JOURNAL OF NATURAL RESOURCES ›› 2012, Vol. 27 ›› Issue (3): 430-439.doi: 10.11849/zrzyxb.2012.03.009

• Resources Ecology • Previous Articles     Next Articles

Soil Organic Carbon Accumulation and Distribution in a Small Watershed and the Effects of Soil Water

ZOU Jun-liang1, GUO Sheng-li1,2, LI Ze1, ZHANG Fang1, ZHANG Yan-jun1, ZHOU Xiao-gang2, NAN Ya-fang1   

  1. 1. College of Resources and Environment, Northwest A & F University, Yangling 712100, China;
    2. State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, CAS and MWR, Yangling 712100, China
  • Received:2011-05-09 Revised:2011-07-14 Online:2012-03-20 Published:2012-03-20

Abstract: 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 terrestrial ecosystem. It can help us better understand the contribution of soil water to SOC accumulation and distribution at a watershed scale, but the strong variability of soil water and relative stability 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 landforms 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 landform, 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×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 accumulation and distribution based on soil water variability.

Key words: soil, soil organic carbon, small watershed, soil water

CLC Number: 

  • S153.6