Global climate change is expected to impact hydrodynamic conditions in stream ecosystems. There is limited understanding of how stream ecosystems interact and possibly adapt to novel hydrodynamic conditions. Combining mathematical modelling with field data, we demonstrate that bio-physical feedback between plant growth and flow redistribution triggers spatial self-organization of in-channel vegetation that buffers for changed hydrological conditions. The interplay of vegetation growth and hydrodynamics results in a spatial separation of the stream into densely vegetated, low-flow zones divided by unvegetated channels of higher flow velocities. This self-organization process decouples both local flow velocities and water levels from the forcing effect of changing stream discharge. Field data from two lowland, baseflow-dominated streams support model predictions and highlight two important stream-level emergent properties: vegetation controls flow conveyance in fast-flowing channels throughout the annual growth cycle, and this buffering of discharge variations maintains water depths and wetted habitat for the stream community. Our results provide important evidence of how plant-driven self-organization allows stream ecosystems to adapt to changing hydrological conditions, maintaining suitable hydrodynamic conditions to support high biodiversity.

中文翻译：

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河流植被的自组织导致河流流量和水位的紧急缓冲

预计全球气候变化将影响河流生态系统的水动力条件。对河流生态系统如何相互作用并可能适应新的水动力条件的了解有限。将数学建模与现场数据相结合，我们证明了植物生长和流量重新分布之间的生物物理反馈触发了通道内植被的空间自组织，为变化的水文条件提供了缓冲。植被生长和流体动力学的相互作用导致河流在空间上被分隔成植被茂密的低流量区域，这些区域被流速较高的无植被通道隔开。这种自组织过程将局部流速和水位与改变河流流量的强迫效应分离。来自两个低地的现场数据，以基流为主的河流支持模型预测，并突出了两个重要的河流层面的紧急特性：植被控制着整个年度生长周期中快速流动渠道中的流量输送，这种排放变化的缓冲保持了河流群落的水深和湿润的栖息地。我们的研究结果提供了重要的证据，证明植物驱动的自组织如何使河流生态系统适应不断变化的水文条件，保持合适的水动力条件以支持高生物多样性。