22.3 General Applications of Ecological Land Classifications in Ecological Assessments
325
7 and 13), and the spatial scale of the area under
consideration.
ELCs are often used to define the spatial scales
and boundaries of seven types of areas that are associated with different activities in an EA: assessment, characterization, analysis, and cumulative
impact areas; and reporting, basic characterization,
and integrated response units.
1. The assessment area is the area under consideration for a specific EA. Although the assessment
area is usually defined by sociopolitical concerns and issues, all or part of its boundary may
be adjusted to reflect ecological boundaries.
2. The characterization area includes the ecological boundaries of the major ecosystem and socioeconomic components of interest in an EA.
The spatial analysis of these components (see
Chapter 13) is conducted in the characterization
area, which is often much larger than the assessment area.
3. The analysis area defines the area in which
analyses are conducted and management recommendations directly influence the patterns
and processes of interest.
4. In the cumulative impact area, the effects of
management decisions are assessed.
5. Reporting units are constructed to facilitate the
reporting of results from different components
of an assessment (e.g., terrestrial, aquatic, and
socioeconomic). Reporting units are important
in very large assessment areas, because they are
the means by which the results of analyses conducted at different spatial scales are communicated to the general public, stakeholders, and decisionmakers.
6. The basic characterization unit defines the grain
of the assessment.
7. Integrated response units are generated using
basic ELU maps at all relevant scales, in conjunction with similarly scaled maps of the complementary biophysical, biotic, and socioeconomic themes that are appropriate for the type
of resource interpretation under consideration,
but were not included in the ELC.
The first five types of areas are the basis for creating regional and local planning and management
frameworks (Slocombe, 1993a, 1993b). In a few
cases, some scales of conservation, political concern, management actions, and ecological responses may be congruent and comparable, and
therefore some of the types of areas may have the
same boundaries. For example, for the Interior Columbia Basin Ecosystem Management Project
(lCBEMP) (Figure 22.2), the assessment area was
defined by an analysis of biophysical, ecological,
and administrative maps in light of political directives to develop an ecosystem management strategy for forests east of the Cascade crest in the U.S.
Pacific Northwest (Quigley and Arbelbide, 1997).
Based on specific objectives, a larger characterization area was delineated that encompassed the distributions of the patterns and processes of interest
(Quigley and Arbelbide, 1997). Subbasins (4thfield hydrologic unit codes) were used as the units
for many biophysical and aquatic analyses (Jensen
et aI., 1997). Thirteen reporting units (Jensen et aI.,
1997) were defined for reporting the effects of land
management activities by the landscape ecology,
terrestrial, aquatic, and socioeconomic science
groups. Subwatersheds (6th-field hydrologic unit
codes) (Jensen et aI., 1997) comprised the basic
characterization units for many ICBEMP studies
(soil erosion, stream recovery potential, fine-scale
vegetation patterns, and fish distributions) (Hann et
aI., 1997; Jensen et aI., 1997; Lee et aI., 1997). For
a conservation assessment in the interior Columbia
River basin (lCRB), over l7,000 land units, representing 689 classes of integrated response units,
were delineated using ELUs defined with direct
(climate, biogeochemical) variables stratified by
PV types (see Chapter 20).
The ecosystem properties that need to be defined
may differ among EAs, but generally include those
that are required to predict the effects of land management, economic development, global or landuse change (O'Callaghan, 1996), or any other factor of interest in a specific EA and region. They
may include hydrological, biogeochemical, ecological, and socioeconomic characteristics (see
Chapters 9 and 16). The properties are usually derived from the multi scaled data analyses that produced the ELUs or ELU-derived units (Urban et
aI., 1987; Bourgeron and Jensen, 1994; Bourgeron
et aI., 1994; Jensen et aI., 1997; also see Chapters
2 and 3). ELU or ELU-derived maps provide a basic template for interpreting the spatial and the temporal variability of a landscape, that is, its dynamics (see Chapters 13, 23, 24, 26, 28, and 29). For
example, predicting the response of a vegetation
type to disturbance is facilitated by identifying the
ELUs in which it occurs (e.g., Arno et aI., 1986;
Host and Pastor, 1998).
ELUs are also used as environmental strata to
characterize the range of variability in which an
ecosystem historically operated. Knowledge of
how far an ecosystem departs from HRV at multiple scales is useful in EAs (Morgan et aI., 1994;
Landres et aI., 1999; Swetnam et aI., 1999; also see
325
7 and 13), and the spatial scale of the area under
consideration.
