Population structure and dynamics of Abies spectabilis at treeline ecotone of Barun Valley, Makalu Barun National Park, Nepal

The population structure and dynamics of high altitude, long-lived treeline species can be utilized as an indicator for climate change. This study was conducted in the treeline ecotone of the Barun Valley, eastern Nepal in order to understand the population dynamics of Abies spectabilis. The A. spectabilis population showed the reverse J-shaped size and age distribution curves indicative of undisturbed old growth forest. The age structure is mostly dominated by the young individuals, however, their mortality was found to be very high. Positive relationships between recruitment and high temperatures during winter months (January, February and December) and one summer month (August) were discovered. No significant relationship was found between precipitation and climate of the region. If warming condition prevails in summer and winter seasons in the near future, then there is chance that more individuals will be established above the treeline area, triggering the treeline advance.