Chapter 5 - Impact of climate change on the river ecosystem

Abstract

An ecosystem is the sum total of interactions among plants, animals, microorganisms and also the interactions among within themselves and amongst the non-living physical and chemical environment. River as an ecosystem having unidirectional flowing water; with a state of constant physical transformation; numerous diverse with fluctuating microhabitats; and irregularity within the water current, flora and fauna that have adapted to flourish within flowing water. The invasion of new flora and fauna species, seasonal alteration, period and place of precipitation and unpredicted upsurge of microbial diversity are numerous projecting effects of climate change on aquatic environment. The consequences of change in climate on watercourses are probable to fluctuate extensively with latitude. The alteration in both temperature and precipitation are the utmost important physical effects of change in climate on river ecosystem. Rivers of temperate climate will be disturbed predominantly by fluctuations in temperature, whereas variations in the season and amount of precipitation could have intense influences on rivers of tropics. The atmospheric conditions are extremely significant and principally accountable for the processes of heat exchange occurring at the surface of water. The flow rate of a river can rise or decline reliant on fluctuations in the mean precipitation. Increase in precipitation leads to frequent floods. Extreme events like flooding and landslides could add significant wood splinters to the rivers/streams and interrupt the whole channels of the river. The main effects of temperature on faunal species are regulating their metabolic rate and rate of development; restraining the development and distribution, reviving to an orientation response, camouflaging or hindering the articulation to further environmental aspects and toxic effects whichever directly destroy the creature or obliquely as a stress effect leads to migration of species. Hence, the climatic conditions affect species distributions and species richness patterns across the globe. However, a successful climate change mitigation, adaptation and restoration must have suitable temporal and spatial scales. Habitat preservation, heterogeneity and conservation of biodiversity are the key factors to manage the river ecosystem in a changing climate. Rare and vulnerable species protection leads to public attention, awareness and funding for conserving the ecosystem. Protection of physical structures like flow pattern of water, morphology of the channel and nutrient stability are most important. Anthropogenic stress like overuse and meagre practices of diverse land use patterns should be improved. Harmful exotic species should be eliminated from the reserves. Watershed management including restoration of drainage basin has functioned the crucial part in protection of aquatic ecosystem. Therefore, importance should be furnished to lower the release of greenhouse gases into the atmosphere and this will lessen the unpredicted alteration in numerous climatological factors.