Agriculture and Holocene deforestation in eastern China

Abstract

Humans have had profound and environmentally changing impacts on land cover, and China has many examples of this. It has been recognised for some time that middle to late Holocene forests in China have undergone changes that are best described as due to human impacts. Hence the Holocene has seen sometimes gradual and sometimes abrupt changes from forest dynamics driven by natural forces to those dominated by human impacts. This leads to a conclusion that it is often difficult to disentangle natural and anthropogenic controls on forest composition. In many cases records show minor changes in the early Holocene giving way to intense changes as agriculture expanded. The two earliest centres of extensive forest changes from 6 to 5 kyr BP were in the middle to lower Yellow and lower Yangtze valleys, where millet and rice agriculture developed. Major forest clearing was later in other areas, including the Pearl River valley, Northeast China and Yunnan. Forest clearing for agriculture was widespread in eastern China by 2 kyr BP. Where data is available it seems that initial clearing took place in valleys adjacent to rivers, presumably because these were the preferred living places for early farmers. Then gradually spread to nearby slopes. New approaches and technologies were needed to achieve this. The records show that north east China, north of the Liao River, and the mountains of central China were amongst the last places to record forest clearing, in some cases just within the last few hundred years, or not at all.