【土壤有机碳在林地转为农业用地过程中的变化】Xiaorong Wei Mingan Shao William Gale & Linhai Li. Global pattern of soil carbon losses due to the conversion of forests to agricultural land. Scientific Reports 4 Article number: 4062 doi:10.1038-srep04062
Abstract
Several reviews have analyzed the factors that affect the change in soil organic C (SOC) when forest is converted to agricultural land; however the effects of forest type and cultivation stage on these changes have generally been overlooked. We collated observations from 453 paired or chronosequential sites where forests have been converted to agricultural land and then assessed the effects of forest type cultivation stage climate factors and soil properties on the change in the SOC stock and the SOC turnover rate constant (k). The percent decrease in SOC stocks and the turnover rate constants both varied significantly according to forest type and cultivation stage. The largest decrease in SOC stocks was observed in temperate regions (52% decrease) followed by tropical regions (41% decrease) and boreal regions (31% decrease). Climate and soil factors affected the decrease in SOC stocks. The SOC turnover rate constant after the conversion of forests to agricultural land increased with the mean annual precipitation and temperature. To our knowledge this is the first time that original forest type was considered when evaluating changes in SOC after being converted to agricultural land. The differences between forest types should be considered when calculating global changes in SOC stocks.
【中国东部森林生态系统中的N15丰度】Wenping Sheng Guirui Yu Huajun Fang Yingchun Liu Qiufeng Wang Zhi Chen & Li Zhang. Regional patterns of15N natural abundance in forest ecosystems along a large transect in eastern China. Scientific Reports 4