Changes in aquatic insect emergence in response to whole‐lake experimental manipulations of introduced trout
Changes in aquatic insect emergence in response to whole‐lake experimental manipulations of introduced trout
复制标题
引入鳟鱼的全湖实验操作导致水生昆虫出现的变化
DOI：
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发表时间：
2009
期刊：
影响因子：
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通讯作者：
S. Lawler
中科院分区：
文献类型：
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作者：
K. Pope;J. Piovia‐Scott;S. Lawler
总结
1. 从高山湖泊中出现的昆虫为许多陆地掠食者提供了重要的食物来源。从湖泊中产生的昆虫补贴量受到捕食者组成的影响，但捕食者的影响可以通过栖息地复杂性的提高而改善。我们进行了一项重复的全湖实验，以测试引入的鱼类捕食者对加利福尼亚州西北部三一阿尔卑斯山荒野 16 个高山湖泊沿岸地区内和新兴的水生昆虫的丰度和组成的影响。
2. 研究处理与加州荒野地区正在实施的渔业管理方案相匹配：(i) 继续放养非本地鳟鱼，(ii) 暂停放养，以及 (iii) 暂停放养和清除鱼类。我们还包括四个自然无鱼的“参考”湖泊。我们比较了处理开始前和处理后 3 年内新兴水生昆虫的丰度和生物量。还比较了处理后第三年的底栖昆虫丰度。
3. 鳟鱼的清除迅速增加了蜉蝣、石蛾和昆虫捕食者的数量，以及湖泊中出现的昆虫总生物量。暂停放养湖与继续放养湖之间没有发现显着差异。与栖息地复杂性相比，鱼类密度是水生昆虫出现的更重要的预测因素。
4. 蜉蝣幼虫对鱼的清除做出积极反应，石蛾幼虫在没有鱼的湖泊中往往更加丰富，但我们没有检测到对捕食性昆虫丰度的影响。然而，与去除鱼或无鱼的参考湖泊相比，我们在有鱼的湖泊的浅水中发现了大型昆虫捕食者。
5. 这些结果深入了解了过去和当前的鱼类放养做法对昆虫猎物从高山湖泊流入邻近陆地环境的持续影响。我们还表明，通过清除非本地鱼类可以迅速扭转这些后果。
Summary
1. Insects emerging from mountain lakes provide an important food source for many terrestrial predators. The amount of insect subsidy that emerges from lakes is influenced by predator composition, but predator effects could be ameliorated by greater habitat complexity. We conducted a replicated whole-lake experiment to test the effects of introduced fish predators on the abundance and composition of aquatic insects within and emerging from the littoral zone of 16 mountain lakes in the Trinity Alps Wilderness in northwestern California.
2. Study treatments matched the fisheries management options being implemented in California’s wilderness areas: (i) continued stocking with non-native trout, (ii) suspension of stocking, and (iii) suspension of stocking and removal of fish. We also included four naturally fishless ‘reference’ lakes. We compared abundances and biomass of emerging aquatic insects before treatments were initiated and for 3 years following their establishment. Abundances of benthic insects were also compared in the third year post-treatment.
3. Trout removal rapidly increased abundances of mayflies, caddisflies, and insect predators, and overall insect biomass emerging from lakes. No significant differences were found between the suspension of stocking lakes and continued stocking lakes. Fish density was a more important predictor of aquatic insect emergence than habitat complexity.
4. Mayfly larvae responded positively to fish removal and caddisfly larvae tended to be more abundant in lakes without fish, but we did not detect effects on abundance of predatory insects. However, we found large insect predators in shallower water in lakes with fish compared to fish removal or fish-free reference lakes.
5. These results provide insights into the continuing effects of past and current fish stocking practices on the flow of insect prey from mountain lakes into the neighbouring terrestrial environment. We also show that these consequences can rapidly be reversed by removing non-native fishes.