EGU22-6676
https://doi.org/10.5194/egusphere-egu22-6676
EGU General Assembly 2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

Interactive effects of land use and soil erosion on soil organic carbon in the dry-hot valley region of southern China 

Yawen Li1, Xingwu Duan1, Ya Li2, Yuxiang Li1, and Lanlan Zhang1
Yawen Li et al.
  • 1Yunnan University, Institute of International Rivers and Eco-security, Yunnan Key Laboratory of International Rivers and Trans-boundary Eco-security, China (yawenlynu@163.com)
  • 2State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
Changes in land use can result in soil erosion and the loss of soil organic carbon (SOC). However, the individual contribution of different land use types on SOC variability as well as the combined impacts of land use and soil erosion are still unclear. The aims of the present study were to: (1) evaluate soil erosion and SOC contents under different land use types, (2) identify the influences of soil depth and land use on SOC content, and (3) determine the contribution of land use and soil erosion on SOC variability. We assessed the SOC and total soil nitrogen (TSN) contents under three types of land use in the dry-hot valley in southern China. Caesium-137 ( 137Cs) and excess lead-210 ( 210Pbex) contents were also measured to determine soil-erosion rates. Land use was found to significantly affect soil erosion, and erosion rates were higher in orchard land (OL) relative to farmland (FL), which is in contrast with previous study results. SOC and TSN contents varied significantly between the three land use types, with highest values in forest land (FRL) and lowest values in OL. SOC was found to decrease with decreasing soil depth; the highest rate of reduction occurred in the reference site (RS), followed by FRL and FL. The interaction between soil erosion and land use significantly impacted SOC in the soil surface layer (0–12 cm); the direct impact of soil erosion accounted for 1.5% of the SOC variability, and the direct or indirect effects of land use accounted for the remainder of the variability. SOC content in deep soil was mainly affected by factors related to land uses (89.0%). This quantitative study furthers our understanding on the interactive mechanisms of land use and soil erosion on changes in soil organic carbon.

How to cite: Li, Y., Duan, X., Li, Y., Li, Y., and Zhang, L.: Interactive effects of land use and soil erosion on soil organic carbon in the dry-hot valley region of southern China , EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-6676, https://doi.org/10.5194/egusphere-egu22-6676, 2022.