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常见草及其相关共生真菌的入侵性。许多早熟禾亚科的草用于牧场和草坪（如公园，路边等）。加拿大起源于欧洲。由于它们的上级性能，它们比本地物种更受欢迎。对于这些物种中的一些，它们在全球的成功部分是由于它们与Epichloë属中的真菌内生菌形成的互利共生。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，具有更高的种子产量，并且比未感染的同种更能耐受胁迫条件，特别是干旱。这些特性对于草坪和牧草应用非常有用，并且围绕利用这种天然存在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，在那里它们改变了生物多样性，改变了生态系统的功能。 ** 在这里，我建议通过完成三个近期研究目标来推进我的研究计划。 ** 目标1：研究CO2浓度升高和真菌菌株之间的相互作用如何影响草产生的代谢化合物，以及这些变化如何影响通才食草动物。 这将导致一个预测模型。*目标二：描述栖息在这些草中的微生物真菌物种的完整真菌生物多样性，并调查这些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进行评估。**目标三：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的作用。 利用2007年建立的一个大型长期实验，我继续绘制了340个人工入侵（和相关对照）在S。安大略影响：作为北美大部分地区的严重入侵物种，了解导致其成功的因素以及这些因素在气候变化下如何变化对于我们管理和保护天然和半天然草原至关重要。 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进展。

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.