Gap Analysis. Introduction

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1 Gap Analysis Version: Date: 16 February 2000 Peer-reviewed: No Patrick Crist Idaho Cooperative Fish and Wildlife Research Unit Moscow, ID as adapted from Handbook version 1 by Blair Csuti Idaho Cooperative Fish and Wildlife Research Unit Moscow, ID Appendix 1 - Distribution of Wolverine in Wyoming (courtesy WY-GAP) Introduction The term and concept of gap analysis was defined in the Preface to this handbook, but briefly, a "gap" is the lack of representation or inadequate representation of a biotic element (plant community or animal species mapped by GAP) in areas managed primarily for natural values. Identification of a gap indicates potential risk of extinction or extirpation unless changes are made by land stewards in the management status of the element. Biodiversity has always been a product of a changing environment, subsequent evolution, and natural extinction events. The need to identify potential gaps stems not so much from the natural pace of evolution and extinction, but rather from recent and accelerating effects of human-caused changes to the natural environment that threaten biodiversity. Noss and Cooperrider (1994) identified four categories of human influences on biodiversity: direct exploitation, indirect exploitation, disturbance, and indirect disturbance such as global warming. Of these, indirect exploitation and disturbance are the primary causes of the alteration of habitat type and structure which are probably the most prevalent, largely irreversible, and controllable of human influences (Bingham and Noon 1997, Noss and Cooperrider 1994). The likely presence or potential for these influences are identified and categorized by GAP into four levels of management status to maintain biodiversity (see Stewardship chapter). Therefore the purpose for conducting gap analysis is to identify gaps that have great potential for mitigation by land stewards and decision-makers. Another substantial contribution of gap analysis is the provision of regional or range-wide analysis of an element s representation that can allow stewards to assess their role and responsibility in the greater context for those elements occurring on their lands. In other words, rather than basing stewardship decisions only on local, observable conditions, stewards can

2 take into account an element s status over a larger geographic region (their state or ecoregion) or throughout an element s mapped range. Objectives To determine the representation of each mapped element (land cover types and animal species as identified in the land cover and animal modeling chapters) in different categories of land stewardship (management authority) and management status. To interpret the results from Objective 1 in a way that is useful for land stewards in their development of land use and management plans that conserve or restore those biotic elements or avoid causing further impairment. To provide the analysis and data sets in suitable form for additional modeling, analyses, biodiversity assessment, and planning activities by a broad group of users. Background There have been a variety of analyses proposed for and by GAP to aid in the identification of both elements at risk and geographic areas that can be managed to reduce those risks. As experience and science progress, the proposed analyses have changed to reflect current knowledge and capabilities. This revised version of the original chapter focuses on the basic Gap Analysis Program requirements, which call only for identification of those biotic elements with potential gaps (see GAP standard final report). It is worthwhile, however, to briefly review some of the previous recommendations and objectives. The identification of "species-rich areas" as an additional filter was described in Scott et al. (1993) and became widely associated with GAP as focusing on "species-rich hot spots". Since then, however, studies show that the species-rich areas of major taxa do not co-occur (Prendergast, 1993, Lawton et al. 1994). This emphasis has been replaced with the goal of identifying complementary sets of geographic units that could represent all (mapped) elements, rather than "hot spots" that would always leave out some elements (Williams 1996). Complementarity analysis is, however, still in the research mode and will therefore be addressed in the Applications chapter (forthcoming). GAP still requires the production of species richness maps for comparative value (see Final Report chapter), however, there is no required analysis at this time, and the subject, therefore, is not covered in this chapter (however see the NM-GAP final report, Thompson, et al. 1996). The ultimate purpose of the application of GAP information by data users is to identify specific geographic locations that can "plug" the gaps through changes in management practices, planning, policy, or stewardship status (Scott et al. 1993). The identification of such geographic locations, however, is relevant to the process of reserve selection which is a complex issue and is described in the Applications chapter (forthcoming). Many researchers, planners, and managers are beginning to use GAP for conservation planning (Scott and Csuti, 1997) and as the science and techniques evolve, they will be incorporated into future revisions of this chapter when adopted as a GAP standard, or the Applications chapter (forthcoming) when provided as a recommended use of the data. Methods Summary of steps and standards Step 1: Prepare the land cover, animal distribution, and stewardship coverages for final analysis according to the respective chapters standards. Step 2: Intersect the land cover and animal distribution (element) coverages with the stewardship coverage so that the element coverages incorporate the stewardship boundaries and attributes.

