Upper Mississippi Center
Biodiversity | Biology | Environmental Indicators and Impact Assessment | Environmental Sciences
Description, Abstract, or Artist's Statement
Alliaria petiolata (garlic mustard), is an invasive biennial herb native to Europe and Asia. Its roots excrete a chemical that inhibits the growth of surrounding plants. When A. petiolata is present, low species diversity results. Once A. petiolata is present, it is almost impossible to eradicate due to how quickly it spreads. Additionally, A. petiolata eliminates native species such as oaks and wildflowers, therefore reducing a site’s richness and evenness. Our research question is how does A. petiolata cover affect native species in the herbaceous understory? Five forest communities were sampled in Northwest Illinois. Sites were separated into four different categories with Lonicera maackii (Amur Honeysuckle) only, A. petiolata only, neither invasive species, and sites where both occur. There were 12 sites for each of the four categories resulting in 48 total. Daubenmire 1m2 plots were placed haphazardly throughout the site. Native relative cover, Shannon's H, native richness, non-native relative cover, non-native shannons, and non-native richness were assessed. There was a site effect for native relative cover, native Shannon’s H, native richness, non-native relative cover, and non-native richness. There was a treatment effect for native relative cover, non-native relative cover, non-native Shannon’s H, and non-native richness. There was a site by treatment interaction for native relative cover, non-native relative cover, non-native Shannon’s H, and non-native richness. The data show that for four of the five sites, the total relative native cover was higher when there was a lower presence of A. petiolata. All five sites had lower non-native Shannon’s H when A. petiolata was present. From the results, it can be determined that A. petiolata significantly impacts the native species of an herbaceous understory. These results correlate with the literature, as A.petiolata can compete with native species, especially in areas with higher disturbances, and lead to less ecosystem diversity.
Augustana Digital Commons Citation
Lundborg, Paige; Schlabowske, Hayley; Koontz, Dr. Jason; and Lundborg, Paige. "Assessment of the Negative Role Garlic Mustard has on Urban Forest Diversity" (2022). Independent Research Projects.