Effects of acidity on dissolved organic carbon in organic soil extracts, pore water and surface litters.
Effects of acidity on dissolved organic carbon in organic soil extracts, pore water and surface litters.
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酸度对有机土壤提取物、孔隙水和表面枯落物中溶解有机碳的影响。
DOI：
10.1016/j.scitotenv.2019.135585
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发表时间：
2019
期刊：
影响因子：
--
通讯作者：
C. Evans
中科院分区：
文献类型：
--
作者：
C. Pschenyckyj;Joanna M. Clark;L. Shaw;R. Griffiths;C. Evans
在过去的30-40年里，溶解有机碳（DOC）浓度增加了土壤溶液和表面沃茨在欧洲和北美的许多酸敏感地区。这与为应对大气污染程度的下降而从酸化中恢复有关。放射性碳测年的证据表明，DOC在表面沃茨是典型的来自最近光合作用的有机质，如植物凋落物和分泌物，但有很少的信息对pH值的敏感性的有机质溶解度，或其分解，在凋落物层和不同的有机土壤。因此，本研究的目的是确定a）不同表层和土壤类型中DOC对酸度的敏感性，以B）提高对DOC增加趋势的关键来源的理解。这些信息是至关重要的理解站点的具体特点，有助于不一致的DOC之间的流域释放，并提高预测的碳通量和budgets.Based收集的数据在四个既定的现场pH值操纵实验在英国的高地地区，我们研究了DOC出口的来源，组成和酸敏感性的垃圾和有机土壤。我们发现，凋落物产生的DOC比有机土壤多近三倍，与放射性碳证据一致，最近的植物输入是DOC的主要来源。凋落物源DOC比有机质DOC的紫外吸光度（苏瓦）低，说明其具有更强的生物降解性，且对酸不敏感。与此相反，有机土壤DOC浓度更强烈地与实验操作的pH值，这意味着该DOC的流动性可能会受到物理化学，而不是生物控制。我们的研究结果表明，物理化学介导的有机物溶解度的控制可能是一个关键的驱动因素背后的广泛观察到的增加地表水DOC正在从酸化恢复的地区。
Over the past 30–40 years, dissolved organic carbon (DOC) concentrations have increased in soil solutions and surface waters in many acid-sensitive areas of Europe and North America. This has been linked to recovery from acidification in response to decreasing levels of atmospheric pollution. Evidence from radiocarbon dating suggests that DOC in surface waters is typically derived from recently photosynthesised organic matter such as plant litter and exudates, yet there is little information on the pH-sensitivity of organic matter solubility, or its decomposition, in litter layers and in different organic soils. Therefore the purpose of this study was to determine a) the sensitivity of DOC to acidity in different surface layers and soil types, in order to b) improve understanding of the key sources contributing to the increasing DOC trend. Such information is vital for understanding site specific characteristics contributing to inconsistencies in DOC release between catchments, and for improving predictions of carbon fluxes and budgets.Based on data collected at four established field pH-manipulation experiments in upland areas of the United Kingdom, we examined the sources, composition and acid-sensitivity of DOC export from the litter and organic soils. We found that litter generated nearly three times more DOC than the organic soils, consistent with radiocarbon evidence that recent plant inputs are a major source of DOC. Furthermore, litter derived DOC had lower specific ultraviolet light absorbance (SUVA) than organic soil DOC, suggesting greater biodegradability, and was not acid sensitive. In contrast, organic soil DOC concentrations were more strongly related to experimentally manipulated pH, implying that the mobility of this DOC may be subject to physicochemical rather than biotic controls. Our results suggest that physicochemically mediated controls on organic matter solubility may be a key driver behind the widely observed increases in surface water DOC in areas undergoing recovery from acidification.
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影响因子：
11.6
作者：
Evans, Christopher D.;Chapman, Pippa J.;Cresser, Malcolm S.
通讯作者：
Cresser, Malcolm S.
影响因子：
11.6
作者：
F. Oulehle;C. Evans;J. Hofmeister;R. Krejci;Karolina Tahovská;T. Persson;P. Cudlín;J. Hruska
通讯作者：
F. Oulehle;C. Evans;J. Hofmeister;R. Krejci;Karolina Tahovská;T. Persson;P. Cudlín;J. Hruska
影响因子：
11.6
作者：
Evans, Chris D.;Jones, Tim G.;Freeman, Chris
通讯作者：
Freeman, Chris
影响因子：
4
作者：
Evans, Chris D.;Goodale, Christine L.;Sheppard, Lucy J.
通讯作者：
Sheppard, Lucy J.
影响因子：
9.8
作者：
Clark, J. M.;Bottrell, S. H.;Chapman, P. J.
通讯作者：
Chapman, P. J.