Differential Effects of Conservational Management on SOC Accumulation in the Grasslands of China.
Differential Effects of Conservational Management on SOC Accumulation in the Grasslands of China.
复制标题
保护管理对中国草原SOC积累的差异性影响
DOI：
10.1371/journal.pone.0137280
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发表时间：
2015
期刊：
影响因子：
3.7
通讯作者：
Zhang W
中科院分区：
文献类型：
--
作者：
Zhang P;Tang J;Sun W;Yu Y;Zhang W
草地保护性管理措施被认为是提高土壤有机碳积累的有效途径之一。然而，不同草地植被类型和环境条件下，保护性管理措施实施后土壤有机碳变化差异显著。目前，还不清楚如果采取保护性管理措施，土壤有机碳累积量沿土壤剖面沿着的变化。在这项研究中，我们收集了663对观测数据的SOC变化与保护性管理措施，在中国草原176篇已发表的文献，有表面（0 - 20 cm）和亚表面（40 cm深度）的SOC测量。分析了退耕前和退耕后土壤有机碳密度（SOCD）在垂直土层中的差异，以建立土壤有机碳在地表和地下变化的定量关系。结果表明，在所有的草地，保护性管理措施有利于增加0.43 × 1.14 Mg C ha-1年-1的SOC积累。但土壤有机碳增量沿土壤剖面向下沿着减弱。保护性管理后，表层土壤有机碳增加了17%，而次表层土壤有机碳仅增加了7%。土壤有机碳累积量与恢复年限、管理前土壤有机碳累积量和环境因子密切相关，不同草地和不同管理措施土壤有机碳累积量差异较大。高寒和山地草地土壤有机碳年增长率高于温带草地，分别为1.62和0.72 Mg C ha-1 yr-1。人工种植园和禁牧保护性管理引起的土壤有机碳增量是撂荒和粗放利用的2倍以上。利用土壤有机碳在各土层间变化的定量关系，提出了一种在只有表层土壤有机碳增量的情况下，估算比IPCC建议深度更深土层土壤有机碳变化的方法。
Conservational management practices in grasslands have been considered one of the efficient options to enhance the soil organic carbon (SOC) accumulation. However, the SOC changes after the conservational management practices vary significantly under different grassland vegetation types and the environmental conditions. At present, it is not clear how the SOC accumulation changes along the soil profile if conservational management practice was adopted. In this study, we collected 663 paired observational data of SOC changes with and without conservational management practices in grasslands of China from 176 published literatures that has both the surface (0‒20 cm) and subsurface (to 40 cm depth) SOC measurements. The differences of SOC density (SOCD) between pre‒management and post‒management in the vertical soil layers were analyzed in order to establish a quantitative relationship of the SOC changes between the subsurface and the surface. The results revealed that in all grasslands, conservational management practices benefits the SOC accumulation by enhancing 0.43‒1.14 Mg C ha–1 yr–1. But the SOC increment weakened downwards along the soil profile. While the surface SOC was enhanced by 17% after conservational management, the subsurface SOC was enhanced by only 7%. The SOC accumulation was closely correlated with restoration duration, pre-management SOCD and the environmental factors and differed greatly among different grasslands and the practices adopted. The alpine and mountain grassland showed a higher annual SOC increment than the temperate grassland with the annual rate of 1.62 and 0.72 Mg C ha-1 yr-1, respectively. The SOC increment caused by the artificial plantation and the grazing exclusion conservational management was more than 2-fold that of the cropland abandonment and the extensive utilization. With the quantitative relationship of the SOC changes between soil layers, we provide a methodological option to estimate SOC changes to layers deeper than the recommendation of IPCC when only the surface layer SOC increment is available.