Multi-level trophic cascades in a heavily exploited open marine ecosystem
Multi-level trophic cascades in a heavily exploited open marine ecosystem
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DOI：
10.1098/rspb.2007.1752
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发表时间：
2008-08-07
影响因子：
4.7
通讯作者：
Kornilovs, Georgs
中科院分区：
文献类型：
--
作者：
Casini, Michele;Lovgren, Johan;Kornilovs, Georgs
人为干扰与气候变化交织在一起，可对海洋生态系统的上层营养层产生巨大影响，并可能向下蔓延至食物网。到目前为止，很难证明远洋海洋环境中的多级营养级联。利用33年期间收集的实地数据，我们首次显示了一个四级社区范围内的营养级联在波罗的海开放。鳕鱼（Gadus morhua）种群的急剧减少直接影响了它的主要猎物，食动物的鲱鱼（Sprattus sprattus），并间接影响了浮游动物和浮游植物的夏季生物量（自上而下的过程）。自下而上的过程和气候水文力量有一个较弱的影响，而浮游植物的变化是完全由自上而下的机制。我们的研究结果表明，为了抑制偶尔有害的藻华的波罗的海，努力不仅要解决控制人为的营养输入，但也要保持结构和功能的较高的营养水平。
Anthropogenic disturbances intertwined with climatic changes can have a large impact on the upper trophic levels of marine ecosystems, which may cascade down the food web. So far it has been difficult to demonstrate multi-level trophic cascades in pelagic marine environments. Using field data collected during a 33-year period, we show for the first time a four-level community-wide trophic cascade in the open Baltic Sea. The dramatic reduction of the cod (Gadus morhua) population directly affected its main prey, the zooplanktivorous sprat (Sprattus sprattus), and indirectly the summer biomass of zooplankton and phytoplankton (top-down processes). Bottom-up processes and climate-hydrological forces had a weaker influence on sprat and zooplankton, whereas phytoplankton variation was explained solely by top-down mechanisms. Our results suggest that in order to dampen the occasionally harmful algal blooms of the Baltic, effort should be addressed not only to control anthropogenic nutrient inputs but also to preserve structure and functioning of higher trophic levels.