Citation:

Bradford, D F. AND W G. Kepner. AN APPROACH FOR DETERMINING REGIONAL LAND COVER AND SPECIES HABITAT DISTRIBUTIONS IN THE AMERICAN SOUTHWEST: THE SOUTHWEST REGIONAL GAP ANALYSIS PROJECT. Presented at Mojave Desert Science Symposium, Redlands, CA, November 16-18, 2004.

Impact/Purpose:

The primary objectives of this research are to:

Develop methodologies so that landscape indicator values generated from different sensors on different dates (but in the same areas) are comparable; differences in metric values result from landscape changes and not differences in the sensors;

Quantify relationships between landscape metrics generated from wall-to-wall spatial data and (1) specific parameters related to water resource conditions in different environmental settings across the US, including but not limited to nutrients, sediment, and benthic communities, and (2) multi-species habitat suitability;

Develop and validate multivariate models based on quantification studies;

Develop GIS/model assessment protocols and tools to characterize risk of nutrient and sediment TMDL exceedence;

Complete an initial draft (potentially web based) of a national landscape condition assessment.

This research directly supports long-term goals established in ORDs multiyear plans related to GPRA Goal 2 (Water) and GPRA Goal 4 (Healthy Communities and Ecosystems), although funding for this task comes from Goal 4. Relative to the GRPA Goal 2 multiyear plan, this research is intended to "provide tools to assess and diagnose impairment in aquatic systems and the sources of associated stressors." Relative to the Goal 4 Multiyear Plan this research is intended to (1) provide states and tribes with an ability to assess the condition of waterbodies in a scientifically defensible and representative way, while allowing for aggregation and assessment of trends at multiple scales, (2) assist Federal, State and Local managers in diagnosing the probable cause and forecasting future conditions in a scientifically defensible manner to protect and restore ecosystems, and (3) provide Federal, State and Local managers with a scientifically defensible way to assess current and future ecological conditions, and probable causes of impairments, and a way to evaluate alternative future management scenarios.

Description:

The Southwest Regional Gap Analysis Project (SWReGAP) is developing seamless digital coverages for land cover, vertebrate animal habitat, and land management status for the 5-state region of Nevada, Arizona, Utah, New Mexico, and Colorado. The project is a second generation effort of the state-based Gap Analysis Program that maps the distribution of plant communities and selected animal species and compares these distributions with land stewardship to identify biotic elements at potential risk of endangerment. SWReGAP is one of the largest and most complex digital mapping efforts in the world. Land cover is modeled using classification trees based on data from remote sensing (Landsat 7 Enhanced Thematic Mapper, 3 seasons, 1.999-2001), biophysical models using elevation-derived layer, and field sampling at 92,170 sites. The 125 mapped land cover types are defined as Ecological Systems, a scheme applicable across North America developed and updated by NatureServe. Distributions of habitat for 833 vertebrate species are modeled using available digital data sets (e.g., land cover, elevation, hydrologic features, land form, and soil characteristics), based on associations with vegetation and other habitat variables derived from literature. Limitations in use of the data, and challenges in the "scale-up" of vertebrate models, will be noted with examples. The provisional land cover data set is currently available (http://earth.gis. usu.edu/swgap), and the data sets for vertebrate habitat distribution and land stewardship are near completion.

Record Details: