Effects of Disturbance and Selective Logging on the Population Structure of Red Sanders (Pterocarpus santalinus L.f.) - An Endemic Tree of Kadapa Hill Ranges, Southern Eastern Ghats

Abstract

The present study assessed the effects of logging and human disturbance on the population structure of Red sanders (Pterocarpus santalinus), an endemic and endangered dominant tree of dry deciduous forests of Kadapa hill ranges. A total of three study sites were selected on the level of two disturbance factors cattle grazing and fire wood collection as less, moderate and high disturbed sites. The objective is to compare the population structure and frequency of the life forms in reference to varied disturbance levels and selective logging across the three sites. Results showed variations in gbh class distribution, Population structure shape among the three study sites. Trees and seed lings formed the major life form. High variation was observed in the saplings distribution as major thinning occurred in the progression from seedling stage to established stages. Moderately disturbed site figured high density of individuals in all life forms and in basal area value. High percentage of cut stems and non- reverse ‘J’ shape population structure occurred astonishingly in less disturbed site. Highly disturbed site significantly lack the large girth size trees. These observations indicate that selective logging as the major factor that influenced the variation in population structure, stem density and basal area. The human disturbances factors especially selective logging of large size trees and rampant indiscriminate logging across all size may explain the variations in the population structure.