Ecologists have sought for years to analyze connectivity to better understand the ecological effects of fragmentation on the landscape. Originally, small scale connectivity analyses were used to understand individual movement and local population distributions. As scientists began expanding the scope, scale, and size of studies, model complexity increased and was restricted by computational capacity, forcing development of new technologies to overcome these limitations. We used one such technique, Circuitscape, which applies electrical circuit theory, to map connectivity across our study area (6km ribbon along the Great Lakes coastline), identifying specific parcels of land vital to improving connectivity. Using the NLCD (National Land Cover Data set), we created a layer indicating resistance to potential movement/dispersal to evaluate connectivity along the Great Lakes coast. Additionally, using PAD-US we compared connectivity of State and Federal protected areas, determining where connectivity is most tenuous, identifying critical regions for maintaining long term connectivity. Lastly, we identified three main habitat (wetlands, forests, and grasslands), using Circuitscape we modeled current connectivity of each habitat type in our study area, comparing them regionally and across the whole coastline
Results/Conclusions
Using the NLCD we created a raster layer representing resistance to movement for our study area, resulting in 2,934,996.54 hectares of land, where two thirds of the area are lower resistance and a third is higher resistance. We ran two connectivity analyses to understand the landscape connectivity (NLCD) compared to the connectivity of protected Areas (PAD) and the overlap between the two analyses. We found similar corridor sizes within the study area between NLCD, PAD, and their overlap (69%, 68.5%, and 68% respectively). The EPA ecoregions were used to break down the coastline in order to understand the connectivity variation. In all analyses the northern part of the Northern Lakes and Forest ecoregion had the largest area within the corridor (89% - 91%) and the Central Corn Belt Plain ecoregion had the least within the corridor (14.8% - 17.71%). The corridor of each analysis had many breaks in the corridor across the study area from both natural (rivers) and unnatural (urban) landscape characteristics. Lastly, when we analyzed the main habitats within our study area we discovered that forests had the largest corridor, then Wetlands, and lastly grasslands.