DISSERTATION RESEARCH: Enemy release and nutrient enrichment: Population- and community-level effects in experimental wetland plant communities

入侵物种会对本地物种和生态系统产生有害影响。有人认为外来物种是有问题的，因为它们留下了病原体、捕食者或食草动物（敌人），这些病原体、捕食者或食草动物（敌人）在它们的本土范围内抑制了它们。然而，许多外来植物似乎只有在土壤氮等必需资源充足的情况下才会具有入侵性。这项工作将验证一个假设，即当土壤氮变得更加丰富时，从敌人手中逃脱的入侵湿地植物物种将获得越来越大的竞争优势，并对本地物种产生越来越大的抑制作用。这项研究更广泛的意义是双重的。陆地生态系统正经历着氮富集的增加，但这对植物物种入侵的影响尚不清楚。了解富集和释放的相互作用是有效管理入侵物种的必要条件。其次，通常引入专门的病原体或食草动物来控制最严重的入侵者（即生物控制），但此类计划的有效性是零星的。如果生物防治本质上依赖于土壤肥力，那么土地管理者可以更好地优先考虑生物防治剂的释放地点，并增加这些计划成功的可能性。该项目的其他更广泛的影响包括培训本科生野外生态学，并通过合作组织开展社区教育项目。该项目还将支持一名博士生的论文研究。

Invasive species can have detrimental effects on native species and ecosystems. It has been argued that exotic species are problematic because they have left behind the pathogens, predators, or herbivores (enemies) that suppressed them in their native range. However, many exotic plants seem to become invasive only when essential resources such as soil nitrogen are abundant. This work will test the hypothesis that an invasive wetland plant species, which escaped from its enemies, will gain a progressively larger competitive advantage and have a progressively greater suppressive effect on native species as soil nitrogen becomes more abundant. The broader implications of this research are twofold. Terrestrial ecosystems are experiencing increased nitrogen enrichment, but the implication of this to plant species invasions are poorly known. An understanding of the interaction of enrichment and enemy release is necessary for effective management of invasive species Second, specialized pathogens or herbivores are often introduced to control the worst invaders (i.e., biological control), but the effectiveness of such programs has been sporadic. If a biological control is inherently dependent on soil fertility then land managers can better prioritize release sites for biological control agents and increase the likelihood of success for those programs. Additional broader impacts of this project include training undergraduates in field ecology, and conducting community education programs through partner organizations. This project also will support the thesis research of a doctoral student.