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ESTIMATING OCCUPANCY ACROSS GEOGRAPHIC RANGES
USING HERBARIUM DATA AND GIS ENVIRONMENTAL COVERAGES


Occupancy is the proportion of sites within a given area where a species is present. This parameter is central in conservation biology because it determines the probability of persistence of a species through time. That is, a species is more likely to persist longer in areas where it has high occupancy than in areas where its occupancy is low. The distribution map of Bignonia heterophylla, selected here as the focal species, shows that occupancy is higher in Central America than in South America. In this case, the lack of presence records (i.e., collections) in the areas of South America that match the ecological niche of the focal species is not the result of lack of botanical work aimed at documenting the occurrence of plant species through collections. Rather, it reflects true absence, or low occupancy, of the focal species.

The localities where a focal species, Bignonia heterophylla, has been collected are indicated by red points

The localities where a focal species, Bignonia heterophylla, has been collected are indicated by red points, and the areas that match the ecological niche of the species are shown in gray. Note that the latter extend beyond areas of known occurrence.
For more information, contact
Iván Jiménez

ANALYSIS UNIT


Director, CCSD, Missouri Botanical Garden, P.O. Box 299, St. Louis, MO 63166 Phone: (314) 577-0871 CCSD@mobot.org © 2014