3 Step 3: Using statistics from the above intersections, generate a table reporting representation of individual elements in each stewardship and management category. Step 4: Prepare additional analyses as applicable from the list in the standard final report. Step 5: Incorporate the results into the standard final report and generate example maps for elements of note or state interest. The following narrative provides details for each step in the process: Step 1: Prepare the land cover, animal distribution, and stewardship coverages for final analysis according to those chapters standards. It is imperative that all coverages are considered to be the final deliverable versions prior to beginning the analyses. If correctable errors are detected during or after analysis, the analysis must be either be run again so that the results apply to those delivered coverages or, if the error was not actually corrected, it should be identified in the metadata and report. Step 2: Intersect the land cover and animal distribution (element) coverages with the stewardship coverage so that the element coverages incorporate the stewardship boundaries and attributes. This intersection will subdivide the element distributions by the stewardship boundaries and apply the stewardship attributes to each segment. The resulting attribute table will allow the calculation of percent of total element distribution by ownership and management categories and support numerous other analyses. Step 3: Using statistics from the above intersections, generate a table reporting representation of individual elements in each ownership and management category as described in detail later in this chapter. The representation of elements by stewardship categories should be reported per Table 1 (one for land cover and one for animal species). The table for mapped animals should be organized by taxonomic group. Note that text is added for explanation in producing the table, you may alter the text within the table to that needed for the reader. Table 1 Suggested caption: This table provides the gap analysis results for each natural/semi-natural land cover type.the first column under each major land steward is the area of distribution in square kilometers (multiply by247 for acres) by GAP management status. The second column is the percent representation (area in columndivided by total state distribution). Statewide totals are included along with measured map accuracy of theelement. This table may be used to identify important land stewards for each element, their relativeresponsibility for management as a function of area and their current intent to manage for the element as afunction of distribution by GAP management status. Projects: Please include all important stewards plus private land and a "misc." category if needed so totalsums to the total mapped area of the element. Use GAP standard fonts (see report instructions) and min 10pt font size. The use of a calculation template in a spreadsheet or database program will make it simple togenerate percentages and totals. IA8Nc3 Picea Glauca Forest Alliance: Fuzzy set level 5 Accuracy 73% State Misc USFS BLM NPS Tribal DNR Public Private Total Status Status Status Status Total

