Habitat distribution modelling for reintroduction of Ilex khasiana Purk., a critically endangered tree species of northeastern India

Abstract

Only ca. 3000 individuals of Ilex khasiana Purk. are surviving today. The tree species is endemic to Khasi hills of northeast India, and is critically endangered. For improving the conservation status of the species, potential area and habitat for reintroduction were predicted using Maximum Entropy (MaxEnt) distribution modelling algorithm. The model was developed using 16 locality data in the native range of Khasi hills, and 16 environmental parameters including enhanced vegetation index (EVI) and digital elevation data. The model predicted that the suitable habitats of I. khasiana was restricted to an area of ≈500 km2 in the Khasi hills of Meghalaya. The distribution of potential habitats was strongly influenced by elevation and the EVI layers for the period April–May, which corresponds to the flowering phase of the species, thus indicating the importance of flowering stage in determining the species distribution. Population status was positively correlated with higher model thresholds in the undisturbed habitats confirming the usefulness of the habitat model in population monitoring, particularly in predicting the successful establishment of the species. The study delineated the potential habitats in the higher elevations of Khasi hills within the current home range where the species can be reintroduced.