Current Science

Md. Firoze Quamar ¹, P. Morthekai ¹

Affiliations
1 Birbal Sahni Institute of Palaeosciences, 53 University Road, Lucknow 226 007, IN

Abstract

In the three-day Young Scientists’ Conclave organized last year, about 150 participants from India, Bangladesh, Pakistan, Kazakhstan, Sri Lanka, South Africa, Maldives, and other countries of central and South Asia participated and presented their research findings as oral and poster presentations. The event was inaugurated by R. Narasimha (JNCASR, Bengaluru). The inaugural function was followed by invited thematic lectures by eminent scientists and presentations by young scientists with poster sessions, wherein different aspects of earth and climate sciences were discussed.

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Jyotsna Dubey ¹, Biswajeet Thakur ¹, Shailesh Agrawal ¹, Anupam Sharma ¹, P. Morthekai ¹, Vaibhava Srivastava ², S. Nawaz Ali ¹

Affiliations
1 Birbal Sahni Institute of Palaeosciences, Lucknow 226 007, IN
2 Department of Geology, Faculty of Science, Banaras Hindu University, Varanasi 221 005, IN

Abstract

Analysis of spatial variation of diatom assemblages and characterization of carbon isotopic composition of surface soil/sediment samples along three high-altitude transects (Chopta, Lashar and Gurudongmar valleys) in North Sikkim, Higher Himalaya have been done to delineate the ecological information (modern analogue). We have studied the variation in the distribution of diatom species and stable carbon composition in three different valleys having variable climatic conditions ranging from sub-humid to semi-arid. The results reveal that the biotic components respond appreciably towards varying environmental conditions. The spatial distribution of diatoms in surface sediments seems to be controlled by physical parameters such as temperature, water and nutrient availability. The overall δ¹³C values vary from ‒25‰ to ‒29‰, suggesting a C₃-dominated vegetation in the region. Higher δ ¹³C values are observed in Gurudongmar samples that are characterized by less moisture and low temperature. The δ ¹³C values suggest that the source of organic matter in soil/sediment is contributed by open grasslands (C₃ grasses). The isotope values clearly demonstrate an increase in δ ¹³C values along with a progressive increase in elevation and decrease in precipitation. The present data will serve as an important archive for future correlations in palaeoclimatic studies.

Keywords

Carbon Isotopes, Diatom Distribution, Extreme Climate, Modern Analogue, Soil Organic Matter.

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