by Kate Wilson
The Aspen Parkland biome – which fills a wide expanse from central Alberta through Saskatchewan and Manitoba to North Dakota – has a northern outlier. This isolated subregion, located in northwestern Alberta and northeastern BC, is known as Peace River Parkland.
In my ramblings around the south-facing slopes overlooking the Peace River townsite, I’ve been building a species list of the native plants that are typical of more southern aspen parkland and even prairie regions of Alberta. A recent discovery was a small patch of stemless Townsend’s daisy (Townsendia exscapa). Thanks to Patsy Cotterill for identifying this uncommon native resident, which is normally found in xeric environments of the western plains or exposed mountain slopes. I’ve also come across showy locoweed (Oxytropis splendens) and prairie cinquefoil (Potentilla pensylvanica).
On a walk up a more westerly-facing slope, in the lee of abandoned and slightly sunken road tracks, I found a scattered display of prairie onion (Allium textile) and harebells (Campanula alaskana). Though these aren’t exclusive to the aspen parkland, they graced the trail as an unexpected and welcome sighting.
While much of what is known as Peace Country is now agricultural, the slopes along many of the steep river valleys are uncultivated and ungrazed by cattle. Mule deer, moose and bear are the predominant large animal grazers and browsers. An Alberta government manual, Ecological Sites and Successional Plant Community Types of the Peace River Parkland Subregion (2021), even notes the presence of pronghorn antelope up until the mid 1800s.
Plant communities of the Peace River Parkland
In their ecological study of the area, M.G. Willoughby et al. (in the publication noted above) characterizes the Peace River Parkland as gently rolling cultivated plains and steep south-facing grassy and forested slopes along the Peace River and its tributaries. Vegetation is a mosaic – featuring dry mixedwood forests, wetlands and small remnant grasslands on the uplands, and dry grasslands and aspen forests on valley slopes.
In northwestern Alberta, the authors map out three sub-areas of the Peace River Parkland. The northernmost of these runs parallel to the Peace River from the town of Peace River to Dunvegan, a distance of about 100 km. It features steep slopes edged by glacial plains that are up to 10 km back from the river banks on the north (south-facing) side. The second and third sub-areas are rolling or undulating plains centred around Spirit River and Grande Prairie to the west. Soils are typically fine textured glacial till, black chernozemic and solonetzic, and weakly saline.
Even with all the cultivation, isolated populations of plants and insects – otherwise associated with the Grassland Natural Region – are still present. All considered, the Peace River Parkland ecoregion is very distinct from the surrounding Boreal landscape.
In the above-mentioned ecological study, six broad community types are delineated. They are upland/slope grasslands and shrubland, moist shrubland, grazing successional grassland and shrubland, deciduous, conifer/mixedwood, and tame.
Of the grasslands and shrublands, there are 19 community associations. Species such as western porcupine grass (Hesperostipa curtiseta), June grass (Koeleria macrantha) and pasture sage (Artemisia frigida) are interspersed with bare mineral soil on dry south-facing slopes of the Peace and Smoky Rivers. Grasses typical of more southern regions and brittle prickly-pear cactus (Opuntia fragilis) are occasional residents. Climbing the exposed slope just above the Peace River outlook, an observant hiker will come across this small cactus claiming the sun wherever it finds bare spots in the grass-dominated cover.
Along the dry south- and west-facing slopes above the town of Peace River, indicator species of the “creeping juniper association” and “grasslands association” include prairie crocus (Pulsatilla nuttalliana), three-flowered avens (Geum triflorum), pasture sage (Artemesia frigida) and milk-vetch (Astragalus) species. Indicator shrubs are prickly rose (Rosa acicularis), Canada buffaloberry (Shepherdia canadensis), snowberry (Symphoricarpos) species, and silverberry (Elaeagnus commutata); grasses include western porcupine grass, June grass, slender wheatgrass (Elymus trachycaulus) and thick-spike wildrye (Elymus lanceolatus), along with blunt sedge (Carex obtusata) and beautiful sedge (Carex concinna).
Here is a small selection of species I’ve found on slopes with a south or southwestern aspect, above the town of Peace River.
Early spring
Prairie crocus - Pulsatilla nuttalliana
Three-flowered avens – Geum triflorum
Spring to mid summer
Townsend’s stemless daisy – Townsendia exscapa
Early blue violet – Viola adunca
Showy locoweed - Oxytropis splendens
Brittle prickly pear cactus – Opuntia fragilis
Low Milkweed – Asclepias ovalifolia
Tufted white prairie aster - Symphyotrichum ericoides
Pasture sage - Artemisia frigida
Creeping juniper - Juniperus horizontalis
Mosses and lichens forming cryptogamic crust
The publication noted in the article can be found here: