Canadian Aspen forests and parklands

July 24, 2012, 9:19 am
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South Block, Rumsey, British Columbia, Canada (Photograph by D. Poulton)

This 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.


 

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 ecoclimate. Summers are short and warm, and winters are cold and long. The 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 milimeters (mm) to just under 700 mm; with the driest area being in the northwestern section of the Mid-Boreal Lowlands. Fire is probably 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.

Biological Distinctiveness

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.

Characteristic wildlife include moose (Alces alces), white-tailed deer (Odocoileus virginianus), black bear (Ursus americanus), 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), Franklin's ground squirrel (Citellus franklinii), sharp-tailed grouse (Tympahuchus phasianellus), ruffed grouse (Bonasa umbellus), black-billed magpie (Pica pica), cormorant (Phalacrocorax spp.), gull (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. White-tailed and black-tailed deer (Odocoileus virginianus and O. hemionus) reach their northern continental limit here.

Conservation Status

Habitat Loss and Degradation

It is estimated that less than 10 percent of the natural habitat in this region remains intact. Of the 90 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 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

There are very high levels of habitat fragmentation due to agriculture. This is particularly true for most forest species.

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 (Backcountry 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

Types and Severity of Threats

Ongoing agricultural conversion of remnant patches of natural habitat, often for grazing and haying, are important threats, as is logging for aspen in many of the remaining forested areas. In fact, aspen pulpwood harvests are expanding in the ecoregion. Extensive use of agricultural pesticides 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.

Suite of Priority Activities to Enhance Biodiversity Conservation

Generally speaking, habitat protection and restoration are needed throughout the ecoregion. Some specific sites 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.
  • Runsey Block of Alberta
  • Beaverhill Lake in Alberta

Conservation Partners

  • 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
  • Sierra Club
  • TREE (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 weave across four Canadian provinces and encompass eight terrestrial 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.

Disclaimer: This article is taken wholly from, or contains information that was originally published by, the World Wildlife Fund. Topic editors and authors for the Encyclopedia of Earth may have edited its content or 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.

 

Glossary

Citation

Fund, W. (2012). Canadian Aspen forests and parklands. Retrieved from http://www.eoearth.org/view/article/150878

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