Climate change and plant biodiversity in Himalaya, India

Abstract

The Himalaya, the geodynamically active youngest mountain system of the Earth, due to high environmental variability supports rich biodiversity, which makes the fundamental basis for ecosystem services that constitute the basic life support for human being. Most of the life support commodities, such as food, shelter, water, quality air and medicine directly or indirectly depend on plant diversity. However, due to climate change and growing anthropogenic pressure ecosystem structure and function is greatly affected posing threat to the availability of biotic resources on sustained basis. Ground and space based observations show that the biozones across the Himalaya have experienced changes in vegetation in recent decades. Many of the high-elevation temperature sensitive plant species are known to be shifting to higher elevations in the Himalayan region, though the rate of shift being highly species and site idiosyncratic. Increasing magnitude of ecosystem fragmentation associated with the developmental activities coupled with projected warming in the twenty-first century could pose a serious threat to biodiversity that include many of the endemic plant species, progenitors of cultivated and economic plants. The change in climatic conditions also accelerates the invasion of alien species having competitive edge over the indigenous ones. Commendable steps have been recently taken for in-situ conservation of species through the establishment of protected areas across the elevations in the Himalayan region. However, species specific ecological studies and long-term ecological monitoring essentially required to understand relative sensitivity of species to environmental changes in the Himalayan region are still lacking. Such empirical studies in long-term perspective are required to adopt appropriate biodiversity management plans for the Himalayan region. For this it is required to ascertain chronology of species dynamics in relation to environmental changes using precisely dated growth rings of plant species. This should provide appropriate clue to the absolute chronology of species dynamics in response to environmental changes.