GENETIC DIVERSITY OF <em>PHYLLANTHUS</em> <em>EMBLICA</em> IN TROPICAL FORESTS OF SOUTH INDIA: IMPACT OF ANTHROPOGENIC PRESSURES

Abstract

In the Indian subcontinent, extraction of non-timber forest products (NTFPs) is a major occupation of the forest dwelling and forest fringe communities. A substantial portion of their livelihood is derived from the extraction of NTFPs. Despite the widespread dependence, little is known of the possible impacts that such extraction has on the regeneration and genetic diversity of the species. We examined the impact of anthropogenic pressures on the regeneration and genetic diversity of Phyllanthus emblica, an important NTFP species, across increasing gradients of pressures (disturbance) at two sites in the deciduous forests of south India. Our studies showed that even under moderate levels of disturbance, there was a significant decrease in the regeneration of the species. Populations close to human settlements (likely to be impacted more), had a relatively less proportion of small size class individuals than those farther away (likely to be impacted less). Several seed and seedling features were significantly affected by disturbance. Isozyme analysis indicated a decrease in percentage heterozygosity of populations with disturbance at one of the forest sites. There was a genetic structuring of the populations due to disturbance. Populations close to settlements (and hence impacted) tended to cluster in a group and were separated from those farther away (not impacted). Thus our studies showed that anthropogenic pressures can adversely affect the regeneration and genetic diversity of NTFP species in tropical forests. Further studies might be required to identify critical levels of disturbance or pressures that a species can tolerate such that protocols for its sustainable extraction can be prescribed.