Palynological studies on mangrove ecosystem of the Chilka Lagoon, east coast of India during the last 4165 yrs BP

The palynological studies of a sediment core collected from the northeastern region of the Chilka Lagoon, reveal the history of mangrove vegetation during the last 4165 yrs BP The Chilka Lagoon (a Ramsar Site) is one of the ecologically and socio-economically important wetlands situated in the humid tropical climatic zone along the east coast of India. The palynological results indicate that the mangrove vegetation was well developed between 4165 and 2549 yrs BP, indicating warm and humid climatic conditions; though, they show a degrading trend in the latter phase of this period. After 2549 yrs BP, mangroves again flourished in the area and persisted until 2246 yrs BP, as a result of relative stability of sea-level. The mangroves disappeared since 2246 yrs BP, as inferred from the marked increase of midland taxa, indicating drier conditions. Along with climatic factors, anthropogenic activities have also accelerated the degradation of mangroves in the study site. The present study provides an understanding of mangrove ecosystem in the past and such investigations could also be useful for the regeneration of the mangroves in the region.