Invasive management practices typically focus on the removal of only the most nuisance species, with further restoration strategies relying on a passive recovery of the native communities through seed bank regeneration and/or seed dispersal. This approach has led to relatively low recovery success and a continuous need for invasive control. These low levels of invasion can then only be sustained with constant human intervention. While invasive plant species differ in their invasiveness, terrestrial communities vary in their vulnerability and resistance to plant invasion. Yet, it is unclear what are the features that confer such characteristics to the native communities, and if they can be ameliorated or enhanced during management actions.
Through a quantitative systematic review (i.e., a meta-analysis), the biotic and abiotic features of terrestrial plant communities that confer vulnerability or resistance to plant invasion were identified. Considering the context-dependency of ecological responses, the data were collected with enough detail to disentangle the specificities that promoted different trends not only to invasive species but also to native community responses.
Results/Conclusions
The raw search returned 4,094 articles. After screening for relevance, the data was extracted from 241 publications amounting to 652 observations. Native species were significantly less vulnerable to plant invasion due to biotic resistance especially under low propagule pressure of invaders. When those results were broken down by vegetation types, the native species resistance was significantly higher in grasslands and shrublands than in other terrestrial systems. Generally, native species responded negatively to disturbance, while invasive species mostly benefited from it. Except for altered hydrology regimes, all other disturbance types tended to negatively affect the native species; effects were highly significant for fire and anthropogenic activities. The most important mechanisms increasing communities’ resistance to invasion were competition, natural enemies and priority effects. Results point to the importance of interspecific interactions in promoting resistance of terrestrial plant communities to invasion. Management practices that involve disturbance, e.g., burns, reducing vegetation, should be further evaluated as they tend to have a positive effect on invasive species but a rather negative effect on native communities.