Investigating the impact of in situ soil organic matter degradation through porewater spectroscopic analyses on marsh edge erosion
Investigating the impact of in situ soil organic matter degradation through porewater spectroscopic analyses on marsh edge erosion
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DOI：
10.1016/j.chemosphere.2020.129266
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发表时间：
2021-04-01
期刊：
影响因子：
8.8
通讯作者：
Cook, Robert L.
中科院分区：
文献类型：
--
作者：
Hayes, Michael P.;Sapkota, Yadav;Cook, Robert L.
沼泽边缘侵蚀导致沿海湿地土壤有机质（SOM）流失，并受到风浪、土壤性质和植被覆盖的不同影响。土壤有机质的退化可能使沼泽边缘易受侵蚀。本研究的目的是调查的影响，在现场土壤化学降解的有机质沼泽边缘侵蚀孔隙水光谱分析。在路易斯安那州的高度侵蚀的沿海盆地之一，在12个断面监测边缘侵蚀。在距沼泽边缘不同距离处共收集了36个岩心。提取孔隙水并分析溶解有机碳（DOC）和光谱指标。北侧和西侧的侵蚀速率（102.38 +/-5.2 cm yr（-1））大于东侧和南侧（78.47 +/-3.3 cm yr（-1））。然而，北部和东部有更大的DOC和难降解碳，但微生物活动较少，表明SOM降解单独没有相关的边缘侵蚀。侵蚀速率与土壤有机质退化在岛的四面之间的交叉趋势表明边缘侵蚀驱动因子的复杂性。河口底部的指标表明，侵蚀的SOM不是重新掩埋，而是降解和排放回大气中的二氧化碳，可能有助于全球变化。如果不采取有效的减缓措施，预计在下一个世纪将经历海平面高上升的海岸线很容易失去大量储存的碳。(C)2020爱思唯尔有限公司保留所有权利。
Marsh edge erosion results in soil organic matter (SOM) loss from coastal wetlands and is differentially affected by wind waves, soil properties, and vegetation cover. The degradation of SOM may make the marsh edge susceptible to erosion. The objective of this study was to investigate the effect of in situ biogeochemical degradations of SOM on marsh edge erosion using porewater spectroscopic analyses. Edge erosion was monitored at 12 transects in one of the highly eroding coastal basins of Louisiana. A total of 36 cores were collected at different distances from the edge of the marsh. Porewater was extracted and analyzed for dissolved organic carbon (DOC) and spectroscopic indicators. The north and west side had greater erosion rates (102.38 +/- 5.2 cm yr(-1)) than east and south side (78.47 +/- 3.3 cm yr(-1)). However, the north and east side had greater DOC and refractory carbon but less microbial activity indicating SOM degradation alone did not correlate to edge erosion. The intersecting trend between erosion rate and SOM degradation among four sides of the island indicates the complex nature of edge erosion drivers. The estuarine bottom indicators suggest the eroded SOM is not reburied but rather degraded and emitted back into the atmosphere as CO2, potentially contributing to global change. The coastlines projected to experience high sea-level rise in the coming century are vulnerable to losing a large amount of stored carbon in the absence of efficient mitigation measures. (C) 2020 Elsevier Ltd. All rights reserved.