To achieve this, GAP is the first state- and national-level effort to complete the following:
map existing natural vegetation to the level of dominant or co-dominant plant
species;
map predicted distribution of native vertebrate species;
map public land ownership and private conservation lands show the current
network of conservation lands;
compare distributions of any native vertebrate species, group of species,
or vegetation communities of interest with the network of conservation lands;
provide an objective basis of information for local, state, and national options
in managing biological resources.
Vegetation is mapped from satellite imagery and other records using the National
Vegetation Classification System (FGDC 1996). Native animal species ranges
are mapped by using museum and agency specimen collection records in conjunction
with known general ranges and the animal's affiliation with the previously
mapped vegetation types and other physical characteristics. These data are
combined and displayed with a computerized geographic information system (GIS)
at a cartographic scale of 1:100,000. Maps of vegetation types, individual
species, or selected suites of species (depending on one's interest) are overlain
on maps of land ownership and land management, showing where land-based conservation
efforts can be focused to achieve the conservation of selected elements of
biodiversity most efficiently, preventing both conservation crises and land-use
surprises.
The Gap Analysis Program is sponsored and coordinated by the Biological Resources Division of the U.S. Geological Survey. Additional support at the national level has been provided by the Department of Defense and the Environmental Protection Agency. The program has a close working relationship with the National Mapping Division of the U.S. Geological Survey and with The Nature Conservancy.
Mapping and analysis is conducted by GAP projects within each state. Additional analyses are conducted for large multi state regions in partnership with state governments, federal agencies and other cooperators. Presently, GAP is made up of over 445 contributing organizations in 44 states. Contributors include business, universities, state and federal agencies, tribes, and non government organizations.
Because GAP provides a standardized method and format, the data can be edge-matched with adjacent states as the state projects are completed. The importance of having data which is consistent across state boundaries is in revealing, for the first time, actual patterns of biodiversity at scales relevant to both the magnitude of present-day changes and the multiple levels of biological organization - from species and natural communities to large landscapes.
One result is the generation of large amounts of information on land cover and zoological geography, and the demand for these data from all sectors is strong. Initial digital products, which are already available for the eleven Western states, Arkansas, Connecticut, Massachusetts, and Rhode Island, are being used for many different purposes by businesses, county planners, state agencies, schools, research institutions, nonprofit organizations, and federal agencies.
These data are disseminated by the state projects and over the Internet World Wide Web as well as in professional journals. Publication and distribution of the data on read-only-memory compact disks (CD-ROMs) is being developed.