PARENT SESSION
Special Session - Landscape ecological modeling and ecological risk assessment: at the cross roads Chair(s): Cole, Marlene¹, Johnson, Alan ², Linkov, Igor¹, ¹ ICF Consulting, Lexington, MA² Clemson University, Clemson, SC
Wednesday, March 31, 2004 1:00 PM - 4:40 PM Apollo Room 1

Landscape ecological modeling and ecological risk assessment are often used to support environmental decision making. While each operates within its own set of methods and tools, decision-making may benefit from the fusion of the two disciplines. This session will bring together researchers involved in landscape ecological analyses and spatially explicit ecological risk assessments. Ecological risk assessment, which has much regulatory utilization and guidance, provides a systematic approach to predict the likelihood of undesired effects arising from environmental stressors. Stressors may include chemical contaminants or other ecological disturbances (land use changes, altered hydrology, invasive species, genetically modified organisms, climate change, etc.). Landscape-level approaches could benefit ecological risk assessment in a number of ways, including: (1) explicit consideration of scale and spatial organization during problem formation, (2) accounting for spatial heterogeneity in exposure characterization, (3) extrapolation from small-scale studies to broad-scale effects, (4) selection of appropriate assessment and measurement endpoints, (5) spatial analysis of uncertainties, and (6) the use of maps or other spatial visualization techniques for risk communication. In turn, ecological risk assessment can benefit landscape ecology because: (1) it has an existing regulatory presence (and is often required), (2) its framework lends itself to addressing environmental questions, and (3) it provides direct application to environmental decision making.

Functional connectivity and ecological risk assessment for metapopulations. ^*JOHNSON, ALAN R. ¹, ALLEN, CRAIG R. ² and SIMPSON, KRISTI AN. ³, ¹ Department of Forestry and Natural Resources, Clemson, SC, USA² South Carolina Cooperative Fish and Wildlife Research Unit, Clemson, SC, USA³ Clemson Institute of Environmental Toxicology, Pendleton, SC , USA

ABSTRACT- Natural and anthropogenic processes leading to habitat fragmentation may threaten the viability of wildlife populations and the maintenance of biodiversity. Stressors occur at many spatial scales, and their impacts on wildlife depend on the scales at which species interact with the landscape. The concept of functional connectivity captures this organism-based view of the relative ease of movement or degree of exchange between physically disjunct habitat patches. Precise estimation of the functional connectivity of a given habitat arrangement for a given wildlife species depends on many details of the organism's life history and behavioral ecology. However, for broad categories of species, quantities such as home range size and dispersal distance scale allometrically with body mass. These relationships can be incorporated into spatial analyses to model functional connectivity, which can be quantified in terms of an index, or displayed graphically in maps of functionally connected clusters. We present a review of indices and GIS-based approaches to estimating functional connectivity, presenting examples from the literature and our own work on mammalian species distributions in the state of South Carolina. Such analyses can be readily incorporated within an ecological risk framework incorporating viability analysis for metapopulations. Estimates of functional connectivity may be useful in a screening-level assessment of the impact of habitat fragmentation relative to other stressors, and may be crucial in detailed population modeling and viability analysis.

KEY WORDS: functional connectivity, fragmentation, metapopulations, ecological risk assessment, population viability analysis