Dissertation Research: Variation in the effects of mycorrhizal fungi on plant resistance to herbivores

智力优势：几乎所有的生物有机体都与其他物种结成伙伴关系，交换资源或服务：这种伙伴关系被称为互惠关系。共生关系在为相关生物提供利益的同时也会产生成本，伙伴关系的最终结果可能从积极（互惠）到消极（寄生）不等。需要量化互惠关系内资源交换的成本和收益，以预测在一系列环境条件下这些相互作用的结果的变化。地球上最常见的共生关系之一发生在植物的根和生活在土壤中的某些真菌之间。真菌为植物提供必需的营养物质，如磷和氮，而植物则为真菌提供糖作为回报。当这些资源被交易时，它可以影响环境中的其他生物，例如以植物为食的昆虫。目前，科学家们无法预测植物-真菌伙伴关系的结果将如何随着土壤中真菌的身份和丰度以及植物的遗传而变化。这项工作将控制植物-真菌共生关系中合作伙伴的身份和丰度，并测量资源如何在它们之间交易。通过研究合作伙伴的表现，该项目将帮助科学家了解合作伙伴关系在自然界中是如何形成和解散的。更广泛的影响：尽管共生现象在自然界非常普遍，但科学家们还没有发展出现实的理论来解释它们是如何工作的。这项工作的结果将被生态学家和进化生物学家广泛应用，他们研究世界各地许多不同种类的生物。此外，研究植物和真菌之间的相互关系所获得的结果可以用于各种人类活动，包括农业和森林生产，退化环境的恢复，环境变化的预测和管理，以及入侵物种的管理。此外，在自然界中，互惠的伙伴关系是人类机构之间进行商品和服务交易的经济伙伴关系的模拟，其结果将适用于整个人类和自然系统。在这里描述的工作中，来自不同社会和种族背景的科学家将接受科学方法方面的培训。最后，这项工作的成果将通过出版物和演讲向地方、国家和国际受众传播。

Intellectual merit: Nearly all biological organisms form partnerships with other species in which they trade resources or services: such partnerships are called mutualisms. Mutualisms incur costs as well as provide benefits to the organisms involved and the net outcome of the partnerships can vary from positive (mutualistic) to negative (parasitic). Quantifying the costs and benefits of resource exchange within mutualisms is required to predict shifts in the outcome of these interactions under a range of environmental conditions. One of the most common mutualisms on earth occurs between the roots of plants and certain fungi that live in soil. The fungi provide essential nutrients to plants, such as phosphorus and nitrogen, while plants provide the fungi with sugars in return. As these resources are traded, it can influence other organisms in the environment, such as the insects that feed on plants. At present, scientists are unable to predict how the outcome of plant-fungal partnerships will vary with the identity and abundance of the fungi in soil and the genetics of the plants. The proposed work will manipulate the identity and abundance of the partners in plant-fungus mutualisms and measure how resources are traded between them. By studying how well the partners perform, the project will help scientists understand how partnerships form and dissolve in nature.Broader impacts: Scientists have yet to develop realistic theories of how mutualisms work, despite the fact that they are extremely common in nature. Results from this work will be broadly applied by ecologists and evolutionary biologists who work on many different kinds of organisms throughout the world. Moreover, results gained from studying mutualisms between plants and fungi can be used in a wide variety of human endeavors including agricultural and forest production, the restoration of degraded environments, the prediction and management of environmental change, and the management of invasive species. Additionally, mutualistic partnerships in nature are mimics of economic partnerships among human institutions in which goods and services are traded, and the results will apply across human and natural systems. During the work described here, scientists from a range of social and ethnic backgrounds will be trained in the methods of science. Finally, results from this work will be transmitted to local, national and international audiences through publications and presentations.