From American grey squirrels displacing European red ones, to Japanese knotweed displacing just about everything everywhere, their purported negative effects on nature are there for all to see.

从美州灰松鼠取代欧洲红松鼠，到日本虎杖取代英国几乎所有本土植物，外来物种对自然造成的负面影响是有目共睹的。