the sedge
National Vegetation Classification, or USNVC. The prod-
family, turned out to be unknown to science—and all the
uct of a two-decade-long collaboration between the Con-
more intriguing because its nearest close relatives were
servancy and the network of Natural Heritage programs,†
found to be boreal species that occur almost 500 miles
the USNVC greatly enhances our ability to recognize,
away. Subsequent inventories at this same small site have
assess, and conserve natural communities everywhere we
documented the presence of an astounding 500 species
work, in the United States and beyond. It represents the
of vascular plants, as well as large populations of several
first U.S. community classification system that is national
globally endangered plants and invertebrates.
in scope and detailed enough in its consideration of
For those dedicated to preserving the nation’s
biodiversity, remarkable discoveries like these are usually
natural diversity to be useful in making local, site-specific
conservation decisions.
a call to action, galvanizing efforts to forge
In the case of the North Carolina site, a
partnerships with members of the local
community classification system allowed bi-
community, negotiate land deals, and initiate protection agreements. These efforts
Preface
ologists to recognize and document that at
least one plant community found there was
are often imbued with a sense of urgency,
extremely rare on a global basis. That real-
as many sites of exceptional biological value
ization was a principal factor in the decision
face encroaching development or other threats. In this
to make the site a Conservancy preserve long before com-
case, however, no sense of crisis ever arose; nothing out
prehensive inventories of species had been conducted there.
of the ordinary happened at all. At the time the scientist
In this report, we present several examples of how
discovered the anomalous sedge, large portions of the site
scientists within and beyond the Conservancy are using
had been a Conservancy preserve for more than five years.
the USNVC to accomplish the best possible conservation.
Ties to the community were already strong, and protec-
Our hope is to make the classification, and its enormous
tion efforts had long been part of the day-to-day work of
potential for improving conservation decisions, accessible
the Conservancy’s North Carolina Field Office.
to a wider audience of conservation practitioners. Essen-
How did the Conservancy come to identify this
tially, we want this tool to be in the hands of those who
specific place as being of critical conservation concern years
need it, wherever they need it, to carry out effective and
before many of the important species discoveries had been
efficient conservation.
made? In large part, the answer has to do with a scientific
 The ecologists of
approach created expressly to meet conservation needs:
The Nature Conservancy,
a classification system for ecological communities.
August 1998
†
The Natural Heritage network is an informal designation of state and other programs that work cooperatively to collect and manage
information on rare species and natural communities.
2
Seeing the Forest and the Trees: Ecological Classification for Conservation
W
hat types of natural vegetation exist across
This standardized approach is allowing assess-
the landscape? Which types are intrinsically
ments of conservation status, trends, and management
rare or have been severely degraded by human activities?
practices for ecological communities across local,
How do we identify the best remaining occurrences of natu-
regional, and national landscapes. It has enhanced the
ral communities across their geographic ranges? To direct
Conservancy’s ability to identify the most important
our limited conservation resources to the specific places
sites for conserving our nation’s biodiversity, and it is
where they will have the greatest impact, we must have
playing an important role in our efforts to identify a
clear answers to questions such as these—answers that
portfolio of conservation sites representative of each
ultimately hinge on how we define and categorize the rich
ecoregion.† Beyond the Conservancy and Heritage pro-
ecological diversity that is one of our nation’s greatest trea-
grams, the system’s utility has been widely appreciated:
sures. To answer these questions, The Nature Conservancy,
it is now accepted as the standard for classification,
in partnership with the network of Natural Heritage pro-
inventory, and mapping work in all U.S. federal agen-
grams, has developed a scientifically sound, consistent, and
cies, including the National Park Service, the National
flexible classification system that can
Forest Service, and the Fish and
be applied to terrestrial ecological
Wildlife Service. These agencies,
communities throughout the world.
The system can be used to classify
Introduction
all types of vegetated communities,
along with other academic and
professional conservation and
management organizations, are
from verdant wetlands to arid deserts nearly lacking in plant
increasingly becoming the Conservancy’s partners in
life, and from the most pristine old-growth forests to
the ongoing development and application of the clas-
cultivated annual crop fields. Using this system, a team of
sification and its provision to a burgeoning number of
Conservancy and Heritage ecologists has now completed a
users and contributors.
first iteration of the natural vegetation types of the United
This report briefly describes the classification
States. This represents the first time the country’s natural
system and identifies major opportunities for applying
terrestrial communities have been classified using a single
it to meet our current conservation challenges, as well as
system on a scale fine enough to be useful for the conser-
those that lie ahead.
vation of specific sites.
†
An ecoregion is a relatively large unit of land and water delineated by the biotic and abiotic factors that regulate the structure and
function of the communities within it. It provides a unit of geography that is more relevant than political units for organizing and
prioritizing conservation planning efforts.1
Seeing the Forest and the Trees: Ecological Classification for Conservation
3
A
ttempts to conserve biological diversity can
species-by-species approach to conservation. Saving
be directed at different biological and eco-
individual species once they are on the brink of extinc-
logical levels, ranging from genes to species to commu-
tion often demands large amounts of time, societal
nities and ecosystems. Communities can be described
concern, and money. Such an approach is clearly neces-
as assemblages of species that co-occur in defined areas
sary for species that are facing particular threats, and it
at certain times and that have the potential to interact
is also reasonable for large mammals, birds, and plants
2,3,4
with one another.
But com-
that are of particular signifi-
munities are more than the
cance to humans, especially
sum of their species; they also
represent the myriad biological
and environmental interactions
that are inherently a part of
Why
Communities?
each unique natural system.
those that inspire a sense of awe
or affinity. But there are an
estimated 10 million to 100
million species on Earth, only
a fraction of which are known
Thus, by describing, tracking, and preserving commu-
to science. 5 These include the little, less glamorous
nities, ecologists can protect a complex suite of organ-
species that create soils, pollinate plants, and play
isms and interactions not easily identified and protected
numerous other ecological roles. Protecting the vast
through other means.
majority of them will require a broader, natural com-
In addition, a consensus has emerged within the
conservation community about the inadequacy of a
munity-based approach that conserves habitats and
species assemblages as a whole.
The best approach to protecting many of our
most imperiled species, such as the elusive
and rare San Gabriel Mountain slender
salamander, is to preserve the habitats on
which they depend. Natural assemblages of
plants are widely regarded as biological
expressions of the complex factors that make
up a particular habitat—factors such as
climate, soils, natural disturbance processes,
and the structure of the plants themselves.
Thus, natural plant communities can be used
as a “coarse filter” for protecting numerous
species, even the less glamorous species whose
very existence—let alone habitat needs—we
may have yet to discover.
San Gabriel Mountain
slender salamander
© Kate Spencer
4
Seeing the Forest and the Trees: Ecological Classification for Conservation
The ecological community concept has been recognized as an important
conservation planning tool for the following reasons:
• Communities have inherent value that is worth conserving. They encompass a unique set of interactions among
species and contribute to important ecosystem functions.
• Communities can be used as surrogates for species and for ecological processes, particularly in species-rich
and data-poor areas such as the tropics.
• By protecting communities, we protect many species not specifically targeted for conservation. This is especially
important for poorly known groups such as fungi and invertebrates.
• Monitoring change over time is often most meaningful when done at the level of communities. Changes may be
detected in overall species abundance, including the proportion of non-native species; in structure, such as the
development of old-growth characteristics; and in function, such as alterations in nutrient cycling.
• Communities are an important tool for systematically characterizing the current pattern and condition of
© James R. Snyder
ecosystems and landscapes.
More Than the Sum
of Its Parts
Tropical forest communities
may comprise an especially
high number of species. Like
all communities, they also
comprise a complex array
of interactions among species
and between species and their
environments. Shown here:
a seasonally flooded tropical
forest, south Florida.
Seeing the Forest and the Trees: Ecological Classification for Conservation
5
T
he Conservancy and the Natural Heritage network
concluded that a basic question—to what extent the natu-
have recognized ecological communities as
ral ecosystems in the United States have been reduced in
important elements of conservation for many years. The
area or degraded in quality due to human activities—
best, most viable occurrences of these communities,
could only be answered “by a relatively crude approach
along with occurrences of rare and imperiled species,
because a systematic approach to understanding these
have formed the basis for protection decisions through-
systems at a national scale was not yet available.”6 Other
out the Conservancy’s history.
basic questions, such as, What are the key environmental
In the past, despite the recognized importance of
factors in relationship to a particular community across
ecological communities, no accepted framework for
its entire range? and, What is the complete geographic
national or international community classification existed.
distribution of a particular community? often could not
be answered at all.
Without a standard approach,
community protection decisions
were made only on a state-bystate or agency-by-agency basis,
based on independently developed classifications. These classifications worked effectively for
the conservation of important
areas within states or jurisdic-
Why Is a
Classification
System
Important?
Recognizing the need for a
national and international system for classifying terrestrial
communities to carry out its
mission effectively, the Conservancy, in conjunction with the
Natural Heritage network, undertook development of the U.S.
National Vegetation Classification
tions, but from a national and
international perspective, they risked unnecessarily redun-
(USNVC) system. A team of more than 100 Conservancy
dant protection of a few communities and inadequate
and Heritage ecologists established the standardized
protection of many others. In addition, in the absence of
classification framework and defined the first iteration
a common classification, the results of many inventory
of U.S. communities within it.† In the coming years, the
and monitoring programs, such as those conducted in
USNVC will be continuously refined and developed by
national forests and parks, state forests and parks, or fish
the Conservancy and an expanding network of partners
and wildlife refuges, could not be integrated or compared.
who are using the system to accomplish their conserva-
As recently as 1995, several prominent researchers
tion and management goals.
†
More detailed information about the classification system, including its development, status, and applications, can be found in the recent
publication International Classification of Ecological Communities: Terrestrial Vegetation of the United States.7 A first iteration of the list of
community types can be found in the second volume of that publication.8 Both volumes are available on the World Wide Web at
www.tnc.org.
