Plants and weeds are creating a biological emergency for Calgary.
A number of experts say foliage that is not native to Alberta threatens insects, birds and even our food supply.
"If we don't have the natural species plants, which our insects rely on and our birds rely on those insects, then we loose those insects and we loose those birds," says Brian Pincott, the alderman for Ward 11.
One of the biggest offenders is the variety of plants purchased for landscaping. "Over time we'll lose the entire native shrub community. All of the choke cherries, Saskatoon berries, buffalo berries, dogwoods, all those species are slowly being choked out by these aggressive Eurasian species," says Andrew Stiles from Bow Valley Weed Initiative.
Invasive species can be found in every part of the city. Thistles cover property along roads and highways; escarpments are being taken over by cotoneaster; and in some areas, 95 percent of the landscape has been taken over by invasive species.
Stiles would like to see more stores and garden centres prohibit the sale of invasive species. "We need to ask the retailers, nicely, please don't sell these species of invasive plants. But please sell these other ones that are beneficial to the environment and don't spread aggressively," says Stiles.
For now, the city's parks department will be taking an inventory of the types of weeds and non-native species that are taking over parks and natural areas.
