Newfoundland Ecoregions
Ecoregions represent areas where a comparable vegetation and soil can be found on sites occupying similar topographic position on the same parent material.
Newfoundland is comprised of 9 ecoregions and 21 sub-ecoregions.
Avalon Forest
This ecoregion represents a sheltered outlier within the more open and exposed Maritime Barrens Ecoregion. Pure stands of Balsam Fir with a significant mixture of White Birch and Yellow Birch dominate this region. Trembling Aspen is rare and Black Spruce is only abundant on wet site types. The Avalon Forest Ecoregion has been spared the ravages of fire that decimated forests in the surrounding landscape, converting it to open heathland. The excessively moist climate and ribbed moraine topography give this small (500 km2) ecoregion its uniqueness. The excessive fog frequency is clearly expressed by the abundance of pendant lichens hanging from the branches of Balsam Fir. Aspect appears to be an important factor controlling forest composition and growth (Delaney and Cahill 1978). North facing slopes are dominated by the Dryopteris-Balsam Fir type whereas south slopes have Clintonia-Balsam Fir and Nemopanthus-Kalmia-Black Spruce with Taxus canadensis abundant. Gleyed Ferro-Humic Podzols with loam to silt-loam texture dominate in the land-type. Silviculturally, these sites are difficult to manage because of the considerable difference in ecological conditions over a very small area. Understocked sites (which are generally rare) have an ericaceous heath vegetation on slope summits with birch and raspberry on the slopes. Also, these forests are subject to considerable climatic stress from wind and large clear-cuts should be discouraged. The low abundance of Black Spruce in these forests suggests they would be prone to softwood regeneration failure after fire.
Maritime Barrens
The Maritime Barrens Ecoregion extends from the east coast of Newfoundland to the the west coast through the south central portion of the island. This ecoregion has the coldest summers with frequent fog and strong winds. Winters are relatively mild with intermittent snow cover particularly near the coastline. Annual precipitation exceeds 1250 mm.
The landscape pattern consists of usually stunted, almost pure stands of Balsam Fir, broken by extensive open heathland. Good forest growth is localized on long slopes of a few protected valleys. The development of the extensive heath landscape was precipitated by indiscriminate burning by European settlers. Railways in the nineteenth century also had a significant impact on fire frequency in the eastern part of the region. The heaths are dominated by Kalmia angustifolia on protected slopes where snow accumulates and by cushions of Empetrum nigrum or Empetrum easmesii on windswept ridges and headlands.
Attemps to afforest these heaths with Picea sitchensis have been unsuccessful, but Eastern larch and Scots Pine may have potential for fuelwood stands (Hall 1986). However, site selection is critical because the historical removal of forest has deflected the natural treeline to low elevations. Wind, lack of protective snow cover and soil frost disturbance are important factors limiting plantation establishment in this ecoregion.
This ecoregion is comprised of four sub-ecoregions
- Northeastern Barrens
- Southeastern Barrens
- South Coast Barrens
- Central Barrens
A. Northeastern Barrens Subregion
This subregion has lower fog frequency and somewhat warmer summers compared to subregions B and C. Arctic-alpine species are absent from the heath vegetation and Yellow Birch is absent from the forest. The landscape is extensively forested with local heath vegetation particularly along the coast.
The tills in the area are generally a shallow rolling ground moraine with sandy loam to loam texture. The Hylocomium-Balsam Fir type occupies mid-slopes and it is usually associated with gleyed podzols or gleysols.
B. Southeastern Barrens Subregion
In this subregion the landscape is dominated by heathlands and the forest only occurs in small acreages which escaped fire. The dominant heath shrub on uplands is Empetrum nigrum with Kalmia angustifolia forming a dense cover only in protected valleys.
The topography is generally undulating with shallow heavily compacted till and numerous large erratics. The Clintonia-Balsam Fir type is most common where the forest is still present. Good forest growth only occurs in a few large protected valleys where the Dryopteris-Balsam Fir type dominates the slopes. Good specimens of Yellow Birch are also found in these stands.
C. South Coast Barrens Subregion
This subregion includes the higher elevations along the south coast and a few small outliers on the isthmus of Avalon and the Hawke Hills that are up to 300m in elevation. Snow cover is shallow and arctic-alpine plants occur locally. Yellow Birch is present in valleys.
D. Central Barrens Subregion
This area occurs south of the Central Newfoundland Ecoregion and north of the South Coast Barrens Subregion. Residual forests that have not been destroyed by fire have moderate forest capability. The dwarf shrub heaths are robust and Rhododendron canadense is a conspicuous component suggesting deep snow cover. Arctic-alpine species are poorly represented and Yellow Birch is absent from the forest.
Eastern Hyper-Oceanic Barrens
This ecoregion occurs on the extreme south coast of the Avalon and Burin Peninsulas and on the northeast coast near Bay de Verde and Cape Feels. Although this ecoregion is 200m or less in elevation the extreme oceanic climate precludes the development of forest other than Balsam Fir krummholz. The heaths in this area have a close affinity to oceanic parts of Northern Scotland and Southern Norway.
Central Newfoundland
Central Newfoundland has the most continental climate of any part of insular Newfoundland. It has the highest summer temperatures and lowest winter temperatures. However, night frost can occur in any summer month. Due to the warm summer and high evapo-transpiration losses, soils in the northern part of this ecoregion display soil moisture deficiency.
The Hylocomium-Balsam Fir forest type occupies the zonal soils of this area. These soils are generally lighter in colour and have lower organic matter content compared to other ecoregions. Forest fires have played a more important role in the natural history of this region relative to other ecoregions. Much of the Balsam Fir-Feathermoss forest types have been converted to Black Spruce and some of the richer site types to hardwood forests dominated by White Birch and Aspen. Although Aspen occurs in other regions, it is most abundant and vigorous in Central Newfoundland. Yellow Birch is absent from this region primarily because of the short frost-free period. Alders rather than Mountain Maple are the most common problem on wet seepage slopes.
