Effects of acid sulphate on DOC release in mineral soils: the influence of SO 4 2 - retention and Al release
Effects of acid sulphate on DOC release in mineral soils: the influence of SO 4 2 - retention and Al release
复制标题
酸性硫酸盐对矿质土壤中 DOC 释放的影响：SO 4 2 - 保留和 Al 释放的影响
DOI：
10.1111/ejss.12048
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发表时间：
2013
影响因子：
4.2
通讯作者：
Palmer S
中科院分区：
文献类型：
--
作者：
Palmer S
酸敏感高地沃茨中的溶解有机碳（DOC）主要来自有机质丰富的土壤的外来输入，尽管在过去几十年中地表水DOC趋势的位置之间存在差异，但土壤DOC释放随酸度变化的位置间差异却很少受到关注。在以前的论文中，我们证明了pH相关的DOC在O层土壤中的保留受酸碱状态的影响，特别是交换性铝含量。 在本文中，我们研究了硫酸盐添加量（0-437 µeq l−1）对同一地点的矿物B层土壤DOC释放的影响。溶解有机碳释放在所有土壤中随着pH值的下降而减少，尽管不同地点的pH-DOC关系的形状不同，反映了控制DOC流动性的多种因素。 在最大酸输入（437 µeq l−1）的处理中，DOC的释放减少了32-91%，其中最大的减少发生在具有非常小的%盐饱和度（BS，< 3%）和/或大硫酸盐（SO 42 −）保留能力（高达添加的SO 42 −的35%）的土壤中。最大的DOC释放发生在土壤中的最大的初始基地状态（12%BS）。 这些结果支持了我们先前的结论，即土壤之间酸碱状态的差异改变了DOC释放对类似硫沉降下降的敏感性。然而，与此叠加的是矿质土壤吸附DOC和SO 42-的能力，需要更多的工作来确定在pH值升高和SO 42-降低的条件下吸附DOC的命运。
Dissolved organic carbon (DOC) in acid‐sensitive upland waters is dominated by allochthonous inputs from organic‐rich soils, yet inter‐site variability in soil DOC release to changes in acidity has received scant attention in spite of the reported differences between locations in surface water DOC trends over the last few decades. In a previous paper, we demonstrated that pH‐related retention of DOC in O horizon soils was influenced by acid‐base status, particularly the exchangeable Al content. In the present paper, we investigate the effect of sulphate additions (0–437 µeq l−1) on DOC release in the mineral B horizon soils from the same locations. Dissolved organic carbon release decreased with declining pH in all soils, although the shape of the pH‐DOC relationships differed between locations, reflecting the multiple factors controlling DOC mobility. The release of DOC decreased by 32–91% in the treatment with the largest acid input (437 µeq l−1), with the greatest decreases occurring in soils with very small % base saturation (BS, < 3%) and/or large capacity for sulphate (SO42−) retention (up to 35% of added SO42−). The greatest DOC release occurred in the soil with the largest initial base status (12% BS). These results support our earlier conclusions that differences in acid‐base status between soils alter the sensitivity of DOC release to similar sulphur deposition declines. However, superimposed on this is the capacity of mineral soils to sorb DOC and SO42−, and more work is needed to determine the fate of sorbed DOC under conditions of increasing pH and decreasing SO42−.