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Geoscience ›› 2012, Vol. 26 ›› Issue (5): 896-909.

• Geochemistry • Previous Articles     Next Articles

Estimation of Soil Organic Carbon Storage and Analysis of Soil Carbon Source/Sink Factors in Qinghai Province

 ZHONG  Cong, YANG  Zhong-Fang, JIA  Hua-Ji, HOU  Jing-Xie, JIANG  Wei   

  1. School of Earth Sciences and Resources,China University of Geosciences,Beijing100083,China
  • Received:2012-05-03 Revised:2012-07-30 Online:2012-10-19 Published:2012-10-23

Abstract:

In this paper, the soil organic carbon density of the topsoil (0-20 cm) and the 0-65 cm soil is calculated according to the data from 2,856 soil profiles which are obtained from the second soil survey of Qinghai Province. Organic carbon reserves of different soil are estimated according to the 1∶4 million digitized soil map. Dominating factor of carbon source/sink is analyzed based on the relationship between organic matter, climate, and the data of changing in land use type in different periods. Results showed opinions as follows. (1) The average weight of SOCD20 of the topsoil (0-20 cm) is 4.509 kg/m2; however, there is a significant distinction in different types of soil, with SOCR20 2.953 Pg. The average weight of SOCD65 of the soil profile is 13.597 kg/ m2, with SOCR65 8904 Pg. Generally, as it is limited by the climate, the soil types, the vegetation types and the altitude, the SOCD in Qinghai Province appears a zonal distribution which decreases  from southeast to northwest.(2)Organic carbon content of Qinghai Province declined significantly in recent 30 years. (3) Our study predicted the carbon source in Qinghai Tibet Plateau under the influence of global change, according to the tend analysis of mean annual temperature in recent 50 years, which is of great importance to the global change. With the anthropogenic factors, the release of soil carbon because of the transformation of land use types, such as changing grassland to arable soil, is also a main carbon source in the study area.

Key words: soil organic carbon density;soil organic carbon storage;spatial distribution;global warming;carbon source/sink, Qinghai Province