A rich repository of medicinal plants are used by various indigenous health care systems in the Indian subcontinent. Over the years, there has been an extensive extraction of the medicinal plants from their natural habitats rendering many of them rare, en¬dangered or threatened. It is feared that unless urgent measures are taken to conserve the genetic resources of the medicinal plant species, the genetic variability of many of the species would be irreversibly lost. We examined the impact of anthropogenic pres¬sures on the regeneration and genetic diversity of two medicinally important plant species, Terminalia bellirica and Terminalia che¬bula in the deciduous forest of south India. Three levels of disturbance namely control, mildly and highly disturbed regions were identified in the forest, based on their proximity to human settlement, extent of forest stand and the extent of harvesting.
Our studies showed that populations close to human settlements had relatively less proportion of small size class individuals com¬pared to populations away from the settlements. While there was no discernible pattern in the genetic diversity parameters of the various populations, there appeared to be significant differentiation of the populations in the two species across the disturbance levels, suggesting that extraction of the medicinal plants may have altered the genetic structure of the populations. We discuss the results of our study in the context of the need to conserve and manage the genetic resources of medicinally important plant species in the country.