Studies on pollen deposition pattern in relation to modern vegetation of flood prone region in Assam, India

Abstract

This paper presents a palynological dataset on Pashumara Wetland and Ranga Reserve Forest to differentiate flooded and non–flooded area in relation to existing vegetation in Assam. Study reveals that the palynoassemblage in Pashumara Wetland is an admixture of arboreal local and extra–local taxa and not fully matches with present vegetation. The various pollen distributions were observed in continuation to study sites and confirmed that pollen deposition pattern in wetland depends on parent plant growth, flood activity and surrounding vegetation. Presence of broken pollen is indicative of long distance transportation under a fluvial environment. The palynoassemblage of Ranga Reserve Forest located in non–flooded area to display modern pollen and vegetation relationship and identification of local arboreal taxa in the region. The main forest elements include Syzigium, Lagerstroemia and Emblica in the palynoassemblage are suggestive of presence of tropical deciduous forest under warm and humid climate. Pollen clumps in the palynoassemblage signifies their local origin and entomophily. This generated palynodata could be precisely utilized to distinguish flooded and non–flooded area and to interpret palaeovegetation and past climate changes in relation to palaeoflood episodes by the analysis of wetland core from the region and to correlate other tropical flood prone region of the globe.