Terrestrial Ecozones, Ecoregions and Ecodistricts of Manitoba

Terrestrial Ecozones, Ecoregions, and Ecodistrictsof Manitoba

An Ecological Stratification of Manitoba’s Natural Landscapes

Research BranchTechnical Bulletin 1998-9E

R.E. Smith, H. Veldhuis, G.F. Mills, R.G. Eilers, W.R. Fraser, and G.W. Lelyk

Land Resource UnitBrandon Research Centre, Research Branch

Agriculture and Agri-Food Canada

Taiga Shield Ecozone

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Kazan River Upland Ecoregion

ClimateThe ecoclimate of the ecozone is classified as Subarctic,which is characterized by relatively short summers withprolonged daylight, and long, very cold winters. Meanannual temperature in the area west of Hudson Bay is aslow as -9.0oC, but it ranges from -1oC to -5oC in Quebecand Labrador, with some areas in Labrador having meanannual temperatures as high as 1oC. A few degrees of frost

is a common occurrence in summer, especially in areaswith the stronger continental climate conditions.

Mean annual precipitation ranges from 200 to 500 mmwest of Hudson Bay, while east of Hudson Bay it rangesfrom 500 to 800 mm, to over 1000 mm locally along theLabrador coast.

Taiga Shield EcozoneThe Taiga Shield Ecozone lieson either side of Hudson Bay.The eastern segment occupiesthe central part of Quebec andLabrador, and the western seg-ment occupies portions of north-ern Manitoba, Saskatchewan,Alberta and the south-easternarea of the continental North-west Territories, and the south-ern part of Nunavut. Character-istic of the zone are the open andoften stunted conifer dominatedforests, and the Precambrianshield with its shallow soils andmany lakes.

Temperature Precipitation Degree Days Frost Free PeriodStation (oC) (>5oC) (days)

Rain(mm) Snow(cm) Total(mm)Brochet A -4.9 261.8 167.5 427.1 952.0 97.0Ennadai Lake -9.3 173.7 117.1 266.7 595.0 78.0Uranium City A -3.5 204.9 197.9 344.8 1111.0 106.0Yellowknife A -5.4 150.2 135.4 266.7 1027.0 111.0

Surficial deposits and landformsMost of this ecozone consists of broadly rolling uplandsand lowlands. The main surface materials are Precambrianbedrock outcrops and till deposits in the form ofdiscontinuous veneers and blankets, and hummocky andridged moraine. Ridged fluvioglacial deposits arewidespread, and occur frequently as groups of eskers withassociated kettle lakes, forming some of the more

distinctive landscape features in this ecozone. Someglaciolacustrine and marine deposits are also present. Theglaciolacustrine deposits are mostly associated withlarger lakes and were deposited when these lakes weremuch larger and deeper.

1 Canadian Climate Normals, 1951-1980. Atmospheric Environment Service, Environment Canada.

Selected Climate Data1 (Annual Means) for the Taiga Shield Ecozone


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There are many lakes of varying sizes, commonly withirregular bedrock-controlled shorelines. Permafrost isdiscontinuous but widespread. Lowlands are commonlywaterlogged or wet for prolonged periods and frequentlycontain shallow and moderately deep peatlands.

SoilsBrunisolic soils are dominant in the southern portion ofthe ecozone west of Hudson Bay, while Humo-FerricPodzolic soils are dominant in the southern portion east ofHudson Bay. Cryosols are dominant in the northern parts,while in the central area, Cryosolic soils and Brunisolic orPodzolic soils are co-dominant. Gleysols and OrganicCryosols occur throughout the ecozone and are foundmainly in the lowland areas.

VegetationGeneral vegetative characteristics are notably governedby latitude. The changes are generally gradual, butbecome significant when compared over a large distance.Because of the extent of this ecozone, and because it formsthe transition from the extensively forested Boreal ShieldEcozone to the south to the treeless Southern ArcticEcozone to the north, the vegetation of this ecozone variesdramatically between its northern and southern sectors.

In the northern half of the ecozone, normal (or mesic) sitesgenerally support very open stands of black spruce andtamarack, with white spruce often part of the community.Ground cover is dominated by dwarf birch, willows,northern Labrador tea, cotton grass, mosses and lichens.Drier sites have open stands of white spruce with a groundcover of various ericaceous shrubs, dwarf birch, mossesand lichens. The lichen component is dominated by theCladina species.

Areas with tree cover are often intermixed with areas oflow shrub-tundra vegetation as found in the SouthernArctic Ecozone. These areas of tundra become lessfrequent toward the south. Poorly drained areas aredominated by tussock sedge and cotton grass along withsphagnum moss. Along rivers, and especially in shelteredvalleys, stands of white spruce, balsam poplar and paperbirch are found.

In the southern half of the ecozone, the forest coverbecomes increasingly more dense with taller trees, withthe decrease in latitude. Paper birch becomes morecommon especially in recently burned areas, while standsof white spruce, paper birch and trembling aspen may befound on warmer, protected sites. Lowland areas havebog-fen complexes. Bog vegetation is composed of blackspruce, Labrador tea, Vaccinium species, bog rosemary,and cloudberry, while the fen vegetation is dominated bysedges and brown mosses.

WildlifeThe ecozone provides winter range for several majorherds of barren-ground caribou. Other characteristicwildlife include arctic fox in northern areas, polar bearalong the coast, moose, wolf, black bear, grizzly bear inthe western sector, and brown lemming and weasel.

Representative birds include arctic and red-throatedloons, northern phalarope, northern shrike, osprey, treesparrow, raven, spruce grouse and grey-cheeked thrush. Inthe marine environment seals are characteristic. Severalfish species, including lake trout, arctic grayling,whitefish and northern pike, are found in lakes andstreams.

Land useThe population of the ecozone is about 34,000, of whichabout 60 percent is aboriginal. Most of the population isconcentrated in the few permanent settlements.Yellowknife, with a population of about 12,000 (1991), isthe largest. The oldest settlements were established alongthe coast during the era of fur trade and whaling. Most ofthe more recent settlements were founded as a result ofmining and hydro-electric developments.

Economic activity is associated primarily with mining andhydro development, government and private serviceindustry, and construction. In a number of southernsectors, forestry provides employment. Tourism is agrowing industry and several lodges operate in theecozone. Although most of the population is found inurban areas, subsistence hunting, fishing and trappingremain important land uses.

There are two ecoregions within the Taiga Ecozone inManitoba.


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The Kazan River Upland Ecoregion is part of the broadtransitional zone between Boreal and Arctic, usuallyreferred to as the Subarctic. The treeline marks its north-ern boundary, while the closed canopy forest of thenorthern Boreal marks its southern boundary. TheSubarctic is a mixture of treeless tundra and stands ofstunted trees. The barren-ground caribou migrates be-tween the northern Boreal or southern Subarctic forestand the northern Subarctic or southern Arctic “BarrenLands”.

The Kazan River Upland Ecoregion


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Figure TS1.Esker complex. Extensiveglaciofluvial sand and gravel depositsin the form of eskers, kames, esker-kame complexes, interlobate moraines,outwash plains etc. occur in northernManitoba, in adjacent Nunavut, and inthe Northwest Territories. Shown aretwo large eskers and their borderingaprons. The lakes closely associatedwith the esker complex are called ket-tle lakes. Lichen vegetation and ex-posed sand and gravel give the lightyellow colour to the eskers. Permafrostmay or may not be present in the crestand upper slope positions due to thecoarse texture of materials, lack of asubstantial organic surface layer and/

Plate TS2.Snow blasted trees. High winds in the tundra environment willdrive hard snow particles with great force. As a result exposedtrees often lack branches and needles along part of their stemwhere the snow blasting is most severe. Close to the ground thebranches are dense with needles as this area is protected by thesnow cover. About 1.0 m to 1.5 m above ground level the snowblasting effect is less severe allowing branches to form.

or the lack of vegetation. If permafrost is present, the active layer is deep (>100 cm). On the lower slopes, mosses and/or shallow peat provide insulation, resulting in widespread permafrost with shallower active layers. Under Subarcticclimatic conditions, Dystric Brunisolic soils are commonly found on the crests and Static Cryosolic soils occur on thelower slopes of these landforms.

Legend: Esker (a); esker apron (b); kettle lake (c)


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Plate TS4.Drumlins. Drumlins are streamlinedhills consisting of glacial drift. Theirlong axis, which can be several hundredmetres long, is parallel to the directionof flow of the ice sheet that formedthem. They may stand over 30 m abovethe surrounding terrain. The crests aregenerally dry and covered with tundravegetation, while the slopes have morelush shrub vegetation. Permafrost isgenerally found throughout their extent,but active layers are deeper on thecrests than on the slopes. Although theyoften occur in groups, the drumlinswithin a group can vary considerably inlength and elevation. Several largedrumlins are visible in the photo, butsome low subdued drumlins are alsopresent in the right foreground.

