A field of tall grass is seen in this picture, part of a brochure on the once-abundant prairie plant. (Nature Manitoba)

The endless sea of shoulder-high prairie grass that greeted settlers of Manitoba's Red River valley centuries ago is disappearing at an alarming rate and near extinction, a study has found.

Less than one per cent of Canada's original 6,000 square kilometres of tall-grass prairies remains. The little that remains is mostly found in Manitoba, and that is disappearing faster than ever, according to the study published this month in the journal Biological Conservation.

Nicola Koper, author of the study and an ecologist at the University of Manitoba, found more than one-third of the remaining tall-grass prairies have disappeared since the last survey in the 1980s.

'Most of it has been heavily impacted by humans and is getting worse.'—Researcher Nicola Koper

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 found.

"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.

Protection needed

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 government and environmental groups, including the Nature Conservancy of Canada, is involved in preserving a large swath of tall-grass prairie in southeastern Manitoba.

Lots of work required

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.

"We've kind of drawn a circle around a part of Manitoba," he said.

Environmentalists are focusing their efforts on maintaining and possibly expanding the current preserve, which is 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."