Results - Biological Diversity Resource Areas

BDRAs cover 34% of the state. They represent 93% of the state's landscape diversity units (LDUs). Running a random selection algorithm again confirmed the relative efficiency of the BDRAs: 72% of the state was sampled randomly before LDU representation reached the 93% level.

Conservation science recognizes the need to complement a "coarse filter" approach like the VBP's with finer-scaled strategies. These can offer protection to some rare species or communities that do not fall within larger conservation areas, and for which local-scale conservation measures may be adequate. BDRAs leave unprotected 21% of the occurrences of rare species and exemplary natural communities in the Vermont Nongame and Natural Heritage Program database, and these may be candidates for such site-scale attention. The 21% figure compares favorably with the 67% of NNHP occurrences left unprotected by the current network of conserved lands in Vermont, which cover 19% of the state. The poor showing of conserved lands is probably due to the fact that 66% of conserved lands lie in the 33% of the state over 1500 feet in elevation.

Species atlases for breeding birds, reptiles and amphibians, bryophytes, vascular plants, and other taxa exist for Vermont, but were judged to be inadequate for a statewide analysis of biodiversity. However, they did offer the only opportunity to evaluate how well the BDRAs represent biological diversity. As the table below shows, the BDRA network performed very well compared to a random sampling design and to the network of currently conserved lands in the state.

Comparison of species richness of biological diversity resource areas (BDRAs), randomly selected hexcells, and currently conserved lands in Vermont.