The ecological importance of invasive Epichloë-Poöideae symbioses

这项研究计划的长期目标是预测气候变化将如何影响一组普通草及其相关共生真菌的入侵。******加拿大用于牧场和草皮（如公园、路边等）的许多Poöideae草原产于欧洲。由于其优越的性能，它们比本地物种更受欢迎。对于其中一些物种来说，它们在全球的成功部分是由于它们与Epichloë属真菌内生菌形成的共生关系。真菌感染的草：产生杀死或阻止食草动物的生物碱，产生更大的营养生长，有更高的种子产量，并且比未感染的同种草更能忍受压力条件，特别是干旱。这些特性对于草皮和牧草的应用非常有用，并且围绕利用这种自然发生的共生关系建立了一个重要的产业。不幸的是，使这些草适合人类使用的相同特性，也使它们在逃避种植时非常成功，因为它们改变了生物多样性，改变了生态系统功能。******在此，我建议通过完成三个近期研究目标来推进我的研究计划。******目的1：研究升高的CO2和真菌菌株之间的相互作用如何影响草产生的一系列代谢化合物，以及这些变化如何影响一个多面手食草动物。这将产生一个预测模型。*******目标2：表征栖息在这些草中的微生物真菌物种的完整真菌多样性，并研究这些Epichloë真菌的存在对更广泛的真菌群落的影响。由此产生的生物多样性的功能后果将通过检查其对通才食草动物的影响来评估。*******目标3：继续跟踪这些草及其真菌共生体的入侵成功，并测试土壤养分在这些入侵者成功中所起的作用。利用2007年建立的一项大型长期实验，我继续绘制出安大略省340次人工入侵（以及相关控制）的时间进程。******影响：作为北美大部分地区的严重入侵物种，了解导致它们成功的因素，以及这些因素在气候变化下如何变化，对我们管理和保护自然和半自然草原非常重要。这项工作为我们预测这些生物入侵的结果和未来变化的能力提供了重大的进步。

The long-term objective of this research program is to predict how climate change will impact the invasiveness of a group of common grasses and their associated symbiotic fungi.******Many Poöideae grasses used in pastures and for turf (e.g. parks, roadsides, etc.) in Canada originated in Europe. Because of their superior performance, they are preferred over native species. For some of these species, their global success is partly due to a mutualism that they form with fungal endophytes in the genus Epichloë. Fungus-infected grass: produce alkaloids that kill or deter herbivores, produce greater vegetative growth, have higher seed production, and are more tolerant of stressful conditions, particularly drought, than uninfected conspecifics. These traits are extremely useful for turf and pasture grass applications, and there is a significant industry built around exploiting this naturally occurring symbiosis. Unfortunately, the same traits that make these grasses desirable for human uses, also make them very successful when they escape cultivation, where they alter biodiversity, and change ecosystem functioning. ******Here I propose to advance my research program by accomplishing three near-term research objectives. ******Objective 1: To study how the interaction between elevated CO2 and fungal strain affects the suite of metabolic compounds that the grasses produce and how these changes affect a generalist herbivore. This will lead to a predictive model.*******Objective 2: To characterize the full fungal biodiversity of microbial fungal species that inhabit these grasses, and to investigate the impacts of the presence of these Epichloë fungi on the broader fungal community. The functional consequences of the resultant biodiversity will be assessed by examining its impact on a generalist herbivore.*******Objective 3: To continue to follow the invasive success of these grasses and their fungal symbionts, and to test the role soil nutrients play in the success of these invaders. Using a large long-term experiment established in 2007, I continue to chart the time course of 340 artificial invasions (and associate controls) in S. Ontario.******Impact: As serious invasive species throughout much of North America, understanding the factors that contribute to their success, and how these factors may change under climate change are important for our management and conservation of our natural and semi-natural grasslands. This work provides significant advancement toward our ability to predict the outcomes and future changes of these biological invasions.