The likelihood for exotic weeds to come up is higher wherever the natural vegetation is disturbed and in turn it is a measure to estimate the degree of disturbance of the vegetation. However, once exotics are spread, they gradually suppress the natural regeneration and take dominance over the other species due to their increased and wide adaptability resulting in the loss of biodiversity and endemism. A considerable area where shifting cultivation was being practised in the past is occupied by exotics. The areas with exotics are spread at various regions of the Sanctuary. The major exotics in the sanctuary are Lantana spp., Parthenium hysterophorus, Argemone mexicana, Vicoa India, Euphorbia spp., Chromolaena odorara etc.
The area composed of barren land and exposed rock constitutes a considerable part of the Sanctuary. As per available records based on the extent of exposed rocks, the habitat is getting degraded. Selection felling in the past in some localities and operations such as preparing the land for plantations in some other localities have resulted in opening up of canopy and weed infestation. Other anthropogenic pressures such as road traffic, fire wood and NWFP collection, grazing, agricultural activities and fire are also responsible for the degradation of a vast area of
forests in the Sanctuary.