Genetic and recruitment patterns predict biodiversity loss from biodiversity offsetting schemes
Understanding the contribution of individual populations to the long-term viability of any given species is critical for both theoretical and practical reasons. For example, recently developed biodiversity offsetting schemes generally assume that populations of species are of equal conservation value. These schemes assume that no net loss of biodiversity will occur if populations are lost or reduced in size in one location, but other populations are established or increase in size. In this study we test these assumptions. Specifically we investigate: 1. Taxonomic status; 2. Genetic structuring, and; 3. Recruitment among populations of the terrestrial orchid Diuris platichila. We investigate how the interaction of these factors affects the contribution of individual populations to the viability of this species.
Genetic and recruitment differentiation among populations indicate that the six studied populations of Diuris platichila cannot be considered to be of equivalent conservation value. These patterns are not predictable and indicate that enhancement of any given population is unlikely to offset for the reduction or loss of other populations. Issues with past collections from these populations provide further difficulties in assessing the legislated threat status of the studied populations and such issues are not uncommon.