Biological Invasions

, Volume 12, Issue 7, pp 2105–2116

Diversity–invasibility relationships across multiple scales in disturbed forest understoreys

  • Andrew J. Tanentzap
  • Dawn R. Bazely
  • Raffaele Lafortezza
Original Paper

DOI: 10.1007/s10530-009-9612-3

Cite this article as:
Tanentzap, A.J., Bazely, D.R. & Lafortezza, R. Biol Invasions (2010) 12: 2105. doi:10.1007/s10530-009-9612-3

Abstract

Non-native plant species richness may be either negatively or positively correlated with native species due to differences in resource availability, propagule pressure or the scale of vegetation sampling. We investigated the relationships between these factors and both native and non-native plant species at 12 mainland and island forested sites in southeastern Ontario, Canada. In general, the presence of non-native species was limited: <20% of all species at a site were non-native and non-native species cover was <4% m−2 at 11 of the 12 sites. Non-native species were always positively correlated with native species, regardless of spatial scale and whether islands were sampled. Additionally, islands had a greater abundance of non-native species. Non-native species richness across mainland sites was significantly negatively correlated with mean shape index, a measure of the ratio of forest edge to area, and positively correlated with the mean distance to the nearest forest patch. Other factors associated with disturbance and propagule pressure in northeastern North America forests, including human land use, white-tailed deer populations, understorey light, and soil nitrogen, did not explain non-native richness nor cover better than the null models. Our results suggest that management strategies for controlling non-native plant invasions should aim to reduce the propagule pressure associated with human activities, and maximize the connectivity of forest habitats to benefit more poorly dispersed native species.

Keywords

Biotic resistanceDiversity–invasibility paradoxFragmentationInvasive non-indigenous species

Supplementary material

10530_2009_9612_MOESM1_ESM.doc (104 kb)
(DOC 104 kb)

Copyright information

© Springer Science+Business Media B.V. 2009

Authors and Affiliations

  • Andrew J. Tanentzap
    • 1
    • 2
  • Dawn R. Bazely
    • 1
  • Raffaele Lafortezza
    • 2
    • 3
  1. 1.Department of BiologyYork UniversityTorontoCanada
  2. 2.Department of Plant SciencesUniversity of CambridgeCambridgeUK
  3. 3.Department of Scienze delle Produzioni VegetaliUniversity of BariBariItaly