WINNIPEG - The endless sea of shoulder-high prairie grass that greeted settlers of Manitoba's Red River valley centuries ago is near extinction and disappearing at an alarming rate, a new study has found.
Less than one per cent of Canada's original 6,000 square kilometres of tall-grass prairies remains -- most of it in Manitoba. The fields are home to more than 1,000 different species and are partially responsible for mitigating potentially devastating spring flooding.
A new study published this month in the journal Biological Conservation has found that what little remains of the tall-grass prairie is disappearing faster than ever before. Nicola Koper, author of the study and ecologist at the University of Manitoba, found more than one-third of the remaining tall-grass prairies have disappeared since they were last surveyed in the 1980s.
Remaining patches of the unique Canadian ecosystem characterized by towering varieties of grass and flowers are being taken over by other species or deteriorating rapidly, she added.
"Even though we knew that it was extraordinarily endangered in the late 1980s and took steps to try to conserve it, in fact, in general the ecosystem has declined even further from this previously seriously endangered state," she said.
"Most of it has been heavily impacted by humans and is getting worse."
The destruction of the tall-grass prairies began when settlers first arrived. Tall-grass prairies relied on bison and wildfires to keep trees and other species at bay, Koper said.
When the West was settled, both bison and wildfires died out, leaving the tall-grass prairies vulnerable. Other alien species, such as dandelions and sowthistles, are moving in and crowding out the tall-grass prairies, she said.
This spells doom for the dozens of butterflies, rare plants and songbirds that make their home in the tall-grass prairies. Pollinating species that are vital for canola crops also use the prairies, Koper added.
The tall-grass prairies have historically minimized the impact of annual flooding in the Red River Valley by slowing the spring snow melt and increasing soil absorption, she said.
Some of the remaining prairies are protected, but more needs to be done, Koper said.
"Do we as a society want to retain this component of our heritage and have tall-grass prairies where we can bring our own children and allow them to pick flowers that are taller than themselves?" she said. "We have to decide as a society what's important for us."
A coalition of govenrment and environmental groups, including the Nature Conservancy of Canada, is involved in perserving a large swath of tall-grass prairie in southeastern Manitoba.
Cary Hamel, conservation science manager with the Manitoba region of the conservancy, said it takes a lot of work to keep that patch of prairie thriving. The area is regularly subjected to grazing and controlled burning to keep woodland species from taking hold, he said.
Essentially, Hamel said, they recreate the conditions that existed before settlers ever arrived in the West.
"Where remnant prairie exists, if it isn't being managed as a prairie, it's being largely invaded by invasive species," he said. "We've kind of drawn a circle around a part of Manitoba."
Still, there are new threats emerging all the time, Hamel said, not the least of which is climate change. For now, environmentalists are just focusing their efforts on maintaining and possibly expanding the current preserve near the U.S. border.
"At that one location, I feel pretty good that it's a case where we can preserve it into the future," Hamel said. "In that area, we're winning the battle."
