Modeling Species Distribution with GIS
425
to use them. As a result of this break, sophisticated systems are often used for
simple operations and their use becomes a goal in itself. Toraldo di Francia
(1978) names this paradox “the law of inversion between the goal and the
instrument.” This has also been the case with gis: the emphasis was on the use
of the tool rather than on solving the problems to which it was applied. During the infancy of the tool’s development its enthusiastic and acritical application was a clear evidence of the low awareness of the tool’s limitations.
Although we don’t believe that the infancy of GIS is over, in recent years we have
seen a growth in the capabilities of the tool and the awareness of its users. We
think that we have enough case studies to define a logical framework in which
the process of gis modeling and more specifically species distribution modeling should be kept. We have tried to accomplish this by identifying the issues
that must be addressed during the entire process.
In an era in which the need to acquire and analyze data at wider scales is
increasing and globalization in environmental assessment applications is
becoming urgent, we should not waste the opportunity GIS offers to wildlife
biologists to cope with these needs. This does not mean that GIS modeling can
substitute for fieldwork and direct observation; especially in the case of rare or
endangered species, all management action should be based on direct site-specific studies. Nevertheless, sound GIS distribution models, which can be
achieved by addressing the different issues we have tried to address in this
chapter, can help to identify areas that require more detailed investigation.
Acknowledgments
We thank Luigi Boitani and Todd Fuller for giving us the opportunity to
organize these ideas. The chapter is also the result of suggestions and comments from Luigi Boitani, Alessandra Pellegrini, Iacopo Sinibaldi, and two
anonymous reviewers.
Notes
1. Area of occupancy is defined as the area within the species’ extent of occurrence that is
occupied by a taxon, excluding cases of vagrancy. The measure reflects the fact that a taxon
will not usually occur throughout the area of its extent of occurrence, which may contain
unsuitable habitats, for example. The area of occupancy is the smallest area essential at any
stage to the survival of existing populations of a taxon (e.g., colonial nesting sites, feeding
sites for migratory taxa) (IUCN1995).
2. Bibliographic database of literature in earth sciences, ecology, and geography published by Elsevier.
425
to use them. As a result of this break, sophisticated systems are often used for
simple operations and their use becomes a goal in itself. Toraldo di Francia
(1978) names this paradox “the law of inversion between the goal and the
instrument.” This has also been the case with gis: the emphasis was on the use
of the tool rather than on solving the problems to which it was applied. During the infancy of the tool’s development its enthusiastic and acritical application was a clear evidence of the low awareness of the tool’s limitations.
Although we don’t believe that the infancy of GIS is over, in recent years we have
seen a growth in the capabilities of the tool and the awareness of its users. We
think that we have enough case studies to define a logical framework in which
the process of gis modeling and more specifically species distribution modeling should be kept. We have tried to accomplish this by identifying the issues
that must be addressed during the entire process.
In an era in which the need to acquire and analyze data at wider scales is
increasing and globalization in environmental assessment applications is
becoming urgent, we should not waste the opportunity GIS offers to wildlife
biologists to cope with these needs. This does not mean that GIS modeling can
substitute for fieldwork and direct observation; especially in the case of rare or
endangered species, all management action should be based on direct site-specific studies. Nevertheless, sound GIS distribution models, which can be
achieved by addressing the different issues we have tried to address in this
chapter, can help to identify areas that require more detailed investigation.
Acknowledgments
We thank Luigi Boitani and Todd Fuller for giving us the opportunity to
organize these ideas. The chapter is also the result of suggestions and comments from Luigi Boitani, Alessandra Pellegrini, Iacopo Sinibaldi, and two
anonymous reviewers.
Notes
1. Area of occupancy is defined as the area within the species’ extent of occurrence that is
occupied by a taxon, excluding cases of vagrancy. The measure reflects the fact that a taxon
will not usually occur throughout the area of its extent of occurrence, which may contain
unsuitable habitats, for example. The area of occupancy is the smallest area essential at any
stage to the survival of existing populations of a taxon (e.g., colonial nesting sites, feeding
sites for migratory taxa) (IUCN1995).
2. Bibliographic database of literature in earth sciences, ecology, and geography published by Elsevier.