Carbon Stock Estimation in Lower Temperate Forest in Shivapuri Nagarjun National Park, Nepal

Abstract

Mitigating the climate change due to increase in CO emissions is gaining increased importance. Forests play an important role in the global carbon cycle as forest vegetation and soil can sequester the atmospheric carbon in the form of biomass and soil organic carbons. Thus buffering the rate of climate change by reducing the atmospheric CO 2

which is one of the GHGs. Maintaining existing stocks of carbon in forests is also important as a cheap way to mitigate climate change. Shivapuri Nagarjun National Park (SNNP) having a luxuriant temperate forest is serving well in carbon sequestration. Temperate region of Shivapuri forest of SNNP was sampled. Quadrats of size 20m×20m were laid randomly at different altitude zones. Four altitude zones (2100m, 2300m, 2500m and 2700m) were considered and sampling was done within 2050-2150m, 2250-2350m, 2450-2550m and 2650-2732m, respectively. In each altitude zone four South-East and four South-West facing quadrats were plotted. Using allometric equations and root shoot ratio the vegetation biomass of tree and shrub of each quadrat was estimated. The biomass was converted to carbon stock. Bulk density, pH, organic carbon content and nitrogen content of soil at different horizontal depths of 0-25cm and 25-50cm were analyzed. The soil carbon stock upto the depth of 50cm was estimated. Then biomass carbon and soil carbon were summed up to get total carbon stock. Mean biomass, biomass carbon stock, soil carbon stock of the temperate forest of Shivapuri were found 797.57, 398.78 and 200.80 t/ha, respectively. Thus mean total carbon stock was 599.58 t/ha. Mean total carbon stock at four different altitude zones were significantly different, whereas at the SE and SW aspects were similar. The altitude zone 2500m was found with highest biomass carbon stock, soil carbon stock and total carbon stock with mean values 682.19, 238.09 and 920.28 t/ha, respectively. The organic carbon content and nitrogen content in the upper horizon (0-25cm) were found higher than that of lower horizon (25-50cm). Whereas the pH and bulk density in the upper horizon (0-25cm) were found lower than that of lower horizon (25-50cm). Temperate forest of Shivapuri was found with more carbon stock in comparision to other forest types of Central Himalaya.