Nutritional constraints in terrestrial and freshwater food webs
Nutritional constraints in terrestrial and freshwater food webs
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DOI：
10.1038/35046058
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发表时间：
2000-11-30
期刊：
影响因子：
64.8
通讯作者：
Sterner, RW
中科院分区：
文献类型：
--
作者：
Elser, JJ;Fagan, WF;Sterner, RW
水生系统和陆地系统之间的生物和环境差异阻碍了对地球不同栖息地的群落和生态系统结构的分析。生态化学计量学（1，2）为此类分析提供了一种综合方法，因为所有生物都由相同的主要元素（C，N，P）组成，其平衡影响生产，营养循环和食物网动态（3，4）。在这里，我们展示了栖息地中初级生产者（自养生物）和无脊椎动物初级消费者（食草动物）的C：N：P比率的相似性和差异。陆地食物网是建立在一个营养极其贫乏的自养基地与C：P和C：N比高于湖泊颗粒物，虽然N：P的比例几乎相同。陆地食草动物（昆虫）和淡水对应物（浮游动物）营养丰富，在C：N：P化学计量学上难以区分。在湖泊和陆地系统中，食草动物在消耗具有典型碳营养比的自养生物时，应该具有较低的生长效率（10 - 30%）。这些化学计量的限制草食动物的生长似乎是定性相似，在这两种环境中普遍存在。
Biological and environmental contrasts between aquatic and terrestrial systems have hindered analyses of community and ecosystem structure across Earth's diverse habitats. Ecological stoichiometry(1,2) provides an integrative approach for such analyses, as all organisms are composed of the same major elements (C, N, P) whose balance affects production, nutrient cycling, and food-web dynamics(3,4). Here we show both similarities and differences in the C:N:P ratios of primary producers (autotrophs) and invertebrate primary consumers (herbivores) across habitats. Terrestrial food webs are built on an extremely nutrient-poor autotroph base with C:P and C:N ratios higher than in lake particulate matter, although the N:P ratios are nearly identical. Terrestrial herbivores (insects) and their freshwater counterparts (zooplankton) are nutrient-rich and indistinguishable in C:N:P stoichiometry. In both lakes and terrestrial systems, herbivores should have low growth efficiencies (10-30%) when consuming autotrophs with typical carbon-to-nutrient ratios. These stoichiometric constraints on herbivore growth appear to be qualitatively similar and widespread in both environments.