Soil Organic Carbon Accumulation and Distribution in a Small Watershed and the Effects of Soil Water
The spatial distribution patterns of soil water and Soil Organic Carbon（SOC） caused by topography and land use provide opportunities to study the coupling of water and carbon of the ter restrial ecosystem. It can help us better understand the contribution of soil water to SOC accumu lation and distribution at a watershed scale, but the strong variability of soil water and relative sta bility of SOC bring new challenges for the work. Thereafter, a resampling approach was used to assess soil water and SOC after rainy season based on the continental water balance. Totally 37 plots covering three different landfornls and three different land uses were sampled 100 cm below surface soil using a 3 cm diameter auger. When compared under the same land use, generally soil water and SOC of valley bottom was higher than ridge slope, while gully slope was intermediate; but the water carbon transferring efficiency presented an inverse order. Under the same land form, soil water and SOC of different land uses had the opposite order, when farmland owned the highest water content, its SOC was the lowest; the same occurred at grassland and woodland. Both the woodland and grassland could transfer water to carbon faster compared to farmland. ／ There was a positive relationship fitted well by an exponential growth model （y = Y0 ＋ log a x ax ） between SOC and soil water. Soil water could partially （7% 37% ） explain SOC accumulation and distribution in the small watershed. This would be very crucial for the prediction of SOC ac cumulation and distribution based on soil water variability.
NETL
NSTL
万方数据
维普
