The comparative importance of species traits and introduction characteristics in tropical plant invasions
Article first published online: 20 JUN 2011
© 2011 Blackwell Publishing Ltd
Diversity and Distributions
Volume 17, Issue 6, pages 1111–1121, November 2011
How to Cite
Dawson, W., Burslem, D. F. R. P. and Hulme, P. E. (2011), The comparative importance of species traits and introduction characteristics in tropical plant invasions. Diversity and Distributions, 17: 1111–1121. doi: 10.1111/j.1472-4642.2011.00796.x
- Issue published online: 13 OCT 2011
- Article first published online: 20 JUN 2011
- Biological invasion;
- East Africa;
- introduction effort;
- life history;
- rain forest
Aim We used alien plant species introduced to a botanic garden to investigate the relative importance of species traits (leaf traits, dispersal syndrome) and introduction characteristics (propagule pressure, residence time and distance to forest) in explaining establishment success in surrounding tropical forest. We also used invasion scores from a weed risk assessment protocol as an independent measure of invasion risk and assessed differences in variables between high- and low-risk species.
Location East Usambara mountains, Tanzania.
Methods Forest transect surveys identified species establishing in disturbed and intact forest. Leaf traits (specific leaf area and foliar nutrient concentrations) were measured from leaves sampled in high-light environments.
Results A leaf traits spectrum was apparent, but species succeeding or failing to establish in either disturbed or intact forest were not located in different parts of the spectrum. Species with high invasion risk did not differ in their location on the leaf trait spectrum compared with low-risk species but were more likely to be bird/primate-dispersed. For 15 species establishing in forest quadrats, median canopy cover of quadrats where seedlings were present was correlated with a species value along the leaf trait spectrum. Species establishing in disturbed forest were planted in twice as many plantations and were marginally more likely to be bird- or primate-dispersed than species failing to become established in disturbed forest. Establishment in intact forest was more likely for species planted closer to forest edges.
Main conclusions Leaf and dispersal traits appear less important in the colonization of tropical forest than introduction characteristics. It appears, given sufficient propagule pressure or proximity to forest, alien species are much more likely to establish independently of leaf traits or dispersal syndrome in continental tropical forests.