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竞争物种之间共存的因素。主要的假设机制是生境异质性，但其他机制包括资源可用性的时间波动、空间限制的扩散以及繁殖力、扩散和竞争能力之间的权衡。只有少数这些机制曾被证明在实地运作，同时评估多种机制的实验测试是罕见的。这项拟议的研究将评估群落生态学中一个新兴模式系统中的替代共存机制-蚂蚁在称为domatia的特殊植物结构中竞争建立殖民地。三种蚂蚁占据了亚马逊树的domatia Tococa bullifera和Maieta guianensis。利用这一系统，非互斥机制，可能促进蚂蚁共存将测试与现场观察，操作实验和数学模型相结合。由于这个系统是由两个专家和一个通才在两个资源上共存组成的，我们的结果可以为生态群落专业化的演变提供独特的见解。该项目将为学生在学术生涯的多个阶段提供充足的机会，以发展研究、建模和指导技能。此外，合作的PI位于少数民族学生较多的院校，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，并使美国学生获得在亚马逊生态系统工作的第一次经验。

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.