Prescribed fire boosts Park prairie

The grassland environment in Glacier National Park’s Big Prairie in the North Fork is unique to the Park. It’s the only large grassland in the Park west of the Continental Divide and is home to elk, deer, wolves, coyotes, fox, Columbian ground squirrels and a host of different bird species, including mountain bluebirds and meadowlarks.

But the landscape relies on wildfire to remain in an open grassland state. Fires kill lodgepole pine saplings that, left unchecked, would slowly take over the prairie.

The last large natural wildfire to touch the prairie occurred in 1988, when the Red Bench Fire raced across the southern end of the grassland. The 2003 Wedge Canyon Fire burned some of the north end.

Last week, fire crews from Glacier Park and the Flathead National Forest set prescribed fires on about 175 acres of the grassland.

According to Park fire ecologist Dennis Divoky, the fire will help rejuvenate and fertilize the prairie soils and kill the lodgepole saplings encroaching on the grasslands. Few large trees died in the fires. Those that do will become fodder for species like northern flickers, that nest in dead trees.

The last prescribed fire in Big Prairie took place nearly 20 years ago. In a natural cycle, fire touches this landscape about every 25 to 40 years, according to previous research that examined growth rings and fire scars on trees.

Big Prairie is home not just to grasses — it also supports sagebrush and some of the few large ponderosa pine stands in the Park. Ponderosa pine is also a fire-dependent species.

The burn operation was split into several units. Firefighters used drip torches to light the grass on fire. It took just a few minutes to blacken 15 to 20 acres. After the fire swept through, it went out just as fast, and the ground was cool to the touch.

The prairie, while black now, will green up quickly after a rain, as the surge of nutrients feed new growth, Divoky said.