Plate TS3.Side slope of esker. Trees and shrubs growing on lee side. The crests of eskers remain largely free of snow duringthe winter. Non-vegetated sections and blowouts are common. The lee side and depressions offer protection from strongwinds, and the accumulation of snow provides additional protection and moisture. As a result, these sites are the areaswhere trees and tall shrubs find a foothold.


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Plate TS5.Nonsorted circle in till. Circles are a form of patternedground. They are formed when thawing and freezing dur-ing the fall and spring causes hydrostatic and cryostaticpressures to develop, forcing soil material to the surface.Nonsorted circles lack a rim of coarse fragments aroundthe circle centre which is a characteristic of sorted cir-cles. Both types have strongly cryoturbated soils. Circlesmay not be active each year; sometimes they become ac-tive after many years of dormancy due to changing mois-ture conditions.

Plate TS7.Frost-heaved boulder. Frost-heaved boulders and frost-heaved bedrock fragments are common. In some areas,the coarse bedrock fragments at the surface are so plenti-ful that these areas are referred to as block-fields. Coarsefragments are heaved to the surface through the forma-tion of ice lenses below the fragments. The formation ofthe ice lens, which occurs before all of the soil material isfrozen, pushes the boulder a short distance closer to thesurface. Although the ice lens melts during the summer,the fragments are prevented from slipping back to theirprevious position by soil material that has slumped into

Plate TS6. Orthic Dystric Turbic Cryosol. These soil are commonthroughout the Taiga Shield Ecozone. They havedeveloped on sandy loam to loamy sand textured tillmaterials derived from the Precambrian Shield. Thematerials are slightly to medium acid and containquantities of small to very large coarse fragments. In thissoil, a brown B horizon has developed, but this horizonhas been disrupted through cryoturbation, resulting in themixing of some of the B horizon material with unalteredparent material, and the movement of some organicmaterial from the surface deeper into the soil.

the cavity or by adhesion to the surrounding soil material. Eventually, after many freeze and thaw cycles, the fragmentswill breech the surface as shown here. Some of the boulder surface is still covered by soil material. The boulder willcontinue to be heaved until it is on the surface. On inclined surfaces, these boulders may also be moved downslope.


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Plate TS9. Taiga fall colours.The Taiga consists of both tundra and open stands of trees. Close to the tree-line, tundra vegetation covers most of theland. Ericaceous shrubs, mosses and lichens are widespread. Alpine and arctic bearberry turn the tundra into a crimsonred in the fall.

Plate TS8.The Tyrrell Sea “Great Beach”. TheTaiga Shield Ecozone in Manitoba is inpart bordered by a complex of TyrrellSea beaches, the so-called “GreatBeach”. After the WisconsinContinental Ice Sheet vacated the area,the Tyrrell Sea invaded and formed asignificant beach complex along itswestern border. The beaches arelargely composed of well drainedsands. However, the lower slopes,especially on the eastern side, aremasked by deep, permanently frozenpeat deposits (peat plateau bogs). Thevegetation on the beaches ischaracterized by open stands of white

spruce with an extensive cover of reindeer lichens. A variety of ericaceous shrubs are present as well, as are species likewild rose and soap-berry. The soils are Eluviated Dystric Brunisols, acidic in the upper part with a brown B horizonunderlying a greyish surface A horizon. The photo shows tracks worn into the lichen ground cover by migrating caribou,which travelled the beaches more frequently in the past.


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The Kazan River Upland Ecoregion spans the boundarybetween Nunavut and northern Manitoba, and stretchesfrom the Seal River in Manitoba to near the East Arm Hillsin the Northwest Territories. This region is part of thebroad area of tundra and boreal transition extending fromLabrador to Alaska.

ClimateThe ecoregion has a High Subarctic Ecoclimate markedby short, cool summers and long, very cold winters. Themean annual air temperature is approximately -8.0oC. Forthe Manitoba portion of the ecoregion, the averagegrowing season ranges from 95 to 117 days, while thenumber of growing degree-days ranges from about 450 toslightly over 600.

Mean annual precipitation ranges from about 380 to 425mm, with about two-fifths falling as snow. Precipitation ishighest during the growing season, but shows greatvariation from year to year. The average yearly soilmoisture deficit is less than 50 mm.

70. Kazan River Upland Ecoregion

-30.9 -29.1 -23.8 -13.1 -2.7 7.2 13 11.5 3.9 -5.0 -17.3 -25.8 -9.3

10.3 6.4 11.7 15.3 19.6 30.7 51.9 41.7 44.7 33.2 16.4 12.6 294.5

0.0 0.0 0.0 0.1 8.7 97.0 247.7 201.1 39.8 0.9 0.0 0.0 595.3

The ecoregion has a very cold, humid, Subarctic soilclimate. The data most relevant is from the station atEnnadai Lake, which is now closed.

Surficial deposits and landformsIn Manitoba, this ecoregion encompasses a portion of theKazan River Upland which is composed of crystallineArchaean massive rocks forming broad sloping uplandsand lowlands. This section of the upland lies between 350masl along its western boundary near Nueltin Lake and 30masl along its eastern boundary near the coastal lowlandof Hudson Bay. Although hummocky bedrock outcropsare common, most of the region is covered with acidicsandy and sandy loam granitic till in the form of veneersand blankets and drumlins. Slopes range from 5 to 30percent.

Fluvioglacial deposits in the form of prominent eskerswith significant local relief (occasionally as high as 50 m),and outwash aprons are common. Side slopes of eskersmay be as steep as 60 percent. Fields of coarse fragmentsare frequently found as boulder lag material, markingformer shores and drainage ways, and as frost-heavedblock fields.

The Kazan Upland slopes gently eastward and drains toHudson Bay via the Seal and Caribou rivers. A network ofsecondary streams and drainage ways tributary to theprimary rivers , as well as numerous small to medium sizelakes are also characteristic of the region.

Selected Climate Data1 for Ennadai Lake


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SoilsDue to the widespread occurrence of permafrost,Cryosolic soils are dominant in this ecoregion. Most of thepermanently frozen soils developed on sandy loam toloamy sand textured till have profiles exhibitingdiscontinuous and distorted horizons (cryoturbatedhorizons) and are classified as Turbic Cryosols. Patternedground in the form of circles, stripes and nets is usuallyassociated with these soils. Static Cryosols, which arepremanently frozen soils that lack strong cryoturbationfeatures but have premafrost within 100 cm of the surface,are associated with sand, coarse sand and gravellyglaciofluvial and till deposits. Both Static and TurbicCryosols are also associated with poorly drained sites ona wide variety of materials.

On warm and/or very dry sites, where near surfacepermafrost is lacking or where the active layer is verydeep, Dystric Brunisolic soils are present. These sites areusually associated with glaciofluvial deposits such aseskers.

Permafrost is continuous in the peatlands and often occurswithin 20 to 30 cm of the surface. Therefore shallow anddeep Organic Cryosols are the soils associated with thesesites.

VegetationThis is the ecoregion where, in Manitoba, the latitudinallimit of tree growth is reached.

The main vegetative distinction between this ecoregionand the Selwyn Lake Ecoregion to the south and west isthat trees here are significantly more stunted and standsare much more open. Open, very stunted stands of blackspruce and tamarack, with secondary quantities of whitespruce and ground cover of dwarf birch, willow, northernLabrador tea, cotton grass, lichen and moss are dominanton well to imperfectly drained sites. Drier sites may bedominated by open stands of white spruce with a groundcover of low ericaceous shrubs, dwarf birch, mosses andlichens. Stands of white spruce, and paper birch arecommon along rivers. Poorly drained sites usually supporttussock vegetation of sedge, cotton grass and sphagnummoss.

Although forested areas are dominant, when includingthose areas which only support a very sparse cover ofdwarf trees, significant areas support low-shrub tundravegetation. This vegetation may be intermixed withforested tracts or it may occur as extensive areasuninterrupted by trees.

WildlifeCharacteristic wildlife includes the barren-groundcaribou, as this ecoregion forms part of its winter range.Other animals in the region include black bear,occasionally grizzly bear, arctic fox, willow ptarmigan,sandhill crane and waterfowl, including ducks and geese.The rivers and lakes contain fish species such as arcticgrayling, northern pike, and lake trout.

