Canadian Aspen forests and parklands
The Canadian Aspen forests and parklands ecoregion stretches in an arc from the Manitoba/North Dakota border in the east to central Alberta in the west with a disjunct occurrence in northwestern Alberta crossing the British Columbia border in the Peace River area. The preponderance of this ecoregion is situated in Canada, with a very small element residing in the USA state of North Dakota.
This ecoregion is classified primarily as having a subhumid low boreal ecoclimate, which distinguishes this ecoregion from the warmer, drier areas to the south and the cooler boreal forests to the north. It also has a transitional grassland climate. Summers are brief and warm, and winters are cold and protracted. Mean annual temperature ranges from 0.5°C to 2.5°C; the mean summer temperature ranges from 13°C to 16°C; and the mean winter temperature ranges from -14.5°C to -12.5°C. The Peace River Lowland area of the region generally represents the coolest temperatures for each range, while the Southwest Manitoba Uplands region represents the warmest temperatures. Mean annual precipitation ranges from 375 millimetres (mm) to slightly less than 700 mm, with the driest area being in the northwestern section of the Mid-Boreal Lowlands. Fire is the most important natural disturbance regime.
Much of the region is underlain by Cretaceous shale, and covered by undulating to kettled, calcareous, glacial till with significant areas of level lacustrine and hummocky to ridged fluvioglacial deposits. Associated with the rougher hummocky glacial till are a large number of small lakes, ponds and sloughs occupying shallow depressions. The gently undulating or sloping lands associated with the Peace River are underlain by Tertiary sandstone and shale strata, covered mainly by imperfectly drained clayey lacustrine sediments with some fine-textured tills and sandy fluvioglacial deltas associated with the major river systems. Finally, the Interlake Plain area is underlain by flat-lying Paleozoic limestone, and covered by broadly ridged, extremely calcareous glacial till, and by shallow, level, lacustrine sands, silts and clays.
Vegetation in this ecoregion is characterized by a cover of Quaking aspen (Populus tremuloides) with secondary quantities of Balsam poplar (P. balsamifera), together with an understory of mixed herbs and tall shrubs. White spruce (Picea glauca) and Balsam fir (Abies balsamea) are the climax species, but are not well represented because of fires. Jack pine (Pinus banksiana) stands may be present on drier, sandy sites. Poorly drained sites are usually covered with sedges (Carex spp.), willow (Salix spp.), some Black spruce (P. mariana), and tamarack (Larix laricina). In the Turtle Mountain and Spruce woods areas, Quaking aspen dominates with secondary quantities of Balsam poplar, although white spruce and balsam fir are the climax species if fires do not occur frequently.
Faunal diversity is generally low in the Canadian Aspen forests and parklands; for example, only 296 vertebrate taxa have been recorded here.
Characteristic mammalian taxa include: Moose (Alces alces), White-tailed deer (Odocoileus virginianus), American black bear (Ursus americanus), Gray Wolf (Canis lupus), Beaver (Castor canadensis), Coyote (Canis latrans), Marten (Martes americana), Mink (Mustela vison), Red fox (Vulpes vulpes), Snowshoe hare (Lepus americanus), Northern pocket gopher (Thomomys talpoides) and Franklin's ground squirrel (Citellus franklinii),
White-tailed and Black-tailed deer (Odocoileus virginianus and O. hemionus) both reach their northern continental limit here.
A considerable number of avian species are found in the ecoregion, including: Sharp-tailed grouse (Tympahuchus phasianellus), Ruffed grouse (Bonasa umbellus), Black-billed magpie (Pica pica), cormorants (Phalacrocorax spp.), gulls (Larus spp.), tern (Sterna spp.), American white pelican (Pelecanus erythrorhynchos) and many neotropical migrant bird species.
Of ecological significance, the Aspen parkland and forests ecoregion represents the most extensive boreal-grassland transition in the world. This ecoregion contains the northernmost breeding distribution for many warbler species (Parulinae) and has some of the most productive and extensive waterfowl breeding habitat on the continent.
There are very few reptilian taxa found in this ecoregion; the totality of snakes are: Common garter snake (Thamnophis sirtalis); Plains garter snake (Thamnophis radix); Red-bellied snake (Storeria occipitomaculata); Western Hog-nosed snake (Heterodon nasicus); Western terrestrial garter snake (Thamnophis elegans); and Smooth green snake (Liochlorophis vernalis). Other reptiles found here are the Northern Prairie skink (Plestiodon septentrionalis); Common snapping turtle (Chelydra serpentina) and Painted turtle (Chrysemys picta).
Only a small number of amphibians occur within the Canadian aspen parklands and forests; anuran species seen here are: Boreal chorus frog (Pseudacris maculata); Cope's gray treefrog (Hyla chrysoscelis), Gray treefrog (Hyla versicolor); Wood frog (Lithobates sylvaticus); Western toad (Anaxyrus boreas); and Northern leopard frog (Lithobates pipiens). Other amphibian species, among Caudata, found here are the Mudpuppy (Necturus maculosus) and the Tiger salamander (Ambystoma tigrinum).
Habitat Loss and Degradation
It is estimated that less than ten percent of the natural habitat in this region remains intact. Of the ninety percent disturbed, most has been converted to agricultural cropland, including Canola (Brassica napsus), Alfalfa (Medicago sativa) and Wheat (Triticum aestivum). Cultivation of land for grazing purposes is also widespread. In those parts of the ecoregion where forests cover was historically more widespread, forest harvesting continues in the remaining farm woodlots.
