摘要 : In lakes, the production and emission of methane (CH_4) have been linked to lake trophic status. However, few studies have quantified the temporal response of lake CH_4 dynamics to primary productivity at the ecosystem scale or co... 展开 In lakes, the production and emission of methane (CH_4) have been linked to lake trophic status. However, few studies have quantified the temporal response of lake CH_4 dynamics to primary productivity at the ecosystem scale or considered how the response may vary across lakes. Here, we investigate relationships between lake CH_4 dynamics and ecosystem primary productivity across both space and time using data from five lakes in northern Wisconsin, USA. From 2014 to 2019, we estimated hypolimnetic CH_4 storage rates for each lake using timeseries of hypolimnetic CH_4 concentration through the summer season. Across all lakes and years, hypolimnetic CH_4 storage ranged from <0.001 to 7.6 mmol CH_4 m~(-2) d~(-1) and was positively related to the mean summer rate of gross primary productivity (GPP). However, within-lake temporal responses to GPP diverged from the spatial relationship, and GPP was not a significant predictor of interannual variability in CH_4 storage at the lake scale. Using these data, we consider how and why temporal responses may differ from spatial patterns and demonstrate how extrapolating cross-lake relationships for prediction at the lake scale may substantially overestimate the rate of change of CH_4 dynamics in response to lake primary productivity. We conclude that future predictions of lake-mediated climate feedbacks in response to a shifting distribution of trophic status should incorporate both varying lake responses and the temporal scale of change. 收起