Should I stay or move? Quantifying landscape of fear to enhance environmental management of road networks in a highly transformed landscape.

The development and expansion of road networks pose considerable threats to natural habitats and wildlife, fostering a landscape of fear. In addition to direct mortality caused by road collisions, road construction and maintenance often result in habitat fragmentation and loss, impeding animal movement and gene flow between populations. Mountain ungulates are already confined to fragmented habitat patches and roads can cause substantial disturbances to their critical ecological processes, such as dispersal and migration. In this study, we employed two key mountain ungulates, the wild goat (Capra aegagrus) and mouflon (Ovis gmelini), as functional models to examine how road networks impact the quantity and connectivity of natural habitats in southwestern Iran, where extensive road construction has led to significant landscape changes. We used the MaxEnt method to predict species distribution, the circuit theory to evaluate habitat connectivity, and the Spatial Road Disturbance Index (SPROADI) to assess road impacts. During the modeling process, we selected eleven important variables and employed a model parametrization strategy to identify the optimal configuration for the MaxEnt model. For SPROADI index we used three sub-indices, including traffic intensity, vicinity impact, and fragmentation grade. We then integrated the results of these analyses to identify areas with the most significant environmental impacts of roads on the coherency of the natural habitats. The findings indicate that suitable habitats for wild goats are widely distributed across the study area, while suitable habitats for mouflon are primarily concentrated in the northeastern region. Conservation gap analysis revealed that only 8% of wild goat habitats and 7% of mouflon habitats are covered by protected areas (PAs). The SPROADI map highlighted that 23% of the study area is negatively influenced by road networks. Moreover, 30.4% of highest-probability corridors for mouflon, and 25.7% for wild goat, were highly vulnerable to the impacts of roads. Our combined approach enabled us to quantitatively assess species-specific vulnerability to the impacts of heavy road networks. This study emphasizes the urgent need to address the negative effects of road networks on wildlife habitats and connectivity corridors. Our approach effectively identifies sensitive areas, which can help inform mitigation strategies and support more effective conservation planning in significantly transformed landscapes.

Application of InVEST habitat quality module in spatially vulnerability assessment of natural habitats (case study: Chaharmahal and Bakhtiari province, Iran).

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.