Modeling ecoregional connectivity

Nature reserves increasingly function as islands in a human-dominated matrix. Habitat conservation initiatives that seek to reconnect patches using functional corridors are increasingly part and-parcel of conservation planning projects. Numerous methods have evolved all based on similar of least cost paths, functional rather than structural connectivity, and landscape resistance. However significant differences in approach exist including whether a network of patches is considered simultaneously or as patch-patch pairs, and whether the goal is to model spatially explicit corridors or movement bottlenecks. We review these approaches and then describe ecological connectivity modeling for an ecoregion using the graph-theoretic approach considering two different patch-node scenarios, at the ecoregion scale and apply a more localized connectivity modeling exercise for a subregion and a single focal species the American Black bear (Ursus americanus). We discuss the difficulties of attempting to model functional corridors for focal species over heterogenous landscapes, and the potential benefits of using 'naturalness' or Human Footprint surrogates for connectivity.