Diatom assemblages as indicators of the ecoregions within lower gangetic plains of india using taxonomic and ecological analyses

Abstract

Ecoregions have conventionally been defined on the basis of complex patterns of the planet determined by climate, geology, altitude and the evolutionary history of the region. Interestingly, the distribution and spread of biodiversity also follows such patterns as designated by ecoregions. Ecoregions are not bounded by clearly fixed and sharp boundaries, but the area newlineenclosed within is where the important evolutionary and ecological processes strongly interact. It is also known that while the ecoregions - namely tropical forests and coral reefs harbour the most newlinebiodiversity and are the traditional targets of conservation priorities, unique manifestations of nature are found in temperate and boreal regions, in deserts and mountain chains, and very importantly in hydro-ecoregions or ecoregions that are terrestrial by nature but with significant newlineinfluence of large aquatic systems in the forms of rivers or seas. Such areas, in many instances are found to occur nowhere else on Earth and are at the risk of being lost forever with changing aquatic patterns if not conserved. newlineImportance of an ecoregion varies greatly not only in their biological distinctiveness but newlinealso for their conservation status. The aim of defining conservation status in accordance with newlineecoregion classification is based on landscape or aquascape-level criteria, such as total loss of newlinehabitat, degree of fragmentation, quality of water, estimates of future threat and conservation of a newlineset of ecoregions which have exceptional levels of biodiversity such as high species richness or newlineendemism and those ecoregions which are Global representative of the worlds habitats (Olson newlineand Dinerstein, 2002).