Habitat Assessment and Regeneration Pattern of Himalayan Birch (Betula utilis) in Royal Botanical Park, Lampelri

The Himalayan Birch (Betula utilis D. Don) an essential tree species due to its ecological and social importance in the himalayan region. The study assessed the effect of environmental factors on habitat, growth, and regeneration patterns of the Himalayan Birch at the Royal Botanical Park, Lampelri, Bhutan . Two vertical transects with a spacing of 75 m were laid across the altitudinal gradient. A total of 10 circular sample plots were laid on each transect with a plot size of 12.62 m for trees, 3.57 m for regeneration, and 0.57 m for ground cover vegetation. A total of 119 vascular plant species under 45 families were recorded in 20 survey plots. The Spearman rho’s correlation showed strong negative correlation between the species abundance and temperature (rs=- .83) and positive correlation with the species count and altitude (rs = .83). The species richness in the study area showed an initial increase up to certain with elevation and then decreased with further increase in elevation. The importance value index (IVI) of tree species showed Tsuga dumosa as the most dominant species. Betula utilis indicated an increasing density with an increase in elevation. The regeneration of Betula utilis was poor as it was mostly found in a sapling stage. From a total of 43 tree species regenerating, 13.95% showed good regeneration, 34.88% fair, 23.25% poor, and 4.65% without regeneration. The remaining 23.25% seems to be either reappearing or immigrating.