AN ECOLOGICAL SURVEY OF THE FAUNA AND FLORAIN THE ISLANDS OF MAHAWELI RIVER IN THE HALLOLUWA AREA, KANDY DISTRICT, SRI LANKA

摘要

River islands are very important from both morphological and ecological points of view. They represent the most natural state of a fluvial system and are influenced by human impact (Picco et al., 2012). River islands are defined as discrete areas of woodland vegetation surrounded by either water-filled channels or exposed gravel (Ward et al., 1999) which exhibit some stability (Osterkamp, 1998) and are not submerged during bank-full flows. Islands have the potential of enhancing the biodiversity within the riparian zone, because their shorelines are characterized by a mosaic of habitat patches of different ages and the level of disturbance and geo-morphological character, which are uncommon features along heavily managed river banks (Gurnell et al., 2001). Because islands are separated from the floodplain, they may offer a safe refuge for wildlife from many predators.