Spatial heterogeneity increases the importance of species richness for an ecosystem process
Spatial heterogeneity increases the importance of species richness for an ecosystem process
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DOI：
10.1111/j.1600-0706.2009.17572.x
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发表时间：
2009-09-01
期刊：
影响因子：
3.4
通讯作者：
Thompson, Richard C.
中科院分区：
文献类型：
--
作者：
Griffin, John N.;Jenkins, Stuart R.;Thompson, Richard C.
自1990年代中期以来，生物多样性在调节生态系统过程中的作用一直是理论和经验关注的焦点。理论预测，物种丰富度和身份效应之间的平衡将严重依赖于环境异质性的程度，这决定了物种之间在资源利用模式上的差异可以表达的程度。我们进行了一个中尺度实验来明确地验证这一假设。我们操纵的丰富性和身份的潮间带软体动物食草动物，以及空间异质性的基板上，他们吃草。藻类消费量的大小被用作我们的焦点生态系统过程。放牧处理包括三个单一的文化和一个单一的混养，包括所有三个物种的异质性表示为地形复杂，平坦的基板的比例。物种身份有很强的影响，均匀的基板上，与身份的最佳表现的物种依赖于基板。在异质基质上，所有三个物种的合适条件都被代表，允许表达资源利用的空间互补性和总藻类消费的增强。我们的研究结果提供了第一个明确的实验证据表明，物理环境的空间异质性可以在介导物种多样性的影响中发挥关键作用。
The role of biodiversity in mediating ecosystem processes has been the subject of focused theoretical and empirical attention since the mid-1990s. Theory predicts that the balance between species richness and identity effects will critically depend on the degree of environmental heterogeneity, which dictates the extent to which differences between species in patterns of resource use can be expressed. We conducted a mesocosm experiment to explicitly test this hypothesis. We manipulated the richness and identity of intertidal molluscan grazers, as well as the spatial heterogeneity of the substrate upon which they grazed. The magnitude of algal consumption was used as our focal ecosystem process. The grazer treatments consisted of three monocultures and a single polyculture including all three species; heterogeneity was represented as the proportion of topographically complex and flat substrate. Species identity had strong effects on homogeneous substrates, with the identity of the best-performing species dependent on the substrate. On the heterogeneous substrate, suitable conditions for all three species were represented, allowing the expression of spatial complementarity of resource use and the enhancement of total algal consumption. Our findings provide the first explicit experimental evidence that spatial heterogeneity of the physical environment can play a key role in mediating effects of species diversity.