Choosing reserve networks with incomplete species information

Existing method for selecting reserve networks require data on the presence or absence of species at various sites. This information, however, is virt ually always incomplete. In this paper, we analyze methods for choosing pri ority conservation areas when there is incomplete information about species distributions. We formulate a probabilistic model and find the reserve net work that represents the greatest expected number of species. We compare th e reserve network chosen using this approach with reserve networks chosen w hen the data is treated as if presence/absence information is known and tra ditional approaches are used. We find that the selection of sites differs w hen using probabilistic data to maximize the expected number of species rep resented versus using the traditional approaches. The broad geographic patt ern of which sites are chosen remains similar across these different method s but some significant differences in site selection emerge when probabilit ies of species occurrences are not near 0 or 1. (C) 2000 Elsevier Science L td. All rights reserved.