In high-latitude lakes, air temperature is an important driver of ice cover thickness and duration, which in turn influence water temperature and primary production supporting lake consumers and predators. In lieu of multidecadal observational records necessary to assess the response of lakes to long-term warming, we used otolith-based growth records from a long-lived resident lake fish, lake trout (Salvelinus namaycush), as a proxy for production. Lake trout were collected from seven deep, oligotrophic lakes in Lake Clark National Park and Preserve on in southwest Alaska that varied in the presence of marine-derived nutrients (MDN) from anadromous sockeye salmon (Oncorhynchus nerka). Linear mixed-effects models were used to partition variation in lake trout growth by age and calendar-year and model comparisons tested for a mean increase in lake trout growth with sockeye salmon presence. Year effects from the best mixed-effects model were subsequently compared to indices of temperature, lake ice, and regional indices of sockeye salmon escapement. A strong positive correlation between annual lake trout growth and temperature suggested that warmer springs, earlier lake ice break-up, and a longer ice-free growing season increase lake trout growth via previously identified bottom-up increases in production with warming. Accounting for differences in the presence or annual escapement of sockeye salmon with available data did not improve model fit. Collectively with other studies, the results suggest that productivity of subarctic lakes has benefitted from warming spring temperatures and that temperature can synchronise otolith growth across lakes with and without sockeye salmon MDN.

中文翻译：

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阿拉斯加西南部湖泊的湖鳟生长对春季温度敏感

在高纬度湖泊中，气温是冰盖厚度和持续时间的重要驱动因素，进而影响支持湖泊消费者和捕食者的水温和初级生产。代替评估湖泊对长期变暖的响应所必需的数十年观测记录，我们使用了来自一种长期居住的湖鱼湖鳟 (Salvelinus namaycush) 的耳石生长记录作为生产的代理。湖鳟是从阿拉斯加西南部克拉克湖国家公园和保护区的七个贫营养深湖中收集的，这些湖泊因来自溯河红鲑鱼 (Oncorhynchus nerka) 的海洋衍生营养素 (MDN) 的存在而变化。线性混合效应模型用于按年龄和日历年划分湖鳟生长的变化，并且模型比较测试了红鲑鱼存在时湖鳟生长的平均增长。随后将最佳混合效应模型的年份效应与温度指数、湖冰指数和红鲑鱼逃逸区域指数进行比较。年度湖鳟生长与温度之间存在很强的正相关性表明，较暖的春季、较早的湖冰破裂和较长的无冰生长季节通过先前确定的产量随变暖自下而上的增加而增加了湖鳟的生长。用可用数据解释红鲑鱼的存在或每年逃逸的差异并没有改善模型拟合。与其他研究一起，