A researcher says ecological collapse of Toronto's vast ravine system has started because of invasive species but one way to save the narrow forested areas would be to form a large public-private partnership. Toronto's ravines are sick, according to a study that looks at what's happened to native plants and trees over a 40-year period. 'The collapse has already begun,' Eric Davies told CBC Toronto on Sunday about Toronto's ravine system. Invasive species not only take up space, they "toxify" the soil, "out-shade" native species and "out-compete for growth." "The key finding was there's been a huge change in Toronto's ravines that we studied since 1977," he said.

Source: CBC News November 04, 2018 18:35 UTC