Influences of fragmentation on plant diversity: An observation in eastern Himalayan tropical forest

Tropical forest fragmentation has been a major concern towards biodiversity conservation. Indices to determine the community structure and their relationship with forest fragmentation have been a matter of investigation. Here, I investigated the plant diversity across a fragmentation gradient in a typical human-influenced forested landscape in eastern Himalaya. The stratification for guiding field sampling was done using satellite remote sensing derived forest type map at 1:50,000 scale. The results of 49 sample plots (nested quadrant of 20×20 m size) following stratified random sampling method were analysed. It was observed that high fragmented forests have fewer plant species, reduced anthropogenic use evidence and newer community types than medium and low fragment forests. In general, species diversity and species dominance were observed to be inversely proportional and directly proportional to forest fragmentation. Basal area followed a decreasing trend along fragmentation gradient. These results revealed that higher level of fragmentation permits low diversity in the eastern Himalayan tropical forests.