Land useThere are no permanent settlements in this ecoregion.Most land use is associated with wildlife trapping andsubsistence hunting. Some water-oriented recreation andtourism are other activities taking place in this region.

The Seal River has been declared a Canadian HeritageRiver.

There are three ecodistricts within the Kazan RiverUpland Ecoregion within Manitoba.


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The Pakulak Lake Ecodistrict spans the boundarybetween Manitoba and Nunavut. Less than half of thedistrict lies within Manitoba.

ClimateThis ecodistrict lies within the High SubarcticEcoclimatic Region in Manitoba. The climate is markedby short, cool summers and long, very cold winters. Meanannual air temperature is about -8.0oC and the averagegrowing season is 95 days, with about 450 growingdegree-days.

Mean annual precipitation is slightly less than 400 mmand is highest during the growing season. Total amountscan vary greatly from year to year. The ecodistrict has anaverage yearly moisture deficit of less than 25 mm.

The ecodistrict has a very cold, subhumid to humid,Subarctic soil climate.

There are no climate stations in the ecodistrict. Thenearest stations are at Churchill (183. Hubbart PointEcodistrict) and at Ennadai Lake, which is now closed(271. Blevens Lake Ecodistrict).

Physiography and DrainageThe Manitoba portion of the Pakulak Lake Ecodistrictranges in elevation from about 200 masl along its westernmargin near Caribou Lake to about 30 masl along itsboundary with the coastal lowland near Hudson Bay. Theterrain slopes gently at the rate of about 2 m per kmeastward toward Hudson Bay. The ecodistrict lies almostentirely above the Tyrrell Sea marine limit, except forsome small areas along its eastern boundary in Manitoba.

The ecodistrict consists largely of a till plain with weaklynorthwest-southeast oriented low hills overlying gentlyundulating granitic bedrock. The till cover occurs asnearly continuous blankets and veneers of acidic sandy toloamy till. Significant areas of polygonal peat plateaubogs and very shallow fens occupy depressional and flatterrain.

A number of prominent fluvioglacial ridged deposits(eskers) are present but are more common north of theManitoba border. These ridges generally have slopesranging from 15 to 30 percent to about 60 precent on thesteepest side slopes, with relief of about 50 m in somecases.

Moderately long (50-150 m) undulating to hummockyslopes range from about 5 to 15 percent. Rock and boulderfields occur as lag deposits marking former shores anddrainage ways as well as areas where blocks and bouldershave been heaved to the surface due to frost action. Manyof these fields are found in toe slope positions. Permafrostis widespread throughout the ecodistrict, but is not quitecontinuous.

Depth and configuration of lakes vary with depth ofoverburden. Where deposits are thick, the lakes tend to beshallow with fairly regular shorelines. In areas where theoverburden is shallow, lakes tend to be deeper and clearer,and have convoluted bedrock-controlled shorelines. Verysmall to medium lakes are common, and together with thefew large lakes, cover about 50 percent of the ecodistrict.

The Manitoba section of the ecodistrict is drained by theSeal, Little Seal and Caribou rivers and their tributarystreams flowing east towards Hudson Bay.

270. Pakulak Lake Ecodistrict (8681 km2)


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SoilsThe dominant soils are well to imperfectly drained TurbicCryosols with permafrost within 0.4 m to 2.0 m of thesurface.

Permafrost is widespread and in many areas the soiltextures are conducive to the development of patternedground in the form of sorted and non-sorted circles, nets,steps and stripes. Consequently, many soil profiles have abroken and uneven horizon development. In addition,Static Cryosols - soils with little or no cryoturbation, andwith permafrost within 1.0 m of the surface - are alsopresent, but are mostly associated with coarse texturedmaterials.

Significant areas of Eluviated Dystric Brunisols are foundwhere the permafrost is below the control section. Thesesoils have developed largely on coarse to very coarsetextured, well to rapidly drained acidic sandy till, and onfluvioglacial deposits. Areas of poorly drained organicCryosols are more common in the southern part of thearea. These are associated with polygonal peat plateaubogs and shallow basin fens, and comprised mainly ofshallow to moderately deep sphagnum and sedge-brownmoss peat.

The severe climate conditions prevent the use of theecodistrict for forestry and agriculture. In addition, lack ofrooting depth to bedrock, limited water holding andnutrient holding capacity and excessive stoniness providesevere constraints to the use of mineral soils. Poor naturaldrainage and slow heat conductance properties limit theusefulness of organic soils.

VegetationThe vegetation, especially in the eastern part, is a mixtureof stunted forest and low-shrub tundra.

Trees in this ecodistrict are more stunted and stands aremuch more open than in areas to the south and west. Open,very stunted stands of black spruce and tamarack, withsecondary quantities of white spruce and a ground coverof dwarf birch, willow, northern Labrador tea, cottongrass, lichen and moss are dominant on well toimperfectly drained sites. Drier sites may be dominated byopen stands of white spruce with a ground cover of lowericaceous shrubs, dwarf birch, mosses and lichens.Poorly drained sites usually support tussock vegetation ofsedge, cotton grass and sphagnum moss.

WaterThe principal sources of water are the many lakes andponds, and the Caribou, Little Seal and Seal rivers andtheir tributary streams that flow through the area.

Land UseThere are no settlements in this ecodistrict. Fishing,water-oriented recreation, wildlife trapping and huntingare the dominant uses of land in this area.

Pakulak Lake Ecodistrict


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The Blevens Lake Ecodistrict spans the boundarybetween Manitoba and Nunavut. Less than one-third ofthe district lies within Manitoba.

ClimateThis ecodistrict has a High Subarctic Ecoclimate, whichin Manitoba is marked by short, cool summers and long,very cold winters. Mean annual air temperature is about -8.0 oC, the average growing season is 117 days, with about600 growing degree-days.

Mean annual precipitation is about 425 mm, of whichabout two-fifths fall as snow. Precipitation varies greatlyfrom year to year, and is highest during the growingseason. The average yearly moisture deficit is about 30mm. The ecodistrict has a very cold, subhumid to humid,Subarctic, soil climate. The nearest climate station isEnnadai Lake which has been closed for many years.However, the data is still valid for this ecodistrict.

271. Blevens Lake Ecodistrict (2998 km2)

-9.3 10.6 6.6 13.0 -30.9

294.5 124.3 188.6 51.9 10.3

173.7/117.1 121.0/3.1 165.7/20.7 51.9/0.0 0.0/9.6

595 545 594 248 0

Physiography and DrainageIn Manitoba, the Blevens Lake Ecodistrict ranges inelevation from 350 masl at Nueltin Lake on the west toabout 300 masl along its boundary with the NejaniliniEcodistrict to the east. The ecodistrict has no distinct tilt,but slopes very gently eastward at the rate of less than 1 mper km toward Hudson Bay. Discontinuous veneers,blankets and drumlins of acidic sandy to loamy tillinterspersed with hummocky bedrock outcrops arecharacteristic.

Moderately long (50 to 150 m), gently undulating to morestrongly hummocky slopes range from about 2 to 15percent slope. Significant areas of shallow fens andpolygonal peat plateau bogs occur throughout. Someprominent eskers with steep side slopes and, in some

cases, relief over 50 m, also occur throughout theecodistrict. Rock and boulder fields occur throughout andconsist of former strandlines, drainage ways and frost-heaved boulder and block fields. Permafrost is verywidespread but discontinuous.

Drainage in the Manitoba part of the ecodistrict is viasmall rivers and streams which connect the numerouslakes. In the western half , these drain north toward theThlewiaza River (Thlewiaza River upper drainagedivision), and in the eastern half, into the Seal River (SealRiver drainage division). Both the Thlewiaza and Sealrivers drain into Hudson Bay. The many lakes, ranging insize from small to large, comprise approximately 50 to 60percent of the surface area of the ecodistrict.



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SoilsPermafrost is widespread and generally near the surfaceexcept on warm, dry, coarse textured sites. Mineral soilswith broken and uneven horizon development are theresult of cryoturbation and the soils are classified asTurbic Cryosols. They are usually associated withpatterned ground features such as non-sorted circles, nets,stripes and steps, and have developed on well toimperfectly drained, loamy, sandy loam and loamy sandtextured till. Static Cryosols, which are premanentlyfrozen soils but lack strong cryoturbation features, arepresent on sandy and gravelly till and glaciofluvialdeposits. These areas may have patterned ground in theform of polygons, although ice wedges appear to belacking in most areas.

