GAP management status and regional indicators of threats
to biodiversity
Stoms, D. M.
Landscape Ecology. 15: 21-33. [abstract
at Kluwer]
Conservation assessment requires quantitative criteria
for evaluating the relative degree of threat faced by species or ecological
communities. Identifying appropriate criteria for communities is complicated
because the species inhabiting them can have many different responses
to land uses and other forms of environmental stress. The Gap Analysis
Program (GAP) uses summary data on the proportion of the community
that is protected as an estimate of its vulnerability. Management
status from a gap analysis of California was compared with three ecological
indicators (permitted land uses, human population growth, and the
spatial extent of road effects) that more directly represent impacts
on biodiversity. The classification of management status appears to
provide a crude first approximation of these three indicators. Public
and private lands that are not formally protected were susceptible
to extensive land use conversion or resource extraction in both rural
and urban settings. Some plant community types are more susceptible
to future infringement by human population increases that were not
well predicted by management status alone. Other community types are
heavily roaded despite being moderately well protected. It is suggested
that indicators such as future growth and current road effects could
complement status in rating the potential vulnerability of plant communities
and setting conservation priorities. The choice of indicators will
depend on the threatening processes in a given region and the availability
of spatial data to map or model them.