More than 70 per cent of Canada’s native prairie grasslands has been lost to agriculture and development, endangering this precious ecosystem and the many species it encompasses. It will take everyone — ranchers, Indigenous people, conservationists and th
More than 70 per cent of Canada’s native prairie grasslands has been lost to agriculture and development, endangering this precious ecosystem and the many species it encompasses. It will take everyone — ranchers, Indigenous people, conservationists and three levels of government — to conserve this precious natural heritage. Plus: Five grasslands species that need protection now!
ONE OF TREVOR HERRIOT’S EARLIEST MEMORIES IS OF walking through tall grass, hand in hand with his father. It was late summer, and they were headed to local fairgrounds in the eastern part of the Qu’appelle Valley near the village of Tantallon, Saskatchewan. The grass stretched above his head, but as it moved, it allowed him to steal glances of the distant hills he says lay like sleeping animals. “It’s the type of grassland I really imprinted on,” says Herriot, now an acclaimed author, naturalist and activist in prairie grassland conservation. “I had a strong sense of the world being benign and safe.”
In his memory, he and his father emerged from the grass to a vibrant fair. Pies, tomatoes, petunias and marigolds were carefully arranged before him with “a sense of pride in produce that comes when you’ve grown it with your own hands.”
That was around 1962, and by then hardworking immigrants had established the ranches and farms that formed the base of the bread belt of Canada. But this came at the cost of most native grassland prairie, lost to the plow in an effort to feed a growing nation. By the time Herriot walked to the fair, roughly two-thirds of these grasslands had been turned over in Alberta, Saskatchewan and Manitoba. Many of the species that were considered incompatible with agriculture, like the swift fox and black-footed ferret, were either eradicated or close to it.
What remains of these grasslands is now scattered in fragments across the Prairie provinces and is slowly being converted to crops or other human uses. Exceptions can be found in a few protected areas, on private ranch lands and on community pastures. Community pastures hold some of the greatest conservation potential, but that may change if the Prairie provinces, having newly acquired responsibility for their management in 2012, don’t support a strong conservation mandate.
At stake are the already dwindling numbers of grassland birds, pronghorn, small mammals, insects and reptiles that evolved to live only in this northern reach of North America’s once vast temperate grassland. Saving what remains of these endangered species and landscapes may rely on the ability of Canadians to support the ranchers, communities and conservationists struggling to hold on to what is left.
Before European settlement, the great temperate grasslands of North America stretched unimpeded from northern Mexico to the Prairie provinces of Canada. Grasses dominated, filling a niche where it was neither wet enough for trees nor dry enough for desert. Plains bison roamed in herds millions strong, their thunderous presence carving habitat in the landscape for a multitude of species including badgers, pronghorn and prairie dogs. Great Plains wolves and the prairie population of grizzly bears dominated the top of the food chain, along with the bison-hunting people who used fire to help maintain the ecosystem. The calls of Sprague’s pipits and chestnut-collared longspurs signalled the start of spring, while great migrants like snow geese stopped in droves to rest and refuel at abundant wetlands and prairie potholes on their way to their Arctic breeding grounds.
By the mid to late 1800s, the bison were all but gone, removing one of the most critical forces that shaped the Prairies. The first people who hunted them were beaten back, and many were forced onto reservations. Conversely, the promised freedom and land ownership lured European immigrants to the Prairies, where they tilled the soil to grow crops. As agriculture took hold and towns and cities grew, there was less room for the swift fox, black-footed ferret, Great Plains wolf and the prairie population of grizzly bears that were eventually hunted, poisoned or pushed out. More than two-thirds of what was once a contiguous stretch of the Prairie Ecozone that spanned over 465,000 square kilometres of the Prairie provinces — almost 5 per cent of Canada’s landmass — was lost forever.
“Wild prairie is now one of the most endangered terrestrial ecosystems,” says Carolyn Callaghan, conservation biologist for the Canadian Wildlife Federation. “A broken prairie is never the same.” She likens the prairie to an iceberg. “Much of the living system is below the surface — the grass is only a small portion of what is really there.” When it is turned over, the lichens, microbes, plants and other members of the soil community are irrevocably altered, which is why she says “Every scrap of native prairie grassland left is precious. We need to keep what we have.”
