Assisted colonization of the near-eastern fire salamander (Salamandra infraimmaculata) in Iran: distribution modeling and landscape analysis

Abstract

Extreme environmental variations, including climate change, represent a substantial threat to species with restricted mobility. To support assisted colonization (AC) efforts for the near-eastern fire salamander (Salamandra infraimmaculata) in protected areas of Kermanshah province in Iran, we used Species Distribution Models (SDMs) and landscape metrics to identify suitable environmental conditions. SDMs along with variables associated with vegetation, precipitation, temperature, and soil characteristics were used to investigate the distribution of S. infraimmaculata. Models were converted into binary based on a baseline threshold to extract suitable conditions for Protected areas (PAs). Landscape metrics including Class Area, Number of Patches, Mean Shape Index, Edge Density, Mean Nearest Neighbor Distance, and Mean Patch Size were employed to assess habitat patches within the PAs. Additionally, we conducted a multi-scale analysis of fragmentation across the landscape, using the foreground area density (FAD) method to identify potential AC areas. Results confirmed model effectiveness in accurately identifying suitable conditions. Soil organic carbon (SOC), precipitation, and temperature emerged as the primary drivers influencing the species' distribution. Shaho and Kusalan, Boozin and Marakhil emerged as the most extensive potential habitat area. The highest number of patches was observed in the Bisotun complex, while the most sizable patch area was concentrated in Shaho and Kusalan. The FAD analysis showed that the Dominance class related to suitable conditions along the Shaho mountain range has the highest value, and other suitable conditions will be more vulnerable to external pressures. These results substantially aid in identifying potential AC candidates.