PARENT SESSION
Contributed Oral Session 131: Biogeography: Ranges; Species Area; Populations
Thursday, August 11, 1:30 PM - 5:00 PM, Meeting Room 515 A, Level 5, Palais des congrès de Montréal

Modelling the historical ranges of Hawaiian plants: implications for conservation at the regional scale.

Price, Jonathan^{*,1, 2}, Jacobi, James², Gon, Samuel³, ¹ Department of Botany, National Museum of Natural History, Washington, DC² Hawai'i Cooperative Studies Unit, Hilo, HI³ The Nature Conservancy, Honolulu, HI

ABSTRACT- We utilize general distributional data of all native Hawaiian plant species to generate GIS models of their ranges in order to guide conservation at the regional scale. For each species, presence data for islands and regions within them, major climatic habitats occupied, preferred substrate and elevational range are processed with corresponding GIS coverages, creating a map approximating the maximum historical range of the species. Modeled ranges are tested against specific point data for a subset of rare and common species. Despite uncertainties at the landscape scale, modeled ranges generally agree with specific locality data. By collating historical ranges of all species, we predict potential floristic biodiversity for all areas, including those where native habitat has been heavily altered. Projected diversity is tested against measured species richness of natural areas across the state to assess accuracy. Next, using a spatial coverage of habitat quality, we determine the proportion of each species' historical range with different levels of human impact in order to assess how its original habitat may have been altered. Compiling these assessments, we find that the most impacted species are from low elevation and dry habitats statewide and from mesic habitats on Oahu and East Maui. These spatial models have several management applications. We recommend consideration for conservation designation or increased management attention for regions predicted to include: 1) putatively high total species diversity, 2) concentrations of species whose ranges have been disproportionately impacted, 3) species whose ranges fall outside presently managed areas, 4) species in novel evolutionary groups, and 5) species upon which native fauna depend. Modeled ranges will be available online for conservation and research applications.

Key words: biogeography, hawaii, flora, geographic range