Growth assessment of Borinda grossa after natural regeneration in relation to environmental factors

Abstract

Mass flowering of Borinda grossa occurred in 2015 in the central region of Bhutan. To assess its growth after natural regeneration, a field study was carried out in the Busa community forest (CF) located in Sephu gewog, Wangduephodrang district. A total of 39 sample plots of quadrat size 10 × 10 m were laid out in a study site of 80 hectares using systematic sampling to carry out bamboo inventory. The soil samples were collected using composite soil sampling from all the plots. Sample plots were categorized into bamboo presence and absence plots. Growth of bamboo was assessed in association with environmental factors. Wilcoxon signed rank test was used to compare environmental parameters between bamboo presence and absence plots. The result indicated significant differences in elevation, canopy cover and soil electrical conductivity. The growth of bamboo by diameter, height and count was highest in the elevation range between 2700 to 2800 m under medium canopy cover of 20 to 40% in loamy-sandy soil. Maximum number of bamboos was found in north and west facing slopes