6
Seeing the Forest and the Trees: Ecological Classification for Conservation
T
he USNVC system blends the features of many
vegetation structure and that occur under similar habi-
existing classification systems that are most
tat conditions.
useful for conservation. It essentially represents a
The association concept encompasses both the
structured compilation of an enormous amount of
dominant species (those that cover the greatest area) and
fine-scale state and local information on vegetation,
diagnostic species (those found consistently in some
and an integration of this information with a modified
vegetation types but not others) regardless of whether
version of UNESCO’s worldwide framework for coarse-
they are large trees or diminutive understory plants.
scale vegetation classification.9
This means associations can reflect a greater ecological
Terrestrial ecological communities are classified
specificity than can a “cover type” or other type based
based on vegetation as it currently exists across the land-
solely on the dominant species of the upper stratum.
scape. Because of their conservation objectives, the
Dominant cover species are often widespread, and may
Conservancy and the Natural Heri-
occur with many different species
tage network are classifying and
over large, heterogeneous land-
describing only the more natural
types of vegetation. The USNVC
framework, however, may be used
What Is the
USNVC?
scapes.10,11 For example, in northern Minnesota and adjacent parts of
Canada, on moist bedrock sub-
to classify all existing vegetation,
strates the “generalist” species jack
including heavily human-influ-
pine (Pinus banksiana) occurs with
enced types such as those in developed areas, crop-
an understory of balsam fir (Abies balsamea), whereas
lands, and places severely altered by past logging or
on dry sandplains jack pine grows with bearberry (Arcto-
farming. (See Appendix A for additional information
staphylos uva-ursi) under its canopy.12 These two distinct
about the key attributes of the USNVC.)
plant assemblages, and the profoundly different environ-
In the USNVC, terrestrial vegetation is classified
mental conditions under which they occur, undoubtedly
within a nested, seven-level hierarchy, the finest level of
represent differences of real ecological significance.
which is called the association. (See Appendix B for a com-
The differences are captured by including dominant
plete explanation of the system’s hierarchical structure.)
and diagnostic species in both the over- and understory,
The confluence of three interrelated criteria—species
as well as habitat conditions, in the association concept.
composition, structure, and habitat—conceptually
Despite their relatively high degree of ecological speci-
defines an association: it represents those plant assem-
ficity, associations must repeat across the landscape.† Indi-
blages that exhibit similar total species composition and
vidual occurrences of the same or different associations,
The association concept is intended to be fine enough to be useful for
identifying specific, ecologically meaningful sites for conservation, but
broad enough to be connected to landscape-scale processes and patterns.
†
A few associations that are restricted to specific and unusual environmental conditions are exceptions to this general rule.
Seeing the Forest and the Trees: Ecological Classification for Conservation
7
© Charlie Ott and Gunther Matschke
Hawaiian cloud forests
m
Death Valley
m
Towering redwoods
m
The Everglades
m
Tallgrass prairies
Encompassing the boreal and the tropical, alpine
summits and deserts well below sea level, the United
States is blessed with a great and beautiful variety
of natural vegetation. Conceptualizing—even in a
general way—the diversity and pattern of this vegetation across the landscape is a daunting prospect.
Doing so in a way that helps us understand relatively
small-scale but ecologically meaningful patterns is even
Death Valley National Monument
more of a challenge.
however, may range greatly in size. For example, some west-
characteristics of the leaves, such as seasonality, shape,
ern grasslands occur naturally in patches of tens of thou-
and texture. These features are referred to as physiognomic
sands of acres. In contrast, southern Appalachian “beech
characteristics, and they are generally much more useful
gaps,” characterized by stunted, gnarled beech trees,
than species composition for rapidly categorizing veg-
often occur in sharply bounded mountaintop patches of
etation over large geographic areas (or in areas where
only a few acres.
little is known about the species composition).
Associations are grouped into the next level of the
At the coarsest level of the USNVC hierarchy,
USNVC hierarchy, the alliance, primarily on the basis of
the class, vegetation is divided into seven types: Forest,
having common dominant species in the upper stratum
Woodland, Shrubland, Dwarf-shrubland, Herbaceous,
of the vegetation. Alliances, in turn, are nested into
Nonvascular, and Sparse Vegetation. A summary of the
progressively coarser levels of the hierarchy, primarily
USNVC’s seven levels is provided in the box on the
based on characteristics related to the structure (height
facing page.
and spacing) and overall shape of the plants, and to
8
Seeing the Forest and the Trees: Ecological Classification for Conservation
© Julie Moore, TNC
A Summary of the U.S. National Vegetation
Classification System
LEVEL
PRIMARY BASIS FOR CLASSIFICATION
EXAMPLE (SEE PHOTO)
Class
Structure of vegetation
Woodland
Subclass
Leaf phenology
Evergreen Woodland
Group
Leaf types, corresponding to climate
Temperate or Subpolar Needle-Leaved
Evergreen Woodland
Subgroup
Relative human impact (natural/semi-natural, or
cultural)
Natural/Semi-natural
Formation
Additional physiognomic and environmental
factors, including hydrology
Saturated Temperate or Subpolar
Needle-Leaved Evergreen Woodland
Alliance
Dominant/diagnostic species of the uppermost
or dominant stratum
Longleaf Pine -- (Slash Pine, Pond Pine)
Saturated Woodland Alliance †
Association
Additional dominant/diagnostic species from
any strata
Longleaf Pine / Little Gallberry /
Carolina Wiregrass Woodland †
The Longleaf Pine / Little
Gallberry / Carolina
Wiregrass Woodland. This
association is found on flat,
poorly drained sites on the
Coastal Plain of North and
South Carolina.
†
Rules for naming alliances and associations: The names of dominant and diagnostic species are used in alliance and association
names. Those species occurring in the same stratum are separated by a hyphen ( - ); those occurring in different strata are separated
by a slash ( / ). Species found less consistently either in all associations of an alliance, or in all occurrences of an association, are
placed in parentheses. In most cases, the word “alliance” appears in alliance names to distinguish them from associations. Examples
of alliance names: American Beech - Southern Magnolia Forest Alliance [Fagus grandifolia - Magnolia grandiflora Forest Alliance];
Longleaf Pine / Oak Species Woodland Alliance [Pinus palustris / Quercus spp. Woodland Alliance]. Examples of association names:
Subalpine Fir / Grouseberry Forest [Abies lasiocarpa / Vaccinium scoparium Forest]; Saltgrass - (Saltmarsh Dropseed) Herbaceous
Vegetation [Distichlis spicata - (Sporobolus virginicus) Herbaceous Vegetation].
Seeing the Forest and the Trees: Ecological Classification for Conservation
9
T
he number of currently defined USNVC types at
environments does this type occur? How much varia-
each level of the system’s hierarchy and the per-
tion (in structure and in species composition) is recog-
centage of associations in each class are presented
nized within the type? How does this type differ from
below. The number of types at the coarser levels of the
similar types? and, How does this type respond to dis-
hierarchy will not change significantly as the classifica-
turbances, both natural and human induced?
tion develops. However, changes will occur at the finest
Conservancy ecologists are providing answers to
levels as the existing alliances and associations are
these questions in the form of detailed descriptions of
refined and new types are added through additional
alliances and associations. Thus far, descriptions have
inventories and analyses.
been completed for about 80 per-
Each of the currently defined
associations has a minimum set
of information associated with it,
including the association’s conservation status, and a list of states and
U.S. Forest Service ecoregions
13
where it is known or thought to
occur. However, to understand
What Is the
Current
Status of the
USNVC?
cent of the currently defined alliances and about 40 percent of the
associations.
An example of a typical
description appears on the facing
page. It depicts the Blackjack Oak Eastern Red Cedar / Little Bluestem
- Orange-Grass St. John’s -Wort
alliances and associations in depth and to recognize
Wooded Herbaceous Vegetation Association. Otherwise
them in the field, ecologists will need answers to more
known as the Shawnee Sandstone Glade, this midwestern
detailed questions about specific types. Important
savanna is naturally restricted to unusually thin-soiled
questions regarding each type include: In what types of
places where droughty conditions prevail.
Total Number of Vegetation
Types at Each Level of the
USNVC
Level
Class
Subclass
Group
Formation
Alliance
Association
Number of Types
7
22
62
231
1,642
4,515
Note: Data shown are current as of August 1998 and
represent types in the Natural/Semi-natural Subgroup only.
10
Dwarf-shrublands
3%
Herbaceous Vegetation
27%
Shrublands
16%
Woodlands
18%
Nonvascular Vegetation
<1%
Sparse Vegetation
2%
Forests
33%
Percentage of Associations in Each Class
Seeing the Forest and the Trees: Ecological Classification for Conservation
Blackjack Oak - Eastern Red Cedar / Little Bluestem - Orange-Grass St. John’s-Wort Wooded
Herbaceous Vegetation [Quercus marilandica - Juniperus virginiana var. virginiana / Schizachyrium scoparium
- Hypericum gentianoides Wooded Herbaceous Vegetation]
SYNONYM: Shawnee Sandstone Glade.
RANGE: This association occurs on the upper slopes and ridgetops of south-facing bluffs and escarpments in the Shawnee
Hills of southern Illinois, western Kentucky, and southern Indiana. The present range of this community is probably very
close to pre-European settlement range.
VEGETATION DESCRIPTION: This community is dominated by graminoid species. Blackjack oak, post oak, and eastern red
cedar are the dominant trees; they are found scattered or in patches throughout the occurrence. These trees are generally small,
stunted, and limby. The overstory cover seldom exceeds 50 percent. The subcanopy is conspicuously thin or absent. Scattered
individual and patches of shrubs occur here, with farkleberry and winged elm the most commonly encountered. Grasses such as
little bluestem and poverty oat-grass dominate the herbaceous layer, along with a diverse mixture of forbs. The patchiness and
uneven distribution of trees, shrubs, and herbaceous vegetation are a response to thin, infertile soils and droughty conditions.