ELCs are often used to define the spatial scales
and boundaries of seven types of areas that are associated with different activities in an EA: assessment, characterization, analysis, and cumulative
impact areas; and reporting, basic characterization,
and integrated response units.
1. The assessment area is the area under consideration for a specific EA. Although the assessment
area is usually defined by sociopolitical concerns and issues, all or part of its boundary may
be adjusted to reflect ecological boundaries.
2. The characterization area includes the ecological boundaries of the major ecosystem and socioeconomic components of interest in an EA.
The spatial analysis of these components (see
Chapter 13) is conducted in the characterization
area, which is often much larger than the assessment area.
3. The analysis area defines the area in which
analyses are conducted and management recommendations directly influence the patterns
and processes of interest.
4. In the cumulative impact area, the effects of
management decisions are assessed.
5. Reporting units are constructed to facilitate the
reporting of results from different components
of an assessment (e.g., terrestrial, aquatic, and
socioeconomic). Reporting units are important
in very large assessment areas, because they are
the means by which the results of analyses conducted at different spatial scales are communicated to the general public, stakeholders, and decisionmakers.
6. The basic characterization unit defines the grain
of the assessment.
7. Integrated response units are generated using
basic ELU maps at all relevant scales, in conjunction with similarly scaled maps of the complementary biophysical, biotic, and socioeconomic themes that are appropriate for the type
of resource interpretation under consideration,
but were not included in the ELC.
The first five types of areas are the basis for creating regional and local planning and management
frameworks (Slocombe, 1993a, 1993b). In a few
cases, some scales of conservation, political concern, management actions, and ecological responses may be congruent and comparable, and
therefore some of the types of areas may have the
same boundaries. For example, for the Interior Columbia Basin Ecosystem Management Project
(lCBEMP) (Figure 22.2), the assessment area was
defined by an analysis of biophysical, ecological,
and administrative maps in light of political directives to develop an ecosystem management strategy for forests east of the Cascade crest in the U.S.
Pacific Northwest (Quigley and Arbelbide, 1997).
Based on specific objectives, a larger characterization area was delineated that encompassed the distributions of the patterns and processes of interest
(Quigley and Arbelbide, 1997). Subbasins (4thfield hydrologic unit codes) were used as the units
for many biophysical and aquatic analyses (Jensen
et aI., 1997). Thirteen reporting units (Jensen et aI.,
1997) were defined for reporting the effects of land
management activities by the landscape ecology,
terrestrial, aquatic, and socioeconomic science
groups. Subwatersheds (6th-field hydrologic unit
codes) (Jensen et aI., 1997) comprised the basic
characterization units for many ICBEMP studies
(soil erosion, stream recovery potential, fine-scale
vegetation patterns, and fish distributions) (Hann et
aI., 1997; Jensen et aI., 1997; Lee et aI., 1997). For
a conservation assessment in the interior Columbia
River basin (lCRB), over l7,000 land units, representing 689 classes of integrated response units,
were delineated using ELUs defined with direct
(climate, biogeochemical) variables stratified by
PV types (see Chapter 20).
The ecosystem properties that need to be defined
may differ among EAs, but generally include those
that are required to predict the effects of land management, economic development, global or landuse change (O'Callaghan, 1996), or any other factor of interest in a specific EA and region. They
may include hydrological, biogeochemical, ecological, and socioeconomic characteristics (see
Chapters 9 and 16). The properties are usually derived from the multi scaled data analyses that produced the ELUs or ELU-derived units (Urban et
aI., 1987; Bourgeron and Jensen, 1994; Bourgeron
et aI., 1994; Jensen et aI., 1997; also see Chapters
2 and 3). ELU or ELU-derived maps provide a basic template for interpreting the spatial and the temporal variability of a landscape, that is, its dynamics (see Chapters 13, 23, 24, 26, 28, and 29). For
example, predicting the response of a vegetation
type to disturbance is facilitated by identifying the
ELUs in which it occurs (e.g., Arno et aI., 1986;
Host and Pastor, 1998).
ELUs are also used as environmental strata to
characterize the range of variability in which an
ecosystem historically operated. Knowledge of
how far an ecosystem departs from HRV at multiple scales is useful in EAs (Morgan et aI., 1994;
Landres et aI., 1999; Swetnam et aI., 1999; also see