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本植物及其相关共生真菌的入侵。 许多用于牧场和草坪(如公园、路边等)的牧草。起源于加拿大，起源于欧洲。由于它们优越的性能，它们比本土物种更受欢迎。对于这些物种中的一些，它们在全球的成功部分归功于它们与表生真菌内生真菌形成的互惠共生。被真菌感染的草：产生生物碱，杀死或威慑食草动物，产生更大的营养生长，有更高的种子产量，比未感染的同种植物更能耐受压力条件，特别是干旱。这些特性对草坪和牧草的应用非常有用，围绕着利用这种自然共生建立了一个重要的行业。不幸的是，使这些草成为人类理想用途的相同特征，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，改变了生态系统的功能。 在这里，我建议通过实现三个近期研究目标来推进我的研究计划。 目的1：研究高浓度二氧化碳和真菌菌株之间的相互作用如何影响草类产生的代谢化合物系列，以及这些变化如何影响多面性食草动物。这将导致一个预测性模型。 目的：研究这些牧草中微生物真菌种类的多样性，并研究这些表观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多面手食草动物的影响来评估。 目标3：继续跟踪这些草本植物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入侵中所起的作用。利用2007年建立的一项大型长期实验，我继续绘制了安大略省南部340次人工入侵(和相关控制)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可能会如何变化，对于我们管理和保护我们的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.