Climate, C/N ratio and organic matter accumulation: An overview of examples from kashmir himalayan lakes

Abstract

This present study provides an overview of the C/N ratio and organic matter (OM) contents in surface sediments of four lakes that occur in the Kashmir Valley. Valleys are depressed areas of land that influence climate and weather at both global and local scales. The oval-shaped intermontane valley is dotted with numerous freshwater lakes of various shapes and depths. These lakes represent the remnants of a substantial Karewa Lake body that extended across the valley floor currently occupied by the modern lakes. The study presented is based on analysis of the organic material deposited on the lake basin floors, transported via both natural and anthropogenic sources. The present deposition of terrestrial organic material in the lake sediments has apparently altered the trophic status of these lakes from oligo- to eutrophic conditions. Analysis of the C/N ratio in the Holocene lake sediments suggests that these lakes are dynamic ecosystems the accumulation of organic material being sources and depositional processes occurring within these lake basins. The report reviews the accumulation of organic material and the C/N ratio of the surface sediments, and discusses their potential value in palaeoclimatic interpretation of fossil sediments in these lake basins to serve as an analogue with older materials. The organic material deposited in these lakes is predominantly a function of climatic conditions in the valley. The organic and isotopic composition of the lake sediments can potentially provide important information of past lake nutrient dynamics, palaeoenvironmental changes and depositional sources influencing the basins through time.