A review of the impacts of invasive alien plants
One hundred and nineteen (119) scientific articles representing 1041 cases of invasion by 135 alien plant species were assembled to gather quantitative evidence from the literature on the ecological impacts of alien plants. The analysis of these publications highlighted the fact that alien plants significantly reduced the growth of resident plant species by 22%, and changed plant community structure by decreasing species’ abundance (by 43.5%) and diversity (by 50.7%). Alien plants also significantly decreased animal species’ abundance by 17%. The impact on plant species and communities were substantial whereas those on nutrient cycling were relatively minor. In addition, total community biomass production increased by 56.8% following invasion. This study also highlighted that there were no significant differences in the mean impacts on species and communities between studies conducted on islands and on the mainland.
The analysis therefore provides rigorous evidence that alien plants species exert significant impacts on many ecological variables.
Sources
Vilà M, Espinar JL, Hejda M, Hulme PE, Jarošik V, Maron JL, Pergl J, Schaffner U, Sun Y ; Pyšek P (2011) Ecological impacts of invasive alien plants: a meta-analysis of their effects on species, communities and ecosystems. Ecology letters 14, 702-708.