The formation of a metalimnetic oxygen minimum exemplifies how ecosystem dynamics shape biogeochemical processes: A modelling study
The formation of a metalimnetic oxygen minimum exemplifies how ecosystem dynamics shape biogeochemical processes: A modelling study
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金属金属氧最小值的形成例证了生态系统动力学如何塑造生物地球化学过程：建模研究
DOI：
10.1016/j.watres.2020.115701
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发表时间：
2020
期刊：
影响因子：
12.8
通讯作者：
Karsten Rinke
中科院分区：
文献类型：
--
作者：
Chenxi Mi;Tom Shatwell;Jun Ma;Valerie Carolin Wentzky;Bertram Boehrer;Yaqian Xu;Karsten Rinke
在许多湖泊和水库中观察到金属湖相氧极小值，但这一现象背后的机制还没有很好地理解。因此，我们使用成熟的二维水质模型（CE-QUAL-W2）模拟了Rappbode水库中的元湖氧最低值（MOM），以系统地量化导致其形成的事件链。我们使用高分辨率的测量数据来校准模型，该模型准确地再现了水库的物理（例如水位和水温），生态地球化学（例如营养物和氧气动态）和生态（例如藻类群落动态）特征，特别是空间和时间范围的变化。结果表明，在底层的总耗氧率约60%来自底栖过程，而其余的来自远洋过程。蓝藻Planktothrix rubescens在变水层中的出现通过光合作用延迟并轻微减弱了光合作用，尽管其腐烂的生物量最终诱导了光合作用。我们的研究还证实了水温的决定性作用，在形成中的浮游生物，因为水温，从而底栖生物和浮游生物的耗氧率，是高于在底层。我们的模型不仅提供了新的结论的驱动力的可持续发展和定量的贡献，它也是一个新的工具，用于理解和预测生态和地球化学水质动态。
Metalimnetic oxygen minima are observed in many lakes and reservoirs, but the mechanisms behind this phenomena are not well understood. Thus, we simulated the metalimnetic oxygen minimum (MOM) in the Rappbode Reservoir with a well-established two-dimensional water quality model (CE-QUAL-W2) to systematically quantify the chain of events leading to its formation. We used high-resolution measured data to calibrate the model, which accurately reproduced the physical (e.g. water level and water temperature), biogeochemical (e.g. nutrient and oxygen dynamics) and ecological (e.g. algal community dynamics) features of the reservoir, particularly the spatial and temporal extent of the MOM. The results indicated that around 60% of the total oxygen consumption rate in the MOM layer originated from benthic processes whereas the remainder originated from pelagic processes. The occurrence of the cyanobacteriumPlanktothrix rubescensin the metalimnion delayed and slightly weakened the MOM through photosynthesis, although its decaying biomass ultimately induced the MOM. Our research also confirmed the decisive role of water temperature in the formation of the MOM since the water temperatures, and thus benthic and pelagic oxygen consumption rates, were higher in the metalimnion than in the hypolimnion. Our model is not only providing novel conclusions about the drivers of MOM development and their quantitative contributions, it is also a new tool for understanding and predicting ecological and biogeochemical water quality dynamics.