Classification, Characterization and Comparison of Aquatic Ecosystems in the Landscape of Adilabad District, Telangana, Deccan Region, India

Abstract

A landscape is a mosaic of natural and/or artificial communities and waterbodies and may contain several distinct ecosystems. Human life depends on many services delivered by the water-based aquatic and land-based terrestrial ecosystems. A wide variety of aquatic ecosystems exist and although they represent a low percentage of the Earth’s surface, their roles and functions make them crucial. Aquatic ecosystems especially inland aquatic ecosystems are rich in biodiversity and home to a diverse array of species and habitats, providing numerous economic and societal benefits to humans. Understanding diversity of aquatic ecosystems within landscape is a fundamental goal of both basic and applied ecological research. This study recognizes, defines, classifies, characterizes and compares for the first time the aquatic resources vis-à-vis aquatic ecosystems in the landscape of Adilabad District, Telangana, “Deccan Region”, India, which was selected as the study area. The study was based on a review of available data on aquatic ecosystems in the District, discussions with key personnel, a week day reconnaissance survey over the study area during the pre- and post-monsoon season and a week day field visit during the dry season, 2010-11 by Vegetable Research Station, Rajendranagar in collaboration with National Bureau of Plant Genetic Resources, Regional Station, Rajendranagar. The study recognizes inland waters as important landscape features and reports exclusively freshwater in these inland waters across the study area. About 4.28% of the total geographical area of the study area is covered by inland water resources and/or inland aquatic ecosystems. We developed preliminary three-tiered classification system, which is based on a top-down, hierarchical classification of aquatic ecosystems, following the functionally-oriented hydrogeomorphic (HGM) approach to classification but incorporating structural attributes at the lower level of the hierarchy. The study reports on only one HGM class of aquatic ecosystems namely inland aquatic ecosystems at first level of classification system. The study reports on four HGM sub-classes of inland aquatic ecosystems namely lotic, lentic, wetland and riparian ecosystems at second level of classification system. Adilabad is in many ways abundant by its 19 diverse HGM units including 8 lotic (rivers, rivulets, tributaries, streams, creeks, waterfalls, springs and canals), 8 lentic (lakes, ponds, vernal pools, seeps, reservoirs, farm ponds and reservoirs, drainage ditches and water tanks) and 3 wetland (swamps, marshes and rice fields) at third level of classification system. Adilabad’s complex edaphic, climatic and topographic conditions might have created a diverse array of HGM units. The HGM units in the study area varied in size from small ephemeral pool to large river. These HGM units are intricately tied to the landscape and provide a variety of ecosystem services. These HGM units as standardized ecosystems, recognized and described for the entire District at a relatively fine scale, are useful for a variety of biodiversity conservation and resource management applications. These data can be used to identify areas deserving of management attention due to their value for biodiversity conservation, as well as the production of ecosystem goods and services. In conclusion, the present investigation emphasizes the differences in biophysical and ecogeographic attributes of HGM classes, sub-classes and units of different types and suggests that a complex ecosystem made up of a plurality of aquatic ecosystem types, such as the Adilabad District’s landscape, constitutes an interesting field laboratory in which to test directly hypotheses concerning factors that limit and regulate detritus processing in aquatic ecosystems. Our study also reports known inland aquatic ecosystem services and characteristics and, where appropriate, highlights important research gaps.