The effect of garlic mustard (Alliaria petiolata, Brassicaceae) on the diversity and composition of oribatid mite communities
Garlic mustard (Alliaria petiolata, Brassicaceae) is a non-native plant that rapidly invades North American forest understories. While garlic mustard has been shown to impact native vegetation, the effect on belowground communities, which are essential in controlling nutrient availability and decomposition, is unclear. My objectives were to investigate the impact of garlic mustard invasion on the community composition and species richness of oribatid mites (Acari: Oribatidae), which are bioindicators of soil health in forest ecosystems. Soil samples were obtained in June 2016 from two sites: Mill Creek Ravine, Edmonton AB and Broadmoor Public Golf Course, Sherwood Park AB. A paired sampling strategy was used to compare areas colonized with garlic mustard to those with native vegetation. Soil samples were collected from six pairs of plots, equalling 12 samples at each of the two sites, for a total of 24 samples. Following Berlese funnel extraction, oribatid mites ≥300 µm were identified. The effect of site and garlic mustard invasion on oribatid species richness, will be evaluated using mixed-model ANOVA and individual-based rarefaction. Oribatid community composition will be assessed with non-metric multidimensional scaling. This project will improve understanding of the impact of invasive species, particularly garlic mustard, on belowground communities.
Faculty Mentor: Dr. Leah Flaherty