Assessment of area endemism of five arid and semi-arid plant species of the Indian Thar desert using stacking species distribution modelling

Endemism is essential for biodiversity conservation, as species with limited ranges are more susceptible to habitat loss due climate change. This study evaluates the Area of Endemism (AoE) for Acacia jacquemontii, Anogeissus sericea var. nummularia, Calligonum polygonoides, Commiphora wightii, and Tecomella undulata, which are found in the arid and semi-arid areas of western India. The Area of Endemism (AoE) for these species was assessed using Machine Learning − Staking Species Distribution Modelling (SSDM). Study indicated that the mean temperature of the wettest quarter (Bio-8, 30 to 33 °C), the maximum temperature of the warmest month (43.3 to 46.2 °C), the annual temperature range (Bio-7, 35.1 to 35.4 °C), and the precipitation of the coldest quarter (Bio-19, 11–13 mm) significantly influence the AoE and percentage of endemism. The Enhanced Vegetation Index (EVI) indicated that the examined endemic species inhabited both homogeneous and diverse settings. The topographical features, including elevation (10 to 30 m), slope 1 (10–15 % gradient), and slope 2 (30 to 45 % gradient), were deemed more appropriate. SSDM modeling indicated that the present optimum AoE is located in the Marwar region of the Thar Desert, covering the western districts of Rajasthan. This investigation revealed the following key trends: (a) as climatic conditions change, suitable habitats are shifting northward, whereas southern Rajasthan (Barmer, Jaisalmer, Nagaur, Pali, Jalore) is seeing a reduction in optimal habitat, (b) optimal AoE is decreasing at a more accelerated rate than the moderate, particularly in north-central Rajasthan and Gujarat, (c) the western limit of Jaisalmer district shows indications of recovery under RCP 8.5, with expected new habitat patches arising in Churu, Bikaner, and Sikar. The results identified specific sites for biodiversity protection, so enabling adaptive management measures to reduce species extinction in vulnerable habitats.