Quantifying ecological mosaic connectivity and hemeroby with a new topoecological index

Connectivity determines a large number of ecological functions of the landscape and is a key to understand fluxes of matter and energy within landscape mosaics. Several approaches to quantify landscape connectivity are possible. Nevertheless, a major shortcoming of most connectivity indices is that they do not allow the inclusion of any qualitative difference between adjacent landscape patches in the computation of the index. Within this context, using potential natural vegetation distribution as reference model, we propose a new graph theoretical index (gamma(te)), which takes into account the serial or catenal nature of the spatial contacts between adjacent vegetation types. Results derived from the analysis of Circeo National Park coastal communities (Central Italy) showed that from an ecological viewpoint, gamma(top) represents an effective measure to quantify land-scape connectivity in an ecologically meaningful way.