There has been a growing pressure of human activities, especially road network, on natural habitats of the world, which has led to habitat degradation and loss of ecosystem services. To mitigate the impacts of human activities, appropriate studies quantifying ecosystem services and assessing ecological impacts of road network are essential. The main goal of this study was modeling habitat quality and habitat degradation of Chaharmahal and Bakhtiari province in the southwestern part of Iran, which is among the most important habitats for wild sheep (Ovis orientalis) classified as vulnerable on the IUCN Red List. In this study, we used the habitat quality module of the InVEST software (Integrated Valuation of Environmental Services and Tradeoffs), which was driven from land use/cover data, information on anthropogenic threats, and expert knowledge. We tested the reliability of the habitat quality values by comparing them with the distribution map of wild sheep obtained from the Department of the Environment. Then, to have a more comprehensive assessment of the roads' effects on the natural habitats of this province, considering ecosystem services model, the Spatial Road Disturbance Index (SPROADI) was applied as a landscape index. The results of this study revealed that the east and north eastern parts of the study area which were among the most suitable habitats for wild sheep were highly affected by road network. Overall, findings of our study provided useful information on the spatially explicit distribution of habitat quality and degradation which were a valuable input for conservation planning and enhancing ecosystem services.
Keywords: Ecological impacts; Ecosystem services; Habitat quality; InVEST; Road network; SPROADI.