We brought the invaders here. They’re thriving. They’re serving Toronto well. But do the Norway maples have to go? Acer platanoides, the Norway maple, is an invasive species. The Ontario Invasive Plant Council calls these trees “a serious threat to woodlands across Ontario” because of their aggressive spread into forests and ability to suppress native species. The city no longer plants Norway maples as a street tree and actively removes them when rehabilitating ravines and natural areas … its long-term goal is to bring their numbers as close as possible to zero. The short-term goal is more complicated. About 13.5 per cent of Toronto’s street trees are Norway maples… If all of them were chopped down tomorrow… their exceptional climate change-fighting properties, would disappear. …decades ago it was recognized that they thrive as a street tree, where road salt, heat stress, vandalism, dog urine, and soil trampling all take their toll.