Mapping the potential distribution of Rhododendron arboreum Sm. ssp. nilagiricum (Zenker) Tagg (Ericaceae), an endemic plant using ecological modeling
Résumé
Rhododendron arboreum Sm. ssp. nilagiricum (Zenker) Tagg, a tree species endemic to the southern Western Ghats of peninsular India, is restricted to a narrow topographic and bioclimatic niche. Since information on ecological and geographic extent of the species is lacking, we used Genetic Algorithm for Rule-set Prediction (GARP), an ecological niche modelling (ENM) method to model its spatial distribution. The model is developed based on its occurrence in the Western Ghats, in relation to topographic and environmental variables. Prediction of R. arboreum ssp. nilagiricum in the Western Ghats is strongly related to local climatic conditions in terms of annual temperature, precipitation and diurnal temperature ranges and not so much dependent on altitudinal variations. The numerous bioclimatic, topographic and anthropogenic factors have led to the formation of islands of species distribution, restricted to the Nilgiri, Anamalai, Palni and Meghamalai hills of the Western Ghats. Predictions allow identification of key areas for in situ conservation of the species and prioritize areas falling in the ecological extent of the species for conservation.