Plant target and animal vector species in ecological network analysis

Natural environments are deeply altered by urban settlements and their ecological structures are strongly affected by land fragmentation. Lack of vegetation generate unsuitable environments for the animals normally living in the region. Ecological networks are among the territorial devices providing functional and spatial connectivity between environmental and landscape components thus ensuring continuity and contrasting fragmentation. This possibility of landscape analysis is particularly applicable in the peri-urban and urban-rural transition zones characterized by residual ecosystems preserving natural values and hosting dispersal processed of plants and animal vectors. Two pilot areas located in the peri-urban fringe areas of the cities of Sassari and Nuoro are identified, analyzed and compared. The presence of agricultural areas, gardens and tree-lined avenues offers the possibilities for the realization of ecological networks that are studied according to the theory of complex networks and starting from the characteristics of the two most widespread plant target species in these areas: the Holm oak and the Olive tree. European jay (Garrulus glandularius) and the common starling (Sturnus vulgaris) have been considered as vector animal species. Combining the study of the green areas (patches distribution and size) and the potential distance of dissemination by birds (corridors), two ecological networks were build for the towns of Nuoro and Sassari.