Influence of relict milldams on riparian sediment biogeochemistry
Influence of relict milldams on riparian sediment biogeochemistry
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DOI：
10.1007/s11368-023-03507-w
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发表时间：
2023-04-03
影响因子：
3.6
通讯作者：
Gold，Arthur J.
中科院分区：
文献类型：
--
作者：
Peck，Erin K.;Inamdar，Shreeram P.;Gold，Arthur J.
河岸带是陆地生态系统和水生生态系统之间营养盐通量的重要调节者。然而，大坝改变河岸带捕获细粒，有机质丰富的沉积物，并创造混合不良，低氧条件，从而影响沉积物的地球化学知之甚少的方式。（一个来自主要农业流域，一个来自混合土地利用/城市流域）生物有效元素浓度的空间格局（Mehlich-3可提取的P，K，Ca，Mg，Mn，Zn，Cu，Fe，B，S和Na）在沉积物上游和下游的milldams，深度，和沿着断面运行平行和垂直的stream. ResultsElements浓度没有明显的相关性与粒度或有机质含量，虽然一般较高，没有显着更集中在上游河岸沉积物相似（浅，饱和）的深度进行比较。显著的差异进行了观察：上游的milldams，沉积物中的钙和镁的浓度最高的饱和浅沉积物，而铁和锰是最高的更深，连续饱和，低氧沉积物。此外，由于土地利用历史的差异（例如，道路盐和化肥的应用/径流）和主导的基岩geology.ConclusionOverall，结果突出了milldams（和相关的影响地下水水文和沉积物氧化还原条件）和外部驱动程序（其他土地利用遗产和基岩地质）的组合重要性，在影响河岸沉积物中的生物可利用元素的空间格局。
PurposeRiparian zones are important modifiers of nutrient flux between terrestrial and aquatic ecosystems. However, dams alter riparian zones—trapping fine-grained, organic matter-rich sediment and creating poorly mixed, low oxygen conditions—thereby affecting sediment biogeochemistry in poorly understood ways.MethodsWe characterized the impact of two relict US mid-Atlantic milldams (one from a primarily agricultural watershed and one from a mixed land use/urban watershed) on spatial patterns of bioavailable element concentrations (Mehlich-3 extractable P, K, Ca, Mg, Mn, Zn, Cu, Fe, B, S, and Na) in sediments upstream and downstream of milldams, with depth, and along transects running parallel and perpendicular to the stream.ResultsElement concentrations were not clearly correlated with grain size or organic matter content and, although generally higher, were not significantly more concentrated in upstream riparian sediments when similar (shallow, variably saturated) depths were compared. Pronounced differences were observed: upstream of milldams, sediment concentrations of Ca and Mg were highest in variably saturated shallow sediments, while Fe and Mn were highest in deeper, continuously saturated, low-oxygen sediments. Additionally, data was significantly different by milldam site, a result of differences in land-use histories (e.g., road salt and fertilizer application/runoff) and dominant bedrock geology.ConclusionOverall, results highlight the combined importance of milldams (and associated influences on groundwater hydrology and sediment redox conditions) and external drivers (other land-use legacies and bedrock geology) in influencing spatial patterns of bioavailable elements in riparian sediments.