Effects of management and land use change on soil carbon in China바카라 사이트™s grasslands
Abstract
Grasslands cover about 40% of China's land area. This paper synthesizes 133 papers from China on the impacts of land use conversion and improved management practices on soil organic carbon (SOC) in China's grasslands. The synthesis finds that overgrazing and conversion of freely grazed grassland to cropland lead to an annual average decline of 2.3바카라 사이트“2.8% in SOC, and have caused a loss of 30바카라 사이트“35% of total grassland SOC in China. Improved management practices may reverse the loss of SOC. Exclosure of degraded grassland from grazing and conversion of cropland to abandoned fields (i.e. natural restoration) increased carbon content by 34% and 62% on average. Carbon sequestration rates were greatest during the first 30 yr after treatments began and tended to be greatest in the top 10 cm of soil. Carbon sequestration potential was negatively related to initial carbon and nitrogen concentrations in soils. Exclosure from grazing and the conversion of cropland to abandoned fields resulted in average carbon sequestration rates of 130.4 g C m−2 yr−1 for 0바카라 사이트“40 cm soil and 128.0 g C m−2 yr−1 for 0바카라 사이트“30 cm soil, representing annual average increases of 5.4바카라 사이트“6.3%. Based on our results, achievement of the national objective to exclude grazing livestock from 150 million ha of China's grasslands and to establish 30 million ha of cultivated pasture by 2020 would sequester over 0.24 Pg C yr−1, which is equivalent to about 16% of fossil fuel CO2 emissions in China in 2006.
Citation
Wang ShiPing; Wilkes, A.; Zhang ZhiCai; Chang XiaoFeng; Lang, R.; Wang YanFen; Niu HaiShan. Management and land use change effects on soil carbon in northern China바카라 사이트™s grasslands: a synthesis. Agriculture, Ecosystems and Environment (2011) 142 (3-4) 329-340. [DOI: 10.1016/j.agee.2011.06.002]