Plant diversity in the threatened sub-tropical grasslands of Nepal

Previously extensive tall grasslands, and their associated fauna, are now restricted to small fragments in protected areas in lowland Nepal and northern India. Conservation management of the remaining grasslands has been hindered by the lack of a grassland classification. A classification of the grasslands in four protected areas in Nepal is presented. Two hundred and forty six plant species were recorded and nine species assemblages, with eight phases, were identified. Royal Chitwan National Park contained the greatest diversity of assemblages, whilst Royal Bardia National Park and Royal Suklaphanta Wildlife Reserve, were of conservation significance for the occurrence of an Imperata cylindrica assemblage and its associated fauna. Early successional assemblages dominated by Saccharum spontaneum and Phragmites karka predominated in Koshi Tappu Wildlife Reserve. The spatial and temporal distribution of grassland assemblages is primarily influenced by fluvial processes but also by fire, cutting and grazing. Changes in the impact of these disturbances, for example as a result of dam building or a change in the fire regime, will alter the diversity and distribution of the plant assemblages together with their associated fauna. Immediate conservation action should involve controlling grazing in Koshi Tappu, removing invading woody species from Imperata cylindrica grassland and mapping the distribution of assemblages in all protected areas. (C) 1999 Elsevier Science Ltd. All rights reserved.