In poorly drained areas that occur throughout theecodistrict, Organic Cryosols are associated with shallowto moderately deep fibric and mesic peat in the form ofpolygonal peat plateaus and shallow basin fens. In wetareas that lack significant peat accumulations, poorlydrained Gleysolic Static and Turbic Cryosols havedeveloped.

Due to the severity of the climate, forestry and agricultureare not possible in this district. Lack of rooting depth topermafrost or bedrock, limited capacity to hold water andnutrients and excessive stoniness are additional severeconstraints to plant growth and possible use of mineralsoils. Poor natural drainage and slow heat conductanceproperties are specific limitations associated with organicsoils.

VegetationThe vegetation is generally similar to that described forthe Kazan River Upland Ecoregion. Open, very stuntedstands of black spruce and tamarack, which include thoseareas that only support a very sparse cover of dwarf trees,and an associated ground cover of dwarf birch, willow,northern Labrador tea, cotton grass, lichens and mossesare widespread on well to imperfectly drained sites. Areasof low-shrub tundra vegetation occur intermixed withforested tracts or as extensive areas uninterrupted bytrees. The latter areas are especially widespread in thenorthern part of the ecodistrict.

Drier sites may be dominated by open stands of whitespruce with a ground cover of low ericaceous shrubs,dwarf birch, mosses and lichens. Poorly drained sitesusually support tussock vegetation of sedge, cotton grassand sphagnum moss. Stands of white spruce and paperbirch are common along rivers.

WaterThe principal sources of water are the many lakes andponds, and the tributary stream of the Thlewiaza Riverthat flows through the ecodistrict.

Land useThe ecodistrict has no permanent settlements. Land use isdominantly subsistence fishing, hunting and trapping bypeople from surrounding areas. Recreational fishing andhunting is catered to by lodges within and outside theecodistrict. Recreational river travel is on the rise and isthe most common form of tourism.

Blevens Lake Ecodistrict


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The Nejanilini Lake Ecodistrict spans the border betweenManitoba and Nunavut. Approximately four-fifths of theecodistrict lies within Manitoba.

ClimateThe climate of the Nejanilini Lake Ecodistrict is classifiedas High Subarctic Ecoclimate, which is marked by short,cool summers and long, very cold winters. Mean annualair temperature is about -7.0 oC, the average growingseason is 104 days, and the number of growing degree-days is about 520.

Mean annual precipitation is about 425 mm, of whichmore than one-third falls as snow. Precipitation variesgreatly from year to year and is highest during the growingseason. The average yearly moisture deficit is less than 25mm. The ecodistrict has a very cold, subhumid to humid,Subarctic soil climate.

No climate stations are located in the ecodistrict. Howeverdata from the station at Ennadai Lake (271. Blevens LakeEcodistrict), which is now closed, and data from thestation at Churchill Airport (183. Hubbart PointEcodistrict) are relevant.

Physiography and DrainageElevations in the Manitoba portion of the Nejanilini LakeEcodistrict range from 315 masl along its western marginnear Nejanilini and Baralzon lakes to about 150 masl as itapproaches adjacent Pakulak Ecodistrict to the east. Theterrain slopes gently eastward toward Hudson Bay at therate of about 2 m per km.

Ridged (drumlinized) to hummocky bedrock covered withnearly continuous veneers and blankets of acidic sandy toloamy till are characteristic. Moderately long (50-150 m),undulating to hummocky slopes range from about 5 to 15percent. Significant areas of shallow fens and polygonalpeat plateau bogs occur throughout the ecodistrict. Anumber of prominent fluvioglacial ridges with side slopesof 60 percent and relief of more than 50 m also occurthroughout. Rock and boulder fields occur at the toe ofhummocky ridges, in former drainage ways, and in areaswhere blocks and boulders have been frost-heaved to thesurface. Permafrost is widespread but discontinuous.

The ecodistrict slopes gently and drains generallyeastward to Hudson Bay via the Seal, Caribou andThlewiaza rivers and their networks of tributary streamsand drainage ways. These connect the many small andmedium lakes, and fewer numbers of large and very largelakes. Surface water comprises approximately 35 to 40percent of this ecodistrict.

SoilsPermafrost is widespread in the ecodistrict and many soilprofiles exhibit broken and uneven horizon development.Therefore the dominant soils are well to imperfectlydrained Turbic Cryosols. These soils are commonlyassociated with patterned ground in the form of non-sorted circles, nets, steps and stripes. Where cryoturbationis lacking or is only weakly expressed in the soil profile,the soils are classed as Static Cryosols. Both soil types areassociated with loamy to sandy acidic till although theStatic Cryosols tend to be coarser. Static Cryosols are alsofrequently associated with sandy fluvio-glacial depositswhen the depth to permafrost is shallow.

272. Nejanilini Lake Ecodistrict (16 714 km2)


41


Dystric Brunisol soils are found on sites where materialsare coarse, well drained, lack permafrost or have activelayers extending beyond the control section depthestablished for the Cryosols. Organic Cryosols areassociated with polygonal peat plateaus and shallow basinfens. Wetlands lacking significant peat development havepoorly drained Static and Turbic Cryosols, depending onthe amount of cryoturbation present in the underlyingmineral materials.

Climatic conditions are too severe for forestry oragriculture. Lack of rooting depth to permafrost orbedrock, limited capacity to hold water and nutrients andexcessive stoniness are other constrains to the use of thesemineral soils. Natural drainage and slow heat conductanceproperties are specific limitations to the usefulness oforganic soils.

VegetationThe vegetation generally follows the trends discussed inthe Kazan River Upland Ecoregion section. In theManitoba portion of the ecodistrict, vegetation consistslargely of very open and stunted forest stands, low-shrubtundra vegetation, and sedge and moss covered wetlands.The trees are more stunted and stands are more open thanin areas to the south and west. Open, very stunted stands ofblack spruce and tamarack, with secondary quantities ofwhite spruce and ground cover of dwarf birch, willow,northern Labrador tea, cotton grass, lichen and moss aredominant on well to imperfectly drained sites.

Nejanilini Lake Ecodistrict

Drier sites may be dominated by open stands of whitespruce with a ground cover of low ericaceous shrubs,dwarf birch, mosses and lichens. Poorly drained sitesusually support tussock vegetation of sedge, cotton grassand sphagnum moss. Low-shrub tundra becomesincreasingly more common with increasing latitude.

WaterThe principal sources of water are the many lakes andponds, and the Seal and Caribou rivers and their numeroustributary streams that flow through the area.

Land useThere are no settlements in the ecodistrict. Fishing, water-oriented recreation, wildlife trapping and hunting are thedominant land uses.

42

Taiga Shield EcozoneSelwyn Lake Upland Ecoregion


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The Selwyn Lake Upland Ecoregion is located in thenorthwest corner of Manitoba and spans the boundarieswith Saskatchewan, Nunavut and the NorthwestTerritories. It is part of a broad area of coniferous foresttransition lying between the sparsely forested region tothe north and the closed Boreal forest to the south. Thisecoregion extends from east of the Churchill River inManitoba to the East Arm Hills east of Great Slave Lake.

ClimateThis ecoregion has a Low Subarctic Ecoclimate, which ismarked by short, cool summers and long, very coldwinters. Mean annual air temperatures range from about -5.0oC to -3.4oC. The average growing season varies fromabout 124 to 137 days, and the number of growing degree-days ranges from about 750 to 950.

Mean annual precipitation varies from about 430 mm tomore than 500 mm and fluctuates greatly from year toyear. Precipitation is highest during the growing season.The ecoregion has average yearly moisture deficitsranging from less than 40 mm to slightly less than 70 mm.The ecoregion has a very cold, subhumid to humid,Cryoboreal, soil climate.

71. Selwyn Lake Upland Ecoregion

-30.9 -29.1 -23.8 -13.1 -2.7 7.2 13.0 11.5 3.9 -5.0 -17.3 -25.8 -9.3

10.3 6.4 11.7 15.3 19.6 30.7 51.9 41.7 44.7 33.2 16.4 12.6 294.5

0.0 0.0 0.0 0.1 8.7 97.0 247.7 201.1 39.8 0.9 0.0 0.0 595.3

-28.5 -24.0 17.1 -5.3 3.6 11.4 15.6 14.0 6.9 -0.3 -13.0 -22.6 -4.9

19.2 13.9 18.3 18.3 32.4 55.1 66.4 52.1 59.2 38.2 29.9 24.1 427.1

0.0 0.0 0.0 4.7 43.5 196.2 331.7 280.1 86.4 9.8 0.0 0.0 952.4

Climate stations are few in the ecoregion. The climatestations at Ennadai Lake along the northern border of theecoregion and Brochet Airport located on its southernborder, are the most relevant to the Manitoba portion ofthe ecoregion.



