How Can Urban Forest Support Protected Areas Connectivity?

Cities continue to grow worldwide and the highly modified urban landscape becomes an inhospitable environment for many species because the natural vegetation cover is commonly fragmented and the remnants are often isolated. Protected Areas (PAs) located surrounding or within urban areas may not achieve their goal of protecting local or regional biodiversity. Thus, an urban ecological network is important to support urban PAs. This study aimed at evaluating the PAs connectivity in an urban landscape and understanding if urban forest fragments can support an urban ecological network connecting the PAs. We used spatial models based on Graph Theory to assess the functional connectivity among PAs in an urban landscape in Brazil. The focal species used in the model were Atlantic Forest birds. We used the participatory technique to determine their dispersal capabilities across the landscape, building a resistance surface map. We found significant gaps-connectivity between PAs. This current ecological network is exceptionally dependent on forest fragments neighboring (outside PAs). However, most of these forest fragments cannot provide the necessary support for the PAs connectivity. We identified only 28 forest fragments spatially connected, presenting several sizes, and are located near large forest areas, substantial PAs, and riparian zones. For building an effective urban ecological network is essential the conservation of the large forest fragments (outside PAs) and the restore of the small-sized forest fragments and riparian zones. We also recommend that local planners pay more attention to these forest fragments when discussing landscape planning for the development of more sustainable cities