ABSTRACT Deicing salt runoff is a cause of freshwater salinisation in many regions. Studies in uplands indicate that soil properties affect storage and movement across the landscape of salt and dissolved organic carbon (DOC). Wetlands have unique soil properties, act as buffers between uplands and aquatic ecosystems, and are major sources of DOC to surface waters, yet less is known about these dynamics in wetlands. Soil cores from three wetlands differing in vegetation and soil organic matter (SOM) were flushed with road salt treatments of 0, 2.5, and 5.0 g chloride L−1 followed by no-salt flushes. Leachate was analysed for chloride (Clin), DOC concentration and quality (as specific UV absorbance (SUVA)), and Clin accumulation in soils was measured. Soils retained 3.6–41% of the added Clin, and there was a significant positive relationship between SOM and Clin retention. Salt treatment significantly reduced DOC export from only one of the three soils and had no effect on SUVA. Our findings suggest that the ability of wetland soils to buffer downstream aquatic systems against salt pollution is highly variable and likely limited to low salt concentrations, and that soil Clin accumulation may have negative impacts on wetland flora, fauna and biogeochemistry.

中文翻译：

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湿地土壤中路盐氯化物的滞留及对溶解有机碳输出的影响

摘要 在许多地区，除冰盐径流是造成淡水盐碱化的一个原因。高地研究表明，土壤特性影响盐和溶解有机碳 (DOC) 景观中的储存和移动。湿地具有独特的土壤特性，充当高地和水生生态系统之间的缓冲区，并且是地表水 DOC 的主要来源，但对湿地中的这些动态知之甚少。来自植被和土壤有机质 (SOM) 不同的三个湿地的土壤核心用 0、2.5 和 5.0 g 氯化物 L-1 的路盐处理冲洗，然后是无盐冲洗。对渗滤液的氯化物 (Clin)、DOC 浓度和质量（作为特定的紫外线吸光度 (SUVA)）进行分析，并测量了土壤中的 Clin 积累。土壤保留了添加的 Clin 的 3.6-41%，SOM 和 Clin 保留之间存在显着的正相关关系。盐处理仅显着降低了三种土壤之一的 DOC 输出，并且对 SUVA 没有影响。我们的研究结果表明，湿地土壤缓冲下游水生系统免受盐污染的能力变化很大，可能仅限于低盐浓度，土壤 Clin 积累可能对湿地植物群、动物群和生物地球化学产生负面影响。