Organic carbon stabilized by iron during slump deformation on the Qinghai-Tibetan Plateau

• Published in: Catena (Giessen) 2020-04, Vol.187, p.104282, Article 104282
• Main Authors: Mu, Cuicui, Zhang, Feng, Mu, Mei, Chen, Xu, Li, Zhilong, Zhang, Tingjun
• Format: Article
• Language: English
• Subjects: Climate warming; Permafrost; Soil variables; Total nitrogen; Vegetation types
• ISSN: 0341-8162; 1872-6887
• DOI: 10.1016/j.catena.2019.104282

•We measured the organic carbon associated with iron in slump deformation landscapes.•Slump deformation changed soil variables and decreased organic carbon and nitrogen.•Changes of the carbon associated with iron varied among vegetation types.•Organic carbon stabilization processes can be affected by slump deformation features. Soil organic carbon (SOC) associated with iron (Fe-OC) can be recognized as an important component of the stabilized carbon pool. In permafrost regions, slump deformation can expose soil organic carbon and alter moisture conditions, which change the Fe-OC distribution. We measured the top 30 cm of soils in five slump deformation landscapes under three vegetation types on the middle and eastern Qinghai-Tibetan Plateau. Three stages of slump deformation were defined according to their microtopography. In the slump deformation areas, the SOC and total nitrogen (TN) contents in the surface 30 cm of soils were all lower than the soils without slump deformation in wet meadow (22% and 26%), meadow (16% and 29%), and steppe (14% and 20%) areas. The contents of Fe-OC in wet meadow were 4.1% and 12.5% in the soils without and with slump deformation, respectively, whereas these contents in the meadow and steppe soils were 25.6% and 17.2%, respectively. Slump deformation greatly changed the physiochemical soil variables and affected the Fe-OC% based on different vegetation types. Fe-OC was correlated with factors such as soil moisture, pH and C/Fe ratio. The study shows that slump deformation greatly affected the SOC and TN distribution and SOC stabilization processes in areas with slump deformation features.