Lichens and mosses are common on exposed bedrock surfaces and on soils not covered with leaf litter and woody debris.
MOST ABUNDANT SPECIES: Post oak (Quercus stellata), blackjack oak (Quercus marilandica), eastern red cedar (Juniperus
virginiana), winged elm (Ulmus alata), farkleberry (Vaccinium arboreum), saw greenbrier (Smilax bona-nox), poverty oat-grass
(Danthonia spicata), little bluestem (Schizachyrium scoparium), Parmelia spp., and Polytrichum spp.
DIAGNOSTIC SPECIES: Blackjack oak (Quercus marilandica), farkleberry (Vaccinium arboreum), saw greenbrier (Smilax
bona-nox), little bluestem (Schizachyrium scoparium), and orange-grass St. John’s-wort (Hypericum gentianoides).
ENVIRONMENTAL DESCRIPTION: This community occurs primarily on south- and southwest-facing slopes. This droughty
environment has thin, acidic soils that can erode easily. Bedrock is sandstone, which occurs on the surface as massive
outcrops, level benches, and boulders. The slope aspect results in frequent periods of freeze and thaw and consequent
erosion and mass wasting. The aspect also contributes to summer temperatures well in excess of those in the cooler and
wetter north- and east-facing slopes.
SUCCESSIONAL STATUS/HISTORY: Natural disturbance includes periodic fire, wind, storm, and drought. Environmental
extremes, including rapidly drained, thin, stony
soils; summer droughts lasting three to five weeks
Known Occurrences of Shawnee Sandstone Glade
or more; and limited water availability for most
of the growing season, favor the establishment
of this glade association. Periodic fire may help
to maintain this community, especially after disturbance from logging or grazing. Fire suppression encourages a transition from glade to woodland. Herds of elk, deer, and buffalo once roamed
these hills, and their grazing and browsing may
have provided a mechanism for maintaining the
“barrens” or glade character.
MANAGEMENT COMMENTS: Prescribed fire is
becoming a commonly used tool for barrens or
glade restoration. Although little data are available concerning presettlement fire frequency, a reduction in this frequency has contributed to recent increases in woody species coverage
(Robertson and Heikens 1994). Some researchers suggest that mechanical removal of larger trees
and periodic burning (every two or three years)
may be necessary to maintain sparse woodland
physiognomy.
LITERATURE CITED:
Robertson, P. A., and A. L. Heikens. 1994. Fire
frequency in oak-hickory forests of southern Illinois. Castanea 59: 286-291.
Occurrence data are from the following sources: the Illinois Department of
Natural Resources, Division of Natural Heritage; the Division of Nature
Preserves, Indiana Department of Natural Resources; and the Kentucky
State Nature Preserves Commission.
Seeing the Forest and the Trees: Ecological Classification for Conservation
11
W
ITHIN THE
CONSERVANCY
The Conservancy’s mission is “to preserve plants, animals,
of community types—typically 5 to 25 associations—that
and natural communities that represent the diversity of life
occur in similar environmental settings. While the same
on Earth by protecting the land and waters they need to
associations will almost always be found everywhere a par-
survive.” Determining which community types urgently
ticular complex occurs, similar, but not identical, associa-
need protection, and which occurrences represent the best
tions are likely to be found in each occurrence of a group.
conservation opportunities for each type, provides the basis
Examples of ecological groups include northern Rocky
for targeting conservation resources appropriately. The
Mountain alpine meadows, southwestern desert riparian
Conservancy uses two complementary approaches to guide
woodlands, and midwestern beech-maple forests. All
these determinations:
associations can be conceptually grouped in this way, and
1. The best, most viable † occurrences of all the
such groups offer a simplified way of understanding and
mapping vegetation pattern over
community types that occur in an
ecoregion, as well as occurrences
of rare species, are selected to be
included in a portfolio of sites that,
collectively, would conserve the full
suite of biodiversity within that
ecoregion. Essentially, these port-
How Is the
the USNVC
Being Used?
folios serve as blueprints for con-
large, diverse landscapes. Especially
in areas where there is limited
information on the precise distribution of associations, ecological
groups provide a coarse-scale
assessment of community diversity
and distribution that can be used as
servation success. The USNVC is being used as a guiding
a basis for targeting conservation resources. Thus, while
framework for these ecoregional blueprints.
the USNVC recognizes communities at a relatively fine
Three principal entities have recently been identified
scale of resolution, it also offers the flexibility to recognize
as ecological targets for conservation: USNVC associations,
natural ecological groupings of those communities at vari-
ecological complexes, and ecological groups. Ecological
ous scales for practical use in conservation planning.
complexes represent associations that are tightly bound by
2. Although the Conservancy is dedicated to conserv-
ecological processes and are invariably found together in
ing the best occurrences of all natural vegetation types,
tight spatial clusters. Because of the predictable and fine-
special attention must be focused on types that are ex-
scale occurrence patterns of the associations within them,
tremely rare or imminently endangered. To identify these,
complexes are most efficiently inventoried, mapped, and
the Natural Heritage network and the Conservancy have
protected as single entities. An example is the upland/wet-
developed a method for evaluating each USNVC associa-
land vegetation mosaic found in coastal dune/swale com-
tion and assigning an appropriate conservation status
plexes. Ecological groups are more conceptual aggregations
rank. Because the USNVC is a standardized classification,
†
Viability is assessed through element occurrence ranking on an excellent to poor scale based on degree of altered species composition and structure, condition, and inferred ecosystem processes.
12
Seeing the Forest and the Trees: Ecological Classification for Conservation
each association can be assessed and ranked based on its
Percentage of Associations at
Each Conservation Status Rank
G5
8%
GU/G?
18%
relative degree of rarity and imperilment on a global, or
rangewide, basis (as well as on more local levels). See the
table and figure adjacent for the definitions of these ranks
GH
<1%
and the percentage of associations assigned to each.
Based on this assessment, more than half of all
G1
11%
G4
17%
defined U.S. associations are of conservation concern,
with 31 percent considered critically imperiled or imperiled and another 26 percent considered vulnerable.
G2
20%
G3
26%
American chestnut forests that once covered much of the
been part of the national landscape, but that now occur
ELIMINATED throughout its range, with no restoration potential due to extinction of dominant or characteristic species.
nowhere in the world.
throughout its
range, with no or virtually no likelihood that it will
be rediscovered, but with the potential for restoration (e.g., American Chestnut Forest).
centage of all the currently defined associations occurring
PRESUMED ELIMINATED (HISTORIC)
CRITICALLY IMPERILED. Generally
5 or fewer occurrences and/or very few remaining acres or very vulnerable to elimination throughout its range due to
other factor(s).
G2
IMPERILED. Generally 6-20 occurrences and/or few
remaining acres or very vulnerable to elimination
throughout its range due to other factor(s).
G3
VULNERABLE. Generally 21-100 occurrences. Either
very rare and local throughout its range or found
locally, even abundantly, within a restricted range
or vulnerable to elimination throughout its range
due to specific factors.
G4
APPARENTLY SECURE. Uncommon, but not rare (although it may be quite rare in parts of its range,
especially at the periphery). Apparently not vulnerable in most of its range.
G5
SECURE. Common, widespread, and abundant
(though it may be quite rare in parts of its range,
especially at the periphery). Not vulnerable in most
of its range.
The maps on the following page illustrate the per-
in each state and in each U.S. Forest Service ecoregion13
that are imperiled (G1 or G2). An astounding 30 percent
© Samuel M. Gon III, TNC
G1
GU
is considered “extinct,” but a few are historic. Like the
East, these are communities that are known to have once
Global Rank Definitions
GH
ranked G? or GU, only a relatively small percentage of
these are believed to be imperiled.) As yet, no association
More than half of all associations are of conservation concern, with nearly a third considered critically imperiled or
imperiled. Note: Data shown are current as of August 1998.
GX
(Although 18 percent of the associations are currently
UNRANKABLE. Status cannot be determined at this
time.
G?
UNRANKED. Status
has not yet been assessed.
Note: “G” refers to global (rangewide) status. National (N)
and subnational (S) ranks can also be assessed.
Critically imperiled Loulu Coastal Mesic Palm Forest, Hawaii
Seeing the Forest and the Trees: Ecological Classification for Conservation
13
Occurrence of Imperiled Associations by State and by Ecoregion
Percentage of
Imperiled (G1, G2)
Associations
> 30%
20 – 30%
10 – 20%
< 10%
Note: Data shown are
current as of August
1998. Data for Alaska
are incomplete and are
not shown.
or more of the natural communities in areas such as
efficient solutions to this national problem will be grounded
Hawaii, the Willamette Valley of Oregon, and vast portions
in conservation planning and action on an association-
of the Midwest and Southeast are in danger of vanishing
by-association, site-by-site, and ecoregion-by-ecoregion
from our national landscape.
basis. The following examples of how the Conservancy and
An awareness of just how large the imperilment
its partners are preserving imperiled communities, habitats,
problem is on a national scale is one of the most sobering,
and landscapes will illustrate some of these solutions. (For a
but potentially useful, insights to emerge from the develop-
comprehensive overview of how the USNVC is being used
ment of a national community classification. Effective and
throughout the nation and beyond, see Appendix C.)
