Becerra Judith X
Department of Biosphere 2, University of Arizona, Tucson, AZ 85721
Proc Natl Acad Sci U S A. 2015 May 12;112(19):6098-103. doi: 10.1073/pnas.1418643112. Epub 2015 Apr 20.
Some of the most fascinating and challenging questions in ecology are why biodiversity is highest in tropical forests and whether the factors involved are unique to these habitats. I did a worldwide test of the hypotheses that plant community divergence in antiherbivore traits results in higher insect herbivore diversity, and that predominant attack by specialized herbivores promotes plant richness. I found strong correlative support for both ideas. Butterfly diversity was greatest in regions where the community average species-pairwise dissimilarity in antiherbivore traits among plant species was highest. There was also a strong positive relationship between specialized (insect) vs. generalized (mammal) herbivores and plant richness. Regions where herbivory impact by mammals was higher than that of insects tended to have lower plant diversities. In contrast, regions in which insects are the main consumers, particularly in the Central and South American tropics, had the highest plant richness. Latitude did not explain any residual variance in insect or plant richness. The strong connections found between insect specialization, plant defense divergence, and plant and insect diversities suggest that increasing our understanding of the ecology of biological communities can aid in considerations of how to preserve biodiversity in the future.
生态学中一些最引人入胜且具有挑战性的问题是，为什么热带森林中的生物多样性最高，以及其中涉及的因素是否是这些栖息地所特有的。我对以下假设进行了一项全球范围的测试：植物群落抗食草动物性状的分化导致更高的昆虫食草动物多样性，以及特化食草动物的主要攻击促进了植物丰富度。我发现这两个观点都有强有力的相关证据支持。在植物物种间抗食草动物性状的群落平均物种对间差异最高的地区，蝴蝶多样性最大。特化（昆虫）与泛化（哺乳动物）食草动物之间以及植物丰富度之间也存在很强的正相关关系。哺乳动物的食草作用影响高于昆虫的地区往往植物多样性较低。相比之下，以昆虫为主要消费者的地区，尤其是中美洲和南美洲的热带地区，植物丰富度最高。纬度并不能解释昆虫或植物丰富度中的任何剩余变异。在昆虫特化、植物防御分化以及植物和昆虫多样性之间发现的紧密联系表明，增进我们对生物群落生态学的理解有助于思考未来如何保护生物多样性。
