A shady phytoplankton paradox: when phytoplankton increases under low light.
A shady phytoplankton paradox: when phytoplankton increases under low light.
复制标题
阴暗的浮游植物悖论：当浮游植物在弱光下增加时。
DOI：
10.1098/rspb.2018.1067
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发表时间：
2018
期刊：
影响因子：
--
通讯作者：
Urabe J.
中科院分区：
文献类型：
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作者：
Yamamichi M;Kazama T;Tokita K;Katano I;Doi H;Yoshida T;Hairston Jr NG;Urabe J.
光是生态系统动态的基本驱动力，影响光合作用和初级生产的速率。尽管它很重要，但与养分负荷相比，人们对其对水生生态系统群落规模的影响知之甚少。了解光限制对于生态系统管理也很重要，因为人类活动正在迅速改变水生生态系统的光可用性。在这里，我们发现，减少光照反而会增加浅湖中浮游植物的丰度。我们的结果基于田间操作实验、田间观察和模型，表明在浮游植物和沉水植物之间对光和养分的竞争下，在高光供应下可能出现替代稳定状态。在大型植物占主导地位的状态下，随着光照的减少，浮游植物密度增加，因为大型植物（有效地竞争从沉积物中释放的养分）受到光照减少的影响更严重。我们的结果证明了物种与空间异质性的相互作用如何在复杂的生态系统中导致意想不到的结果。我们的研究结果意味着，与直觉相反，用于控制有害藻华的部分表面遮荫可能会通过减少大型植物来增加浮游植物的丰度。因此，为了预测浅湖生态系统如何应对环境扰动，必须考虑光对中上层和底栖生产者之间相互作用的影响。
Light is a fundamental driver of ecosystem dynamics, affecting the rate of photosynthesis and primary production. In spite of its importance, less is known about its community-scale effects on aquatic ecosystems compared with those of nutrient loading. Understanding light limitation is also important for ecosystem management, as human activities have been rapidly altering light availability to aquatic ecosystems. Here we show that decreasing light can paradoxically increase phytoplankton abundance in shallow lakes. Our results, based on field manipulation experiments, field observations and models, suggest that, under competition for light and nutrients between phytoplankton and submersed macrophytes, alternative stable states are possible under high-light supply. In a macrophyte-dominated state, as light decreases phytoplankton density increases, because macrophytes (which effectively compete for nutrients released from the sediment) are more severely affected by light reduction. Our results demonstrate how species interactions with spatial heterogeneity can cause an unexpected outcome in complex ecosystems. An implication of our findings is that partial surface shading for controlling harmful algal bloom may, counterintuitively, increase phytoplankton abundance by decreasing macrophytes. Therefore, to predict how shallow lake ecosystems respond to environmental perturbations, it is essential to consider effects of light on the interactions between pelagic and benthic producers.