Despite the longstanding significance of North America's Great Lakes, little is known about their preindustrial ecology. Here, we report on when and how humans first became a main driver of Lake Ontario's nutrient dynamics. Nitrogen isotope analyses of archaeological fish show that, prior to the 1830s, Lake Ontario's nitrogen cycle and the trophic ecology of its top predators had remained stable for at least 800 yrs, despite Indigenous and historical European agricultural land management across the region. An abrupt shift in the nitrogen isotope composition of Lake Ontario's fish community is evident in the early to mid‐19^th century and reflects the initiation of industrial‐scale forest clearance. These data show how the nitrogenous nutrient regimes of even the world's largest freshwater ecosystems can be highly sensitive to short‐term watershed forest cover disturbances and indicate a profound shift in the relationship between humans and their environment.

中文翻译：

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森林砍伐导致大湖​​氮循环突然转变

尽管北美五大湖具有长远的意义，但对其工业化前的生态知之甚少。在这里，我们报告人类何时以及如何首次成为安大略湖营养动态的主要驱动力。对考古鱼类的氮同位素分析表明，在1830年代之前，尽管该地区有本土和历史悠久的欧洲农业土地管理，但安大略湖的氮循环和其主要掠食者的营养生态至少持续了800年。在安大略湖的鱼类群落的氮同位素组成的突然转变是在年初明显的中期19^日世纪，反映了工业规模森林砍伐的开始。这些数据表明，即使是世界上最大的淡水生态系统，氮素养分制度如何对短期流域的森林覆盖扰动高度敏感，并表明人与环境之间关系的深刻变化。