4 The above table should appear as an appendix because of its length, but the standard final report asks for lists of species with 0-<1%, 1-<10%, 10-<20%, and 20-<50% of their distribution in management status 1 or 2 within the body of the report. A workshop convened in fall 1995 concluded that, without better methods for establishing adequate levels of conservation representation, these arbitrary levels, which have been published in the literature, will allow the data user to judge which species may be at risk depending on the criterion applied. (Noss and Cooperrider 1994, Noss 1991, Odum 1972, Specht, Roe, and Boughlon 1974, Ride 1975, Miller 1994). This information can also be easily extracted from a query of the intersection table. For example, for element X, sum the area of its distribution in status 1 and 2 and divide by the total area for element X. Select for elements with resulting value <0.1, <0.2, and <0.5 and report per Table 2. Also, in that table, provide the status ranks according to federal, state, and The Nature Conservancy (TNC) systems. Narratives that explain or hypothesize about the results for select elements are important to give meaning to the raw numbers. There is currently no standard for which elements should have narratives or what the narratives should contain, but see the WY-GAP final report (Merrill et al. 1996) for an excellent example. We expect to provide more specific guidelines on this as the collective experience of GAP expands and our cooperators indicate what information is of most use to them. Table 2. Elements with less than 0-<1, 1-<10%, 10-<20%, and 20-<50% representation in GAP management status 1 and 2 and their status according to federal and state governments and The Nature Conservancy (TNC) as of the date of analysis. Element code Element name Federal Status State Status TNC Status accuracy < 1% < 10% < 20% < 50% IA8Nc3 Picea glauca Forest Alliance 73% 13.3% Step 4: Prepare additional analyses as applicable from the list in the standard final report. Report the results per Table 1. As of this writing, the optional analyses include: Analysis of Important Statewide Species Assemblages. For example, if migratory waterfowl are of special state interest, report the analysis results for the group. Analysis of Statewide Endemics. Special Features Analysis. For example, riparian vegetation as a group can be analyzed. Ecoregional Analyses. GAP encourages results to be reported by Bailey s 1995 Provinces or Sections, especially if such a unit s sole U.S. representation lies wholly within the study area. If available, the multiagency ECOMAP (McNab and Avers, 1994) subsection boundaries should be used to develop the ecoregion boundary. Analysis shall be reported the same as described in step 3, but will identify the ecoregion as the area of analysis. The statistics necessary for these analyses should be readily extractable from the attribute table resulting from Step 3. The Ecoregional Analyses will require the additional intersection of the ecoregion boundaries to segment element distributions and stewardship information by those units. Step 5: Incorporate the results into the standard final report and generate example maps for elements of note or state interest. The above tables and lists are the required items for the report, but example maps showing the element s distribution colored (or patterned) by management status and ownership categories are useful graphics (See Appendix 1), Maps of elements can be selected for scientific interest, such as species believed either to be especially at risk, or not at risk and shown otherwise by the gap analyses, or species generally of interest in the state. Refer to the standard final

5 report template for resolution of inconsistencies with this document and for formatting requirements, with the final report template taking precedence. Limitations The limitations, described in the Gap Analysis Program Description (see the GAP home page) and the chapters for land cover, animal modeling, and stewardship, should be consulted in addition to the following: There is no accuracy assessment of the analyses results. Measures of mapped accuracy for element distributions is provided only as a guide for the general reliability of the results. Further research is needed on how to interpret the analysis results for a particular element relative to the mapped accuracy. In some cases, the conservation status of an element may be either better or worse than reported, depending on the nature of the mapping error (see Animal Modeling, and Land Cover Assessment chapters). It is for this reason we state that no on-the-ground actions should be taken based solely on these analyses, and that ground-based surveys should be conducted prior to taking a specific management action. Because historic distribution of an element is usually unknown, the measure of percent of total distribution in high stewardship status may not account for a large loss in its historic range (see Noss et al. 1995). In other words, if an element has already been reduced by 90% from its historic distribution, and gap analysis indicates 50% occurrence in status 1 or 2 areas, the result is that only 5% of its historic distribution is represented in conservation lands. GAP currently does not predict element viability. For most species and plant communities, viability measures - such as habitat quality and species abundance - and population trends are unknown and cannot be assessed given current knowledge (Boyce, 1992 and Shaffer, 1994). Therefore, GAP only provides information on representation, with the objective of highlighting at-risk species. Generally, analysis of animal species must be used with more caution than analysis of land cover types for various reasons, including: a) land cover maps are actual, typically with a statistically valid accuracy assessment, while animal distributions are predicted and difficult to validate; b) land cover types are stationary and change relatively slowly, while animal species are mobile and expand and contract geographically over relatively short time spans; and c) effects of management status on land cover types are generally easier to predict than on animal species. Continuing Research To date, GAP has devoted substantial effort to the science of producing the element maps, but has only recently had sufficient data to devote more effort to the analysis phase. Concurrently, the objectives for the analysis, and thus the techniques needed, have changed. Continuing research for developing more resolved and accurate element distribution maps will always be required to increase confidence in the analysis results, but specific research needed for analysis includes: Providing interpretations of the reported map accuracy for an element relative to its management status. Providing better stewardship information to allow analysis that includes better measures of risk for individual elements. For example, some species will thrive in status 3 areas while others may perish in status 2 areas. Incorporating a time factor that can account for current management status relative to risk. For example, elements may occur in status 4 land that is currently well managed and not foreseeably threatened with habitat conversion. This information could help focus priorities on species that are more imminently threatened. Some initial work in this area was conducted by CA-GAP (Davis and Stoms 1996).

