ABSTRACT
Precise data on the proportion of native as opposed to non-native species in towns and cities is hard to find. By favoring native species it is also argued that various potential adverse impacts associated with non-native planting can be avoided. The close relationship between native plants and co-evolved herbivorous insects is believed to partly explain the invasion paradox. Influenced by the various studies discussed, the consensus in invasion biology and ecological thinking more generally has been that non-native species are generally harmful, impoverishing biodiversity and even upsetting the benign balance of nature. Non-native plant species will have a continuing role to play in planting schemes, bringing vibrancy and joy, and sometimes also considerable value to native fauna. Large-scale planting of native species into recognizable communities can also create impressive habitat analogues that can make important contributions to biodiversity targets.
