Tree carbon stock in middle mountain forest types: A case study from Chandragiri hills, Kathmandu, Nepal

The forest carbon stock usually depends on the forest types, forest density, age of forest, size of trees, site quality, wood density, annual precipitation, and species composition. This research aims to analyze the relationship among tree carbon stock, species richness, soil chemical properties such as soil organic carbon, and soil pH in the Forests of Chandragiri Hills, Kathmandu, Central Nepal. Along this forest, five square plots (20 × 20 m2 ) each were established along the two transects at a maximum interval of 100 m. Carbon stock of each tree was estimated by using allometric equation based on measured tree height and DBH. The mean tree carbon stock was found to be highest in Mixed Forest (87.13 t/ha) followed by Oak Forest (52.75 t/ha), and Pine Forest (22.5 t/ha). The tree carbon stock showed significant negative correlation with tree species richness (r = -0.56, p = 0.001). The tree carbon stock showed significant positive correlation with soil organic carbon (r = 0.57, p = 0.001) and soil pH (r = 0.37, p = 0.05). Tree carbon was found positively highly significant correlation with altitude, Soil organic carbon, pH, and Shannon diversity index.