14
Seeing the Forest and the Trees: Ecological Classification for Conservation
EXAMPLE 1
Preserving the
Rarest Communities in
the Great Lakes States
In the Great Lakes basin, scattered from northern New York across southern Ontario and northern Michigan,
there are a few places with globally rare native communities collectively known as “alvar” types. These communities, composed of a mixture of prairie and boreal plant species, include woodlands, shrublands, and
grasslands that occur as a mosaic on thin soils overlying flat expanses of limestone.14 All are extremely dry in
summer, but some are very wet in spring and fall. Many are known to have locally rare species associated with
them, and certain species or subspecies of snails may be endemic to these communities. But the communities
as a whole are of fundamental significance. Each represents a unique assemblage of plants and animals and a
distinct set of species interactions and ecological processes that are inherently worth conserving. We cannot
hope to know and understand all the facets of these species, interactions, and processes, but the communities
have already provided some surprising discoveries and insights. For example, some alvar communities are
now believed to be old-growth habitats, with stunted northern white-cedar (Thuja occidentalis) trees that are
at least 500 years old and possibly much older.15
Classification of the Great Lakes alvar communities has clarified and highlighted the diversity, rarity, and
vulnerability of these systems. It has also clarified distinctions between these communities and related systems
found elsewhere in North America and Scandinavia. The ability to compare the degree of rarity of these alvar
communities relative to other types and to understand these communities across their entire geographic range
has played an important role in ensuring their protection. For example, Canadian and U.S. conservationists
recently met to review all currently known high quality sites, and to identify innovative conservation strategies, including a range of private and public initiatives, to
protect them.16 In addition,
ongoing biological and hydrological monitoring studies on
several of the sites are establishing conservation and management priorities that will
protect these unique communities in perpetuity.
© Carol Reschke
Alvar grassland transitioning to calcareous pavement barrens, Geum Prairie, Chaumont
Barrens, New York
Seeing the Forest and the Trees: Ecological Classification for Conservation
15
EXAMPLE 2
Preserving Habitats
and Species in
North Carolina
Natural assemblages of plants are a biological expression of environmental conditions such as climate, soils,
hydrology, topography, and natural disturbance processes. Essentially, such assemblages are an easily observable
indicator of habitats.17 Thus, although defined on the basis of vegetation, each plant community almost certainly
© B. A. Sorrie
represents a unique set of organisms, including vertebrates, invertebrates, vascular and nonvascular plants, bacteria, and fungi. For this
reason, protecting viable examples of every association is a proactive way of protecting whole assemblages of species before any individual species declines into endangerment. Although it is difficult to
precisely quantify the success or failure of this “coarse filter” approach,
some of the most easily discernible successes will occur in those
associations that are naturally rare. (Such associations are a manifestation of unusual environmental conditions and are therefore likely
to support naturally rare species adapted to those conditions.)
One such success story takes place in the few places on the
Atlantic Coastal Plain where coquina limestone, a cemented mixture of broken marine shells and corals, forms the bedrock. Here,
on the thin, wet, calcareous soils that form over the coquina, an
unusual woodland community occurs. Longleaf pine (Pinus palustris)
and pond pine (P. serotina) form a scattered, open canopy over a
variety of herbaceous species such as Carolina dropseed (Sporobolus
pinetorum) and toothache grass (Ctenium aromaticum). Both the composition and the structure of the vegetation are unusual, and the
Carex lutea, a recently discovered species of
sedge, known from only nine populations
worldwide
community is known to occur only in eastern North Carolina.
In the early 1980s, the Conservancy made the Neck Savanna, a primary site for this woodland, a conservation priority. The site was chosen on the basis of the known presence of this globally rare community, as well as
several rare species. Because the site was preserved and made accessible to biologists, the ensuing 15 years have
revealed the presence of numerous additional G1–G3 species, including many invertebrates. The largest known
population of the rare Venus flytrap cutworm (Hemipachnobia subporphyria subporphyria), for example, was
found here. So was a species of sedge previously unknown to science (Carex lutea). The newly described sedge,
a tall, clump-forming plant with a long, narrow inflorescence, turned out to be a widely disjunct member of an
otherwise boreal group of plants that occur nearly 500 miles away.18 Found only in these naturally rareand
now protected“islands” of calcareous savanna, the sedge is now known from a total of nine populations in the
world. The decision to protect this site based on the presence of a rare community protected this thenunknown species, as well as populations of other species of great biological value.
16
Seeing the Forest and the Trees: Ecological Classification for Conservation
EXAMPLE 3
Creating a Blueprint for
Conservation Success in
the Intermountain West
The ability to evaluate and compare community types across broad geographic areas is one of the principal
advantages of the standardized USNVC system. The Conservancy uses this advantage in planning conservation at the ecoregional level, where types, and occurrences of types, must be compared and assessed within
and across these huge landscapes. One of the first ecoregional plans was developed for the Conservancy’s
Columbia Plateau ecoregion. Stretching across seven states, but primarily located in northern Nevada, southern Idaho, and eastern Washington and Oregon, the Columbia Plateau ecoregion has been described as a
300,000-square-kilometer expanse of “sagebrush-covered volcanic plains and valleys, punctuated by isolated
mountain ranges and the dramatic river systems of the Snake, Owyhee, Boise, and Columbia.” 19
In developing the ecoregion’s conservation plan, the Conservancy and its partners addressed two related
questions: Where in this vast and diverse area should we target our conservation resources? and, How can we
preserve the biological diversity that is representative of the region as a whole? One part of the answer is to
focus on preserving the best, most representative occurrences of the communities that occur in the ecoregion.
At least 449 USNVC associations have been defined within the Columbia Plateau ecoregion—a measure of
the tremendous biodiversity of the area. Of these, 105 are considered rare or imperiled (G1 or G2), including
once-extensive grassland types of the Palouse prairies that now only occur as fragmented remnants. To ensure
that these associations are not lost
entirely, the ecoregional planning
team included most of the viable
occurrences of them as priorities for
conservation site selection. Associations that are more common were
prioritized partly on the basis of how
much fidelity to the ecoregion they
exhibit. Those associations that can
be protected only within the Columbia Plateau because they are endemic
or very limited to it were generally
considered to be a higher conservation priority than more widespread
types or those that primarily occur
in adjacent ecoregions and are only
peripheral in the Columbia Plateau.
The planning team chose priority occurrences of associations by
The Columbia Plateau Ecoregion
Seeing the Forest and the Trees: Ecological Classification for Conservation
17
taking into account minimum size
requirements, the level to which the
occurrence had been affected by human activities, and how all the occurrences could best reflect the natural
distribution of the type across the
ecoregion. Where specific occurrences
of associations were unknown, cover
types were used as predictors of the
likelihood of an association occurring
© Harold Malde
in the area. However, the degree to
which the blueprint succeeds in capturing all the representative biodiversity of
the ecoregion will be assessed on the
The Columbia Plateau
basis of how well the actual associations
were selected. Thus, the USNVC is being used as the framework for understanding the distribution of vegetation types within and among ecoregions, for determining which types are particularly imperiled,
andultimatelyfor evaluating our blueprints to ensure that they maintain all the significant aspects of the
unique biological and ecological character of the Columbia Plateau ecoregion, and of all the ecoregions in
which we work.
18
Seeing the Forest and the Trees: Ecological Classification for Conservation
B
EYOND THE
CONSERVANCY
Many federal agencies, including the Department of
preserving the plants, animals, and natural communi-
Defense, the Environmental Protection Agency, the
ties that represent the diversity of life on Earth—
National Park Service, the U.S. Fish and Wildlife
organizations like the Conservancy are becoming
Service, and the U.S. Forest Service, have supported
increasingly aware of the importance of working with
the development of the USNVC as a useful tool to
partners and leveraging our effectiveness by sharing
help them meet their conservation and resource man-
the best conservation tools and practices. The follow-
agement goals. (See Appendix C.)
ing examples illustrate how the USNVC is helping
EXAMPLE 1
Given the magnitude of the challenge before us—
effect conservation “beyond the Conservancy.”
Detecting Gaps in Protection:
Superior National Forest,
Minnesota
As is the case with the Conservancy’s ecoregions, a management goal for all lands owned by the U.S. Forest
Service has long been to preserve and maintain landscape-scale ecosystem and species diversity. The Forest
Service accomplishes this in part through designating research natural areas (RNAs), which, along with other
types of established natural areas, form a network of protected lands that are representative of the vegetation
and ecosystems of each national forest. The proposed targets of RNA representation include the natural communities, defined by USNVC alliances, that are contained in each subsection (large areas with similar landforms and geologic structures).20
On one of the Forest Service’s lands, Superior National Forest, an assessment was recently completed
to determine what gaps exist in the protection of types. Occupying more than two million acres in the
Silhouettes of pine, birch, spruce,
fir, and cedar—examples of trees
that can be found in Superior
National Forest, Minnesota.
Provided by staff of Northwest
Science and Technology, Ontario
Ministry of Natural Resources.
Seeing the Forest and the Trees: Ecological Classification for Conservation
19
Arrowhead region of northeastern Minnesota, Superior National Forest is a lake-studded, hilly expanse characterized by a diverse mix of jack, red, and white pine; balsam fir; white and black spruce; white cedar; birch;
and aspen. Thirty-seven USNVC alliances have been found there. High-quality examples of every alliance
occurring in each of the forest’s six subsections are the proposed targets for an RNA network representative of
the vegetation throughout Superior National Forest. Ecologists identified 117 of these alliance-by-subsection
targets, only 32 of which (27 percent) were currently protected in natural areas. † Perhaps surprisingly, particular gaps were noted in some of the most widespread, predominant alliances, which were not represented
at all in RNAs or other natural areas within most of the subsections. Detecting these fundamental gaps in
protection is the first step toward ensuring that our national forest lands remain truly representative of our
EXAMPLE 2
nation’s forests.
