Primary purpose
To provide a framework for making comparisons between landscape subunits (e.g., watersheds, ecoregions, or counties) so that impacts to wetlands can be considered in management decisions. Designed to assist wetland regulators, but current applications are directed at more general uses such as watershed planning and prioritizing areas for restoration or protection.
Expertise needed
A team of individuals including a resource manager, resource specialist (e.g., permit reviewer), and technical analyst.
Applicable habitat types
All wetland types in the United States.
Categories assessed
Four aspects of wetland ecosystems can be assessed: function (habitat, water quality, and hydrologic); value; functional loss; and replacement potential. The specific titles will vary depending upon the objectives and intended use of the assessment.
Procedure
A manager defines the goals of the assessment and criteria (step 1) including the required level of accuracy. A resource specialist defines a specific set of synoptic indices (step 2) that will meet the objectives and intended use of the assessment. The four general indices (function, value, functional loss, and replacement potential) are replaced with a set of indices specific to the objectives. Landscape indicators are selected (step 3) and used to estimate the synoptic indices. The resource specialist and technical analyst explicitly identify the underlying assumptions for the use of each indicator. The technical analyst conducts the assessment (step 4) by gathering appropriate data sources, calculating the synoptic indices, ranking index values, and displaying results on synoptic maps. Finally, reports are prepared on how the information was derived and how it can be used (step 5).
Key Terminology
Capacity: maximum amount of a particular material that an ecosystem can remove from the active pool were the material not limiting; also referred to as "assimilative capacity".
Function: a synoptic index; refers to the total amount of some function provided by one or more ecosystems within a landscape without consideration of benefits. Capacity and input are components of function.
Functional loss: a synoptic index; refers to the complete or partial loss of one or more ecological functions as a result of impacts.
Input: the total amount of material imported into sink ecosystems from one or more sources.
Landscape indicator: the actual data or measurements used to estimate a synoptic index (e.g., area of hydric soils may be used to estimate historic wetland area).
Landscape subunit: the basic subdivision of a landscape for which synoptic indices are calculated. Landscape subunits could be defined environmentally (e.g., watersheds or ecoregions), politically (e.g., counties or conservation districts), or by other criteria.
Replacement potential: a synoptic index; refers to the degree to which a wetland and its valued functions can be replaced by creation or restoration. Specifically refers to the landscape characteristics as opposed to on-site characteristics that control replacement.
Synoptic index: a landscape variable that is used in a synoptic assessment as a basis for comparing landscape subunits. There are four general synoptic indices (function, value, functional loss, and replacement potential); in an actual assessment, a specific index would be defined for one or more of the general indices.
Value: a synoptic index: refers to the benefits obtained by individuals or society from an ecological function. Could include benefits received indirectly, i.e., when the function acts on something of value (e.g., flood reduction is valuable because it reduces loss of life and loss of valued property).
Contact person
Scott Leibowitz, U.S. Environmental Protection Agency, 200 SW 35th Street, Corvallis, OR 97333 phone: (541) 754-4508; fax: (541) 754-4716; e-mail: leibo@mail.cor.epa.gov
Output
Measures of function, value, functional loss, and/or replacement potential of a landscape subunit within a defined geographic area (e.g., watershed within a state).
Estimated time to assess 1 acre site
Total 1040-4160 hours for a geographic area (e.g., river basin).
1040-4160 hours [months of work]: Define goals and criteria (step 1), define synoptic indices (step 2), and select landscape indicators (step 3).
Comparison of habitat types
Cannot directly compare individual wetland areas. Could enable direct comparison of landscape subunits within a geographic area (e.g., watersheds within a state).
Use as guide to design
The Synoptic Approach should not be used as a guide to design, but can be useful in guiding site selection. As a landscape-level procedure, the Synoptic Approach does not include elements important to design at the site-specific level. However, some of the synoptic indices (e.g., replacement potential index) and data may be useful for identifying suitable areas for restoration/creation. For example, the replacement potential index will indicate the degree to which a wetland and its functions can be replaced due to conditions in the surrounding landscape.
Related procedures
None.
Extent of use/field testing
The Synoptic Approach has been applied in several areas including: four watersheds in Pennsylvania (Brooks et al. 1995); Oregon (Dagget 1994); Tensas River basin in Louisiana (Rainer et al. 1994); Illinois and Nebraska (see Abbruzzese and Leibowitz 1997); and the prairie pothole region (EPA 1998 in review). Most applications of the Synoptic Approach have been for research and development purposes, and only include hypothetical applications. The Arkansas application was designed to support prioritization of wetland restoration projects. The EPA Region 7 (Missouri, Iowa, Nebraska, and Arkansas) application was to support wetland protection efforts. The Synoptic Approach has been used three times over the last two years.
Proposed future revisions
EPA is preparing a manuscript on an assessment of the prairie pothole analysis which should be submitted for publication in 1998. This manuscript incorporates the following modifications and improvements to the Synoptic Approach: simplification of the terminology; use of a benefit: cost ratio to formulate the synoptic index; use of conceptual source/sink/transport models to link the relevant landscape processes to the specific management objective, and to guide indicator selection; inclusion of concept/indicator diagrams that explicitly map the relationship between indicators, intermediate concepts, and endpoints; and use of sensitivity analysis to investigate effects of uncertainty. The prairie pothole and EPA Region 7 applications include the improvements (Personal communication; Scott Leibowitz; USEPA; June 12 1998).
Key References
Leibowitz, S.G., B. Abbruzzese, P.R Adamus, L.E. Hughes, and J.T. Irish. 1992. A Synoptic Approach to Cumulative Impact Assessment: A Proposed Methodology. EPA/600/R-92/167. U.S. EPA, Environmental Research Laboratory, Corvallis, OR. 129 pp.
Abbruzzese, B., and S.G. Leibowitz. 1997. A synoptic approach for assessing cumulative impacts to wetlands. Environmental Management 21(3):457-475.
Additional references
Brooks, R.B., C.A. Cole, L. Bishel, F.H. Wardrop, D.J. Prosser, D.E. Arnold, and G.W. Peterson. 1995. Evaluating and Implementing Watershed Approaches for Protecting Pennsylvania’s Wetlands: Volume I. Environmental Resources Research Institute Report No. ER9506. Pennsylvania State University, University Park, Pennsylvania, 64 pp.
Dagget, S. 1994. Stage 1 Watershed Assessment: Final report. Oregon Division of State Lands, Salem, Oregon, 52 pp.
Rainer, M., J. Conti, B. Yantis, and G. Townsley. 1994. Selecting Sites for Wetland Restoration in the Tensas River Basin, Louisiana: A Case Study of Landscape Analysis Using the Synoptic Assessment Methodology. US Department of Agriculture, Soil Conservation Service, Water Resources Planning Staff, Alexandria, Louisiana, 88 pp.