Soil carbon stock and floristic biomass carbon under different agroforestry systems along an elevation gradient

An inventory of floristic diversity and carbon stock in vegetation and soil (0-30 cm depth) of traditional agriculture-based agroforestry system (TAAF) along an elevation gradient (E-1 < 850 meters above mean sea level (amsl); E-2 851-1150 meters amsl; E-3 1151-1450 meters amsl; E-4 1451-1750 meters amsl; E-5 > 1751 meters amsl) in the Western Himalaya was developed. A total of 56 species from 43 genera and 23 families were documented in TAAF, of which 57.14% of species comprised of trees and 42.86% of agriculture crops. The total biomass carbon stock of TAAF was 29.87 Mg C ha(-1). The contributions of crops, forest trees and fruit trees to total biomass carbon were 22.84%, 42.31% and 34.85%, respectively. The total carbon stock (vegetation and soil) was maximum at E-4 (92.64 C Mg C ha(-1)) which was at par with E-3 and E-5. The soil organic carbon stock accounted for 65-67% of the total carbon stock across different elevation zones. A positive correlation was found between woody diversity and vegetation carbon stock, whereas correlation between woody diversity and soil organic carbon stock was non-significant. Thus, TAAF of Western Himalayas have a significant role in climate change mitigation and conservation of native crops and tree biodiversity.