Meeting Our Global Stewardship
Responsibilities: Guantanamo
Bay Naval Station, Cuba
In part because of restricted public access to many of its lands, the U.S. Department of Defense has become an
important steward of many sites of significant biological value. The U.S. Naval Station at Guantanamo Bay,
Cuba, is no exception. Like many islands, Cuba has a high biological value because of the many species and
communities that have evolved there and occur nowhere else. Within Cuba, the U.S. Naval Station is of
especially high value. It encompasses a wide variety of coastal and dry tropical habitats and harbors several
species of animals that appear to be abundant and thriving within the station’s confines, even as their populations elsewhere are in decline.21
To meet its obligations regarding management of natural resources, the Department of Defense recently
funded a rapid ecological assessment (REA) of the station to take a quick, scientific “snapshot” of its biodiversity
Given the magnitude of the challenge it faces, the Conservancy
is becoming increasingly aware of the importance of working with
partners and leveraging its effectiveness by sharing the best
conservation tools and practices.
†
At least 1 example of nearly all of the 37 alliances is protected within one area of the national forest, the Boundary Waters
Canoe Area Wilderness, but natural areas in other parts of the forest do not protect a representative mix of natural forest
types.
20
Seeing the Forest and the Trees: Ecological Classification for Conservation
and inform a plan for
managing its resources.
USNVC alliances and
associations were used to
C
help create this snapshot.
U
B
Aerial photographs and
A
satellite imagery were
used to target and supplement more time- and
labor-intensive field sur-
Guantanamo Bay Naval Station
veys, and 25 associations
were delineated at the station. Ecologists targeted 11 of these for conservation action, including several unique
palm scrub, cactus scrub, and tropical arid forest types that are known to provide critical habitat for birds of
conservation concern. Many of the targeted types are restricted in the total geographic area in which they occur
and are degraded nearly everywhere they occur except within the confines of the naval station. The Navy now
has a documented, compelling reason to seize this exceptional opportunity to protect these globally endangered
EXAMPLE 3
ecological communities and their component species.
Understanding Our National
Park Lands: Scotts Bluff National
Monument, Nebraska
What types of communities and species may already be protected on public, Conservancy, or other lands? Are
we achieving our management goals in these places? How can the wealth of natural diversity on these lands be
portrayed to their ownersU.S. taxpayers, Conservancy members, and others? Standardized inventory and
monitoring programs are the keys to answering these questions.
As the foundation of its inventorying and monitoring program, the National Park Service is using the
USNVC system to map the vegetation across all of its lands. An example can be seen in the detail of the map of
Scotts Bluff National Monument shown on the following page. Scotts Bluff is a prominent natural landmark
in western Nebraska that was used by emigrants on the Oregon Trail. In 1919 it was set aside with adjacent
lands in a 3,000-acre national monument within the National Park Service system. Recent surveys have found
that the monument contains 20 USNVC associations
For each of Scotts Bluff’s 20 associations, a description has been written characterizing the type on a range
wide basis, as well as its local expression at the monument. Monument staff will use the map and associated
descriptions in several ways: to direct searches for state-listed rare plant species suspected to occur within the
Seeing the Forest and the Trees: Ecological Classification for Conservation
21
Community Map of Scotts Bluff National Monument - Detail
Nebraska
Siltstone - Clay Butte Sparse
Vegetation
Inland Siltstone Bluff - Cliff Sparse
Vegetation
Sand Bluestem - Prairie Sandreed
Herbaceous Vegetation
Needle-and-Thread Grass - Blue
Grama - Threadleaf Sedge
Herbaceous Vegetation
Ponderosa Pine / Rocky Mountain
Juniper Woodland
500 feet
Approximate Scale
Published courtesy of the USGS-NPS Vegetation Mapping Program
monument; to locate long-term monitoring plots in major prairie types of concern; to monitor the results of
restoration efforts; and to track long-term changes in vegetation at the monument. Staff members also intend to
use the vegetation descriptions as a means of assessing potential fuel loads and fire behavior when they plan
prescribed burns. In addition to these applications, the map and descriptions will form the basis of interpretive
displays used to provide visitors with a better understanding of the natural diversity present at the monument.
22
Seeing the Forest and the Trees: Ecological Classification for Conservation
O
ver the past decade, the Conservancy and the
m Maintain and expand
Natural Heritage programs have developed
partnerships
a national classification system for vegetation, and many
types within this system have been defined and charac-
Existing partnerships between the Conservancy, Heritage
terized. This classification, the USNVC, has been invalu-
programs, and federal and state agencies have been very
able in supporting conservation planning, site identifi-
successful in developing the USNVC. In addition, the Eco-
cation, and biodiversity monitoring and management.
logical Society of America has established a panel for veg-
Use of the system has now expanded to a broader part-
etation classification that has brought together many
nership that includes conservationists, vegetation scien-
ecologists from academia to refine standards and provide
tists, and resource managers across academic institutions,
review. Future development and implementation of the
USNVC increasingly depends on a
federal and state agencies, private
organizations, and other nonprofit
organizations. The following challenges remain for the Conservancy
and its partners in their ongoing
efforts to develop, maintain, document, and support the USNVC:
Summary
and Future
Challenges
strong, shared vision of a national
classification system and a heightened
spirit of cooperation among all partners. In addition, new partnerships
will need to be forged to address the
needs of an increasingly broad network of contributors and users.
m Continue to develop and refine
USNVC types and type descriptions
m Maintain momentum
The Nature Conservancy and the network of Heritage
For the Conservancy and its partners, the ongoing devel-
programs are continuously collecting and analyzing
opment of the USNVC is immensely rewarding. The
new data, with a particular focus on communities of
undertaking has gained momentum as the importance of
conservation concern, areas in which classifications are
a national classification system to address conservation,
lacking, and areas in which classification confidence is
stewardship, and research needs has become increasingly
low. Groups of experts will continue to be brought to-
obvious. Strong commitments to the USNVC’s develop-
gether on a project-by-project and geographic basis to
ment are critical to its continued use in effectively and
refine the classification system and the descriptions of
efficiently conserving and managing our nation’s extraor-
the vegetation types so that users will have the infor-
dinary biodiversity.
mation they need to use the system to its fullest.
Seeing the Forest and the Trees: Ecological Classification for Conservation
23
APPENDICES: The Nuts and Bolts of the USNVC System
Appendix A—
F
Key Attributes
our key attributes characterize the USNVC system:
1. It is based on vegetation.
2. It has been applied to natural vegetation.
Classifications of ecological systems can be based on a
The USNVC framework may be used to classify all
variety of factors, such as vegetation, soils, and landforms,
vegetation, from the extremes of natural (types that
that can be used either singly or in combination. Conser-
appear to be unmodified by human activities) to cul-
vancy ecologists, however, made a pivotal decision to
tural (planted and maintained types, such as annual
develop a terrestrial classification system that is based
croplands, tree plantations, orchards, and vineyards).
primarily on vegetation. Several factors led to that deci-
However, because the Conservancy’s focus is on the pro-
sion. First, because the Conservancy’s mission is to pro-
tection of natural vegetation, only the more natural types
tect biodiversity, a classification that emphasizes the
are being classified and described by the Conservancy
biotic component of ecological systems was seen as being
and the Natural Heritage network. These include types
the most relevant. Second, vegetation is an easily measured
that occur spontaneously without regular management,
component of an ecological system. Indeed, it is often cho-
maintenance, or planting, and that generally have a
sen as the most useful single factor for classifying terres-
strong component of native species.
trial ecological systems because it integrates more measurably than any other factor or set of factors the environ-
3. It is based on existing vegetation.
mental conditions, ecological processes, and biogeographical dynamics that operate on a site or landscape.10,11 Third,
Vegetation classifications are based on either existing
vegetation can describe many facets of biological and eco-
or potential natural vegetation (PNV). PNV types repre-
logical patterns across the landscape. Plants provide the
sent the projected mature or stable end points of veg-
habitat and structure for many other organisms in an eco-
etation development over time (late seral types). These
logical community, and vegetation is often used to infer
are vegetation types projected to occur and persist on a
soil and climate patterns. Fourth, building a single-factor
site in the absence of disturbance, whether human-
system was simply more practical than building a more
caused or natural. PNV classifications offer insight
complex, multifactor system.
into vegetation-site relationships and can be helpful in
24
Seeing the Forest and the Trees: Ecological Classification for Conservation
projecting the type of vegetation expected under a certain set of ecological factors. However, disturbances have
4. It is a hierarchical system, defined by
physiognomy and floristics.
a profound influence on the structure and composition
of vegetation, and each major successional stage follow-
The USNVC has a hierarchical taxonomic structure with
ing a natural disturbance (or a human-caused distur-
physiognomic criteria used at the coarsest levels of the
bance that closely mimics a natural one) is biologically
hierarchy and floristic criteria used at the finest. Physiog-
and ecologically distinct and of inherent worth. Indeed,
nomy refers to the structure (height and spacing) and over-
important habitat is provided by many communities
all shape of plants, and to leaf characteristics, such as sea-
that are not at mature or stable end points of vegetation
sonality, shape, duration, size, and texture. These features
development. For this reason, the Conservancy believes
provide a fast, efficient way to categorize vegetation on
the conservation of all existing natural community types
broad geographic scales. Physiognomic features can
will ensure the survival of the greatest possible number
often be linked to remote sensing signatures, are easily
of species, both plant and animal.
recognized in the field, and can be applied even in places
In addition to its usefulness for conservation
where very little information about the flora exists.
purposes, a classification of existing, rather than
Floristics refers to species composition. Using species com-
potential, vegetation makes fewer assumptions about
position or species groups to characterize vegetation
natural processes and vegetation dynamics and allows
reveals finer-scale local and regional patterns than are
the classification to be grounded in what is directly
likely to be perceived using physiognomic characters.
observable and measurable. Finally, the focus on exis-
A combined physiognomic-floristic system allows
ting vegetation can support a wide number of uses,
for most of the advantages of both approaches and pro-
including inventorying and monitoring the current sta-
vides a unifying framework within which to relate typi-
tus of vegetation. Thus, while the USNVC framework
cally coarse-scale physiognomic systems to more local and
is comprehensive with regard to existing vegetation—
regional floristic systems. Additionally, structuring the
encompassing the spectrum from natural to culti-
USNVC in a hierarchical fashion allows it to be used at
vated—the Conservancy’s efforts have focused on the
different taxonomic scales, depending on the amount of
best existing occurrences of natural types, both natu-
information available and the resolution needed.
rally disturbed (early and mid-seral) and naturally
undisturbed (late seral).
