Valley bottom is excellent habitat

• By Michael Morris, Mount Revelstoke and Glacier National Parks
• May 14, 1999

Revelstoke residents frequently use the flats south of Revelstoke to ride horses or mountain bikes, to walk their dogs, or to take advantage of one of the hottest bird watching spots in the Kootenays. Few realize we are enjoying one of the most endangered ecosystems in North America, the cottonwood floodplain.

Grade four students birdwatching at Revelstoke Flying Club viewpoint.

Cottonwood trees and willow thickets provide birds with perches and nest sites. Along with many other plants that grow along rivers, they are maintained by spring floods laden with silt, a natural fertiliser. Floods also create side channels, which are critical to young fish survival, and are valued habitats for beavers, otters, muskrats, deer, elk, osprey, eagles and many species of waterfowl.

In mountain regions, valley bottoms are the most productive habitats and contain the greatest diversity of plant and animal species. In much of British Columbia, these areas make up a small part of the landscape and are poorly represented among the region’s protected areas. Yet they are critical for most of the wildlife we consider typical of interior British Columbia. Mount Revelstoke and Glacier National Parks protect areas of wetland, Skunk Cabbage Marsh and the Beaver River fens to name a few, but neither compares with the potential richness of the Columbia River floodplain.

Along most of the shoreline near Revelstoke, the cottonwood complexes now occur along only the edges of their former terrain. Spring floods are prevented by the Columbia River dams and the sediment generated by hundreds of creeks in the Columbia Basin settles out in reservoirs. High water no longer brings the silt that could replace soil lost to erosion. Extended periods of high water in the reservoir eliminated ground cover and resulted in erosion from wind and water. However, the dust storms that once plagued Revelstoke have been successfully controlled by rye grass planted by BC Hydro.

The seeding program has important additional benefits. It enables some native plant species to return and may even be leading to the start of a self-sustaining cover. Wildlife is returning, birds of many species, from Yellowthroats to Short-eared Owls, appear to increasing, and deer use the flats at night. During high water when the flats are underwater, fish and other aquatic life find meals of algae and insects in the submerged vegetation.

Volunteer groups are also active. The Illecillewaet Greenbelt Society has led efforts to make the floodplain accessible for recreation and has planted many trees to stabilize the ground. The Friends of Mt. Revelstoke and Glacier have joined Parks Canada and the Canadian Wildlife Service to monitor the use of the flats by migratory birds. Together these groups are contributing to the growing knowledge and appreciation of an important habitat.