Selected Climate Data1 for Brochet Airport

1 Canadian Climate Normals, 1961-1990. Atmospheric Environment Service, Environment Canada.2 Canadian Climate Normals, 1951-1980. Atmospheric Environment Service, Environment Canada.


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Surficial Deposits and LandformsWithin Manitoba, this ecoregion is part of the Kazan Up-land with its underlying bedrock of crystalline Archeanmassive rocks that form broad sloping uplands and low-lands. The elevation of this upland lies between 510 maslalong the Saskatchewan - Manitoba border and 120 maslalong its border with the Hudson Bay Lowland and theCoastal Hudson Bay Lowland ecoregions.

Surficial deposits vary across the Manitoba part of theecoregion. In the western section, ridged to hummockybedrock outcrops covered with discontinuous veneers andblankets of acidic, bouldery, sandy granitic till aredominant. The southeastern section has significant areasof calcareous loamy till. This till is generally thick enoughto mask most of the underlying bedrock, but is itself oftenoverlain by peat deposits and lacustrine sediments.Significant clayey lacustrine veneers and blankets occurat lower elevations around lakes as well. Prominentfluvio-glacial ridges, some with maximum relief of 50 mor more and steep side slopes, are found throughout theecoregion.

Bog-fen sequences are the dominant wetlands, and arevery prevalent in the southeastern section where theycover between 25 and 50 percent of the terrain.

The upland tilts gently and drains northeastward toHudson Bay via the Churchill and Seal rivers and theirnetwork of secondary streams and drainage ways.Numerous small, medium and large lakes are common anddrain directly, or through stream and creeks, into themajor drainage ways. Small to medium lakes are verynumerous in the northwest part of the Manitoba section.

Permafrost is widespread and discontinuous. Most of thepermafrost is associated with peat plateau bogs, areas withimpeded drainage, and fine textured soils. Ice content inmineral soils is generally low to medium. Ice wedgesoccur sporadically throughout the region. Permafrostbecomes much less widespread towards the southernboundary of the ecoregion, especially in the mineraldeposits.

SoilsDystric Brunisols, and to lesser extent Static Cryosols,associated with upland sandy morainal deposits aredominant in the western section of the region. In theeastern section, Organic Cryosols, typical of peatlands,are more widespread. Significant soil inclusions are GrayLuvisols on calcareous silty to clayey sediments nearSouthern Indian Lake and elsewhere, Eutric Brunisols oncalcareous till and Turbic Cryosolic soils on loamy to claytextured materials distributed throughout the ecoregion.The Turbic Cryosols have profiles exhibiting uneven andoften discontinuous or distorted soil horizon developmentas a result of past and present cryoturbation.

Periglacial features such as active and relic sorted andnon-sorted circles on coarse loamy to sandy till material,and earth hummocks (a form of non-sorted circle) onclayey sediments occur throughout the ecoregion.

Climatic conditions are too severe for forestry oragriculture. Lack of rooting depth to permafrost orbedrock, limited water and nutrient holding capacity andexcessive stoniness adds additional contraints to the useof mineral soils. Natural drainage and slow heatconductance properties are specific limitations to theusefulness of organic soils.

VegetationIn this ecoregion, the typical closed coniferous borealforest gives way to open stands of low black spruce withunderstories of dwarf birch, Labrador tea, lichens, andmosses. This change in forest cover is one of the maindifferences between this ecoregion and the ChurchillRiver Upland and Hayes River Upland ecoregionsbordering to the south. Although black spruce is theclimax species in the ecoregion, drier sites can bedominated by open stands of white spruce and paper birch,with a discontinuous understorey of ericaceous shrubslike bearberry and rock cranberry. White spruce, birch andaspen also occur on warmer protected sites.

Bog vegetation is dominated by sphagnum mosses,ericaceous shrubs and black spruce, whereas fens have avegetation of sedges and brown mosses, with a minorshrub component.

44


WildlifeCharacteristic wildlife includes barren-ground caribou,for which the region provides important winter range.Other wildlife characteristic of the region are black bear,arctic fox, snowshoe hare, spruce grouse, osprey,waterfowl including ducks, geese and swans.

Land useThe ecoregion is only sparsely populated. The Northlandsand Barrenland First Nations, Sayisi Dene First Nation(Tadoule Lake) and Lac Brochet are the only settlementsin the Manitoba part of the ecoregion. Economic activityis very limited. Trapping, hunting, water-orientedrecreation and tourism are the dominant land uses.

The Seal River has been declared a Canadian HeritageRiver.

There are six ecodistricts within the Selwyn Lake UplandEcoregion in Manitoba.

45


Landscapes of the Selwyn Lake Upland EcoregionThe northern part of the Selwyn Lake Upland Ecoregion in Manitoba is a patchwork of open tundraand small stands of stunted black and white spruce. Large complexes of sandy and gravelly eskersare common in this area.

46


The Nueltin Lake Ecodistrict spans the borders withSaskatchewan, Nunavut and the Northwest Territories.About two-fifths of the ecodistrict lies within Manitoba,extending from the northwestern corner of Manitoba, atthe conjunction of the Saskatchewan, Nunavut andNorthwest Territories borders, eastward to Nueltin Lake.

ClimateIn Manitoba, the Nueltin Lake Ecodistrict has a LowSubarctic ecoclimate, which is marked by short, coolsummers and long, very cold winters. Mean annual airtemperature is approximately -4.2 oC, average growingseason is 130 days, and the number of growing degree-days is about 880.

Mean annual precipitation is around 435 mm, with abouttwo-fifths falling as snow. Precipitation fluctuates greatlyfrom year to year. While precipitation is highest duringthe growing season, the average yearly moisture deficit isabout 60 mm. The ecodistrict has a very cold, subhumid tohumid Cryoboreal soil climate.

There are no climate stations in the ecodistrict. The datafrom the station at Ennadai Lake (271. Blevens LakeEcodistrict) has relevancy to the ecodistrict.

Physiography and DrainageElevations range from about 480 masl along theSaskatchewan boundary to about 305 masl near NueltinLake on the east. The area slopes gently northeastward atthe rate of about 1 m per km.

Ridged to hummocky bedrock outcrops covered withdiscontinuous veneers and blankets of acidic sandy toloamy till are characteristic. Moderately long (50-150 m),undulating to hummocky slopes range from about 5 to 15percent slope. Significant areas of shallow and deeporganic deposits occur throughout the ecodistrict on levelto depressional terrain.

Numerous prominent fluvioglacial ridges also occurthroughout the ecodistrict. Slopes range mostly from 15 to30 percent, but some prominent ridges have side slopes ofup to 60 percent, and relief of 50 m in some cases. Rockand boulder fields occur at the toe of hummocky ridges,and in areas of past or present frost-heaving. Permafrost iswidespread and discontinuous throughout the ecodistrict.

The upland slopes gently and most of the ecodistrictdrains northeastward to Hudson Bay via the ThlewiazaRiver drainage system. The most southwestern part of theecodistrict drains southward through the Cochrane Riverdrainage system into the Churchill River drainage system.Some of the most easterly parts are drained by the NorthSeal River, while northern portions are part of the KazanRiver drainage division or the Thlewiaza River upperdrainage division. Small, medium, large and very largelakes, which include Nueltin, Snyder, Kasmere, Tice andPutahow lakes, occupy 40 to 50 percent of the surfacearea.

276. Nueltin Lake Ecodistrict (14 565 km2)

47


SoilsThe dominant soils are well to imperfectly drainedDystric Brunisols, and Static and Turbic Cryosols onsandy to loamy till. Dystric Brunisols dominate on sandyfluvio-glacial deposits. The distribution of Cryosols isgreatly influenced by the thickness of the turf or peatlayer. Soil profiles that exhibit broken and uneven horizondevelopment are associated with relic and active non-sorted circles, which are generally found on mediumtextured materials.

Organic Cryosols occur throughout the ecodistrict onpolygonal peat plateau bogs and are comprised mainly ofsphagnum and sedge peat. Local areas of granitic bedrockalso occur.

Climatic conditions are too severe for forestry oragriculture. Lack of rooting depth to permafrost orbedrock, limited capacity to hold water and nutrients andexcessive stoniness are additional constraints to the use ofmineral soils. Poor natural drainage and slow heatconductance properties limit the usefulness of organicsoils.

