Integrating habitat risk assessment and connectivity analysis in ranking habitat patches for conservation in protected areas

Abstract

Ecological habitat connectivity, human disturbances, and habitat availability are strongly related to each other for distribution and abundance of species. In Varjin protected area, Iran, habitat loss due to human pressures is the main factor in the rapid decline of Ovis orientalis (wild sheep) population. In this research, we proposed a framework to analyze the connectivity of the mountainous landscape by considering human disturbances. The integrated framework is aimed at obtaining a procedure that can be used to rank individual habitat patches for conservation priorities. We identified patches with high-risk values using the InVEST model. By applying patch removal techniques and in tandem with a fragmentation scenario, an analysis of the network-based modeling connectivity metrics was performed within and among the habitat patches. We evaluated the local and habitat connectivity by calculating Betweenness Centrality (dBC) as a network metric and Probability of Connectivity (dPC) as the habitat availability metric. Average dBC and dPC metrics decreased by 62.41 % and 8.23 %, respectively by applying risk values. Results demonstrated that habitat patches in the east and southeast of the protected area show the biggest difference value in response to human disturbance. These patches are the priorities for habitat conservation. Our methodology provides a habitat-based conservation tool by combining connectivity metrics and considering habitat risks. As a result, the impact of habitat loss on connectivity metrics and future vulnerability of the protected area is assessed in one procedure.