Climate change dominates recent sedimentation and organic carbon burial in Lake Chenghai, southwest China

Climate change dominates sedimentation and carbon burial

Abstract

Lacustrine ecosystems are directly influenced by terrestrial soil erosion, and excessive sediment loading constitutes a significant and widespread environmental issue. In order to investigate the response of catchment soil erosion and organic carbon burial to climate change and human activity, a sediment core spanning the last 160 years was retrieved from Lake Chenghai in southwest China. Multi-proxy analysis including grain-size composition and geochemical indicators were undertaken in this study. The result of grain-size vs standard deviation method shows that the sensitive component with a modal size of 13.2 μm is related to fluvial processes and sensitive to the catchment soil erosion. The increasing intensity of soil erosion was mainly determined by the weakening of Indian summer monsoon and global warming, as well as intensive human activities during the middle of 20^th century, which resulted in decreasing vegetation cover in Lake Chenghai catchment. The organic carbon burial rate was also attributed to the catchment disturbance, indicating that increased catchment soil erosion may impact the terrestrial carbon recycling.

Keywords

• Soil erosion
• lacustrine sediment
• climate change
• human activity
• carbon burial.