VegetationThe vegetation in this ecodistrict is varied because itextends more than 300 km from south to north - fromabout 58o N latitude in the south to 61o N at its northernborder. Vegetation composition, and especially standclosure, changes significantly from south to north for thisecodistrict as a whole. Although the changes are not asgreat in the Manitoba portion of the ecodistrict, foreststands are more closed and taller in its southern sectionthan along the boundary with the Northwest Territories.

The typical closed coniferous boreal forest to the south ofthis ecodistrict gives way to open stands of low blackspruce, with understories of dwarf birch, Labrador tea,lichens, and mosses. Although black spruce is the climaxspecies in the ecodistrict, drier sites can be dominated byopen stands of white spruce and paper birch, with adiscontinuous understorey of ericaceous shrubs such asbearberry and rock cranberry. White spruce, birch, andaspen also occur on warmer protected sites.

Bog vegetation is dominated by sphagnum mosses,ericaceous shrubs and black spruce, whereas fens havesedges and brown mosses, with a minor component ofshrubs.

WaterSources of water include the many lakes, and theCochrane and North Seal rivers and their tributary streamsthat flow through the ecodistrict.

Land useThere are no settlements in the ecodistrict. Fishing, water-oriented recreation, trapping and hunting are the dominantland uses and some employment is provided by the fewlodges.

Nueltin Lake Ecodistrict

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The Seal River Ecodistrict is located east and south of theNueltin Lake Ecodistrict and is wholly within Manitobaexcept for a small area in the southwest corner that lies inSaskatchewan.

ClimateThis ecodistrict has a Low Subarctic Ecoclimate markedby short, cool summers and long, very cold winters. Meanannual air temperature is approximately -3.4oC, averagegrowing season is around 132 days, with about 900growing degree-days.

Mean annual precipitation is around 460 mm and variesgreatly from year to year. More than one-third of theprecipitation falls as snow. Precipitation is highest duringthe growing season and the average yearly moisturedeficit is about 70 mm. The ecodistrict has a very cold,subhumid to humid, Cryoboreal soil climate.

Brochet Airport on the shore of Reindeer Lake, whichborders the ecodistrict in the southwest corner, is the onlyclimate station in the ecodistrict.

279. Seal River Ecodistrict (30 525 km2)

-4.9 13.7 10.3 15.6 -28.5 427.1 173.6 265.2 66.4 19.2

261.8/167.5 170.0/1.7 245.2/16.5 66.4/0.0 0.0T/20.3

952.0 808.0 938.0 332.0 0.0

Physiography and DrainageThe ecodistrict ranges in elevation from 450 masl alongthe Saskatchewan boundary to about 250 masl at itseastern margin near Shethanei Lake. The terrain slopesgently in a generally easterly direction at the rate of about1 to 2 m per km toward the Hudson Bay Lowland.

Ridged to hummocky bedrock outcrops covered withdiscontinuous veneers and blankets, and hummocks ofacidic sandy to loamy till are characteristic of the area.Moderately long (50-150 m), undulating to hummockyslopes range from about 5 to 15 percent. Significant areas

of shallow and deep organic deposits occur indepressions. Long, sinuous eskers are common in thedistrict, some of which may extend for 50 km and attainelevations of 50 m or more in some sections, with side-slopes of 60 percent. These fluvioglacial ridges and theirassociated aprons are some of the most prominentlandscape elements in the ecodistrict.

Rock and boulder fields occur at the toe of hummockyridges, at the location of former drainage ways, and wherefrost heaving has moved large quantities of boulders,

Selected Climate Data1 for Brochet Airport


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blocks and rock fragments onto the surface. Permafrost iswidespread and discontinuous and usually associatedwith areas of shallow peat (<40 cm thick), veneer bogs ongently sloping sites, and polygonal peat plateau bogs indepressional areas.

The central part of the ecodistrict drains eastward via theNorth Seal River into the Seal River, while the easternportion is drained by the Seal River directly. Thesoutheastern part of the district is part of the CochraneRiver drainage division, which is part of the ChurchillRiver drainage system. All these waters drain eventuallyinto Hudson Bay. Numerous lakes of a variety of sizes aredistributed throughout the ecodistrict.

SoilsThe dominant soils are well to imperfectly drainedDystric Brunisols, and Static and Turbic Cryosols,developed on coarse loamy to sandy acidic till. Sandyfluvioglacial deposits have generally Dystric Brunisols,except where the presence of a significant organic surfacelayer has provided sufficient insulation to allowpermafrost development. Soil profiles exhibiting brokenand uneven horizon development are associated with relicand active non-sorted circles on loam to sandy loamtextured deposits. Fine textured sediments such as clayand clay loam often have patterned ground in the form ofearth hummocks (a particular type of non-sorted circle).However, in many localities the earth hummocks are relicfeatures as they lack permafrost at the present.

Poorly drained areas generally have Cryosolic soils,especially if there is some peat accumulation. Where peatdeposits exceed 40 cm in depth, Organic Cryosols are thecommon soils and are associated with peat plateau andpolygonal peat plateau bogs. These peat soils havedeveloped mainly from mixed moss and sedge peat,sphagnum moss peat and, in the southern sector, woodymoss (forest) peat. Veneer bogs occur more commonly inthe southern part of the district. Areas of granitic bedrockoutcrop occur throughout the area, and are locallywidespread.

In addition to severe climatic constraints which preventthe use of the ecodistrict for forestry or agriculture, thelack of rooting depth to permafrost or bedrock, limitedwater and nutrient holding capacity and excessivestoniness would also severely limit the use of mineral soilsfor forestry or agriculture. Stands of marginallymerchantable timber are found only on some favourablesites. Poor natural drainage and slow heat conductanceproperties are additional severe limitations to the use oforganic soils.

VegetationThe vegetation is very much similar to that described forthe Nueltin Lake Ecodistrict. Tree cover is very patchyand stunted in the northern part of the ecodistrict.Polygonal peat plateaus with primarily moss, lichen andericaceous shrub vegetation are common in the north aswell.

WaterThe ecodistrict has abundant sources of water. Theprincipal sources are the numerous small to medium lakes,and the North Seal and the Seal rivers.

Land useThe Northlands and Barren Lands First Nations, SayisiDene First Nation (Tadoule Lake) and Lac Brochet are theonly communities in the ecodistrict. Fishing, trapping andhunting are the dominant land uses. Activities associatedwith water-oriented recreation, such as the operation oflodges and eco-tourism are slowly increasing.

Seal River Ecodistrict

50


The Sprott Lake Ecodistrict occupies the central part ofthe Manitoba section of the Selwyn Lake Ecoregion, andis completely contained within Manitoba.

ClimateThis ecodistrict has a Low Subarctic Ecoclimate markedby short, cool summers and long, very cold winters. Meanannual air temperature is approximately -3.5oC, theaverage growing season is 136 days and the number ofgrowing degree-days is around 940.

Mean annual precipitation, of which more than one-thirdfalls as snow, is about 500 mm and fluctuates greatly fromyear to year. Precipitation is highest during the growingseason and the average yearly moisture deficit is about 60mm. The ecodistrict has a very cold, subhumid to humid,Cryoboreal, soil climate.

No climate station is located in the ecodistrict. The nearestclimate station is Brochet Airport to the west (276.Nueltin Lake Ecodistrict).

Physiography and DrainageThe Sprott Lake Ecodistrict is part of the Kazan Upland. Itslopes gently eastward from 400 masl in the west to 275masl near North Knife Lake in the east. It is characterizedby ridged to hummocky bedrock outcrops covered withdiscontinuous veneers and blankets of acidic sandy toloamy till. Moderately long (50 to 150 m), undulating tohummocky slopes range from about 5 to 15 percent slope.Prominent fluvioglacial ridges (with about 50 m relief insome cases) occur throughout.

Shallow peat in the form of veneer bogs is widespread ongentle slopes, while deeper organic deposits in the form ofbasin fens and peat plateau bogs are present indepressions. Permafrost is widespread, discontinuous andusually associated with imperfectly and poorly drained,fine textured sediments, and veneer and peat plateau bogs.

The upland slopes gently at the rate of about 1 to 2 m perkm and drains northeastward to Hudson Bay via the NorthSeal, South Seal and Knife rivers and their network oftributary streams and drainage ways. Numerous verysmall to large lakes are distributed throughout theecodistrict.

SoilsThe dominant soils are Organic Cryosols associated withpeat plateau bogs and veneer bogs. These peatlands arecharacterized by widespread permafrost. Peat materialsconsist of mixed mosses, sedge and woody forest peat.The soils of shallow and deep fens are generally OrganicMesisol soils, as these peatlands are largely withoutpermafrost.

