PARENT SESSION
Oral Session # 86: Invasive Species VII: Forests.
Presiding: C Huebner
Thursday, August 7. 1:30 PM to 5:00 PM, SITCC Meeting Room 204.
Community and landscape features that influence the invasion of Lonicera maackii.
Bartuszevige, Anne1, Gorchov, David1, 1 Miami University, Oxford, OH, USA
ABSTRACT- Although invasive plants are recognized as a major ecological problem, little is known of the role of dispersal agents and landscape structure on the invasion process. Lonicera maackii (Rupr.) Herder (Caprifoliaceae), a bird-dispersed shrub introduced to the United States in 1898, has become invasive in 24 eastern U.S. states. As part of our investigation of how the invasion of this species is shaped by landscape features and by movement patterns of the birds that disperse its seeds, we explored the relationship between its distribution and woodlot characteristics at an invasion front in southwest Ohio. During summer 2002, 11 woodlots were sampled using the point-quarter method. Basal areas, densities, and importance values of shrub, sapling, and tree species were calculated. For each woodlot, we also calculated mean gap fraction (canopy openness) using a Licor LAI 2000. Digital Ortho Quarter Quad photos and ArcView GIS were used to collect landscape parameters from the same woodlots. Stepwise multiple regression analysis was used to determine the community and landscape factors that best explain L. maackii density. The best predictor of woodlot L. maackii density was the density of L. maackii on the perimeter of the woodlot (R2 = 0.897). This perimeter density, in turn, was best predicted by the gap fraction of the woodlot (R2 = 0.334) and number of corridors connecting to other woodlots (R2 = 0.212). Additional woodlots will be sampled in 2003, but the results to date suggest that both community factors (e.g. canopy openness) and landscape factors (connectivity) are important in the invasion of L. maackii.
Key words: invasive species, Lonicera maackii, landscape and community features