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Dendrochronological analysis of Pinus merkusii (Merkus pine) collected from Mishmi Hills, Arunachal Pradesh, North–east India shows its potential to provide continuous and long–term information about changes in river flow of Lohit River Basin (LRB). A 170 years (1830–1999 C.E.) long regional tree-ring width chronology of Merkus pine was prepared using 80 tree cores. Based on the correlation analysis between tree-ring chronology and river discharge data, the river flow was reconstructed for the month of May from 1846 to 1999 C.E. The reconstruction showed long term low and high flow periods along with extreme drought and pluvial years. Past river flow reconstruction for hydro–climatic variability in this southwest monsoon-dominated region of North–east India requires further notice. Longer tree–ring records along with wider spatio-temporal network of discharge data from Arunachal Pradesh will help to develop better records of river flow reconstructions of the region.

The vegetation distribution in Tripura, Northeast India was studied from the modern pollen assemblages at various sites in the region. Sediment samples and moss cushions were collected along transects from North to South Tripura to assess the modern pollen taxa dominant in the region. A number of taxa showing a modern day distribution of moist deciduous mixed vegetation dominant in Tripura were observed in the modern pollen data. Statistical significance of the modern–pollen data was verified using one–way ANOVA technique. Despite the limited pollen taxa recorded in the surface samples the analysis proved the potential of the pollen data and scope for future palynological studies. The impact of anthropogenic activity is clearly visible through the low sample yield and presence of taxa such as Poaceae, Amaranthaceae, Solanaceae, etc. Other factors such as entomophilous tendency and/or low yield of pollen in tropical plants, excessive rainfall, sediment distribution and jhum cultivation could contribute to the lack of pollen preservation in the region.