%0 Journal Article %T Capacity of soil to protect organic carbon and biochemical characteristics of density fractions in Ziwulin Haplic Greyxems soil %A Gang Wang %A Chunyan Wang %A Wenying Wang %A Qiji Wang %A
WANGGang %A WANGChunyan %A WANGWenying %A WANGQiji %J 科学通报(英文版) %D 2005 %I %X Physical protection is one of the important ways to stabilize organic carbon in soils. In order to understand the role of soils as a carbon sink or source in global climatic change and carbon cycles and properly manage soils as a carbon sink, we ought to know how many organic carbon (OC) in a given soil could be protected. By a density fractionation approach and ultrasonic technique, each soil sample was divided into three fractions: free light fraction (free-LF), occluded fraction (occluded-LF) and heavy fraction (HF). The obtained fractions were analyzed for total OC content, carbohydrate content and recalcitrant OC content. The results showed: (i) In the whole soil profile, dominance of OC consistently decreased in the following order: HF, free-LF, occluded-LF. This suggested that OC in soils were mostly protected. From 0–10 to 60–80 cm horizons, the OC in free-LF decreased from 25.27% to 3.72%, while OC in HF they were increased from 72.57% to 95.39% The OC in occluded-LF was between 2.16% and 0.89%. (ii) Organic carbon recalcitrance in free-LF was similar to that in HF, and was even higher than that in HF below the surface horizon. This suggested that free-LF was not always the most fresh and non-decomposed fraction. OM quality of HF was higher than that of free-LF in the surface 10 cm below, namely the protected OM had higher quality than free OM in these horizons. %K Ziwulin %K Haplic Greyxems soil %K organic carbon %K physical %K protection %K density fractionation
有机碳 %K 物理保护 %K 生物化学特征 %K 密度分数 %K (Ziwulin %K Haplic %K Greyxems)土 %K 土壤保护 %U http://www.alljournals.cn/get_abstract_url.aspx?pcid=01BA20E8BA813E1908F3698710BBFEFEE816345F465FEBA5&cid=96E6E851B5104576C2DD9FC1FBCB69EF&jid=DD6615BC9D2CFCE0B6F945E8D5314523&aid=2E0451765BE4D58F837D0FC1482392D1&yid=2DD7160C83D0ACED&vid=771152D1ADC1C0EB&iid=CA4FD0336C81A37A&sid=DB817633AA4F79B9&eid=9971A5E270697F23&journal_id=1001-6538&journal_name=科学通报(英文版)&referenced_num=0&reference_num=29