Integrating Consumer-Resource Theory into Density-Dependent Mechanisms for Limiting Population Growth and Overexploitation in a Pollinating Seed-eating Mutualism

共生的物种在其人口比率和自然丰度上可以表现出很大的变化。推进互惠相互作用研究的核心是对其密度依赖性和种群动态的机制理论和实证检验。本项目将捕食者-猎物和竞争相互作用的消费者-资源理论扩展到互惠相互作用的密度依赖，利用墨西哥和亚利桑那州索诺兰沙漠中senita仙人掌和senita飞蛾之间的授粉-吃种子互惠作用。利用实验和建模方法，该项目将研究每个互惠主义者的密度变化如何影响另一个互惠主义者的人口比率和丰度的变化，反过来，这种依赖密度的消费者-资源相互作用如何防止无限制的人口增长和过度开发的出现。解决这一缺陷可能更广泛地有助于理解互惠共生如何促进全球生物系统的模式和过程，从许多动植物的繁殖、生存和传播，到它们的生态系统服务（如授粉、种子传播、固氮）所产生的日益增长的保护努力。该项目还为本科生提供研究、教育和跨文化培训，直接让他们参与与墨西哥和美国国家公园有关的国际研究和公共宣传。

Mutualistic species can show great variation in their demographic rates and natural abundances. Central to advancing the study of mutualistic interactions is a mechanistic theory for and empirical tests of their density dependence and population dynamics. This project extends consumer-resource theory of predator-prey and competitive interactions to the density dependence of mutualistic interactions using the pollinating seed-eating mutualism between senita cacti and senita moths in the Sonoran Desert of Mexico and Arizona. Using both experimental and modeling methods, the project will examine how variation in the densities of each mutualist affects variation in the other's demographic rates and abundance, and in turn, how such density-dependent consumer-resource interactions may prevent unbounded population growth and overexploitation from arising. Addressing such a shortcoming may more generally aid in understanding how mutualism contributes to patterns and processes of biological systems worldwide, ranging from the reproduction, survival, and dispersal of many plants and animals to ever growing conservation efforts arising from their ecosystem services (e.g., pollination, seed dispersal, nitrogen fixation). The project also provides research, education, and cross-cultural training for undergraduate students by directly involving them in international research and public outreach associated with National Parks in Mexico and the United States.