Restoration ecology of Garry oak ecosystems impacted by invasive species and grazing

由于外来入侵物种的威胁，本地物种和栖息地可能会迅速消失，整个加拿大都在发出警报。因此，控制入侵物种的努力正在进行，但对入侵物种生态学的科学认识显然缺乏。两个关键问题是：1)未能在更大的恢复生态学背景下理解入侵物种的作用；2)将生态恢复的研究局限于小地块水平。需要在更大的空间尺度上进行更长期的研究，以全面了解入侵生态学的复杂性，包括放牧和其他干扰类型的影响、植物功能类型的多样性、生殖生态、传播和种子库。盐湖岛Garry oak meadows （GOM）的研究项目以西三一大学乌鸦巢生态研究区（CNERA）为中心，该研究区与大多数剩余的GOM一样，以入侵的非本地草为主，因此提供了一个具有代表性的恢复实验室。该计划建立在7年的前期研究基础上，并通过在CNERA隔离大部分GOM，将调查提升到一个新的水平。短期目标包括：1)测试大规模的封闭和/或刈割处理是否比小规模实验中观察到的更大的植物群落组成变化，2)评估种植加里橡树草甸牧草是否显著增强恢复潜力，3)测试道格拉斯冷杉的移除是否促进加里橡树原生群落结构，4)评估Propertius duskywing butterfly种群数量是否随着栖息地的恢复而增加。

Throughout Canada alarm is being raised over the potentially rapid loss of native species and habitats to the threat of invasive species. In response, many efforts are underway to control invasive species, but a scientific understanding of invasive species ecology is clearly lacking. Two key issues are: 1) failure to comprehend the roles of invasive species within the larger context of restoration ecology and 2) limiting the study of ecological restoration to a small-plot level. Longer-term research at larger spatial scales is needed to understand invasion ecology in its full complexity, including impacts of grazing and other disturbance types, diverse plant functional types, reproductive ecology, dispersal and seedbanks. The proposed program to study Garry oak meadows (GOM) on Salt Spring Island is centered on Trinity Western University's Crow's Nest Ecological Research Area (CNERA) which, like most remnant GOM, is dominated by invasive non-native grasses, and thus provides a representative restoration laboratory. The program builds on 7 years of prior research, and takes the investigation to the next level by fencing off large portions of the GOM at CNERA. Short-term objectives include: 1) Testing if large exclosures and/or mowing treatments cause greater shifts in plant community composition than observed in smaller scale experiments, 2) Evaluating if planting of Garry oak meadow forbs significantly enhances restoration potential, 3) Testing whether Douglas-fir removal promotes Garry oak native community structure, and 4) Evaluating whether Propertius duskywing butterfly populations increase with habitat restoration.