Significant areas of mineral soils are dominantly well toimperfectly drained Dystric Brunisols on sandy to coarseloamy, acidic till. Associated soils are imperfectly topoorly drained Static and Turbic Cryosols on till depositsand on localized areas of fine textured glaciolacustrinesediments. Evidence of the past and present effect ofpermafrost on soil development is found in soil profileswith uneven and broken horizon development, and in thepresence of non-sorted circles on till and earth hummockson glaciolacustrine sediments. Areas of granitic bedrockoccur locally.

280. Sprott Lake Ecodistrict (14 443 km2)

51


The ecodistrict is not suitable for agriculture or forestrydue to severe climatic constraints. In addition, poornatural drainage and slow heat conductance propertieslimit the usefulness of organic soils. Lack of rooting depthto permafrost or bedrock, excessive stoniness and limitedwater and nutrient holding capacity are additional severeconstraints to the use of mineral soils.

VegetationThe vegetation is typical of the southern part of theSubarctic and is dominated by open, stunted black sprucestands with a ground cover of mosses, lichens andericaceous shrubs on well to imperfectly drained sites andby peatlands. Peatland vegetation consists of blackspruce, ericaceous shrubs and mosses on peat plateaubogs, and sedge, brown mosses and tamarack on fens.

In the most southerly parts of the ecodistrict, closed standsof marginally merchantable timber may be found onfavourable sites.

WaterSuitable sources of water are plentiful with the principalsources being the numerous lakes, and the South Seal,North Seal and Knife rivers and their tributary streamsthat flow through the area.

Land UseThe ecodistrict has no permanent settlements. Fishing,trapping and hunting are the dominant land uses.

Sprott Lake Ecodistrict

52


The Embleton Lake Ecodistrict occupies the southeasternpart of the Selwyn Lake Upland Ecoregion. Theecodistrict is totally contained within Manitoba.

ClimateThis ecodistrict has a Low Subarctic Ecoclimate, which ismarked by short, cool summers and long very coldwinters. Mean annual air temperature is approximately -4.9oC, the average growing season is 124 days, with about770 growing degree-days.

Mean annual precipitation, of which about two-fifths fallsas snow, is about 480 mm and varies greatly from year toyear. Although precipitation is highest during the growingseason, the average yearly moisture deficit is around 40mm. The ecodistrict has a very cold, subhumid to humid,Cryoboreal soil climate.

There are no climate stations located in the ecodistrict.The nearest climate station is at Gillam Airport (360.Knee Lake Ecodistrict) located south of the ecodistrict.

Physiography and DrainageThe Embleton Lake Ecodistrict lies between 305 maslalong its western boundary near Northern Indian Lake and120 masl along its eastern boundary. The terrain slopesgently eastward at the rate of about 1.2 m per km towardthe boundary with the Coastal Hudson Bay Lowland andthe Hudson Bay Lowland ecoregions. The uplandgenerally drains northeast and east toward Hudson Bay.For some distance, the ecodistrict boundary consists of amajor relic beach marking the extent of the Tyrrell Sea.

Most of the ecodistrict is underlain by Precambriangranitic bedrock, but the most easternly section isunderlain by Ordovician limestone. None of the limestonebedrock is exposed, and only limited Precambrianbedrock areas are exposed.

Morainal drift, glaciolacustrine blankets and veneers, andorganic deposition mask the underlying bedrock. The tillmaterial in the eastern sector is calcareous, loamy andoften drumlinized. The till is in part covered by veneersand blankets of clayey, calcareous, glacio-lacustrinesediments, which are especially prevalent in low lying

areas. In turn, these sediments are often masked byextensive peatland development. Therefore, large areasof mineral deposits are covered by shallow to deep peat inthe form of veneer bogs, peat plateau bogs and fens. Thesewetlands cover more than 50 percent of the land area in theeastern and southern sectors of the ecodistrict. Shalloworganic veneer with discontinuous permafrost is commonon gentle slopes, while horizontal fens, and permanentlyfrozen peat plateau and palsa bogs occupy depressionalareas.

To the northwest, peatlands are less extensive, but are stilla prominent landscape element. The till materials in thatpart of the ecodistrict are medium to coarse textured,acidic, and usually contain large quantities of coarsefragments. Moderately long (50-150 m), undulating tohummocky slopes range from about 5 to 15 percent slope.Prominent fluvioglacial ridges and hummocks (esker-kame complexes and interlobate moraines with relief ofover 60 m in some cases) mark its western and southernboundaries. Raised marine beaches mark the eastern limitadjacent to the Hudson Bay Lowland.

Permafrost is widespread but discontinuous and isassociated mostly with peat plateau and veneer bogs,although fine textured soils contain locally low to mediumice-content permafrost. Although active layer depths are

281. Embleton Lake Ecodistrict (25 235 km2)

53


strongly affected by organic surface layer depth and soiltexture, depth to permafrost on mineral soils is usuallybetween 60 to 100 cm.

The ecodistrict is part of a number of drainage systems.The most northerly part drains via the Knife River and itstributaries, while the cental part drains via the ChurchillRiver and its tributary streams and rivers. The east-centralpart is drained by the Owl River system, while the mostsoutherly part of the district drains via the LimestoneRiver system into the Nelson River. There are somemedium to large lakes and many small lakes which aremost numerous in the western and central part of thedistrict.

SoilsThe dominant soils are Organic Cryosols developed onveneer and peat plateau bogs and Organic Mesisols andFibrisols developed on fens. The bogs have widespreadpermafrost and consist of weakly decomposed, shallowsphagnum peat overlying moderately decomposed(mesic) forest or sedge peat.

Significant areas of mineral soils consisting of well toimperfectly drained Eutric Brunisols on loamy calcareoustill occur on exposed sandy marine ridges along theeastern margin of the district. Dystric Brunisols havedeveloped on the sandy and coarse loamy acidic tilldeposits in the western sector. Gray Luvisols are typical inthe silty and clayey glaciolacustrine sediments. Locallythese soils exhibit uneven horizon development and haverelic non-sorted circles and earth hummocks on thesurface, which is evidence of past, more extensive,permafrost conditions. Although recently developedpermafrost areas do occur locally in mineral soils,cryoturbation is minimal and the soils are typically StaticCryosols.

Severe climate constraints, poor natural drainage andslow heat conductance properties limit the use of organicsoils for agriculture and forestry. Most of the ecodistrict’smineral soils have additional limitations due to lack ofrooting depth to permafrost, low soil temperatures, orcompact basal till, stoniness and coarse textures. Howeversome areas could support limited forestry, althoughgrowth rates are low, and rotations are long.

VegetationThe vegetation of the ecodistrict generally reflects itsnorthern location. In the northern sector, stands aregenerally open and dominated by black spruce, mosses,lichens and ericaceous shrubs. The peatlands, widespreadin the eastern sector, have black spruce, sphagnum andother mosses, lichens and ericaceous vegetation, whilefens have sedges, brown mosses and a varying componentof tamarack and shrubs.

In the southern sector, stands are more closed and taller,with more trembling aspen and white spruce onfavourable sites. In this sector, the presence ofmerchantable timber increases significantly, but it is stillconfined to the best sites.

WaterGood sources of water are fairly plentiful and arecomprised of the lakes and rivers in the central andwestern sectors and the rivers in the peatland dominatedeastern sector.

Land useThere are no permanent settlements in the ecodistrict.Most of the land-based activities are associated withtrapping and hunting. Subsistence and recreationalfishing are also important. Economic activity is alsoassociated with the railroad from Thompson to Churchill,which traverses part of the eastern sector. The railroad anda few winter roads provide the only land access to theecodistrict.

Embleton Lake Ecodistrict

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The Big Sand Lake Ecodistrict is located in the southernpart of the Selwyn Lake Upland Ecoregion, and liesentirely within Manitoba.

ClimateThis ecodistrict has a Low Subarctic Ecoclimate, which ismarked by short, cool summers and long, very coldwinters. The mean annual air temperature is approximately-3.5 oC, the average growing season is 135 days, withabout 950 growing degree-days.

Mean annual precipitation, of which more than one-thirdfalls as snow, is around 500 mm and varies greatly fromyear to year. Although precipitation is highest during thegrowing season, the average yearly moisture deficit isabout 50 mm. The ecodistrict has a very cold, subhumid tohumid Cryoboreal soil climate.

There are no climate stations in the ecodistrict. Thenearest relevant station is at Brochet Airport (279. SealRiver Ecodistrict).

Physiography and DrainageThe Big Sand Lake Ecodistrict is underlain byPrecambrian granitic bedrock, and ranges in elevationfrom slightly over 400 masl near its western boundary toabout 300 masl at its eastern margin.

