A study of the ecology of select species of weeds in different vegetation types of Nilgiri Biosphere Reserve

Abstract

Invasion by weedy species of plants has serious impact on natural and managed ecosystems. Weedy species invade agricultural lands, fallow lands, roadsides, disturbed forests and plantations. Invasion by such species modifies the ecosystem structure and function. Invading species may dominate and displace the native vegetation and cause extinction of certain native species, leading to alteration in the original biodiversity of an area. In recent years, biological invasion is being recognised as a serious threat to biodiversity conservation (Pimm and Gulpin 1989, Vitousek et al. 1996). In contrast to studies in agricultural fields, not much attention is given to plant invasion in natural ecosystems. Nevertheless, the colonisation of natural forest ecosystem by weedy species is growing as a threat. In recognition of the threats posed by plant invasions in natural vegetation and realising the scarcity of ecological information on various colonising plant species