Soil organic carbon stock and sink potential in high mountain temperate himalayan forests of India

The estimation of soil organic carbon stock along altitudinal gradient was carried out in Kedarnath Wildlife Sanctuary of Garhwal Himalaya in different vegetation types. The moisture content in the soil increased with increasing altitude and the highest moisture was recorded in Betula utilis forest at an elevation of 3550 m amsl followed by Grassland (3050 m), Rhododendron arboreum forest, (2550 m), mixed forest (Quercus and Rhododendron species, 2050 m) and Pinus roxburghii forest (1550 m). The bulk density also followed similar trend as moisture, which increased with increasing altitude. The soil carbon stock also increased with altitude and the highest carbon stock (35.4±1.8 Mg C ha-1) was in Betula utilis forest soils and the lowest (19.2±2.7 Mg C ha-1) in Pinus roxburghii forest soils. Thus moisture showed positive correlation with carbon stocks, higher the moisture, higher was carbon stock. Thus high precipitation and low temperature is associated with increasing altitude which enhances soil carbon stock at higher altitudes.