Cary Institute of Ecosystem Studies, Millbrook, NY 12545, USA.
Proc Natl Acad Sci U S A. 2011 Feb 1;108(5):1975-80. doi: 10.1073/pnas.1012807108. Epub 2011 Jan 18.
Cross-ecosystem subsidies to food webs can alter metabolic balances in the receiving (subsidized) system and free the food web, or particular consumers, from the energetic constraints of local primary production. Although cross-ecosystem subsidies between terrestrial and aquatic systems have been well recognized for benthic organisms in streams, rivers, and the littoral zones of lakes, terrestrial subsidies to pelagic consumers are more difficult to demonstrate and remain controversial. Here, we adopt a unique approach by using stable isotopes of H, C, and N to estimate terrestrial support to zooplankton in two contrasting lakes. Zooplankton (Holopedium, Daphnia, and Leptodiaptomus) are comprised of ≈ 20-40% of organic material of terrestrial origin. These estimates are as high as, or higher than, prior measures obtained by experimentally manipulating the inorganic (13)C content of these lakes to augment the small, natural contrast in (13)C between terrestrial and algal photosynthesis. Our study gives credence to a growing literature, which we review here, suggesting that significant terrestrial support of pelagic crustaceans (zooplankton) is widespread.
跨生态系统的食物网补助可以改变接收（补助）系统中的代谢平衡，并使食物网或特定消费者摆脱本地初级生产的能量限制。尽管已经很好地认识到了陆地和水生系统之间的底层生物的跨生态系统补助，但陆地对浮游消费者的补助更难以证明，并且仍然存在争议。在这里，我们采用一种独特的方法，使用 H、C 和 N 的稳定同位素来估计两个对比湖泊中浮游动物的陆地支持。浮游动物（Holopedium、Daphnia 和 Leptodiaptomus）由约 20-40%的有机物质组成，这些物质来自陆地。这些估计与通过实验操纵这些湖泊的无机（13）C 含量以增加陆地和藻类光合作用之间（13）C 的天然小差异来增加（13）C 的先前测量值一样高，甚至更高。我们的研究证实了越来越多的文献，我们在这里对其进行了综述，这些文献表明，浮游甲壳类动物（浮游动物）的大量陆地支持是广泛存在的。
