History of human activity in South China since 7 cal ka BP: Evidence from a sediment record in the South China Sea

Abstract

Human modifications of the Earth System have been getting increasing attention and this has resulted in the concept of the “Anthropocene”. A complete sequence of human-environment interactions needs to be reconstructed to define the onset of the Anthropocene. To address the chronological gaps and provide a general history of human impact in South China during the Holocene, we present a comprehensive reconstruction of the vegetation, chemical weathering, and heavy metal emissions in the Pearl River and Hainan catchments since 7.0 cal ka BP, using a continuous record of black carbon, clay minerals, and major and trace element concentrations of sediment in Core ZK001 taken from the northwestern South China Sea. Based on high-resolution sediment records, combined with archaeological and historical documents, we propose that human impact in South China can be divided into three stages: a hunting-gathering age (7.0–2.9 cal ka BP), a transitional period (2.9–2.0 cal ka BP) and an intensive farming age (<2.0 cal ka BP). Climate controlled both the vegetation and chemical weathering intensity before 2.9 cal ka BP, after which forest clearance by human-induced fire became significant. Along with population growth and technological progress, enhanced human activities including deforestation, cultivation, and metallurgical activities, gradually superseded natural processes and profoundly impacted the environment in South China, especially after 2.0 cal ka BP. Combined with previous studies from the Pearl River catchment, the Anthropocene likely commenced at 2−3 cal ka BP at least in South China.