Patterns and processes of alien plant invasions across habitats

全球贸易和人类迁徙造成了前所未有的生物传播，超出了它们的自然分布范围。虽然大多数引进的植物物种无法建立，但一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，但我们在景观中遇到的各种栖息地类型中驱动入侵性的原因尚未得到很好的理解。已经提出了几个假设，但经验证据是混合的，难以解释。科学进步的缺乏最终剥夺了从业者预防和管理外来入侵计划的工具。我的研究计划的目标是提高我们预测和增加栖息地对外来入侵植物的恢复能力。尽管过去一直强调生境恢复力的重要性，但入侵物种管理迄今主要侧重于通过生物、化学和机械手段控制已经建立的植物。我之前的研究表明，这种方法会导致公共荒地除草剂的大量使用，并且会抑制非目标本地植物和有益菌根，从而危及生态恢复。通过分析植被调查数据，我已经表明，栖息地显示出不同程度的入侵，这提出了一个问题，即入侵是否主要是由栖息地特性驱动的，例如不同的营养物质（“资源”）可用性，不同的暴露于外来植物的种子和植物材料（“繁殖压力”），或不同的容忍人类干扰的能力（“人类足迹”）。在我设想的探索基金（DG）项目中，我将进行三个主题的研究，每个主题都关注以下问题之一：(1)资源可用性是否导致了不同栖息地入侵水平的差异？(2)在遥远地区和全球范围内，跨栖息地的入侵是否遵循类似的趋势？(3)人类足迹和种群压力如何影响生境可入侵性？大部分计划将在艾伯塔省进行，据报道，那里16%的种植外植物群是外来的。此外，我还将在中亚进行一项研究，我在中亚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，我的目标是发现潜在的普遍机制，使栖息地容易受到外来植物入侵。从长远来看，我将建立一个基于栖息地的方法来管理外来入侵植物的概念。

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.