Terrestrial Ecosystems were mapped by delineating physically distinct areas as the fundamental structural units and subsequently labeling these into the appropriate ecosystem classification. Structural units were developed from the union of source layers including those listed below.
Metadata:
United States,
South America
Topograhic Moisture Potential was derived for the United States and Africa to help contribute substrate moisture regimes and was based on the derivation of ground moisture potential using a combination of computed topographic characteristics and mapped inland water body boundaries.
Metadata:
United States,
Africa
Land Surface Forms for the United States and Africa were generated based on the methodology developed by the Missouri Resource Assessment Partnership (MoRAP) that made modifications to Hammond's land surface form classification.
Metadata:
United States,
Africa,
South America
Surficial Materials Lithology was derived from the appropriate existing geology and/or surficial materials data for each country. This existing data was generalized and reclassified as needed in order to dervive the set of lithologies that typically control or influence the distribution of vegetation types.
Metadata:
United States,
Africa,
South America
Isobioclimates were generated for the United States and Africa by combining the thermotypes (warm/cold) and ombrotype (dry/wet gradients) climate classes produced from the Rivas-Martínez method based on the concept of a quantifiable classification system which would closely relate the distribution of vegetation to climatic parameters and indices.
Metadata:
United States,
Africa,
South America
More detailed information about the creation of each of these layers for a specific country is available on the appropriate "Project Areas" page.
Raster Lookup Tables:
United States,
Africa,
South America
U.S. Department of the Interior |
U.S. Geological Survey