Urban beaver ponds show limited impact on stream carbon quantity in contrast to stormwater ponds
Urban beaver ponds show limited impact on stream carbon quantity in contrast to stormwater ponds
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DOI：
10.1007/s11252-024-01536-y
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发表时间：
2024-03-15
期刊：
影响因子：
2.9
通讯作者：
Ledford，Sarah H.
中科院分区：
文献类型：
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作者：
Sheppy，Julian;Sudduth，Elizabeth B.;Ledford，Sarah H.
城市河狸和雨水池塘在收集富含溶解有机物(DOM)的径流的同时，提供了景观中的水文保持，可以提高初级生产力。我们的目标是确定DOM在城市雨水和河狸池塘系统中的数量、来源和生物有效性是如何变化的，然后将这两种池塘类型相互比较。2021年3月至12月，我们测量了美国佐治亚州亚特兰大七个池塘上游、内部和下游的溶解有机碳(DOC)和254 nm比紫外线吸光度(SUVA254)。此外，我们还在2021年夏秋两季完成了为期28天的池塘进出水的实验室微宇宙孵化。我们发现池塘和雨水池塘的出水中DOC浓度较高，而海狸池塘没有引起任何变化。池塘类型(河狸和雨水)对浓度的影响比其他对照更大，包括流量和季节。相比之下，SUVA254在两个系统下都显示出向更多芳香碳的转变，而池塘类型之间没有明显的差异。海狸和雨水池流出的DOM在夏季的生物有效性范围相似，但在秋季，这两个地点的生物有效性都下降到接近零的水平。总体而言，我们发现雨水塘和河狸塘对芳香性和生物利用度的影响相似，但雨水塘增加了DOC的数量，而河狸塘没有。这表明，除了增加城市化系统中的水文停留时间外，城市河狸池可能会限制生物可用碳的出口，并减少下游的微生物加工。
Urban beaver and stormwater ponds provide hydrologic retention in the landscape while collecting dissolved organic matter (DOM)-rich runoff that can promote primary productivity. Our objective was to determine how the quantity, source, and bioavailability of DOM changed across urban stormwater and beaver pond systems, then compare the two pond types to each other. We measured dissolved organic carbon (DOC) and specific ultraviolet absorbance at 254 nm (SUVA254) from upstream, within, and downstream of seven ponds in Atlanta, GA, USA, biweekly from March to December 2021. Additionally, we completed 28-day laboratory microcosm incubations of pond in- and out-flow during summer and autumn of 2021. We found higher concentrations of DOC in the pond and outflows of stormwater ponds, whereas beaver ponds did not cause any change. Effects of pond type (beaver vs. stormwater) were greater than other controls on concentration, including flow and season. In contrast, SUVA254showed a shift toward more aromatic carbon below both systems without a clear difference between pond types. Beaver and stormwater pond outflows had similar ranges of DOM bioavailability in summer, but during autumn bioavailability at both sites declined to near zero. Overall, we found that stormwater ponds and beaver ponds had similar impacts on aromaticity and bioavailability, however stormwater ponds increased the quantity of DOC while beaver ponds did not. This suggests that in addition to increasing hydrologic residence times in urbanized systems, urban beaver ponds may limit the export of bioavailable carbon and reduce microbial processing downstream.