PHYTO-ECOLOGY OF THE LION-TAILED MACAQUE (Macaca silenus) HABITATS IN SOUTHERN INDIA

Abstract

The causal factors for the very high species diversity in tropical rainforests have been the focus of ecological research for several decades. It has become obvious that the high tropical species diversity has three major components, local (often called α-diversity), regional (β-diversity), and landscape (γ- diversity). Contribution of each of these components to overall diversity might vary from place to place, and from taxon to taxon. The pattern of variation in plant diversity is of particular interest since this would have a profound impact of the distribution and abundance of secondary consumers. In this study, I examine the nature and extent of spatial variation in the species diversity of woody plants in the rainforest of the Western Ghats mountain ranges in south India, one among the eight most threatened biodiversity hotspots of the world. I also examine whether the diversity of food trees of the lion-tailed macaque (Macaca silenus), an endemic to the tropical rainforest of the Western Ghats and phylogenetically the ancestor of all extant Asian macaques, also show variation at different spatial scales that is similar to that of all wood plants. Since the phenology of plants also affects the secondary consumers, this issue is examined at one site. Although the Western Ghats mountain ranges extend over 1600 km, from 8°-21° N, this study was restricted to the tropical rainforest between 8°30’ and 14°17’ N within an altitudinal range of 100-1500 m, which formed the habitat of the lion-tailed macaque. The rainforest north of this is also heavily disturbed and highly fragmented. The variation in the woody plant community was examined primarily with reference to their species richness, density, and basal area.