What is Gap Analysis? Gap Analysis is a broad-scale conservation
evaluation method that uses GIS technology to assess the status
of biodiversity. Three primary data layers are combined in an
overlay analysis to identify "gaps" in biodiversity A data layer
of vertebrate distributions is refined into detailed maps of
predicted species occurrence by using habitat models to extract
areas of suitable habitat from a land cover map. This land cover
map constitutes the second data layer, and generally consists of
vegetation types and other cover types delineated from Thematic
Mapper satellite imagery. Predicted species occurrences can be
combined to create maps of species richness for all species, for
specific taxa, or for groups of special concern (e.g.,
endangered species). These predictions of species richness can
then be compared to the third primary data layer: a map of
conservation lands. Biodiversity hot-spots that are not
currently protected within the network of conservation lands
would be high-priority area