Global warming-related changes to freshwater ecosystems in Arctic and Subarctic regions have been magnified by nutrient input from increasing waterfowl populations. To gain insight into how these changes might affect ecosystem function, we conducted a mesocosm experiment in the Subarctic by enriching N and P (1 ×, 10 ×, and 20 × treatments) and increasing mean water temperatures ≤ 3°C. We measured responses of two species of larval amphibians, periphyton, and phytoplankton. Wood frog (Rana sylvatica) larvae developed quicker (odds ratio [OR] for 1°C increase = 0.903, 95% CI 0.892–0.912) and were more likely to metamorphose (OR 1.076, 95% CI 0.022–14.73) in warmer waters. Boreal chorus frogs (Pseudacris maculata) also developed quicker with warmer temperatures (OR 0.880, 95% CI 0.860–0.900), despite a non-significant trend toward reduced survival (OR 0.853, 95% CI 0.696–1.039). Periphyton and phytoplankton concentrations increased with nutrient additions, as did size of wood frog metamorphs. Periphyton and phytoplankton did not vary with temperature, but periphyton was limited by tadpole abundance. Our results highlight the potential for non-linear responses to ecosystem change, with species-specific consumer and ecosystem responses that depend on the magnitude of changes.

中文翻译：

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实验性变暖和营养物质富集对北极边缘湿地群落的影响

北极和亚北极地区淡水生态系统与全球变暖相关的变化因水禽数量增加而导致的营养输入被放大。为了深入了解这些变化可能如何影响生态系统功能，我们通过富集 N 和 P（1 ×、10 × 和 20 × 处理）并将平均水温提高 ≤ 3°C，在亚北极地区进行了中宇宙实验。我们测量了两种两栖动物幼虫、附生生物和浮游植物的反应。林蛙 (Rana sylvatica) 幼虫发育更快（升高 1°C 的比值比 [OR] = 0.903，95% CI 0.892–0.912）并且在较温暖的水中更有可能变态（OR 1.076，95% CI 0.022–14.73） . 北方合唱蛙（Pseudacris maculata）也随着温度升高而发育得更快（OR 0.880，95% CI 0.860–0.900），尽管存活率降低的趋势不显着（OR 0.853，95% CI 0.696–1.039）。附生生物和浮游植物浓度随着营养物的添加而增加，林蛙变质体的大小也是如此。附生生物和浮游植物不随温度变化，但附生生物受到蝌蚪丰度的限制。我们的结果强调了对生态系统变化的非线性响应的潜力，特定于物种的消费者和生态系统响应取决于变化的幅度。