Impact of anthropogenic factors on abundance variability among lichen species in southern Assam, north east India

The paper deals with a study of species abundance pattern in lichen communities. Three areas with different anthropogenic pressure levels were evaluated for lichen community structure. It is observed that the area with least anthropogenic pressure shows a general universal pattern of natural communities i.e. a J-curve pattern where majority of the species are rare and few are abundant. With a small change in anthropogenic pressure there is little effect on rare species but the abundant species increased. With major changes both the rare and the abundant species decrease changing the overall community composition. The J-curve changes to a uni-modal curve; the moderately abundant species are found to be resilient against anthropogenic pressure levels. The community ecology of organisms has its root in evolutionary history, succession, and biogeography. The studies on community ecology, therefore, may help in throwing significant light on these important aspects and can also be used as indicators of ecosystem health.