Data and code from: Impacts of changing winters on lake ecosystems will increase with latitude

Climate warming is especially pronounced in winter and at high latitudes. Warming winters are leading to the loss of lake ice and changing snow cover on lakes. Historically, lake scientists have paid less attention to the ice cover period, leading to data and theory gaps about the role of winter conditions in lake ecosystem function and the consequences of changing winters. Here we use simple models to show that the latitudinal interaction between ice cover duration and light flux seasonality has profound and underappreciated implications for lakes. Our models focus on light and temperature, two key drivers of ecosystem processes. We show that the relative amount of light arriving in lakes during ice cover increases non-linearly with latitude and that the light climate of high-latitude lakes is much more sensitive to changing winter conditions than that of lower-latitude lakes. We also demonstrate that the synchronicity between high light and warm temperatures may decrease with latitude, with implications for primary and secondary production. Our results suggest that ice loss may lead to greater relative change in productivity and biotic interactions in higher latitude lakes and also offer several testable predictions for understanding the consequences of climate-induced changes across latitudinal gradients.

气候变暖在冬季及高纬度地区表现得尤为显著。暖冬现象正导致湖泊冰盖消融，并改变湖泊覆雪状况。长期以来，湖泊生态学界对冰盖存续周期的关注度不足，导致有关冬季环境在湖泊生态系统功能中的作用，以及冬季环境变化所引发的后续效应的相关数据与理论均存在缺口。本研究借助简易模型证明，冰盖持续时长与光照通量季节变化之间的纬度交互作用，对湖泊生态系统具有深远且尚未被充分认知的影响。我们的模型聚焦于光照与温度这两大生态系统过程的核心驱动因子。研究发现，冰盖覆盖期内入射至湖泊的相对光照量随纬度呈非线性增长，且高纬度湖泊的光照环境对冬季环境变化的敏感度远高于低纬度湖泊。此外，本研究还证实，强光与高温的同步性可能随纬度升高而减弱，这将对初级生产与次级生产产生影响。研究结果表明，冰盖消融可能会导致高纬度湖泊的生产力与生物交互作用发生更为显著的相对变化，同时也为理解气候变化引发的、沿纬度梯度分布的环境变化所带来的后果，提供了若干可验证的预测方向。