Richness-productivity relationships between trophic levels in a detritus-based system: significance of abundance and trophic linkage.
Richness-productivity relationships between trophic levels in a detritus-based system: significance of abundance and trophic linkage.
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基于碎屑的系统中营养级之间的丰富度-生产力关系：丰富度和营养级联系的重要性。
DOI：
10.1007/s00442-007-0837-5
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发表时间：
2007
期刊：
影响因子：
2.7
通讯作者：
Juliano,StevenA
中科院分区：
文献类型：
--
作者：
Yee,DonaldA;Yee,SusanHarrell;Kneitel,JamieM;Juliano,StevenA
大多数关于生产力-物种丰富度关系的理论和实证研究都没有考虑营养级之间的联系。我们量化的生产力丰富度的关系，在碎屑为基础的，充满水的树洞社区两个营养水平：无脊椎动物的消费者和原生动物，他们的饲料。通过类比营养水平之间的生物量分配理论，我们预测，消费者控制将导致丰富的原生动物在较低的营养水平不受生产力的增加，而丰富的无脊椎动物消费者将增加生产力。我们的数据与这一预测是一致的：消费者的丰富度呈线性增长，但原生动物的丰富度与生产力的变化无关。所有类群的生产力丰富度的关系相结合，不一定与每个营养级内的关系一致。我们使用通径分析来研究可能产生所观察到的营养级对生产力变化的反应的机制。我们测试了生产力对丰富度的直接影响和生产力对总丰度的间接影响的重要性。对于原生动物，只有生产力对丰富度的直接影响是重要的，但生产力对丰富度的直接和间接影响对无脊椎动物都很重要。原生动物的丰富程度受到自上而下的无脊椎动物丰富程度的强烈影响。这些结果是一致的营养级之间的生物量分配的理论，并建议丰富和丰富的营养级内和之间的强有力的联系。了解营养级的相互作用如何决定生产力丰富度的关系可能是必要的，以便我们实现全面了解多样性的决定因素。
Most theoretical and empirical studies of productivity–species richness relationships fail to consider linkages among trophic levels. We quantified productivity–richness relationships in detritus-based, water-filled tree-hole communities for two trophic levels: invertebrate consumers and the protozoans on which they feed. By analogy to theory for biomass partitioning among trophic levels, we predicted that consumer control would result in richness of protozoans in the lower trophic level being unaffected by increases in productivity, whereas richness of invertebrate consumers would increase with productivity. Our data were consistent with this prediction: consumer richness increased linearly, but protozoan richness was unrelated to changes in productivity. The productivity–richness relationships for all taxa combined were not necessarily consistent with relationships within each trophic level. We used path analysis to investigate the mechanisms that may produce the observed responses of trophic levels to changes in productivity. We tested the importance of the direct effect of productivity on richness and the indirect effect of productivity mediated by effects on total abundance. For protozoans, only direct effects of productivity on richness were important, but both direct and indirect effects of productivity on richness were important for invertebrates. Protozoan richness was strongly affected by top-down impacts of abundance of invertebrates. These results are consistent with theory on biomass partitioning among trophic levels and suggest a strong link between richness and abundance within and between trophic levels. Understanding how trophic level interactions determine productivity–richness relationships will likely be necessary in order for us to achieve a comprehensive understanding of the determinants of diversity.