Contrasting patterns in the invasions of European terrestrial and freshwater habitats by alien plants, insects and vertebrates
Abstract
There are two ecologically distinct groups of alien species (plants and insects versus vertebrates) with strikingly different habitat affinities. Wetland and riparian habitats support relatively high numbers of alien insect and plant species.
Invasions by vertebrates are more evenly distributed among habitats, with aquatic and riparian, woodland and cultivated land most invaded. Invasions by these two contrasting groups are complementary in terms of habitat use, which makes an overall assessment of habitat invasions in Europe possible.
Since numbers of naturalized species in habitats are correlated among taxa within these two groups, the data collected for one group of vertebrates, for example, could be used to estimate the habitat-specific numbers of alien species for other vertebrate groups with reasonable precision, and the same holds true for insects and plants.