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Please use this identifier to cite or link to this item: http://repository.iitr.ac.in/handle/123456789/6124
Title: An environmental record of changes in sedimentary organic matter from Lake Sattal in Kumaun Himalayas, India
Authors: Choudhary P.
Routh J.
Chakrapani G.J.
Published in: Science of the Total Environment
Abstract: Sattal a small mountainous lake in the Kumaun Himalayas has been impacted by various cultural activities in recent years. We explored the effects of human-induced changes in this lake by using various geochemical proxies. Shifts in TOC and N flux, C/N ratio, stable isotopes (?13C and ?15N), n-alkane, and pigment concentrations in sediments indicate a steady increase in primary productivity over the last few decades. The trophic status of the lake has changed from mesotrophic to eutrophic condition. The C/N, CPI, and TAR based ratios in sediments indicate accumulation of algal matter derived primarily from in situ production, with limited input of terrestrial organic matter from the watershed. The low (between 0.1 and 1‰) ?15N values imply N2-fixation by cyanobacteria, and the decrease in ?13C values up-core represent the effect of sewage input and land based runoff, or possible contribution from microbial biomass. The pigments change from non-N2 fixing cyanobacterial species to the N2-fixing community, and are consistent with the proxy-based productivity shifts inferred in the lake. The deeper sediments are affected by post-diagenetic changes causing an increase in ?13C (and possibly ?15N) due to mineralization of organic C and N. © 2008 Elsevier B.V. All rights reserved.
Citation: Science of the Total Environment (2009), 407(8): 2783-2795
URI: https://doi.org/10.1016/j.scitotenv.2008.12.020
http://repository.iitr.ac.in/handle/123456789/6124
Issue Date: 2009
Keywords: Cyanobacteria
Hydrocarbons
Pigments
Productivity
Stable isotopes
ISSN: 489697
Author Scopus IDs: 36839712400
7003939387
6701873646
Author Affiliations: Choudhary, P., Department of Earth Sciences, Indian Institute of Technology Roorkee, Roorkee, 247667, India
Routh, J., Department of Geology and Geochemistry, Stockholm University, 10691 Stockholm, Sweden
Chakrapani, G.J., Department of Earth Sciences, Indian Institute of Technology Roorkee, Roorkee, 247667, India
Funding Details: P. Parthasarathy and R. Saini helped in sampling the lake. Supriyo Das helped with the pigment analysis. Klara Hajnal and Heike Seigmund are acknowledged for their help in the laboratory. Dr. Bhism Kumar is acknowledged for providing the lab facilities for lead dating. Discussion with Philip Meyers and Volker Bruechert was helpful. We thank the anonymous reviewers for their careful review and suggestions. The Swedish Research Link-Asia program funded the study. PC was supported on a CSIR fellowship.
Corresponding Author: Routh, J.; Department of Geology and Geochemistry, Stockholm University, 10691 Stockholm, Sweden; email: joyanto.routh@geo.su.se
Appears in Collections:Journal Publications [ES]

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