McNaughton S J, Oesterheld M, Frank D A, Williams K J
Biological Research Laboratories, Syracuse University, New York 13244-1220.
Nature. 1989 Sep 14;341(6238):142-4. doi: 10.1038/341142a0.
Ecosystems are structurally organized as food webs within which energy is transmitted between trophic levels and dissipated into the environment. Energy flow between two trophic levels is given by the amount of production at the lower level and by the proportion of production that is consumed, assimilated and respired at the higher level. Considerable evidence indicates that food-web structure varies predictably in different habitats, but much less is known about quantitative relationships among food web fluxes. Many of the energetic properties of herbivores in African game parks are associated with rainfall and, by inference, with net primary productivity. Respiratory costs per unit production at the consumer trophic level are higher for homeotherms than for heterotherms. Plant secondary chemicals affect herbivore dietary choices and the allocation of plant resources to those chemicals varies with resource availability. How these phenomena are translated into ecosystem fluxes is unknown. We present evidence that herbivore biomass, consumption and productivity are closely correlated with plant productivity, suggesting that the latter is a principal integrator and indicator of functional processes in food webs.
生态系统在结构上被组织成食物网，能量在食物网中在营养级之间传递并消散到环境中。两个营养级之间的能量流动由较低营养级的生产量以及较高营养级消耗、同化和呼吸的生产量比例决定。大量证据表明，食物网结构在不同栖息地会有可预测的变化，但对于食物网通量之间的定量关系却知之甚少。非洲野生动物保护区中食草动物的许多能量特性都与降雨有关，由此推断，也与净初级生产力有关。恒温动物在消费者营养级的单位生产量呼吸成本高于变温动物。植物次生化学物质会影响食草动物的饮食选择，并且植物资源分配到这些化学物质的情况会随资源可用性而变化。这些现象如何转化为生态系统通量尚不清楚。我们提供的证据表明，食草动物的生物量、消耗量和生产力与植物生产力密切相关，这表明植物生产力是食物网中功能过程的主要整合者和指标。
