As part of its science strategy, the USGS is striving to develop and mainstream various aspects of ecosystem science. The new ecosystems strategy specifically identifies the development of "national ecosystem maps from a study of the connections between physiographic setting, climate, hydrologic regime, biogeochemistry, ecological processes and biotic interactions" as one of its key goals (USGS, 2007). This strategy also identifies the USGS as the global leader of a process to classify and subsequently map standardized, global ecosystems (USGS, 2007). Moreover, the ecosystems strategy is also closely linked to the Climate Variability and Change strategy as impacts to ecosystems have been identified as a priority focus of climate change studies.

In light of this new ecosystems emphasis, the Rocky Mountain Geographic Science Center (RMGSC) has become the technical lead for several ecosystems activities; establishment of a global methodology for the mapping of ecosystems, implementation of this methodology for both the contiguous United States and Africa, and implementation of a web-based ecosystem dissemination system. The results of these activities will produce standardized geospatial ecosystem models, enabling the use of ecosystem occurrences as the spatial unit of analysis for assessing climate change effects on ecosystems. Spatial data on ecosystem distributions will be useful for many applications, and will facilitate research collaborations on spatially explicit valuation of ecosystem goods and services.

Labeled Ecosystems for the conterminous United States

A standardized, global ecosystem mapping methodology was finalized in February of 2008. This method is based on the mapping and integration of fundamental ecosystem structural elements, specifically landforms, surficial, lithology, bioclimates, soil moisture, and associated land cover as a proxy for vegetation. This approach promotes ecosystems as unique physical environments and their associated biota, and is a modification of a prototype method to map standardized, continent-wide mapping of the ecosystems of South America (Sayre et al., in press, AAG).

The RMGSC completed the implementation of this methodology for the conterminous United States in November of 2008. The first step in this implementation effort was the development/acquisition of all of the required data layers (landforms, lithology, isobioclimates, soil moisture index, etc.). Following the completion of these base layers, each was spatially combined based on the established methodology in order to produce a map of ecosystem structure units, or ecosystem footprints, which were then aggregated and labeled using the Nature Serve Ecological Systems of North America Classification (Comer et al., 2003). The process for applying these labels was developed by Patrick Comer of NatureServe, and is based on the development of "lookup" tables and rulesets linking each unique combination of ecosystem geophysical attribution to the appropriate label. The final labeled ecosystems product and each of the base data layers (landforms, surficial lithology, and isobioclimates) are now available for use by resource management and a variety of research and modeling applications like climate change assessments, ecosystems services quantification and valuation, forecasting future ecosystem condition, etc.

The final global mapping activity for the RMGSC is implementation of the global mapping methodology in Africa. But although the ecosystems effort for Africa is based on the same method used to delineate ecosystem footprints for the conterminous United States, data with a slightly coarser spatial resolution, or from different data sources, will be used. For instance, although the source elevation data for use in Africa will also be 30-meter, it's based on reflective surface information instead of bare-earth and was therefore generalized to 90-meters in order to minimize canopy issues. Completion of the Africa ecosystems activity is currently scheduled for winter of 2009.

Global Ecosystems Project

Featured in the May '07 copy of

Abstract

NORM ED Data