Late Quaternary vegetational and climatic changes from tropical peats in southern India - An extended record up to 40,000 years BP

Rajagopalan, G and Sukumar, R and Ramesh, R and Pant, RK and Rajagopalan, G (1997) Late Quaternary vegetational and climatic changes from tropical peats in southern India - An extended record up to 40,000 years BP. In: Current science, 73 (3). pp. 60-63.

Preview

PDF 17.pdf - Published Version Download (652kB)

Abstract

Stable carbon isotope ratios of peats dated (by C-14) back to 40 kyr BP from the montane region (> 1800 m asl) of the Nilgiris, southern India, reflect changes in the relative proportions of C3 and C4 plant types, which are influenced by soil moisture (and hence monsoonal precipitation), From prior to 40 kyr BP until 28 kyr BP, a general decline in delta(13)C values from about - 14 per mil to - 19 per mil suggests increased dominance of C3 plants concurrent with increasingly moist conditions, During 28-18 kyr BP there seems relatively little change with delta(13) C of - 19 to - 18 per mil, At about 16 kyr BP a sharp reversal in delta(13)C to a peak of - 14.7 per mil indicates a clear predominance of C4 vegetation associated with arid conditions, possibly during or just after the Last Glacial Maximum, A moist phase at about 9 kyr BP (the Holocene Optimum) with dominance of C3 vegetation type is observed, while arid conditions are re-established during 5-2 kyr BP with an overall dominance of C4 vegetation, New data do not support the occurrence of a moist phase coinciding with the Mediaeval Warm Period (at 0.6 kyr BP) as suggested earlier, Overall, the climate and vegetation in the high altitude regions of the southern Indian tropics seem to have responded to past global climatic changes, and this is consistent with other evidences from India and other tropical regions.

Item Type:	Journal Article
Publication:	Current science
Publisher:	Indian Academy of Sciences
Additional Information:	Copyright of this article belongs to Indian Academy of Science.
Department/Centre:	Division of Biological Sciences > Centre for Ecological Sciences
Date Deposited:	27 Jan 2010 10:00
Last Modified:	19 Sep 2010 05:51
URI:	http://eprints.iisc.ac.in/id/eprint/24685

Actions (login required)

View Item