Assessing habitat connectivity: A comparative analysis of four methodologies applied to peri-urban landscapes

Empirical literature proposes a variety of methodologies assessing ecological connectivity, with vastly different data prerequisites, algorithm complexity, and computational effort. They evaluate multiple aspects of habitat connectivity, each tailored to specific objectives and ecological scales. In this study, we applied four distinct methodologies that assess the same topical issue (namely, ecological connectivity) to the same study area, the cadastral region of Liberec City (Czech Republic). This area encompasses urban and peri-urban districts, including vast plots of the surrounding forest-agricultural landscape matrix. Notably, deciduous forests dominate the investigated landscape, thus constituting the focus of connectivity assessment in this study. We first used a simple indicator quantifying 'structural connectivity', namely the Patch Cohesion Index. The second approach was based on a 'distance to nature' metric taken as a straightforward indicator of functional connectivity. The third method, hereafter 'ConVia', was originally developed in this study as a more sophisticated, large-scale measure of functional connectivity. The most advanced method scrutinized within the study area was the 'probability of connectivity' index rooted in graph theory (hereafter 'Conefor'). By encompassing technical background, data requisites, and applicability of each individual methodology, comparing the outcomes of these four approaches sheds further light in the ecological assessment theory. Result interpretation, graphical rendering, strengths and weaknesses of each method were extensively discussed and generalized to broader contexts.