Monsoonal climatic reconstruction from Central India during the last ca. 3600 cal yr: signatures of global climatic events, based on lacustrine sediment pollen records

Abstract

Pollen analyses of a 90 cm deep lacustrine sediment profile from the Mahasamund District of Chhattisgarh State, central India demonstrated that between ca. 3600 and 2500 cal yr BP (Neoglacial climate interval), open forest vegetation occupied the landscape in the region under a dry climate, probably indicating reduced monsoon (the Indian Summer Monsoon: ISM) rainfall. Further, the open forest vegetation was succeeded by a mixed tropical deciduous forest between ca. 2500 and 1650 cal yr BP (∼550 BC to AD ∼300) under a warm and humid climate with increased monsoon rainfall. The warming period and an amelioration of climate (strong ISM condition) is comparable to the Roman Warm Period (RWP), recorded globally between 2500–1600 cal yr BP (∼550 BC to AD ∼350), and also known as the ‘Golden Age of India’ owing to increased agricultural output, trade commerce and socio-economic prosperity in India. Subsequently, between ca. 1650 and 950 cal yr BP (AD ∼300–1000), the existing mixed tropical deciduous forest transformed into an open mixed tropical deciduous forest under a warm and relatively less humid climate with reduced monsoon rainfall, correlatable with the Dark Ages Cold Period (DACP). Finally, between ca. 950 cal yr BP to the present (AD 1000 onwards), mixed tropical deciduous forest again came into existence and occupied the landscape around the study area under a warm and relatively more humid climate with intensification of the monsoon rainfall, corresponds with the Medieval Warm Period (MWP), which is known between AD 740 and 1150 worldwide.