Seeing the Forest and the Trees: Ecological Classification for Conservation
25
APPENDICES: The Nuts and Bolts of the USNVC System
Appendix B—
Structure &
Type Definition
T
STRUCTURE
he USNVC terrestrial † classification system
Shrubland: Shrubs generally greater than 0.5 meter tall
consists of a seven-level hierarchy. Five levels
with individuals or clumps overlapping to not touching
(class, subclass, group, subgroup, and formation) are
(generally forming greater than 25 percent cover, with
based on physiognomic characteristics, and two
trees generally forming less than 25 percent cover). Veg-
levels (alliance and association) are based on species
etation dominated by woody vines is generally treated in
composition.
this class.
Physiognomic Levels
Dwarf-shrubland: Low-growing shrubs, usually less
than 0.5 meter tall, with individuals or clumps overlap-
The physiognomic levels of the USNVC are a modifica-
ping to not touching (generally forming greater than 25
tion of the UNESCO world physiognomic classification
percent cover; with trees and tall shrubs generally form-
of vegetation.
9
ing less than 25 percent cover).
CLASS
Herbaceous: Herbaceous plants dominant (generally
The formation class (or “class”) is based on the structure
forming at least 25 percent cover, with trees, shrubs, and
of the vegetation: classes are determined by the type,
dwarf-shrubs generally forming less than 25 percent cover).
height, and relative percentage of cover of the dominant,
uppermost life-forms. There are seven classes:
Forest: Trees with their crowns overlapping (generally
forming 60 percent to 100 percent cover).
Nonvascular: Nonvascular cover (bryophytes, noncrustose lichens, and algae) dominant (generally forming
at least 25 percent cover).
Sparse Vegetation: Abiotic substrate features dominant.
Woodland: Open stands of trees with crowns not usu-
Vegetation is scattered to nearly absent and generally re-
ally touching (generally forming 25 percent to 60 percent
stricted to areas of concentrated resources (total vegeta-
cover).
tion typically forming less than 25 percent cover).
†
26
The terrestrial system is defined to include all wetland and shallow-water vegetation with rooted vascular plants.
Seeing the Forest and the Trees: Ecological Classification for Conservation
SUBCLASS
Group, the Temperate Broad-Leaved Evergreen Wood-
The Forest, Woodland, Shrubland, and Dwarf-shrubland
land Group, and the Temperate or Subpolar Needle-
Classes each include three formation subclasses (or “sub-
Leaved Evergreen Woodland Group.
classes”) based on leaf character: evergreen, deciduous, or
Both climate and the presence and character of
mixed evergreen-deciduous. The Herbaceous Class com-
woody strata are used to separate subclasses into groups
prises four subclasses based on a combination of persis-
in the Herbaceous and Nonvascular Classes. For example,
tence and growth-form characteristics: perennial grasslands,
in the Perennial Graminoid (grassland) Subclass, the
perennial forb vegetation, annual grasslands or forb veg-
Tropical or Subtropical Grassland Group is separated from
etation, and hydromorphic vegetation. The relative domi-
Temperate or Subpolar Grasslands, as well as from Tropi-
nance of either lichens, mosses, or algae divides the
cal or Subtropical Grasslands with a Sparse Tree Layer.
Nonvascular Class into three subclasses. Lastly, the three
Sparse Vegetation subclasses are separated into
subclasses of the Sparse Vegetation Class are defined pri-
groups based on major topographic position types or
marily by the particle sizes of the substrate features: con-
landforms (for example, cliffs versus flat to gently slop-
solidated rock; boulder, gravel, cobble, or talus; and un-
ing bedrock).
consolidated material (soil, sand, or ash).
SUBGROUP
GROUP
Each group is divided into either a Natural/Semi-natural
The subclasses of the Forest, Woodland, Shrubland,
Formation Subgroup or a Cultural Formation Subgroup,
and Dwarf-shrubland Classes are further divided into
providing a consistent dichotomy between vegetation
formation groups (or “groups”) based on leaf charac-
actively planted or maintained by humans and all other
teristics, such as broad-leaved or needle-leaved. These
types of vegetation. This distinction is useful for mapping
units are defined and named in conjunction with broad
vegetation types across the natural and cultural landscape.
climatic types. For example, the Evergreen Woodland
Its placement at the subgroup level allows for the develop-
Subclass includes the Tropical or Subtropical Broad-
ment of culturally distinct formations (for example,
Leaved Evergreen Woodland Group, the Tropical or
orchards and annual croplands) within the overall USNVC
Subtropical Needle-Leaved Evergreen Woodland
hierarchy.
Hierarchical Vegetation Classification System
for the Terrestrial Ecological Communities
SYSTEM: TERRESTRIAL
FORMATION CLASS
FORMATION SUBCLASS
FORMATION GROUP
FORMATION SUBGROUP
physiognomic levels
FORMATION
floristic levels
ALLIANCE
ASSOCIATION
Seeing the Forest and the Trees: Ecological Classification for Conservation
27
FORMATION
The formation level represents vegetation types that share
species (those found consistently in some vegetation
types but not in others) are considered as well.
a definite physiognomy within broadly defined environmental factors, landscape position, or hydrologic regime.
ALLIANCE
Structural factors such as crown shape and lifeform of the
Within a formation, the alliance is a group of plant
dominant stratum are used in addition to the physiogno-
associations (see “Association” below) sharing one or
mic characters already specified at the higher levels.
more dominant or diagnostic species, usually found in
Hydrologic modifiers, adapted from Cowardin and
the uppermost or dominant stratum of the vegetation.
22
others , are used for wetlands. Examples include the
Rounded-Crowned Temperate or Subpolar Needle-Leaved
ASSOCIATION
Evergreen Forest Formation, the Semipermanently
An association is defined as a plant community with a
Flooded Tropical or Subtropical Broad-Leaved Evergreen
definite floristic composition, uniform habitat condi-
Shrubland Formation, and the Short Alpine or Subalpine
tions, and uniform physiognomy. With the exception
Sod Grassland Formation.
of a few associations that are restricted to specific and
unusual environmental conditions, associations repeat
across the landscape. They occur at variable spatial scales
Floristic Levels
depending on the steepness of environmental gradients
The lower two levels of the hierarchy—the alliance and
and the patterns of disturbances. The association is the
the association—are based on species composition. Both
lowest level of the USNVC hierarchy, as well as the basic
are primarily defined by their dominant species (those
unit for vegetation classification in the USNVC in North
that are most abundant or prevalent). Diagnostic
America.
HOW TYPES ARE DEFINED
Many methods are used to define USNVC alliances and
about vegetation patterns. About 80 percent of the
associations. They range from directly adopting types
associations have been defined with the benefit of quan-
from compatible state or local classification systems,
titative analyses of plot data, analyses either published
especially Heritage program classifications, to conduct-
in the scientific literature or, less commonly, conducted
ing field studies in which new vegetation information is
by Conservancy or Heritage ecologists expressly to
collected and analyzed. The great majority of existing
define USNVC types. Regardless of the specific approach
associations has been defined with a mixture of quanti-
used, the cornerstone of type definition is structured peer
tative analysis of available vegetation data and a review
review by experienced local, state Heritage program, and
of more qualitative, descriptive types of information
regional ecologists.
28
Seeing the Forest and the Trees: Ecological Classification for Conservation
APPENDICES: The Nuts and Bolts of the USNVC System
Appendix C —
P
Partners in
Development &
Application
artnerships with federal agencies have been instru-
the USNVC in many portions of the country. In addi-
mental throughout the development of the USNVC.
tion, the Federal Geographic Data Committee facilitated
The first national list of rare and threatened ecological
a multi-agency review of the physiognomic levels of the
communities was compiled with the support of the
classification hierarchy as part of a process that led to
U.S. Fish and Wildlife Service.23 The development of the
the endorsement of the USNVC system as the federal
national list of vegetation alliances and their descriptions
standard for vegetation classification and information.25
is being strongly supported by the Gap Analysis
Finally, the Ecological Society of America has established
Program, a multi-agency program that employs alliances
a panel of experts to refine the processes for defining
as the standard for state vegetation cover maps used in
and reviewing floristic types..
evaluating the conservation status of target species. A
Strong partnerships such as these have evolved over
biodiversity assessment across 13 Great Plains states,
the course of the USNVC’s development as agencies and
funded by the U.S. Environmental Protection Agency,
organizations have become increasingly aware of the need
helped to standardize the associations between the
for a standardized national classification to accomplish
24
Conservancy’s Midwest, Southeast, and West Regions.
their conservation and resource management goals more
The U.S. Forest Service is providing ongoing support to
efficiently and effectively. At the same time, within the
Conservancy ecologists to revise all levels of the classifi-
Conservancy and in other conservation organizations, the
cation hierarchy and to document the vegetation on
importance of working with partners has become increas-
national forests in the Southeast. The Forest Service
ingly obvious as we strive to dramatically expand our
is also supporting classification efforts in other regions.
impact in an era of pressing conservation needs.
On a national scale, it supports the development and
An overview of how and where the USNVC has
documentation of conservation status ranks for rare
been used and, where possible, some measure of its
associations.
impact are presented here in the hope that the range
These agencies and others have also provided fund-
and scope represented will inspire even greater use of
ing at local, or project-specific, scales. This support has
the classification as a tool to accomplish the important
been important in the development and application of
work ahead.
