CHANGES IN SOIL LABILE ORGANIC CARBON UNDER DIFFERENT LAND USE IN THE LIUPAN MOUNTAIN FOREST ZONE

作者：Wu Jian · 发表于：Acta Phytoecologica Sinica · 年份：2004 · 被引用次数：5 · 研究领域：Rangeland Management and Livestock Ecology、Plant Ecology and Soil Science、Forest, Soil, and Plant Ecology in China

Soil carbon is a large component of the global carbon cycle, and the influence of land-use changes on soil carbon pools can significantly affect atmospheric CO 2 concentrations. Labile soil organic carbon (LSC) is the fraction of soil organic matter that is most sensitive to changes in land-use. Over the last several centuries, extensive areas of native vegetation in the Liupan Mountain Forest Zone have been converted to croplands and rangelands and, in last several decades, some of these former croplands and rangelands have returned to forests. The impacts of these land-use changes on soil organic carbon (SOC) are unclear. In order to assess the impacts of land-use change on LSC, we compared the LSC concentrations in adjacent plots of secondary forest (i.e. dominated by Quercus liaotungensis, Populus davidiana, or brushwood), cropland, rangeland, and 13, 18, and 25-year old larch (Larix principis-rupprechtii) plantations that were planted on former croplands and rangelands. All plots were the same elevation, exposure and soil type. The LSC concentrations were determined using a KMnO 4 (333 mmol·L -1 ) oxidation technique. It was found that the mean content of LSC in 0-110 cm deep soil layer was 60% lower under cropland (0.605 gC·kg -1 ) and 36% lower in rangeland (0.973 gC·kg -1 ) than under the secondary forest (1.612, 1.68 and 1.325 gC·kg -1 for the brushwood, Populus davidiana and Quercus liaotungensis forests, respectively). LSC was 129% and 29% higher under the plantati...