Integrated Coastal-Terrestrial Conservation Planning for landscape-scale reserve design in Southeastern Iran

Abstract

Natural habitats of Southeastern Iran are threatened by both natural and anthropogenic pressures such as long-term drought, dust storms, and land use change. Surveys on habitat suitability of vulnerable species and integration of protected areas have raised alarm over potential species extinction and geographical isolation of populations. Reducing the threats of human activities on sensitive terrestrial and coastal ecosystems requires integrated planning and management of terrestrial and coastal protected areas, however many of these areas have been selected and managed independently. Selecting coastal protected areas network require a systematic conservation planning approach, to reduce the development impacts on sensitive habitats. Therefore, this study aimed to identify an optimized integrative network of terrestrial and coastal protected areas in southeast Iran. An attempt was made to maximize biodiversity conservation, reduce the isolation of populations, and increase the resilience of the region’s natural habitats to new development plans by including coastal habitats meeting the requirements of key species. Firstly, suitable habitats for seven key species were simulated by Species Distribution Models (SDMs) performed via Generalized Linear Model (GLM), Generalized Boosted Model (GBM), Random Forest (RF), and Maximum Entropy (MaxEnt) models fitted with 20 ecological and anthropogenic variables. A habitat suitability map was produced by integrating the SDM-derived habitat suitability maps with the suitable extents identified for egg-laying green sea turtle and potential habitat for aquatic and semi-aquatic birds. An attempt was then made for selecting new terrestrial and coastal protected areas using the simulated annealing algorithm under six scenarios. All SDMs exhibited promising performances in predicting the distribution of suitable habitats with AUC values of above 0.8 and the discrimination power of GBM and RF was higher than that of the other SDMs. In total, more than 34 percent of the study area, along the coastline, was categorized as sensitive or extremely sensitive habitat. An east-west habitat corridor presently unprotected playing an important role in connecting habitats needs to be safeguarded to maintain regional biodiversity. Moreover, our study revealed that the majority of suitable habitats with high potential for sensitive species are not currently protected by the existing protected area network.