No. 9/2004
CONSERVATION OF WILDLIFE. A BIO-ECONOMIC MODEL OF A WILDLIFE RESERVE UNDER
THE PRESSURE OF HABITAT DESTRUCTION AND HARVESTING OUTSIDE THE RESERVE.
Claire W. Armstrong
Anders Skonhoft
Abstract:
Biodiversity is today threatened by many factors of which destruction
and reduction of habitats are considered most important for terrestrial
species. One way to counteract these threats is to establish reserves
with restrictions on land-use and exploitation. However, very few reserves
can be considered islands, wildlife species roam over large expanses,
often via some density dependent dispersal process. As a consequence,
habitat destruction, and exploitation, taking place outside will influence
the species abundance inside the conservation area. The paper presents
a theoretical model for analysing this type of management problem. The
model presented allows for both the common symmetric dispersal as well
as what is called asymmetric dispersal between reserve and outside area.
The main finding is that habitat destruction outside may not necessarily
have negative impact upon the species abundance in the reserve. As a consequence,
economic forces working in the direction of reducing the surrounding habitat
have unclear effects on the species abundance within the protected area.
We also find that harvesting outside the reserve may have quite modest
effect on the species abundance in the reserve. This underlines the attractiveness
of reserves from a conservation viewpoint.
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