PARENT SESSION
Poster Session 7: Invasive Species.
Monday, August 2 Presentations from 5:00 PM to 6:30 PM, Exhibit Hall A 1.
Competitive effects of garlic mustard (Alliaria petiolata) on woody seedlings in Central Ohio.
Kirchner, Nicole*,1, Johnson, David1, Anderson, Laurel1, 1 Ohio Wesleyan University, Delaware, OH
ABSTRACT- The biennial herb garlic mustard (Alliaria petiolata) is an established invader of mesic, mature forests in Ohio, USA. A. petiolata is known to have negative effects on herbaceous native plants, but its influences on woody plants are less clear. We examined the competitive interactions between A. petiolata and three woody species prominent in mesic forests: Fraxinus americana, Prunus serotina, and Acer saccharum. Using previous surveys of A. petiolata populations in the Ohio Wesleyan University Kraus Wilderness Preserve, nine field sites were established containing one experimental plot with high densities of first year A. petiolatarosettes (A. petiolata densities > 12.5 plants per m2), and an associated control plot where all woody seedlings were > 1 m from an A. petiolata individual. Four seedlings (< 30 cm height) of each woody species were randomly chosen in each plot, and basal diameter, total height, and the last two years of growth (assessed by bud scars) were measured with a ruler and calipers. Data were analyzed using three-way analysis of variance with species and A. petiolata presence as fixed factors and site (1-9) as a random factor. While there were significant differences in tree seedling size and growth among species and sites, A. petiolata did not significantly affect any aspect of growth for any of the woody species (all P > 0.05). Therefore, the rosette stage of A. petiolata does not appear to compete significantly with these woody plants, despite the high densities the invader can achieve in the vicinity of a tree seedling. This study will be continued to determine if the second-year, reproductive growth of A. petiolata has detrimental effects on young trees in this site.
Key words: garlic mustard, invasive plants, Alliaria petiolata, competition