Ecological impacts of invasive alien plants: a meta-analysis of their effects on species, communities and ecosystems
Abstract
A global meta-analysis of 1041 field studies that in total describe the impacts of 135 alien plant taxa on resident species, communities and ecosystems revealed that alien plants had a significant effect in 11 of 24 different types of impact assessed. The magnitude and direction of the impact varied both within and between different types of impact.
On average, abundance and diversity of the resident species decreased in invaded sites, whereas primary production and several ecosystem processes were enhanced. Overall, alien species impacts are heterogeneous and not unidirectional even within particular impact types.
Our analysis also reveals that by the time changes in nutrient cycling are detected, major impacts on plant species and communities are likely to have already occurred.