Biological Invasions

, Volume 9, Issue 7, pp 849–855

Apparent competition: an impact of exotic shrub invasion on tree regeneration

Original Paper

DOI: 10.1007/s10530-006-9086-5

Cite this article as:
Meiners, S.J. Biol Invasions (2007) 9: 849. doi:10.1007/s10530-006-9086-5


Invasion of habitats by exotic shrubs is often associated with a decrease in the abundance of native species, particularly trees. This is typically interpreted as evidence for direct resource competition between the invader and native species. However, this may also reflect indirect impacts of the exotic shrubs through harboring high densities of seed predators––known as apparent competition. Here I present data from separate seed predation experiments conducted with two shrub species exotic to North America; Rosa multiflora, an invader of abandoned agricultural land, and Lonicera maackii, an invader of disturbed or secondary forest habitats. Both experiments showed significantly greater risks of seed predation for tree seeds located under shrub canopies when compared to open microhabitats within the same site. These results indicate the potential importance of indirect impacts of exotic species invasions on native biota in addition to the direct impacts that are typically the focus of research.


Exotic shrubsHabitat selectivityLonicera maackiiNorth AmericaRosa multifloraSeed predationSurvival analysis



Douglas-Hart Nature Center


Hutcheson Memorial Forest Center

L. maackii

Lonicera maackii

P. leucopus

Peromyscus leucopus

R. multiflora

Rosa multiflora

Copyright information

© Springer Science+Business Media, Inc. 2007

Authors and Affiliations

  1. 1.Department of Biological SciencesEastern Illinois UniversityCharlestonUSA