The ridged to hummocky bedrock is largely covered withveneers and blankets of acidic sandy to coarse loamy till,but exposed bedrock is common, especially along lakeshores.

Moderately long (50 to 150 m) undulating to hummockyslopes range from about 5 to 15 percent slope. Prominent,sinuous fluvioglacial ridges (eskers) occur throughout.Several of these eskers are many kilometres long, withrelief of about 30 m in some cases, and side-slopes as steepas 60 percent.

Significant areas of clayey glaciolacustrine veneers andblankets occur at lower elevations in the southern sectionof the ecodistrict. However, wetlands are extensive andpeatlands cover the mineral deposits in many lowlandareas. Shallow to deep peatlands in the form of

permanently frozen peat plateau bogs, veneer bogs, andpalsa bogs, mixed with non-frozen basin and horizontalfens are common. Permafrost is widespread, discontinuousand mostly associated with peatlands and poorly drainedmineral soils overlain by thin surface peat.

The upland slopes gently at the rate of about 1 to 2 m perkm and drains generally eastward to Hudson Bay. Most ofthe ecodistrict is drained by the South Seal River and itstributary streams, and a small section in the southeastdrains toward South Indian Lake which is part of theChurchill River drainage system. Big Sand Lake is by farthe largest lake, but the ecodistrict also contains manysmall and some medium and a few large lakes. Lakesoccupy about 30 percent of the surface area.

282. Big Sand Lake Ecodistrict (6938 km2)

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SoilsThe dominant soils in the Big Sand Lake Ecodistrict arewell to imperfectly drained Dystric Brunisols on sandyacidic till. Some soil profiles exhibit uneven horizondevelopment, while some non-sorted circles are presenton the surface, and are evidence of the impact of formerand present permafrost conditions on soil development.Local areas of Turbic Cryosols, associated with loamyand clayey materials, occur as inclusions. Bedrockoutcrops also occur throughout the area.

Organic Cryosols are associated with significant areas ofpeat plateau and veneer bogs overlying loamy till andclayey glaciolacustrine sediments. The organic materialsare comprised mainly of woody forest peat and sphagnumpeat. Deeper peat deposits generally underlain by sedgepeat are more common in the eastern sector.

The severe climate, lack of rooting depth to permafrost orbedrock, excessive stoniness and limited water-holdingcapacity and nutrient retention severely constrain the useof mineral soils for forestry and agriculture. Poor naturaldrainage and slow heat conductance properties, inaddition to climatic constraints, are the most severelimitations to the use of organic soils.

VegetationThe vegetation of the ecodistrict is typical of the southernpart of the subarctic and is dominated by open, stuntedblack spruce stands with a ground cover of mosses,lichens and ericaceous shrubs on well to imperfectlydrained sites, and by peatlands. Peatland vegetationconsists of black spruce, ericaceous shrubs and mosses onpeat plateau bogs, and sedge, brown mosses and tamarackon fens. In the most southerly parts of the ecodistrict,closed stands of marginally merchantable timber may befound on favourable sites.

WaterThe principal sources of water are Big Sand Lake and themany smaller lakes, the South Seal River and its tributarystreams that flow through the ecodistrict.

Land UseThere are no permanent settlements in the ecodistrict.Fishing, water-oriented recreation, trapping and huntingare the dominant land uses.

Big Sand Lake Ecodistrict

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The Northern Indian Lake Ecodistrict is located in thesouthern part of the Selwyn Lake Ecoregion, and liesentirely within Manitoba.

ClimateThis ecodistrict has a Low Subarctic Ecoclimate markedby short, cool summers and long, very cold winters. Meanannual air temperature is approximately -3.4oC, theaverage growing season is 137 days, and the number ofgrowing degree-days is about 950.

Mean annual precipitation is about 525 mm, of whichmore than one-third falls as snow. Precipitation variesgreatly from year to year. Although precipitation ishighest during the growing season, the average yearlymoisture deficit is about 50 mm. The ecodistrict has a verycold, subhumid to humid, Cryoboreal soil climate.

There are no climate stations in the ecodistrict and thenearest are at Brochet (279. Seal River Ecodistrict) to thewest and Gillam Airport (360. Knee Lake Ecodistrict) tothe southeast.

Physiography and DrainageThe Northern Indian Lake Ecodistrict lies between 365masl along its western boundary near Big Sand Lake and240 masl southeast of Northern Indian Lake. It ischaracterized by hummocky Precambrian bedrockcovered with almost continuous veneers and blankets ofclayey glaciolacustrine deposits and, to a lesser degree,with acidic sandy to loamy till.

Moderately long (50 to 150 m) undulating to hummockyslopes range from about 2 to 15 percent slope. Prominentfluvioglacial ridges in the form of interlobate morainesborder the area to the east. Some prominent eskers arefound throughout the ecodistrict.

Organic deposits are widespread and cover between 25and 50 percent of the land surface. They overlie extensive

areas of clayey, glaciolacustrine sediments. Peatlandsoccur in the form of veneer bogs on gentle slopes and aspeat plateau bogs and horizontal fens in level todepressional areas. Permafrost is widespread,discontinuous and is mostly associated with veneer bogson gentle sloping sites and peat plateau bogs on level anddepressional terrain.

The upland slopes gently at the rate of about 0.5 to 1 m perkm and is drained eastward by the Churchill River and itsnetwork of tributary streams and drainage ways. Whilethe northern portion of Southern Indian Lake andNorthern Indian Lake dominate the area, many smallerlakes are distributed throughout the ecodistrict.

The flow of the Churchill River is markedly reduced fromhistoric flows by the Missi Falls control dam, situatedwhere the Churchill River flows out of Southern IndianLake. The reduced outflow has resulted in higher waterlevels in Southern Indian Lake, resulting in severeshoreline erosion. Most of the new shoreline is beingestablished in clayey sediments and organic materials,which extensively contain ice-rich permafrost. On theother hand, water levels in Northern Indian Lake and inother smaller lakes have been lowered throughdrawdown, resulting in the creation of new shorelines atlower elevations.

283. Northern Indian Lake Ecodistrict (10 332 km2)

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SoilsThe dominant soils in the Northern Indian LakeEcodistrict are Gray Luvisols that have developed onclayey sediments, Organic Cryosols associated withwidespread peat plateau bogs and veneer bogs, andOrganic Mesisols developed on fens. Dystric Brunisols onacidic till and eskers, and Eutric Brunisols associatedwith sandy fluvioglacial (interlobate moraine) depositsalso occur in the ecodistrict. Local areas of graniticbedrock also occur.

Clayey mineral soils frequently exhibit uneven andbroken horizon development and incorporation of organicmaterials below the surface. These soils are associatedwith relic and active earth hummocks. These surfacefeatures are evidence of the effect of former and currentpermafrost conditions on soil development. Althoughpermafrost is not as widespread in fine textured sedimentsas it is in organic deposits, areas of Turbic Cryosols occurin terrain with earth hummocks, while Static Cryosolsoccur where closed stands of black spruce and/or feathermoss groundcover create conditions favourable forpermafrost development.

Severe climatic constraints, poor natural drainage andslow heat conductance properties limit the use of organicsoils for forestry or agriculture. Lack of rooting depth topermafrost or bedrock, and in some cases excessivestoniness, limited water and nutrient holding capacity areadditional severe constraints to the use of mineral soils.

VegetationThe vegetation of the ecodistrict is typical of the southernpart of the Subarctic and is dominated by open, stuntedblack spruce stands with a ground cover of mosses,lichens and ericaceous shrubs on well to imperfectlydrained sites, and by peatlands. Peatland vegetationconsists of black spruce, ericaceous shrubs and mosses onpeat plateau bogs, and sedge, brown mosses and tamarackon fens. Along the Churchill River and in the mostsouthern parts of the district, closed stands of marginallymerchantable timber may be found on favourable sites.

WaterThe principal sources of water are the numerous lakesalong the Churchill River and the Churchill River itselfand its tributaries.

Land UseTrapping and hunting are the dominant land use activities.Commercial fishing is an important activity on the twolarge lakes. Although this enterprise has suffered as aresult of the change in water levels and the continuingerosion of shorelines, it remains an important economicactivity for a number of people from the First Nation’scommunity of South Indian Lake. Fishing, canoeing andother water-oriented recreation are typical uses of theecodistrict’s natural resources.

Northern Indian Lake Ecodistrict

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Terrestrial Ecozones, Ecoregions and Ecodistricts of Manitoba

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