Prairie ecosystems are not just homes for animals; they also provide important services for the people who live there, says Dan Kraus, conservation biologist with Nature Conservancy of Canada. The underground root systems of grasslands retain moisture in the land and help hold back floodwaters in a way tilled soil cannot. They also release moisture during drought. Native prairies store more carbon than they produce, and Kraus points out they may prove to be more resistant to future drought and the subsequent erosion that will likely be exacerbated by climate change.
The Prairie Ecozone is divided up into several types of grasslands, all of which have suffered massive range contractions. In 2010, according to the Canadian Biodiversity: Ecosystem Status and Trends Report of the Canadian Councils of Resource Ministers, only 25 per cent (about 10,000 sq. km) of mixed and fescue prairie were left in the Prairies ecozone. Tallgrass prairie had all but disappeared, with only 100 sq. km left of its former 6,000 sq. km in Manitoba. Since then, grasslands continue to succumb to crop conversion and urban expansion, and we may be losing even more than we think.
Nicola Koper is a professor at the Natural Resources Institute at the University of Manitoba who has been studying prairie ecosystems for 18 years. A lot of her work has focused on grassland bird communities. She says it’s not just the conversation of grasslands to other uses, but the additional loss to “edge effect” that is having a tremendous impact on grassland birds. “This results in a much higher loss of suitable habitat across the landscape than we as humans realize when we convert these areas.” “Edge” is created any time native prairie grassland comes up against altered habitat, like human infrastructure and cropland. Edge effects are created from things like recreational activities, roads or cropland. Oil wells bring noise and roads. Sometimes, things that seem benign can have an effect, Koper says. For example, fences around croplands create perches for raptors and cowbirds where there were none before. All of these things change the landscape for grassland birds, she says “and unfortunately, in many cases it makes it a lot less suitable for them.”
Complicating matters is the fact that, like all ecosystems, the prairies are not a monoculture, but a diverse patchwork of subtly different habitats. Many species are specialists in a particular type of grassland. What’s good for one is not necessarily good for another.
“The species that like moderate vegetation are doing pretty well in Canada,” says Koper. Moderately grazed grasses are well maintained by ranchers, who have been
WHEN CANADIANS THINK ABOUT GLOBALLY RARE ECOSYSTEMS, THEY THINK ABOUT RAINFORESTS AND CORAL REEFS. BUT IN THE HEARTLAND OF CANADA IS AN ECOSYSTEM THAT IS AS IMPORTANT, RARE AND ENDANGERED AS ANY ON THE PLANET
successful in avoiding erosion in this way, she says. “But those species that like lightly grazed or undisturbed habitat are declining.” The Sprague’s pipit is one of those birds, preferring to stay hidden in tall grasses. Listed as threatened under Canada’s Species at Risk Act, like many grassland specialists its population has declined significantly over the past four to five decades, says Koper.
Conversely, there are also declines in species that like heavily grazed pastures, like the chestnut-collared longspur, also a threatened species. These birds evolved to take advantage of the way bison grazed, and “bison really hammered some areas,” says Koper. “Birds that really adapted to that environment are now losing their habitat.”
By better mimicking the way bison used the landscape, conservationists and ranchers can work together to protect native grassland prairie. It’s a resilient system, Koper says. “Even if one area is really heavily grazed, once you remove the livestock, the habitat comes back pretty much the way it was before.”
To that end, the biggest pastures are the best, Koper says. Cattle choose where they graze more similarly to the way bison did. Some areas are heavily grazed, while others are not grazed at all. High intensity over short durations, with long rest periods to follow, is key.
COLOURS OF THE LAND (Left) A lichen-covered rock, 70 Mile Butte in the distance. (Right) Pronghorn (Antilocapra americana) which are related to giraffe
GRASSLANDS AT RISK RISK • Southwest Manitoba Uplands • Cypress Upland • Fescue Grassland • Lake Manitoba Plain • Aspen Parkland • Mixed Grassland • Moist Mixed Grassland • Aspen Parkland
MORNING HAS BROKEN... Sunrise over the Frenchman River Valley in Grasslands National Park in southern Saskatchewan