Patterns and processes of alien plant invasions across habitats

全球贸易和人类迁徙造成了超出其自然分布范围的生物的前所未有的传播。虽然大多数引进的植物物种未能建立，但有些物种大量传播，并对生态系统功能和服务产生有害影响(“外来入侵植物”)。理论预测，植物群落的易感性(‘入侵性’)是外来植物入侵成功的关键因素，但是什么驱动了我们在景观中遇到的各种生境类型的入侵性还没有被很好地理解。已经提出了几个假说，但经验证据含混不清，难以解释。科学进步的缺乏最终剥夺了实践者预防和管理外来入侵计划的工具。我的研究提案的目标是提高我们预测外来入侵植物的能力，并增加栖息地对外来入侵植物的适应能力。尽管过去一直强调生境弹性的重要性，但到目前为止，入侵物种管理主要集中在通过生物、化学和机械手段控制已经建立的植物。我以前的研究表明，这种方法导致公共荒地上除草剂的使用量很高，并可能通过抑制非目标本地植物和有益的菌根而危及生态恢复。通过分析植被调查数据，我发现栖息地表现出不同的入侵水平，这提出了一个问题，即入侵能力是否首先受到栖息地特性的驱动，例如养分(“资源”)的可用性、对外来植物种子和植物材料的不同暴露(“繁殖压力”)，还是容忍人类干扰的不同能力(“人类足迹”)。在我设想的探索赠款(DG)计划中，我将在三个主题上进行研究，每个主题都集中在以下问题上：(1)资源可用性是否会导致不同栖息地入侵水平的差异？(2)不同栖息地的入侵是否在遥远地区和全球遵循类似的趋势？(3)人类足迹和繁殖压力如何影响栖息地的入侵能力？大部分设想的项目将在艾伯塔省进行，据报道，那里16%的种植外植物是外来的。与之相辅相成的是在中亚的一项研究，我在这个地区有丰富的研究经验。计划中的研究将使用广泛的方法，包括植被调查、建模和实验，并将涉及20名高素质的人员。通过关注各种各样的栖息地类型，包括全球数据挖掘，我的目标是发现使栖息地容易受到外来植物入侵的潜在普遍机制。从长远来看，我将在外来入侵植物的管理中建立基于栖息地的方法的概念。

Global trade and human migration have caused an unprecedented spread of organisms beyond their natural distribution range. While most introduced plant species fail to establish, some spread in large numbers and have detrimental effects on ecosystem functioning and services (`invasive alien plants'). Theory predicts that the susceptibility of a plant community (`invasibility') is a key factor for the success of alien plant invasions, but what drives invasibility across the diverse array of habitat types we encounter in the landscape is not well understood. Several hypotheses have been proposed, but empirical evidence has been mixed and difficult to interpret. The lack of scientific progress ultimately deprives practitioners of tools to prevent and manage invasive alien plans. The goal of my research proposal is to improve our ability to predict and increase the resilience of habitats to alien invasive plants. Although the importance of habitat resilience has been stressed in the past, invasive species management has so far focused mostly on controlling already established plants through biological, chemical and mechanical means. My previous research has shown that this approach leads to high herbicide usage on public wildlands and can endanger ecological restoration by suppressing non-target native plants and beneficial mycorrhizae. By analyzing vegetation survey data, I have shown that habitats display contrasting levels of invasion, which raises the question whether invasibility is foremost driven by habitat properties, such as varying nutrient (`resource') availability, diverging exposure to seed and plant material of alien plants (`propagule pressure'), or a different capacity to tolerate human disturbance (`human footprint'). In my envisioned Discovery Grant (DG) program, I will pursue research in three themes, each focusing on one of the following questions: (1) Does resource availability drive differences in the levels of invasion across habitats? (2) Do invasions across habitats follow similar trends in distant regions and globally? (3) How do human footprint and propagule pressure affect habitat invasibility? Most of the envisioned program will be conducted in Alberta, where 16% of the flora outside of cultivation has been reported to be alien. It will be complemented by a study in Central Asia, an area where I have extensive research experience. The planned studies will use a broad array of methods, including vegetation surveys, modeling and experiments, and will involve 20 highly qualified personnel. By focusing on a wide variety of habitat types and including global data mining, I aim to detect underlying universal mechanisms that make habitats susceptible to alien plant invasions. In the long-term, I will build concepts for a habitat-based approach in the management of invasive alien plants.