Chin J Plant Ecol ›› 2007, Vol. 31 ›› Issue (1): 66-74.DOI: 10.17521/cjpe.2007.0009

• Research Articles • Previous Articles     Next Articles

SOIL ORGANIC CARBON AND NITROGEN DYNAMICS DURING THE RE-VEGETATION PROCESS IN THE ARID DESERT REGION

JIA Xiao-Hong(), LI Xin-Rong, LI Yuan-Shou   

  1. Shapotou Desert Research and Experiment Station, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of sciences, Lanzhou 730000, China
  • Received:2005-09-09 Accepted:2005-12-13 Online:2007-01-30 Published:2007-01-30

Abstract:

Aims It is an important aspect that the soil organic carbon and nitrogen sequestration or release contribute to the soil fertility and atmosphere CO2. However, soil organic carbon and nitrogen dynamics has been argued during the process of desertification, the soil organic carbon and nitrogen is rarely explain during the re-vegetation process in the arid desert region. Furthermore, there have some debates about the relation between the soil particle content and soil organic carbon and nitrogen. So, the following questions toe will be sought (a) Does soil organic carbon and nitrogen content during the re-vegetation process differs in time and space? (b) How is there the relation between soil particle content and the soil organic carbon and nitrogen content?

Methods The distributions of particle size fractions, organic carbon and total nitrogen content in soils profile of 0-5 cm (include soil crust), 5-10 cm, and 10-20 cm at different years since re-vegetation were analyzed.

Important findings The results showed that soil organic carbon and nitrogen contents increased with time since re-vegetation but decreased with soil depth. Fine sand (0.1-0.05 mm), silt and clay (<0.05 mm) content showed similar temporal and spatial patterns. However, sand (0.5-0.1 mm) content decreased with time since re-vegetation and soil depth. Soil organic carbon and nitrogen contents positively correlated with the contents of fine sand and silt+clay (p<0.01) and negatively correlated with the sand content (p<0.01).From the point of view of the reversed desertification or re-vegetation process, our results suggest that change of land use can result in carbon sequestration because of the increment of soil protected carbon content in arid desert region. The spatial and temporal changes of soil organic carbon and nitrogen contents as indices for soil fertility may positively feed back to vegetation succession.

Key words: desert region, re-vegetation, soil organic carbon, total nitrogen