Non-additive effects of foundation species determine the response of aquatic ecosystems to nutrient perturbation.
Non-additive effects of foundation species determine the response of aquatic ecosystems to nutrient perturbation.
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基础物种的非加性效应决定了水生生态系统对营养扰动的响应。
DOI：
10.1002/ecy.3371
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发表时间：
2021-05
期刊：
影响因子：
4.8
通讯作者：
Moritz D. Lürig;Anita Narwani;Hannele Penson;B. Wehrli;P. Spaak;B. Matthews
中科院分区：
文献类型：
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作者：
Moritz D. Lürig;Anita Narwani;Hannele Penson;B. Wehrli;P. Spaak;B. Matthews
富营养化是对全球水生生态系统的持续威胁。基础物种，即那些在群落结构和生态系统功能中发挥核心作用的物种，可能对水生生态系统面对干扰的恢复能力很重要。然而，人们对这些物种之间的相互作用如何影响生态系统对营养扰动的反应知之甚少。在这里，我们使用了一个阵列（N=20）的室外实验池塘生态系统（15000 L），控制了两种基础物种的存在，即大型植物狐尾豆科植物和多态贻贝，并量化了生态系统对多种营养干扰的响应，时间长达两年。第一年，我们增加了5个营养脉冲，从7月中旬到10月中旬的10周时间里，从10到50μg P/L，第二年，我们在10月中旬增加了一个50μg P/L的大脉冲。我们使用自动探空仪来模拟整个生态系统的代谢，并在高频（15分钟间隔）测量多种生态系统的特性，包括浮游植物和溶解有机物的荧光。总体而言，这两种基础物种都强烈影响生态系统对营养扰动的响应，并且正如预期的那样，最初抑制了营养添加后浮游植物丰度的增加。然而，当这两个物种都存在时，浮游植物生物量相对于其他处理组合大幅增加：在两年中营养扰动后，多个生态系统指标的非可加性很明显，但在我们的扰动之间的中间几个月减弱。总的来说，这些结果证明了基础物种之间的相互作用如何导致水生生态系统对营养添加的预期反应出现惊人的强烈偏差。
Eutrophication is a persistent threat to aquatic ecosystems worldwide. Foundation species, namely those that play a central role in the structuring of communities and functioning of ecosystems, are likely important for the resilience of aquatic ecosystems in the face of disturbance. However, little is known about how interactions among such species influence ecosystem responses to nutrient perturbation. Here, using an array (N=20) of outdoor experimental pond ecosystems (15000 L), we manipulated the presence of two foundation species, the macrophyte Myriophyllum spicatum and the mussel Dreissena polymorpha, and quantified ecosystem responses to multiple nutrient disturbances, spread over two years. In the first year we added five nutrient pulses, ramping up from 10 to 50μg P/L over a 10-week period from mid-July to mid-October, and in the second year we added a single large pulse of 50μg P/L in mid-October. We used automated sondes to model whole-ecosystem metabolism, and to measure multiple ecosystems properties at high frequency (15min intervals), including phytoplankton and dissolved organic matter fluorescence. Overall, both foundation species strongly affected the ecosystem responses to nutrient perturbation, and, as expected, initially suppressed the increase in phytoplankton abundance following nutrient additions. However, when both species were present, phytoplankton biomass increased substantially relative to other treatment combinations: non-additivity was evident for multiple ecosystem metrics following the nutrient perturbations in both years but was diminished in the intervening months between our perturbations. Overall, these results demonstrate how interactions between foundation species can cause surprisingly strong deviations from the expected responses of aquatic ecosystems to nutrient additions.