Biology Department, Rhodes College, 2000 North Parkway, Memphis, Tennessee, 38103, USA.
Instituto de Química, Universidade de São Paulo, Av. Prof. Lineu Prestes, 748, Bloco 11 Térreo, São Paulo, São Paulo, 05508-000, Brasil.
Ecology. 2017 Jul;98(7):1750-1756. doi: 10.1002/ecy.1875.
A longstanding paradigm in ecology is that there are positive associations between herbivore diversity, specialization, and plant species diversity, with a focus on taxonomic diversity. However, phytochemical diversity is also an informative metric, as insect herbivores interact with host plants not as taxonomic entities, but as sources of nutrients, primary metabolites, and mixtures of attractant and repellant chemicals. The present research examines herbivore responses to phytochemical diversity measured as volatile similarity in the tropical genus Piper. We quantified associations between naturally occurring volatile variation and herbivory by specialist and generalist insects. Intraspecific similarity of volatile compounds across individuals was associated with greater overall herbivory. A structural equation model supported the hypothesis that plot level volatile similarity caused greater herbivory by generalists, but not specialists, which led to increased understory plant richness. These results demonstrate that using volatiles as a functional diversity metric is informative for understanding tropical forest diversity and indicate that generalist herbivores contribute to the maintenance of diversity.
生态学中长期存在的一个范式是，草食动物多样性、特化性和植物物种多样性之间存在正相关关系，其重点是分类多样性。然而，植物化学多样性也是一个信息丰富的指标，因为昆虫草食动物与宿主植物的相互作用不是作为分类实体，而是作为营养物质、初级代谢物和吸引和排斥化学物质混合物的来源。本研究考察了草食动物对作为热带胡椒属挥发相似性测量的植物化学多样性的反应。我们量化了由专食性和广食性昆虫引起的自然发生挥发变化与食草性之间的关联。个体间挥发性化合物的种内相似性与整体食草性增加有关。结构方程模型支持这样一种假设，即植物挥发物相似性导致了更多的一般性草食动物取食，而不是专门性草食动物取食，从而导致林下植物丰富度增加。这些结果表明，将挥发物作为功能多样性指标用于理解热带森林多样性是有意义的，并表明广食性草食动物有助于维持多样性。
