Climate change alters hydrologic regimes, including their variability. Effects will be pronounced in aquatic ecosystems, where resource subsidies (e.g., nutrients, carbon) drive key ecosystem processes. However, we know little about how changing hydrologic regimes will modulate the spatiotemporal dynamics of lake biogeochemistry and ecosystem metabolism. To address this, we quantified ecosystem metabolism and nutrient dynamicsat high spatial resolution in Acton Lake, a hyper-eutrophic reservoir in the Midwestern US. We captured two consecutive growing seasons with markedly different watershed discharge and nutrient loading. Temporal variability often exceeded spatial variability in both wet and dry years. However, relative spatial variability was higher in the dry year, suggesting that internal processes are more important in structuring spatial dynamics in dry years. Strikingly, marked differences in watershed discharge and nutrient loading between years produced relatively small differences in many lake metrics, suggesting resilience to hydrologic variability. We found little difference in gross primary productivity between wet and dry years, but ecosystem respiration was higher in the wet year, shifting net ecosystem production below zero. Discrete storm events produced strong, yet ephemeral and spatially explicit effects, reflective of the balance of stream input and discharge over the dam. Increases in limiting nutrients were restricted to near stream inlets and returned to pre-storm baseline within days. Ecosystem metabolism was suppressed during storm events, likely due to biomass flushing. Understanding how changing hydrologic regimes will mediate spatiotemporal dynamics of ecosystem metrics is paramount to preserving the ecological integrity and ecosystem services of lakes under future climates.

气候变化会改变水文状况，包括其可变性。在水生生态系统中，其影响将是显着的，其中资源补贴（例如养分，碳）是关键的生态系统过程的驱动力。然而，我们对改变水文状况将如何调节湖泊生物地球化学和生态系统代谢的时空动态知之甚少。为了解决这个问题，我们以高空间分辨率对Acton Lake（美国中西部的超富营养水库）中的生态系统代谢和营养动力学进行了定量分析。我们捕获了两个连续的生长期，分水岭流量和养分含量明显不同。在潮湿和干旱的年份，时间变异性经常超过空间变异性。但是，在干旱年份，相对空间变异性较高，这表明内部过程在构造干旱年份的空间动力学方面更重要。引人注目的是，年份之间流域流量和养分含量的显着差异在许多湖泊指标中产生了相对较小的差异，表明对水文变异性的适应力。我们发现干湿年之间的总初级生产力差异不大，但湿年中的生态系统呼吸作用较高，从而使生态系统净产量降至零以下。离散风暴事件产生了强烈但短暂而又在空间上明显的影响，反映了大坝上水流输入和流量的平衡。限制养分的增加仅限于近流入口，并在数天内恢复到暴风雨前的基线。暴风雨期间生态系统的代谢受到抑制，可能是由于生物量冲刷造成的。