Department of Biology, Stanford University, Stanford, CA 94305, USA.
Ecol Lett. 2011 Aug;14(8):773-81. doi: 10.1111/j.1461-0248.2011.01639.x. Epub 2011 Jun 23.
Mutualistic interactions involving pollination and ant-plant mutualistic networks typically feature tightly linked species grouped in modules. However, such modularity is infrequent in seed dispersal networks, presumably because research on those networks predominantly includes a single taxonomic animal group (e.g. birds). Herein, for the first time, we examine the pattern of interaction in a network that includes multiple taxonomic groups of seed dispersers, and the mechanisms underlying modularity. We found that the network was nested and modular, with five distinguishable modules. Our examination of the mechanisms underlying such modularity showed that plant and animal trait values were associated with specific modules but phylogenetic effect was limited. Thus, the pattern of interaction in this network is only partially explained by shared evolutionary history. We conclude that the observed modularity emerged by a combination of phylogenetic history and trait convergence of phylogenetically unrelated species, shaped by interactions with particular types of dispersal agents.
互利共生关系，包括传粉和蚂蚁与植物的互利共生网络，通常具有紧密联系的物种组成模块。然而，在种子扩散网络中，这种模块性并不常见，这可能是因为对这些网络的研究主要包括单一分类动物群（如鸟类）。在这里，我们首次研究了一个包含多个分类群种子散布者的网络中的相互作用模式以及模块性的基础机制。我们发现，该网络是嵌套的和模块化的，有五个可区分的模块。我们对这种模块性的基础机制的研究表明，植物和动物的特征值与特定的模块相关，但系统发育效应有限。因此，网络中相互作用的模式仅部分可以用共同的进化历史来解释。我们的结论是，观察到的模块性是由系统发育历史和与系统发育无关的物种的特征趋同共同作用的结果，而这些物种与特定类型的传播媒介相互作用而形成。