Seeing the Forest and the Trees: Ecological Classification for Conservation
29
SITE-BASED APPLICATIONS
Site, State
Projected or Actual Use
Approximate
Acres Affected
NATIONAL PARK SERVICE
Acadia National Park, Maine
Inventory and mapping, monitoring, management
70,000
Inventory and mapping, monitoring, management
3,300
Inventory and mapping, monitoring, management,
acquisition
15,977
Badlands National Park, South Dakota
Inventory and mapping, monitoring, management
1,314,447
Chickamauga and Chattanooga National Military Park,
Georgia and Tennessee
Pilot community mapping and classification
Congaree Swamp National Monument, South Carolina
Inventory and mapping, monitoring, management
24,400
Devils Tower National Monument, Wyoming
Inventory and mapping, monitoring, management
5,920
Fort Laramie National Historic Site, Wyoming
Inventory and mapping, monitoring, management
Gates of the Arctic, Alaska
Glacier National Park, Montana
Inventory, classification, and mapping
8,202,517
Inventory and mapping, monitoring, management, rare
species habitat modeling
1,250,000
Agate Fossil Beds National Monument, Nebraska
Assateague Island National Seashore, Maryland
8,119
1,200
Golden Gate National Recreation Area, California
Inventory and mapping, monitoring, management
80,000
Great Smoky Mountains National Park, North Carolina
and Tennessee
Inventory and mapping, monitoring, management
120,000
Isle Royale National Park, Michigan
Inventory and mapping, monitoring, management
133,781
Jewel Cave National Monument, South Dakota
Inventory and mapping, monitoring, management
9,658
Joshua Tree National Monument, California
Inventory and mapping, monitoring, management
792,749
Kennesaw Mountain National Military Park, Georgia
Pilot community mapping and classification
2,884
Mount Rushmore National Memorial, South Dakota
Inventory and mapping, monitoring, management
5,946
Point Reyes National Seashore, California
Inventory and mapping, monitoring, management
78,000
Rock Creek National Park, Washington, D.C.
Inventory and mapping, monitoring, management
1,800
Russell Cave National Military Park, Alabama
Pilot community mapping and classification
Scotts Bluff National Monument, Nebraska
Inventory and mapping, monitoring, management
(including planning prescribed burning), planning
restoration activity, rare species habitat modeling
3,200
Shiloh National Military Park, Tennessee
Theodore Roosevelt National Park, North Dakota
Pilot community mapping and classification
3,972
Inventory and mapping, monitoring, management, exotic
species habitat modelling, animal habitat modeling
310
384,041
Tuzigoot National Monument, Arizona
Inventory and mapping, monitoring, management
800
Voyageurs National Park, Minnesota
Inventory and mapping, monitoring, management
300,000
Wind Cave National Park, South Dakota
Inventory and mapping, monitoring, management
Yosemite National Park, California
Inventory and mapping, monitoring, management, fire
modeling
84,201
1,000,000
U.S. FOREST SERVICE
Angelina National Forest, Texas
Community classification, keys, ecological classification
153,179
Apalachicola National Forest, Florida
Community classification, keys, ecological classification
565,543
Bienville National Forest, Mississippi
Black Hills National Forest, South Dakota and Wyoming
Community classification, keys, ecological classification
178,400
Community classification, keys, ecological classification,
comprehensive inventory of all natural communities
1,531,735
Community classification, keys, ecological classification
634,075
Cherokee National Forest, Tennessee and North Carolina
30
Conecuh National Forest, Alabama
Community classification, keys, ecological classification
83,859
Daniel Boone National Forest, Kentucky
Community classification, keys, ecological classification
547,285
Seeing the Forest and the Trees: Ecological Classification for Conservation
Site, State
Projected or Actual Use
Approximate
Acres Affected
U.S. FOREST SERVICE (CONTINUED)
De Soto National Forest, Mississippi
Community classification, keys, ecological classification
506,026
George Washington National Forest, Virginia and West
Virginia
Community classification, keys, ecological classification
1,064,562
Homochitto National Forest, Mississippi
Community classification, keys, ecological classification
191,572
Jefferson National Forest, Virginia and Kentucky
Community classification, keys, ecological classification
716,073
Kisatchie National Forest, Louisiana
Community classification, keys, ecological classification
603,158
Monongahela National Forest, West Virginia
Community classification, keys, ecological classification
909,136
Nantahala National Forest, North Carolina
Community classification, keys, ecological classification
527,486
Ouachita National Forest, Arkansas and Oklahoma
Community classification, keys, ecological classification
1,762,567
Ozark National Forest, Arkansas
Community classification, keys, ecological classification
1,133,567
Pisgah National Forest, North Carolina
Community classification, keys, ecological classification
504,787
Sabine National Forest, Texas
Community classification, keys, ecological classification
160,656
Shawnee National Forest, Illinois
Community classification, keys and descriptions,
ecological classification
277,506
Sumter National Forest, South Carolina
Community classification, keys, ecological classification
360,753
Talladega National Forest, Alabama
Community classification, keys, ecological classification
389,189
Uwharrie National Forest, North Carolina
Community classification, keys, ecological classification
50,189
Caribbean National Forest (El Yunque), Puerto Rico
Alliance-level community classification
27,831
U.S. DEPARTMENT OF DEFENSE
Arnold Air Force Base, Tennessee
Vegetation mapping and classification, and application to
resource management
Camp Shelby, Mississippi
Consultation on community classification and conservation
significance
Eglin Air Force Base, Florida
Tier mapping, community classification, and inventory
463,452
Fort Benning, Georgia and Alabama
Vegetation mapping and classification, and application to
resource management
182,000
Fort Bliss, New Mexico
Inventory and characterization of natural resources on part
of the Fort
Fort Gordon, Georgia
Vegetation mapping and classification, and application to
resource management
Fort Stewart, Georgia
Guantanamo Bay Naval Station, Cuba
Longleaf pine restoration and community monitoring
Moody Air Force Base, Georgia
Inventory and characterization of natural resources
Naval Station Ingleside, Texas
Inventory and characterization of natural resources
483
Nellis Air Force Bombing and Gunnery Range, Nevada
Inventory and characterization of natural resources
3,500,000
Panama Department of Defense lands
Rapid ecological assessment, inventory, classification at the
sub-formation level, mapping, and conservation
recommendations
Shepherd Air Force Base, Texas
Inventory and characterization of natural resources
5,480
White Sands Missle Range, New Mexico
Inventory and characterization of natural resources
2,000,000
Rapid Ecological Assessment, community classification,
mapping, inventory, and management recommendations
40,118
134,000
* acres affected not
available
56,000
279,270
20,000
6,050
75,000
U.S. FISH AND WILDLIFE SERVICE
Chincoteague National Wildlife Refuge, Virginia
Inventory and mapping, monitoring, management, land
acquisition, breeding bird monitoring and management
14,014
Grays Lake National Wildlife Refuge, Idaho
Vegetation mapping and classification and application to
resource management
16,739
Red Rock Lakes National Wildlife Refuge, Montana
Vegetation mapping and classification and application to
resource management
45,597
Seeing the Forest and the Trees: Ecological Classification for Conservation
31
Site, State
Projected or Actual Use
Approximate
Acres Affected
THE NATURE CONSERVANCY
(Bioreserves and Other Multi-jurisdictional Areas of Interest)
United States
ACE (Ashepoo - Combahee - Edisto) Basin, South Carolina
Community classification, inventory, mapping, and
management recommendations
Altamaha River Bioreserve, Georgia
Community classification, mapping, and management
planning
1,200,000
Block Island, Massachusetts
Inventory and mapping; maps used for understanding
large landscapes
6,400
Gauley River, West Virginia
Inventory and mapping; maps used for understanding
large landscapes
acres affected not
available
Gray Ranch, New Mexico
Protection of representative vegetation with compatible use
Lahontan Valley Wetlands, Nevada
Classification, mapping, and management planning
Meadow River, West Virginia
Inventory and mapping; maps used for understanding
large landscapes
Schenob Brook, Massachusettes
Inventory and mapping
Shawangunks, New York
Inventory and mapping; maps used for understanding
large landscapes (Mapped to a state Heritage classification; data
350,000
32,700
200,000
15
90,000
gathered and analyzed during the project were used to further development
of the state classification and the USNVC.)
Waterboro Barrens, Maine
Inventory and mapping; maps used for understanding
large landscapes (Mapped to a state Heritage classification; data
2,140
gathered and analyzed during the project were used to further development
of the state classification and the USNVC.)
