THE MINERALIZATION OF SOIL ORGANIC CARBON UNDER DIFFERENT LAND USES IN THE LIUPAN MOUNTAIN FOREST ZONE

作者：Wu Jian · 发表于：Acta Phytoecologica Sinica · 年份：2004 · 被引用次数：7 · 研究领域：Plant Ecology and Soil Science、Rangeland Management and Livestock Ecology、Soil Carbon and Nitrogen Dynamics

Soil organic carbon (SOC) is a large component of the global carbon cycle and the influence of land-use changes on SOC pools can significantly affect atmospheric CO 2 concentrations. The response of soil carbon mineralization rates to changes in land-use type is the crux for understanding the influence of land-use changes on SOC. Over the last several centuries, extensive areas of the native vegetation of the Liupan Mountain forest zone has been converted to cropland or rangeland and, over the last several decades, some of these former croplands and rangelands have returned to forests. However, the impacts of these land-use changes on the SOC are unclear. In order to assess the impacts of land-use change on LSC, we compared the LSC concentrations in adjacent plots of natural secondary forest (i.e. dominated by Querces 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. To determine the rate of SOC mineralization, soils were collected from each of these land use types, incubated in the laboratory at 30 ℃ with a constant moisture of 60% field water capacity over 180 days and the amount of cumulative CO 2-C released over 180 days was compared among the different land use types. It was found that the mean concentration (g CO 2-C·kg -1 soil·180 d -1) of SOC mineralization in the 0-110 cm soil layer was 155% and 17% higher under the plan...