NATURAL REVEGETATION ON LANDSLIDES IN HUMID TROPICAL ARUNACHAL PRADESH: COMMUNITY DYNAMICS AND SOIL PROPERTIES

Abstract

Vegetation patterns and soil properties of areas disturbed by landslides within the state of Arunachal Pradesh, northeast India, were investigated. Four sites with varying degrees of ecosystem recovery and one control site were examined for their vegetal status and various physical, chemical and biological properties of the landslide soils. Disturbed sites were first invaded by annual forbs. Perennial species that entered the ecosystem gradually gained dominance by prohibiting the immigrants through niche pre-exemption. The dominance of plant species showed an increasing trend along the recovery gradient. Young sites showed greater percentage of sand content in the soil. Higher acidity and temperature were found in disturbed areas. Soil organic matter increased gradually for the four years of the revegetation study. Concentration of soil organic carbon, total Kjeldahl nitrogen and available phosphorus increased with recovery period. Soil respiration and microbial population also increased with time following landslide occurrence.