MICROSITES AND DIVERSITY OF UNDERSTOREY SHRUBS IN SOUTHERN WESTERN GHATS, INDIA

Abstract

This study examines the diversity of understorey shrubs in their microhabitats in a primary wet evergreen forest of south India. A matrix of environmental factors and the species distribution across quadrats were analysed using correspondence analysis to identify the microhabitats of understorey shrubs. Slope of the terrain, level of light, soil cover and tree density were important parameters that defined the microhabitats of the shrubs. Most shrub species (85%) were clumped in their dispersion patterns. Moderate overstorey cover supported greater diversity of understorey shrubs. Capturing diversity and increasing density were not operationally similar for shrubs. While shaded conditions tended to increase the density and dominance of certain species, disturbance-mediated light regimes increased species diversity. The narrow-endemic species had greater richness in tree fall gap, while broad-endemic and non-endemic species maximised richness in openings. For all groups, high densities were observed in shade.