6 Developing maps of historic range or distribution to better assess the amount of historic loss or gain in an element s distribution relative to GAP status. For current research being funded by GAP and its cooperators, see the Research section of the home page. Literature Cited Bailey, R.G Description of the ecoregions of the United States. 2nd ed. Rev. and expanded (1st ed. 1980). Misc. Publ. No (rev.), Washington, DC: USDA Forest Service. 108 p. With separate map at 1:7,500,000. Bingham, B.B., and B.R. Noon Mitigation of Habitat "Take": Application to Habitat Conservation Planning. Conservation Biology, pg , v. 11 n. 1. Boyce, M. S Population viability analysis. Annual Review of Ecology and Systematics 23: Davis, F.W. and D.M. Stoms Sierran Vegetation: A Gap Analysis. Sierra Nevada Ecosystem Project: Final Report to Congress, v II. Assessments and Scientific Basis for Management Options. Davis, University of California, Centers for Water and Wildland Resources pg McNab, W.H. and P.E. Avers Ecological subregions of the United States: Section Descriptions. Administrative Publication WO-WSA-5. Washington, D.C.: U.S. Dept of Agriculture, Forest Service. Merrill et al The Wyoming Gap Analysis Project Final Report. Wyoming Cooperative Fish and Wildlife Research Unit, University of Wyoming, Laramie, WY. Miller, K.R In J.A. McNeely and K.R. Miller, editors. National parks conservation and development. Smithsonian Institution, Washington, D.C. Noss, R.F Report to the Fund for Animals in Washington, D.C. Noss, R.F., and A.Y. Cooperrider Saving nature s legacy. Island Press, Washington, D.C. Noss, R.F., E.T. LaRoe, and J.M. Scott Endangered Ecosystems of the United States: A Preliminary Assessment of Loss and Degradation. U.S. Department of the Interior, National Biological Service. Washington, D.C. Odum, E.D., and H.T. Odum Proceedings of the North American Wildlife and Natural Resources Conference 39:178. Prendergast, J.R., R.M. Quinn, J.H. Lawton, B.C. Eversham, and D.W. Gibbons Rare species, the coincidence of diversity hotspots and conservation strategies. Nature 365: Ride, W.L.D In F. Fenner, editor. A national system of ecological reserves in Australia. 64 p. Scott, J.M., F. Davis, B. Csuti, R. Noss, B. Butterfield, C. Groves, H. Anderson, S. Caicco, F. D'Erchia, T.C. Edwards, Jr., J. Ulliman, and R.G. Wright Gap Analysis: A geographic approach to protection of biological diversity. Wildlife Monographs 123. Scott, J. M., and B. Csuti Gap Analysis for biodiversity survey and maintenance. Pages in M. L. Reaka-Kudla, D. E. Wilson, and E. O. Wilson, editors. BioDiversity II: Understanding and protecting our biological resources. Joseph Henry Press, Washington, D.C. Shaffer, M. L Population viability analysis: determining nature's share. Pages in Principles of Conservation Biology (Gary K. Meffe and C. Ronald Carroll, editors). Sinauer Associates,

7 Inc., Sunderland, Massachusetts. Specht, R.L., E.M. Roe, and V.H. Boughlon Australian Journal of Botany Supplement Series. Supplement No. 7. Thompson, B.C., P.J. Crist, J.S. Prior-Magee, R.A. Deitner, D.L. Garber, and M.A. Hughes Gap Analysis of Biological Diversity Conservation in New Mexico Using Geographic Information Systems. New Mexico Cooperative Fish and Wildlife Research Unit. New Mexico State University, Las Cruces, NM. Williams, P., D. Gibbons, C. Margules, A. Rebelo, C. Humphries, and R. Pressey A comparison of richness hotspots, rarity hotspots and complementary areas for conserving diversity using British birds. Conservation Biology 10: