Using restoration to test community assembly in a heavily invaded ecosystem

生态恢复是协助生态系统恢复的过程，是减轻自然系统人为退化影响的一个重要工具。例如，旱地的恢复已被用于防治荒漠化，河流的恢复可改善鲑鱼等鱼类的生境。然而，尽管其重要性，恢复项目的成功可能很难实现，结果往往是不可预测的。鉴于这些挑战，我的研究计划旨在将生态理论和恢复实践联系起来，以提高恢复的可预测性和成功率。在接下来的五年里，我将利用社区组装和基于特征的生态学理论来揭示生态系统对干扰，入侵和恢复的反应机制。社区集会框架侧重于环境如何过滤掉不适应当地条件的物种。特别强大的过滤器将选择植物性状的子集，例如干燥条件过滤掉用水效率低下的物种。这可能会导致社区内的趋同，所有物种都具有类似的特征，以应对最强的过滤器。我将通过大规模和小规模的实地实验和观测研究相结合，评估干扰作为草本植物群落中的过滤器的作用。具体来说，我的研究集中在不列颠哥伦比亚省的加里橡树草地。基于低强度鹿压力到高强度的梯度，我将跟踪放牧强度时群落特征的收敛。干扰也与非本地物种入侵率的增加有关，尽管这通常是从到达和殖民化的角度来理解的，而不是外来物种固有的特征。然而，外来物种可能代表一个强烈的偏见的生殖和生长性状的基础上，他们与人类的关系，可能会更好地代表种子投入，并可能逃脱干扰，如放牧。因此，外来物种的放牧反应可能是不同的本地人，并可能会驱动社区组装前，期间和干扰后，以不可预测的方式，如果起源被忽略。因此，我的工作将同时考虑干扰和入侵的社区集会，既作为驱动程序组成的退化社区和恢复行动下的恢复预测。我将分别和一起评估放牧对本地和外来物种性状的影响，并将通过跟踪鹿的饮食偏好、草地中的种子投入和外来物种性状的偏差来分析外来物种可能做出不同反应的原因。最后，我将测试如何管理放牧，去除外来物种，或实施这两种策略影响本地社区的恢复结果。我的工作将通知管理在加拿大的最高优先保护区之一，并将提高生态干扰和入侵如何改变社区组装模式的理解。

Ecological restoration, the process of assisting the recovery of an ecosystem, is an essential tool for mitigating the effects of human-induced degradation in natural systems. For example, restoration in drylands has been used to fight desertification, and stream restoration can enhance habitat for fish such as salmon. Despite its importance, however, success in restoration projects can be difficult to achieve, and outcomes are often unpredictable. In light of these challenges, my research program seeks to link ecological theory and restoration practice to enhance the predictability and success of restoration. Over the next five years, I will use theories of community assembly and trait-based ecology to uncover mechanisms of ecological responses to disturbance, invasion, and restoration. Community assembly frameworks focus on how the environment acts to filter out species that are not well adapted to local conditions. Particularly strong filters will select for a subset of plant traits, such as dry conditions filtering out species that use water inefficiently. This can cause convergence within a community, with all species having a similar set of traits in response to the strongest filter. I will assess the role of disturbance as a filter in herbaceous communities through a combination of large- and small-scale field experiments and observational studies. Specifically, my research focuses on Garry oak meadows in British Columbia. Based on a gradient of low intensity deer pressure to high intensity, I will track community trait convergence as grazing intensifies. Disturbance is also linked to increased rates of invasion by non-native species, though this is generally understood in terms of arrival and colonization rather than traits intrinsic to exotic species. However, exotic species may represent a strongly biased set of reproductive and growth traits based on their relationship to humans, may be better represented in seed inputs, and may escape disturbances like grazing. Thus, exotic species' response to grazing may be distinct from natives, and may drive community assembly pre-, during, and post-disturbance in unpredictable ways if origin is ignored. As a result, my work will simultaneously consider disturbance and invasion in community assembly, both as drivers of composition in degraded communities and as predictors of recovery under restoration actions. I will assess grazing impacts on traits in native and exotic species separately and together, and will pull apart why exotic species may respond differently by tracking deer diet preferences, seed inputs in meadows, and bias in exotic species traits. Finally, I will test how managing grazing, removing exotics, or implementing both strategies influence restoration outcomes in native communities. My work will inform management in one of the highest priority conservation areas of Canada, and will enhance ecological understanding of how disturbance and invasion alter community assembly patterns.