The relative conservation value of remnant patches of native vegetation in the wheatbelt of Western Australia: I. Plant diversity

Abstract

Accurate assessment of the relative conservation value of remaining areas of native vegetation is of primary importance to both land planners and land managers wishing to conserve the biodiversity of an area. Selection procedures aimed at identifying sets of patches for nature reserve networks stress the importance of retaining beta diversity (or diversity of habitats). This paper describes a new procedure that incorporates a measure of relative alpha diversity (or within habitat diversity) of plant species, as well as beta diversity, using the Kellerberrin area of the Western Australian wheatbelt as an example. The inclusion of such an algorithm in selection procedures is justified since beta and alpha diversity, together with genetic diversity, determine the overall biotic heterogeneity of an area. A five-step ranking method is used to prioritize remnant patches of native vegetation with respect to plant diversity, both at regional and local scales. Ranking at a regional scale is important for state authorities able to deal with only a limited number of widely dispersed sites such as nature reserves; whereas ranking at the local scale provides a guideline for the conservation of biodiversity at a level where many land use and management decisions are made by local government and private citizens.