Fungal suppression as a means to control leafy spurge and restore range health

多叶大戟（Euphorbia esula）是一种广泛的入侵植物，在北美已经侵染了近200万公顷的土地，仅在加拿大的成本预计就超过10亿美元。这些影响中有许多来自于这样一个事实，即多叶大戟形成了大量的单一栽培，减少了生物多样性和牲畜的饲料。由于叶大戟产生广泛的根茎和丰富的种子，它可以从干扰中迅速恢复，难以控制。然而，多叶大戟依赖于共生土壤真菌（菌根真菌）的营养：用杀真菌剂破坏这些共生关系可能会使入侵地区的居民植被恢复。还可以通过使多叶大戟落叶（这将减少遮荫）和重新播种不依赖于菌根真菌获得土壤养分的定居物种来促进定居植被的恢复。拟议的研究评估杀菌剂作为控制措施，叶大戟，通过建立一个实验抑制真菌，落叶叶大戟使用除草剂和割草，和补种本地植物。这项实验将分布在萨斯喀彻温省的24个原生草原站点，跨越多叶大戟入侵的范围。在实验中，我们将监测对多叶大戟种群的影响，以及本地植物群落的结构，丰度和营养价值。这些数据将用于评估拟议的控制措施的效果，并将与当地环境测量相结合，以确定哪些条件有利于控制多叶大戟和植被恢复。此外，为了评估处理对植物-土壤相互作用的影响，我们将联合收割机将这些结果与多叶大戟根的微生物定殖和土壤微生物群落结构的测量相结合。这个项目将增加我们对叶大戟入侵的影响的了解，特别是在萨斯喀彻温省。此外，我们将使用这些结果来开发上下文相关的建议，包括本地物种可以抑制叶大戟控制。

Leafy spurge (Euphorbia esula) is a widespread invasive plant that has infested nearly two million hectares of land in North America, with costs projected to exceed a billion dollars in Canada alone. Many of these effects derive from the fact that leafy spurge forms large monocultures that reduce biodiversity and forage for livestock. Because leafy spurge produces extensive rhizomes and abundant seed, it can recover rapidly from disturbance and is difficult to control. However, leafy spurge is reliant on symbiotic soil fungi (mycorrhizal fungi) for nutrients: disrupting these symbioses with fungicide may allow resident vegetation to recover in invaded areas. Recovery of the resident vegetation may also be enhanced by defoliating leafy spurge - which would reduce shading - and by reseeding resident species that do not rely on mycorrhizal fungi for soil nutrients. The proposed research evaluates fungicide as a control measure for leafy spurge, by establishing an experiment suppressing fungi, defoliating leafy spurge using herbicide and mowing, and reseeding native plants. This experiment will be distributed across 24 native grassland sites spanning the range of leafy spurge invasion in Saskatchewan. Within the experiment, we will monitor effects on leafy spurge populations as well as the structure, abundance, and nutritive value of the native plant community. These data will be used to evaluate the efficacy of the proposed control measures, and will be combined with local environment measurements to identify which conditions facilitate leafy spurge control and vegetation recovery. Additionally, to evaluate treatment effects on plant-soil interactions, we will combine these results with measurements of microbial colonization of leafy spurge roots and soil microbial community structure. This project will increase our understanding of the effects of leafy spurge invasion in general, and in Saskatchewan in particular. Further, we will use these results to develop context dependent recommendations for leafy spurge control, including which native species can be reseeded to suppress leafy spurge.