Edge transition impacts on swamp plant communities in the Nilgiri Mountains, southern India

Abstract

Swamps represent a relatively understudied ecosystem in many regions, which contrasts markedly with the research attention which other wetlands and Mangrove ecosystems have received. In the upper Nilgiris of southern India, montane swamps are restricted to geographic areas with flat surfaces and bounded by different edge transition vegetation types including grasslands and shola forests. Our study examined whether species richness, endemism, edge and the composition of swamp interior communities have a significant relationship with swamp area. Using species-area curves we continued sampling for species in each swamp until species richness reached the asympote within that swamp. Our results suggest that species richness (log n), log endemism, and edge and swamp interior species composition do not increase significantly with increasing area due to edge effect. Moreover, swamp area and vegetation parameters showed no significant relationships. However our results did indicate that swamps species richness and endemism were affected by abiotic and biotic edge effects, particularly physical topographic environment and the structure of adjoining matrix vegetation. Therefore swamp protection and restoration, in addition to the preservation and management of buffer regions may be important conservation criteria to preserve these fragile ecosystems. © 2014, ALÖKI Kft., Budapest, Hungary.