COLLABORATIVE RESEARCH: Pathogen accumulation and its consequences for invasive plants

非本土物种的入侵是常见和普遍的，但入侵的长期结果尚不清楚。最初，躲避专门的捕食者和病原体可能会使引进物种比本地物种更具竞争力，但如果新栖息地的捕食者或病原体转向它们，引进物种的优势可能会逆转。或者，攻击引入物种的本土病原体可能会溢出，感染共生的本土物种，并加剧入侵的影响。这个项目将评估病原体积累对入侵物种的生态后果，以提供关于寄主-病原体动态的一般生态学理论，并提高我们对入侵的长期后果的理解。一项实地调查将量化高脚草上积累的病原体的盛行率和丰富度。Microstegium vimineum是一种侵袭美国东部森林林下植被的侵入者。通过使用广泛的时间序列，这项研究将显示积聚在一种重要入侵植物上的病原体的时间变化、地理范围和物种多样性。在隔离的温室环境中的接种实验将被用来评估病原体对微囊藻和共生的本地牧草性能的影响。总之，这些结果将有助于评估病原体在入侵物种上积累并减少入侵物种的种群增长或溢出到竞争的本地物种上并间接促进入侵的假说。引进物种的生物入侵是美国的一个主要环境问题。通过提供关于促进或抑制入侵的因素的新信息，该项目将用于土地管理和恢复工作。研究的物种本身在一些东部州引起了极大的关注。研究结果将通过网站和出版物分发给土地管理人、公众以及环境和自然保育组织。此外，该项目将为本科生和博士后研究员提供经验和培训，并为职业生涯早期的科学家提供研究支持。

Invasions by non-native species are common and widespread, but the long-term outcomes of invasions are unclear. Escape from specialized predators and pathogens may initially enable introduced species to outcompete native ones, but the dominance of introduced species may be reversed if the predators or pathogens in their new habitat switch onto them. Alternatively, native pathogens that attack introduced species might spill back, infect co-occurring native species, and exacerbate the impacts of invasions. This project will evaluate the ecological consequences of pathogen accumulation on invasive species to inform general ecological theory on host-pathogen dynamics and improve our understanding of the long-term outcomes of invasions. A field survey will quantify the prevalence and richness of pathogens that accumulate on stiltgrass, Microstegium vimineum, an aggressive and widespread invader of forest understories in the eastern U.S. By employing a broad chronosequence of sites, the study will show the temporal change, geographical extent, and species diversity of pathogens accumulating on an important invasive plant. Inoculation experiments in quarantined greenhouse environments will be used to evaluate the effects of pathogens on the performance of Microstegium and co-occurring native grasses. Together, these results will serve to evaluate the hypotheses that pathogens accumulate on and reduce population growth of invasive species or spill back onto competing native species and indirectly facilitate invasions.Biological invasions by introduced species are a major environmental problem in the U.S. By providing new information on the factors that promote or inhibit invasions, this project will be of use in land management and restoration efforts. The study species is itself of significant concern in a number of eastern States. Research findings will be disseminated to land managers, the public, and environmental and conservation organizations via a website and publications. In addition, this project will provide experience and training for undergraduate students and a post-doctoral researcher, and research support to an early-career scientist.