A Vector Approach for Modeling Landscape Corridors and Habitat Connectivity

Abstract

Landscape connectivity is an important consideration in understanding and reasoning about ecological systems. Two features within a landscape can be viewed as connected whenever a path exists between them. In many applications, the relevance of a potential path is assessed relative to the cost or resistance it presents to traversal. Typically, the least-cost paths between landscape features are used to approximate the potential for connectivity. However, traversal of a landscape between two locations may not necessarily conform to a least-cost path. Moreover, recent research has begun to cast some doubt on the how different types of landscape features may influence movement. Thus, it is important to consider the geographic bounds to movement more broadly. Continuous (i.e., raster) and discrete (i.e., vector) representations of connectivity are commonly used to model the spatial relationships among landscape features. While existing approaches can shed meaningful insights on system topology and connectivity, they are still limited in their ability to represent certain types of movement and are heavily influenced by scale of the areal units and how cost of landscape traversal is derived. In order to better address these issues, this paper proposes a new vector-based approach for delineating the geographic extent of corridors and assessing connectivity among landscape features. The developed approach is applied to evaluate habitat connectivity for salamanders to highlight the benefits of this modeling approach.