Collaborative Research: Elucidating the Mechanisms of Coexistance in Communities of Ant-plant Mutualists

生态学的一个主要目标是了解促进相互竞争的物种共存的因素。在假设的机制中，主要是栖息地异质性，但替代机制包括资源可获得性的时间波动、空间限制的扩散以及繁殖力、分散度和竞争能力之间的权衡。这些机制中只有一小部分曾被证明在现场运行，同时评估多个机制的实验测试也很少见。这项拟议的研究将评估群落生态学中一种新兴的模式系统中的替代共存机制--蚂蚁在被称为Domatia的专门植物结构中竞争建立群体。三种蚂蚁在亚马逊河流域的树上定居，分别是豆科树种和贵州岛毛蚁树种。利用这个系统，可以促进蚂蚁共存的非互斥机制将通过现场观察、操纵实验和数学模型相结合进行测试。由于这个系统是由两个专家组成的，他们在两个资源上共存，我们的结果可以为生态社区专业化的演变提供独特的见解。该项目将为处于学术生涯不同阶段的学生提供充足的机会来发展研究、建模和指导技能。此外，合作的PI是在少数族裔入学人数较多的机构，这将使他们能够继续指导来自代表性不足群体的学生。最后，该项目将加强充满活力和富有成效的国际合作，并让美国学生获得他们在亚马逊生态系统中工作的第一次经验。

A major goal of ecology is to understand the factors promoting coexistence among competing species. Chief among the hypothesized mechanisms is habitat heterogeneity, but alternatives include temporal fluctuations in resource availability, spatially restricted dispersal, and tradeoffs among fecundity, dispersal, and competitive ability. Only a handful of these mechanisms have ever been shown to operate in the field, and experimental tests simultaneously evaluating multiple mechanisms are rare. The proposed study will evaluate alternative coexistence mechanisms in an emerging model system in community ecology - ants that compete to establish colonies in specialized plant structures known as domatia. Three species of ants colonize the domatia of the Amazonian trees Tococa bullifera and Maieta guianensis. Using this system, non-mutually exclusive mechanisms that may promote ant coexistance will be tested with a combination of field observations, manipulative experiments, and mathematical models. Because this system is composed of two specialists that coexist with a generalist on two resources, our results could provide unique insights into the evolution of specialization in ecological communities. The project will provide ample opportunities for students at multiple stages of their academic careers to develop research, modeling, and mentorship skills. Furthermore, the collaborating PI's are at institutions with large minority enrollments, which will allow them to continue mentoring students from underrepresented groups. Finally, this project will strengthen a dynamic and productive international collaboration, and allow US students to gain their first experience working in Amazonian ecosystems.