Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 2/16/2006
Publication Date: 2/16/2006
Citation: Bisikwa, J., Becker, R.L., Jordan, N.R., Biesboer, D.D., Katovich, S.A., Forcella, F. 2006. Effect of surface litter on seedling emergence and establishment of European buckthorn (Rhamnus cathartica) [abstract]. Weed Science Society of America. p. 35. Interpretive Summary:
Technical Abstract: We determined the effect of surface litter depth on emergence and establishment of buckthorn at Eagle Lake Regional Park, Maple Grove, MN, and in the greenhouse in 2002 and 2003. We also investigated effect of litter on the physical environment of seedlings to determine mechanisms underlying observed patterns in buckthorn seedling emergence. Results from our study showed that increasing litter depth resulted in decreased buckthorn seedling emergence and establishment in both field and greenhouse experiments. Among litter treatments, the deepest litter depth resulted in the lowest buckthorn seedling densities, while no-litter control treatment (bare-ground) resulted in the highest seedling densities in the greenhouse and field, respectively. In addition to reduced seedling emergence, litter cover reduced buckthorn shoot height and biomass. Deeper litter cover decreased solar radiation at the soil surface, thus reducing soil temperatures and increasing soil moisture retention. In the greenhouse, soil temperature decreased with increasing litter depth. Regression analysis showed that light transmittance and soil temperature influenced buckthorn seedling establishment in the greenhouse, while in the field only light transmittance influenced seedling establishment. Thus, litter may suppress buckthorn seedling establishment via reduced soil temperatures and light interception. Soil moisture, while higher with increased litter depth, likely is not differentially limiting buckthorn seedling establishment. However, since there were various canopy layers in the field (i.e. overstory oak trees and understory shrubs) reducing photosynthetically active radiation (PAR) at the forest floor to 20% of light incident on the overstory forest canopy, soil temperatures seemed not to be further affected by litter cover. According to our findings, litter cover has the capacity to reduce buckthorn seedling recruitment and establishment but can not completely prevent seedling emergence and survival. Thus, management strategies should be designed to control the establishment of buckthorn seedlings in order to prevent further buckthorn populations from establishing.