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

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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.