Seed maturity and other phenological studies acquire a new importance because its relation to climate change and can be used to predict the adaptiveness of a species. We have investigated maturity period of a rare distributed, under canopy tree Carpinus viminea (Himalayan Hornbeam). The main objective of the study is to find out seed maturity period along the environmental gradient in relation to change in climatic conditions (especially the temperature and rainfall) for its better regeneration, conservation and multiplication. The study indicated that seed moisture negatively relation with germination (r2=0.43, 29df, p<0.001) while positively with seed fresh weight (r2=0.34, 29df, p=0.001). Elevation showed positive relation for both seed germination (r2=0.38, 29df, p=0.002) and filled seed production (r2=0.40, 29df, p<0.001). Seed maturity period was found in the first week of November. The elevations 2100 to 2300m are the potential for its seed collection and regeneration programs. Early flowering due to temperature rise and high rainfall during flower maturation may be responsible for low pollination success and could be the reason for low sound seed percentage consequently the germination in year 2nd. Such erratic climatic irregularities will likely to be more pronounced in coming future due to climate change. Under such conditions existence of the species below 2000m in will be in jeopardy.
