Effects of grazing and experimental warming on DOC concentrations in the soil solution on the Qinghai-Tibet plateau
Effects of grazing and experimental warming on DOC concentrations in the soil solution on the Qinghai-Tibet plateau
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DOI：
10.1016/j.soilbio.2009.09.006
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发表时间：
2009-12-01
影响因子：
9.7
通讯作者：
Zhao, Xinquan
中科院分区：
文献类型：
--
作者：
Luo, Caiyun;Xu, Guangping;Zhao, Xinquan
关于全球变暖和土地管理对田间土壤溶液中溶解有机碳(DOC)浓度的影响的信息很少。在这里，我们首次在2006和2007年的受控升温-放牧实验中使用了自由空气增温(FATE)系统来检验放牧改变土壤溶液DOC浓度对实验变暖的响应的假设。增温免牧(WNG)较不增温免牧(NWNG)分别在2006年和2007年增加了土壤温度1.3~1.4℃的土壤溶解有机碳(DOC)浓度14.1%和17.2%。然而，放牧增温(WG)、不增温放牧(NWG)和放牧增温(NWNG)之间没有显著差异，说明适度放牧改变了增温对土壤溶液DOC浓度的影响。放牧对土壤溶液中DOC浓度的影响因采样日期和土壤深度不同而不同。土壤温度和土壤水分对土壤溶液中DOC浓度变化的直接贡献一般较小。表层土壤溶解有机碳浓度与林分死亡质量和地下生物量呈正相关。10 cm土层立枯枝落物和地下生物量中的木质素/氮比可以解释10 cm土层DOC平均浓度变化的60%。土壤水分和地下生物量解释了2007年土壤溶液DOC平均浓度到40 cm土层变化的79%。(C)2009爱思唯尔有限公司。保留所有权利。
Little information is available about the effects of global warming and land management on dissolved organic carbon (DOC) concentration in soil solution in the field. Here, for the first time, we used a free-air temperature enhancement (FATE) system in a controlled warming-grazing experiment in 2006 and 2007 to test the hypothesis that grazing modifies the response of soil solution DOC concentration to experimental warming. Warming with no-grazing (WNG) significantly increased the average soil solution DOC concentration to 40 cm soil depth by 14.1 and 17.2% compared with no-warming with no-grazing (NWNG) in 2006 and 2007 respectively based on 1.3-1.4 degrees C soil temperature increase. However, the lack of significant differences among warming with grazing (WG), no-warming with grazing (NWG) and NWNG indicate that moderate grazing modified the effect of warming on DOC concentration in the soil solution. The effect of grazing on DOC concentration in the soil solution varied with sampling date and soil depth. Generally, the direct contribution of soil temperature and soil moisture to variation of DOC concentration in the soil solution was small. Positive correlations were observed between soil solution DOC concentration in the surface soil and standing death quality and belowground biomass. The Lignin:N ratio in the standing death and belowground biomass at 10 cm soil depth explained 60% of the variation of mean DOC concentration at 10 cm soil depth. Soil moisture and belowground biomass explained 79% of the variation of the mean soil solution DOC concentration to 40 cm soil depth in 2007. (C) 2009 Elsevier Ltd. All rights reserved.