Structural Composition and Productivity Assessment of the Grassland Community of Kaziranga National Park, Assam

Abstract

Grassland communities of Kaziranga National Park (KNP) classified as Eastern Wet Alluvial Grasslands. It comprised of tall grasses (61%) as well as short grasses (only 3%). Rapid periodic changes occurred due to recurrence of flood, erosion and alluvial deposition and have direct implications for the establishment of early successional species. Grassland can be viewed in terms of upland grasslands and lowland grasslands. Apluda mutica, Arundinella bengalensis, Imperata cylindrica, Thysanolaena maxima, Saccharum spp., Vetiveria zizanioides, characterize the upland grassland and the lowland grasslands comprise predominantly of Phragmites karka, Imperata cylindrica, Saccharum spontaneum, Arundo donax and Saccharum narenga which considered being early successional species. Seven tall grasses and three short grasses communities have been identified. Above ground biomass increased from June to October due to rapid growth after the commencement of monsoon rain and declined during the winter months. The peak growth rate of total above ground biomass (31.94 g m^-2 day^-1) is much higher than the other grassland types reported elsewhere in India. Frequent burning resulted drier habitat and Pharagmites karka was replaced by Saccharum, Sclerostachya, Themeda and Imperata species. Excessive grazing favours the establishment of unpalatable species like mperata cylindrica, Vetiveria zizanioides etc. and several pure stands of these grasses developed.