Sebastián-González Esther, Pires Mathias M, Donatti Camila I, Guimarães Paulo R, Dirzo Rodolfo
Department of Biology Stanford University Stanford CA USA.
Departamento de Ecologia Universidade de São Paulo São Paulo Brazil.
Ecol Evol. 2017 May 17;7(12):4496-4506. doi: 10.1002/ece3.2865. eCollection 2017 Jun.
Species phenotypic traits affect the interaction patterns and the organization of seed-dispersal interaction networks. Understanding the relationship between species characteristics and network structure help us understand the assembly of natural communities and how communities function. Here, we examine how species traits may affect the rules leading to patterns of interaction among plants and fruit-eating vertebrates. We study a species-rich seed-dispersal system using a model selection approach to examine whether the rules underlying network structure are driven by constraints in fruit resource exploitation, by preferential consumption of fruits by the frugivores, or by a combination of both. We performed analyses for the whole system and for bird and mammal assemblages separately, and identified the animal and plant characteristics shaping interaction rules. The structure of the analyzed interaction network was better explained by constraints in resource exploitation in the case of birds and by preferential consumption of fruits with specific traits for mammals. These contrasting results when looking at bird-plant and mammal-plant interactions suggest that the same type of interaction is organized by different processes depending on the assemblage we focus on. Size-related restrictions of the interacting species (both for mammals and birds) were the most important factors driving the interaction rules. Our results suggest that the structure of seed-dispersal interaction networks can be explained using species traits and interaction rules related to simple ecological mechanisms.
物种表型特征影响种子传播相互作用网络的相互作用模式和组织。了解物种特征与网络结构之间的关系有助于我们理解自然群落的组装以及群落如何发挥功能。在此，我们研究物种特征如何影响导致植物与食果脊椎动物之间相互作用模式的规则。我们使用模型选择方法研究一个物种丰富的种子传播系统，以检验网络结构背后的规则是由果实资源利用的限制、食果动物对果实的偏好性消耗，还是两者的结合所驱动。我们分别对整个系统以及鸟类和哺乳动物组合进行了分析，并确定了塑造相互作用规则的动植物特征。在鸟类的情况下，分析的相互作用网络结构通过资源利用的限制能得到更好的解释，而对于哺乳动物来说，则是通过对具有特定特征果实的偏好性消耗来解释。在观察鸟类 - 植物和哺乳动物 - 植物相互作用时这些截然不同的结果表明，同一类型的相互作用是由不同过程组织起来的，这取决于我们所关注的组合。相互作用物种（包括哺乳动物和鸟类）与大小相关的限制是驱动相互作用规则的最重要因素。我们的结果表明，种子传播相互作用网络的结构可以用与简单生态机制相关的物种特征和相互作用规则来解释。