Remaining Blocks of Intact Habitat
Few significant blocks of intact habitat remain. These include:
- Moose Mountain Provincial Park - southeastern Saskatchewan - approx. 266 km2
- Elk Island National Park - central Alberta - 194 km2
- Bronson Forest - Saskatchewan
- Wainwright Military Reserve - Alberta
Degree of Fragmentation
Degree of Protection
- Moose Mountain Provincial Park - Saskatchewan - 265.91 km2
- Spruce Woods Provincial Park (Backcountry zones) - southern Manitoba - 201 km2
- Elk Island National Park - Alberta - 194.3 km2
- Turtle Mountain Provincial Park (Back-country zones) - southwestern Manitoba - 118 km2
- Rumsey Ecological Reserve - south-central Alberta - 34.32 km2
- Sand Lakes Natural Area - central Alberta - 28.44 km2
- Wainwright Dunes Ecological Reserve - eastern Alberta - 28.21 km2
- Jack Pines Natural Area - central Alberta - 18.59 km2
- Silver Valley Ecological Reserve - western Alberta - 18.05 km2
Ongoing agricultural conversion of remnant patches of natural habitat, often for grazing and haying, are significant threats, as well as logging for aspen in much of the remaining forested areas. In fact, aspen pulpwood harvests are expanding in the ecoregion. Extensive use of agricultural pesticides and herbicides is a major concern for wildlife populations. Predator control is still occurring in some areas, and is becoming more problematic with the start-up of game farms. Seismic oil and gas exploration is widespread in many areas.
Priority Activities to Enhance Biodiversity Conservation
Generally speaking, habitat protection and restoration are warranted, throughout the ecoregion. Some specific priority sites for such conservation include:
- Porcupine Forest, Bronson Forest and Nisbet Forest in Saskatchewan
- Major Sand Hills throughout the ecoregion.
- Establish Manitoba Lowlands National Park
- Shilo Defense Base in Manitoba
- Protection standard upgrades required for select wildlife management areas in Manitoba.
- Rumsey Block of Alberta
- Beaverhill Lake in Alberta
- Alberta Wilderness Association
- Brandon Naturalists' Society
- Canadian Parks and Wilderness Society, Calgary/ Banff Chapter
- Canadian Parks and Wilderness Society, Edmonton Chapter
- Critical Wildlife Habitat Program
- Ducks Unlimited Canada
- Endangered Spaces Campaign - Manitoba
- Endangered Spaces Campaign - Saskatchewan
- Federation of Alberta Naturalists
- Friends of Elk Island Society
- Friends of Prince Albert National Park
- Lower Fort Garry Volunteers
- Manitoba Heritage Habitat Corporation
- Manitoba Naturalists Society
- Meewasin Valley Authority
- Nature Saskatchewan
- The Nature Conservancy, Alberta
- The Nature Conservancy, British Columbia
- Red Deer River Naturalists
- Resource Conservation Manitoba
- Saskatchewan Forest Conservation Network
- Time to Respect the Earth's Ecosystems
- Watchdogs for Wildlife
- The Wildlife Society
- World Wildlife Fund Canada
Relationship to other classification schemes
The Canadian aspen forest and parklands is designated by the World Wildlife Fund as ecoregion NA0802, lying within the Temperate Grasslands, Savannas, Shrublands biome. It weaves across four Canadian provinces and encompasses eight terrestrial sub-ecoregions: the Peace Lowland, Western Boreal, Boreal Transition, Interlake Plain, Aspen Parkland, and Southwest Manitoba Uplands. These ecoregions lie in both the Boreal Plains Ecozone and the Prairies Ecozone. The Boreal sections are Manitoba Lowlands, Aspen-Oak, Aspen Grove, Mixedwood, and Lower Foothills. This ecoregion also overlaps some of the grasslands adjacent to the south of this ecoregion.
- Central British Columbia mountains forests, at the northwest
- Northern mixed grasslands, to the south and south-southeast
- Northern tall grasslands, to the southeast
- Alberta-British Columbia foothills forests, to the west and northwest, and betwixt the northern and central disjunctive units
- Muskwa-Slave Lake forests, at the north
- Mid-Continental Canadian forests, at the northeast
- J. M. Hoekstra; Molnar, J. L.; Jennings, M.; Revenga, C.; Spalding, M. D.; Boucher, T. M.; Robertson, J. C.; Heibel, T. J. et al. 2010. Molnar, J. L., ed. The Atlas of Global Conservation: Changes, Challenges, and Opportunities to Make a Difference. University of California Press. ISBN 978-0-520-26256-0Bill Mathews and Jim Monger. 2005. Roadside Geology of Southern British Columbia. Mountain Press Publishing Company. ISBN 0-87842-503-9.
- Taylor H. Ricketts. 1999. Terrestrial ecoregions of North America. Island Press
Disclaimer: This article some contains information that was originally published by the World Wildlife Fund. Topic editors and authors for the Encyclopedia of Earth have edited its content and added new information. The use of information from the World Wildlife Fund should not be construed as support for or endorsement by that organization for any new information added by EoE personnel, or for any editing of the original content.