Planning Ecological Corridors: A Cost Distance Method Based on Ecosystem Service Evaluation in the Sardinian Cork Oak Forests

Cork oak forests in Sardinia cover about 139,500 ha of land both as pure stands or wooded pastures. Starting from a research activity carried on the territories of Goceano, focused on the application of a methodology on the evaluation of Ecosystem Services (ESs) provided by cork oak forests, this study presents a methodology for designing and implement local ecological networks able to maximize the value of ESs (in particular, provisioning, regulation and cultural) through a GIS-based cost distance analysis (least cost path method). The least cost path method supports the best corridors for connecting landscape patches to be adopted in ecological infrastructure planning for Goceano. Two GIS layers (the source layer and the impedance layer) are used as inputs: the source layer represents the landscape patches from which connectivity is calculated according to the cost of ecosystem services related to local ecological network. The impedance layer represents resistance values assigned by summarizing the weight values of the relative costs of traveling through each land use type and geographical position. The framework of values provided and the local ecological network automatically calculated can be useful bases to better define multi-functional management systems and development strategies aimed to assist the evolution of these rural landscapes in response to climate and societal changes.