Virginia Coast Reserve, Virginia
Winyah Bay Focus Area / Sandy Island, South Carolina
Community classification
444,551
Community classification, mapping, and management
planning
525,000
International
Amapa, Brazil (Champion Paper Company lands)
Rapid ecological assessment, inventory, and mapping
700,000
Blue and John Crow Mountains National Park, Jamaica
Rapid ecological assessment, inventory, mapping, park
planning
194,000
Chaco, Paraguay
Rapid ecological assessment, inventory, and mapping
TOTAL ACRES AFFECTED
32
Seeing the Forest and the Trees: Ecological Classification for Conservation
2,000,000
39,359,365
OTHER APPLICATIONS
Location
Projected or Actual Use
U.S. FOREST SERVICE
Research Natural Area (RNA) Projects
All U.S. Forest Service Region 1, Region 2, Region 4, and Region 8 Forests
Identifying gaps in protection by assessing alliance coverage in
designated RNAs
All U.S. Forest Service Region 9 Forests
Identifying gaps in protection by assessing alliance distribution and
protection status in RNAs or RNA-equivalents for all subsections
that include U.S. Forest Service land
Other projects
All national forests in the northern Great Plains: Montana, northern
Nebraska, North Dakota, South Dakota, Wyoming
Descriptions of all G1 and G2 associations
Southern Appalachian Assessment for Pisgah, Nantahala, Cherokee, George
Washington, Jefferson, Talladega, Chattahoochee, and Sumter National
Forests (Alabama, North Carolina, South Carolina, Tennessee, Virginia,
West Virginia)
Rare community classification and matrix with rare species
occurrences
Alabama, Arkansas, Connecticut, Delaware, Florida, Georgia, Kentucky,
Louisiana, Maine, Maryland, Massachusetts, Mississippi, New Hampshire,
New Jersey, New York, North Carolina, Oklahoma, Pennsylvania, Puerto
Rico, Rhode Island, South Carolina, Tennessee
Attribution of all alliances to all U.S. Forest Service subsections to
characterize subsection vegetation
Region 4 Forests: Payette, Boise, and Sawtooth National Forests, Southwest
Idaho Ecogroup Forest Plan Amendment
Attribution of all alliances to all U.S. Forest Service subsections to
characterize vegetation
Region 8 Forests
Comprehensive classification for all units for ecosystem
management, forest planning, timber typing, and biodiversity
conservation
U.S. Forest Service ranking project
Development of conservation status ranks, descriptions, and
supporting information for imperiled community types
U.S. DEPARTMENT OF DEFENSE
Arnold Air Force Base: Tennessee, Kentucky, Alabama
Barrens Assessment; management planning and context for barrens
ecosystems
U.S. DEPARTMENT OF ENERGY
Oak Ridge Reservation, Tennessee
Inventory, management, natural area planning
Savannah River Site, South Carolina
Historic vegetation mapping and modeling
Hanford Nuclear Reserve, Washington
Inventory, management, natural area planning
TENNESSEE VALLEY AUTHORITY
TVA: Alabama, Georgia, Kentucky, Mississippi, North Carolina, Tennessee,
Virginia
Pilot community mapping
ENVIRONMENTAL PROTECTION AGENCY
Multistate Surveys
Calcareous fens: Maine, New Hampshire, Vermont, Massachusetts, New
York, Pennsylvania, Connecticut, Rhode Island
Inventory and prioritization for conservation action
Atlantic white cedar swamps: Massachusetts and New Hampshire
Inventory and prioritization for conservation action
Northern white cedar swamps: Vermont and New Hampshire
Inventory and prioritization for conservation action
Floodplain forests: Maine, New Hampshire, Massachusetts, Maryland, West
Virginia
Inventory and prioritization for conservation action
Seeps and seepage forests: Pennsylvania, Maryland, New Hampshire
Inventory and prioritization for conservation action
Seeing the Forest and the Trees: Ecological Classification for Conservation
33
Location
Projected or Actual Use
ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)
Other Projects
Colorado riparian vegetation
Standardized descriptions of all riparian types for EPA use produced
by the Conservancy and the Colorado Natural Heritage Program
(USGS-BRD develped a CD-ROM for delivery of these data to
partners in an easy-to-use medium)
Connecticut River Watershed: Vermont, New Hampshire, Massachusetts,
Connecticut
Conservation of neotropical migrant birds, predictive community
modeling, biophysical/vegetation assessment of watershed
Midwest Oak Ecosystem Recovery Plan
Classification of oak savanna and woodland types in the Midwest
prairie-forest border region
South Platte Watershed: Nebraska, Colorado, Wyoming
Inventory of natural resources, management planning
Southern Idaho wetlands
Identification, classification, inventory, and prioritization of
wetlands
Upper Arkansas Watershed, Colorado
Inventory and prioritization for conservation action
Upper Yellowstone Watershed: Montana, Wyoming
Inventory and prioritization for conservation action
U.S. GEOLOGICAL SURVEY GAP ANALYSIS PROGRAM
Arizona, Florida, Georgia, Illinois, Indiana, Iowa, Kansas, Kentucky,
Louisiana, Michigan, Minnesota, Nebraska, North Carolina, South Carolina,
South Dakota, Tennessee, Wisconsin
Consultation relative to alliance classification and GAP mapping
Connecticut, Delaware, Maine, Maryland, Massachusetts, New Hampshire,
New Jersey, New York, Pennsylvania, Rhode Island, Vermont, Virginia,
West Virginia
Regional classifications used by all states; ongoing GAP work
incorporating national classification in some states
Nationwide
Development of alliance descriptions for use by state GAP programs
U.S. FISH AND WILDLIFE SERVICE
East Gulf Coastal Plain savannas and flatwoods: Alabama, Florida,
Mississippi
Inventory for high-quality communities for conservation planning
Conterminous United States
Development of a list of rare imperiled types for protection
prioritization
STATE HERITAGE PROGRAMS AND CANADIAN CDCs*
State Natural Heritage programs: Alabama, Arkansas, California, Colorado,
Connecticut, Delaware, Florida, Georgia, Hawaii, Idaho, Illinois, Indiana,
Iowa, Kansas, Kentucky, Louisiana, Maine, Maryland, Massachusetts,
Michigan, Minnesota, Mississippi, Missouri, Montana, Nebraska, Nevada,
New Hampshire, New Jersey, New Mexico, New York, North Carolina,
North Dakota, Ohio, Oklahoma, Oregon, Pennsylvania, Rhode Island, South
Carolina, South Dakota, Tennessee, Texas, Utah, Vermont, Virginia,
Washington, West Virginia, Wisconsin, Wyoming
Various inventory and conservation planning work
CDCs: Alberta, British Columbia, Ontario, Saskatchewan
*Heritage Programs and CDCs are using the USNVC to various degrees. Many are using it in conjunction with state and other classifications.
THE NATURE CONSERVANCY
United States multistate surveys
34
Coastal Plain ponds: Maine, Massachusetts, Connecticut, New Jersey,
Maryland, Delaware
Inventory, data collection and prioritization for conservation action
Pine barrens: Maine, Massachusetts, Connecticut, New Jersey, Maryland,
Delaware
Inventory, data collection and prioritization for conservation action
Shale barrens: Pennsylvania, Maryland, Virginia, West Virginia
Inventory, data collection and prioritization for conservation action
Seeing the Forest and the Trees: Ecological Classification for Conservation
Location
Projected or Actual Use
THE NATURE CONSERVANCY (CONTINUED)
United States active Conservancy ecoregional plans
Central Appalachians, Central Shortgrass Prairie, Central Tallgrass Prairie,
Columbia Plateau, East Gulf Coastal Plain, Great Lakes, Interior Low
Plateau, Lower New England, Mid-Atlantic Coastal Plain, Mississippi River
Alluvial Plain, Mojave Desert, North Atlantic Coast, Northern Appalachians,
Northern Great Plains Steppe, Northern Tallgrass Prairie, Osage Plains/Flint
Hills, Puget Trough/Willamette Valley, Sonoran Desert, South Atlantic
Coastal Plain, Southern Blue Ridge, West Gulf Coastal Plain (Pineywoods),
Western Allegheny Plateau
Assessment of viable communities, conservation portfolio design,
conservation prioritization, GAP analysis of inventory needs
International
International Alvar Initiative: Michigan, New York, Ohio, Ontario,
Wisconsin.
Inventory, classification, ecological research, conservation planning
and stewardship
West Indies/Caribbean Islands
Various: rapid ecological assessment, development of classification,
conservation prioritization, inventory, mapping, park planning
Seeing the Forest and the Trees: Ecological Classification for Conservation
35
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Seeing the Forest and the Trees: Ecological Classification for Conservation
37
Natural Heritage Programs and Conservation Data Centers
in North America north of Mexico
Alabama Natural Heritage Program
Alaska Natural Heritage Program
Alberta Natural Heritage Information Centre
Arizona Heritage Data Management System
Arkansas Natural Heritage Program
Atlantic Canada Conservation Centre
British Columbia Conservation Data Centre
California Natural Heritage Division
Colorado Natural Heritage Program
Connecticut Natural Diversity Database
Delaware Natural Heritage Program
District of Columbia Natural Heritage
Program
Florida Natural Areas Inventory
Georgia Natural Heritage Program
Hawaii Natural Heritage Program
Idaho Conservation Data Center
Illinois Natural Heritage Division
Indiana Natural Heritage Data Center
Iowa Natural Areas Inventory
Kansas Natural Heritage Inventory
Kentucky Natural Heritage Program
Louisiana Natural Heritage Program
Maine Natural Areas Program and Maine
Department of Inland Fisheries and
Wildlife
Manitoba Conservation Data Centre
Maryland Heritage and Biodiversity
Conservation Programs
Massachusetts Natural Heritage and
Endangered Species Program
Michigan Natural Features Inventory
Minnesota Natural Heritage and Nongame
Research and Minnesota County
Biological Survey
Mississippi Natural Heritage Program
Missouri Natural Heritage Database
Montana Natural Heritage Program
Navajo Natural Heritage Program
Nebraska Natural Heritage Program
Nevada Natural Heritage Program
New Hampshire Natural Heritage Inventory
New Jersey Natural Heritage Program
New Mexico Natural Heritage Program
New York Natural Heritage Program
North Carolina Natural Heritage Program
Ohio Natural Heritage Data Base
Oklahoma Natural Heritage Inventory
Ontario Natural Heritage Information
Centre
Oregon Natural Heritage Program
Pennsylvania Natural Diversity InventoryCentral
Pennsylvania Natural Diversity InventoryEast
Pennsylvania Natural Diversity InventoryWest
Le Centre de Données sur le Patrimoine
Naturel du Québec
Rhode Island Natural Heritage Program
Saskatchewan Conservation Data Centre
South Carolina Heritage Trust
South Dakota Natural Heritage Data Base
Tennessee Division of Natural Heritage
Tennessee Valley Authority Regional Natural
Heritage
Texas Conservation Data Center
Utah Natural Heritage Program
Vermont Nongame and Natural Heritage
Program
Virginia Division of Natural Heritage
Washington Natural Heritage Program
West Virginia Natural Heritage Program
Wisconsin Natural Heritage Program
Wyoming Natural Diversity Database