95th ESA Annual Meeting (August 1 -- 6, 2010)

OOS 50-1 - Comparing landscape networks at the ecoregion scale: Can we expect corridor umbrellas?

Thursday, August 5, 2010: 1:30 PM
401-402, David L Lawrence Convention Center
Ryan M. Perkl, Department of Planning and Landscape Architecture, Clemson University, Clemson, SC and Robert F. Baldwin, School of Agricultural, Forest, and Environmental Sciences, Clemson University, Clemson, SC
Background/Question/Methods

Planners and researchers alike are faced with a multitude of potential choices when attempting to enhance connectivity at the ecoregion scale. A simplifying assumption is often that coarse-scale corridors may provide overlapping or “umbrella” effects. To examine this assumption, we assessed the differences in connectivity outputs among a series of equally valid conservation scenarios. Three landscape connectivity scenarios were developed for the Northern Appalachian/Acadian Ecoregion (330,000 km2) using an ecoregional human footprint (90m resolution). The scenarios included landscape networks using GAP 1 Protected Areas (N=95), Last of the Wild areas (HF<10; N=120), and focal species marten (Martes americana) source habitat patches (N=105) as sets of reserve nodes.

Results/Conclusions The resulting landscape networks were made up of 4, 3, and 2 subgraphs respectively. This indicated to varying degrees that while local connectivity was potentially present, widespread ecoregional connectivity was not. A gap analysis consisting of overlays of landscape network patches and corridors indicated that < 1% of the patch areas for all 3 scenarios was spatially coincident, 19% was coincident over 2 scenarios, while the majority of patch area (80%) was non-redundant. Additionally, < 2% of the corridor area for all 3 scenarios was spatially coincident, 24% was coincident over 2 scenarios, while the majority of corridor area (73%) was non-redundant. These results indicate that selecting “what” to connect at the ecoregion scale has significant implications for selected corridors. As there was so little modeled corridor area in common among scenarios, there is little reason to believe alternate corridors would be functionally equivalent. Finally, our results indicate that connecting any one set of habitat nodes, e.g., existing protected lands or focal species source patches, would not serve as a corridor umbrella for the other.