Late Pleistocene and Holocene vegetation changes and anthropogenic impacts in the Cauvery delta plains, southern India

Abstract

A 5 m long core from Uttarangudi in the distal plain of Cauvery delta in South India provides evidences of vegetation, climate and anthropogenic activities during the late Pleistocene and Holocene. The pollen catchment area for this region is the localised sources, including the adjoining Tertiary upland plateau. The recorded variation in pollen assemblages and sediments indicates that the environmental conditions have changed over time from aerial oxidising to lacustrine or ponded environment. The lack of pollen records from 17,802 cal BP until 11,535 cal BP suggests severe drier conditions and an extremely patchy, species-poor Tropical Dry Evergreen Forest (TDEF) vegetation community associated with an arid climate. Between 11,535 and 8487 cal BP, partial climatic amelioration appears to have occurred, and the trend become humid until 7034 cal BP characterised by the expansion of the TDEF vegetation and strengthening of the monsoon precipitation. The period from 7034–3553 cal yr BP recorded a regressive transition of the forest taxa influenced by a weakened monsoon precipitation and enhanced anthropogenic activity. The subsequent increase of disturbance signals post 3553 cal yr BP is in agreement with independent archaeological evidences obtained from this region.