Analyzing Environmental Determinants of Tree Species Distributions and Regeneration Pattern in Western Himalaya via National Forest Inventory of India

ABSTRACT Tree distribution has been considered crucial to assess the relationships between species occurrence and changing climate across the globe, and accordingly in designing the conservation action plans. Therefore, it becomes imperative to understand the most influential parameters for tree species distribution and its regeneration pattern. We used National Forest Inventory data collected in Western Himalaya (WH) and environmental parameters to reveal the aforesaid relationship and pattern. Three topographical factors (altitude, aspect, and slope), four major climatic variables (temperature, temperature seasonality, precipitation and its seasonality) and four edaphic factors (soil depth, soil humus, soil consistency and soil coarse fragments) were considered. The results indicated that the altitude and temperature were the major determining factors followed by temperature seasonality in shaping the distribution of major tree species in WH. The study also indicated an upward shift of regenerating individuals of these tree species toward higher altitude. These information about the extent of current tree distribution and their regeneration over the last one and half decade might help in systematic conservation planning and monitoring tree range dynamics under climate change scenario.