A methodological framework for prioritizing habitat patches in urban ecosystems based on landscape functional connectivity

Urban landscape can support a many wild species, especially within green areas like remnants of native forests. Thus, conserving such remnants of native habitat patches is crucial for maintaining urban biodiversity. However, because limited resources and conflicting interests preclude the conservation of all patches, it is necessary to prioritize the most relevant ones, including the ones that facilitate organisms' dispersal across landscapes, maintaining the landscape functional connectivity. Here we present a framework for prioritizing patches based on their functional connectivity role in the urban landscape, using Rio de Janeiro, Brazil, as a model city. Functional connectivity was assessed through the Probability of the Connectivity Index of the entire landscape, using two model species that represent low- and high-dispersal scenarios. We then prioritized patches based on their individual contribution to the connectivity of the landscape (dPC values). Our results showed that Rio de Janeiro has very low functional connectivity, with only 20 priority forest fragments out of the ca. 1,400 available in the landscape. We propose four main strategies to ensure that prioritized patches can fulfil their functional connectivity role in urban landscapes: i) incorporate unprotected patches into the landscape's Protected Areas network; ii) use other effective area-based conservation measures for patches unlikely to become PAs; iii) resolve legal uncertainties about the land ownership situation; and iv) effectively manage already protected patches. Our proposed methodological framework and recommendations apply to any urban landscapes that contain remnants of native habitat patches. It requires easily obtainable data and provides a step toward the implementation of more science-based conservation strategies for urban areas.