title: [Soil organic carbon mineralization of Black Locust forest in the deep soil layer of the hilly region of the Loess Plateau, China].
abstract: The deep soil layer (below 100 cm) stores considerable soil organic carbon (SOC). We can reveal its stability and provide the basis for certification of the deep soil carbon sinks by studying the SOC mineralization in the deep soil layer. With the shallow soil layer (0-100 cm) as control, the SOC mineralization under the condition (temperature 15 degrees C, the soil water content 8%) of Black Locust forest in the deep soil layer (100-400 cm) of the hilly region of the Loess Plateau was studied. The results showed that: (1) There was a downward trend in the total SOC mineralization with the increase of soil depth. The total SOC mineralization in the sub-deep soil (100-200 cm) and deep soil (200-400 cm) were equivalent to approximately 88.1% and 67.8% of that in the shallow layer (0-100 cm). (2) Throughout the carbon mineralization process, the same as the shallow soil, the sub-deep and deep soil can be divided into 3 stages. In the rapid decomposition phase, the ratio of the mineralization or organic carbon to the total mineralization in the sub-deep and deep layer (0-10 d) was approximately 50% of that in the shallow layer (0-17 d). In the slow decomposition phase, the ratio of organic carbon mineralization to total mineralization in the sub-deep, deep layer (11-45 d) was 150% of that in the shallow layer (18-45 d). There was no significant difference in this ratio among these three layers (46-62 d) in the relatively stable stage. (3) There was no significant difference (P > 0.05) in the mineralization rate of SOC among the shallow, sub-deep, deep layers. The stability of SOC in the deep soil layer (100-400 cm) was similar to that in the shallow soil layer and the SOC in the deep soil layer was also involved in the global carbon cycle. The change of SOC in the deep soil layer should be taken into account when estimating the effects of soil carbon sequestration in the Hilly Region of the Loess Plateau, China.
authors: College of Resources and Environment, Northwest Agriculture and Forestry University, Yangling 712100, China. maxinxin125@126.com
authors: Xin-Xin
authors: XX
authors: Ma
authors: Ming-Xiang
authors: MX
authors: Xu
authors: Kai
authors: K
authors: Yang
mesh_terms: D000531:Altitude; D002244:Carbon / Q000032:analysis*; D057965:Carbon Sequestration / Q000502:physiology; D002681:China; D008903:Minerals / Q000737:chemistry*; D009930:Organic Chemicals / Q000032:analysis*; D031301:Robinia / Q000254:growth & development* / Q000502:physiology; D012987:Soil / Q000737:chemistry*
chemical_list: D008903:Minerals; D009930:Organic Chemicals; D012987:Soil; D002244:Carbon