This Ecoregion is comprised of four sub-ecoregions
A. Northcentral Subregion
The Northcentral Subregion has higher summer maximum temperatures, lower rainfall and higher fire frequency than anywhere else in Newfoundland. The subregion extends from Clarenville in the east to Deer Lake in the west and for the most part has a rolling topography below 200m. Pure Black Spruce forests and Aspen stands dominate this area because of the prevalence of fire in the natural history of the subregion. Also, the high summer temperatures are thought to stimulate Aspen root suckering and contribute to the local success of Aspen (Damman 1983). Relatively low moisture, coarse soils and the prevalence of Black Spruce cover types make this subregion particularly susceptible to regeneration failure. Furthermore, where tree regeneration is lacking, succession to dwarf shrub heath dominated by Kalmia angustifolia occurs on the nutrient-poor coarse textured till that is prevalent through much of this area.
The rolling to undulating topography is characterized by shallow, medium quality till with a soil texture range from sandy loam to loam. Midslopes are dominated by the Hylocomium-Balsam Fir type, or the Black Spruce-Feathermoss type on seepage gleysols after fire. There are also local areas covered by poor sandy till over galcio-fluvial deposits and outwash deposits along some of the major river systems such as the Terra Nova, Exploits and Indian River. It is in these land types that succession of productive Black Spruce forest types to ericaceous heath dominated by Kalmia angustifolia is most prevalent.
B. Red Indian Lake Subregion
This subregion is cooler than subregion A with more precipitation and a shorter growing season. Balsam Fir cover types predominate and White Birch rather than Black Spruce is most prominent in the landscape.
Much of the topography of this subregion is similar to subregion A, however there are some local areas of deeper, nutrient rich till. The southern slopes of Red Indian Lake to Noel Paul and Harpoon River systems provide good examples of this richer landtype. The Rubus-Balsam Fir and Dryopteris-Lycopodium-Balsam Fir types dominate the landtype. The soils have a texture ranging from silt loam to loam usually with a fragipan that promotes seepage in the rooting zone. These are by far the most productive forest types in Central Newfoundland. However, succcession to Alder thickets after cutting and fire is a serious silvicultural problem.
C. Portage Pond Subregion
This subregion is characterized by rugged topography including the Annieopsquotch Mountains. Balsam Fir is the dominant tree on upland sites. However, there are a number of very productive Black Spruce fire stands in this subregion.
D. Twillick Steady
This subregion occurs immediately to the north of the Bay d’Espoir Subregion of the Western Newfoundland Ecoregion. Trembling Aspen is absent from this area and Balsam Fir is the most common upland cover type.
North Shore
This ecoregion represents a narrow coastal zone 20-25km in width extending from Bonavista Bay to the Baie Verte Peninsula.
Black Spruce and Balsam Fir form a continuous forest except where barrens dominate on the coastal headlands. White Spruce is more common than in Central Newfoundland, but Trembling Aspen is sporadic and rarely forms pure stands. Alnus crispa replaces Alnus rugosa as the dominant alder on both upland and lowland sites. The vegetation season is shorter and cooler than in Central Newfoundland but the frost-free period is several weeks longer. The summers are relatively dry and warm and soil moisture deficiencies may occur. As with the Central Newfoundland Ecoregion, encroachment of ericaceous shrubs on dry nutrient-poor sites after cutting and fire is a serious silvicultural problem. Also, the quality of growth diminishes with proximity to the coastline. There are no subregions in this ecoregion. The land types are similar to those for the Central Newfoundland Ecoregion.
Long Range Barrens
This ecoregion includes the mountainous areas above treeline. Trees only occur as krummholz usually dominated by Black Spruce and Eastern Larch. Small patches of forest may occur in sheltered valleys. The vegetation is dominated by arctic-alpine plants clearly indicating that these barrens, unlike the Maritime Barrens, were never forested.
This ecoregion is further broken down into three sub-ecoregions.
- Southern Long Range
- Buchans Plateau- Topsail
- Northern Long Range
Western Newfoundland Regions
This ecoregion is characterized by a humid climate with a relatively longer frost-free period. It contains some of the most favourable sites for forest growth although there is considerable variation due to altitude and proximity to the coast.
The Dryopteris-Hylocomium-Balsam Fir forest type is the zonal forest for this region. The zonal soils are nutrient rich humic podzols with a very dark podzolic B horizon due to humus enrichment. The absence of prolonged dry periods appears to have excluded fires from all but the most coarse textured soils. Consequently, Balsam Fir rather than Black Spruce is the dominant forest cover. Yellow Birch is common in protected valleys below 200m elevation. This species (Yellow Birch) also occurs in less vigorous forms in the Maritime Barrens and Avalon Forest Ecoregions, but it is absent at higher elevations and north of Deer Lake. Red Maple is also most common and robust in this ecoregion.
As a general rule overstocking is a more common silvicultural problem than understocking in Western Newfoundland. Localized regeneration failures can occur in forests with a very dense fern and herb stratum such as the Rubus-Balsam Fir and the Dryopteris-Balsam Fir forest types. On these types, hardwoods, particularly Mountain Maple on seepage slopes, can form semistable thickets. These thickets may eventually develop into hardwood forest types. The development of ericaceous heath after logging or fire is only observed on very small areas of coarse textured till. This is in stark contrast to Central Newfoundland where succession to Kalmia Heath is a common occurrence. The Western Newfoundland Ecoregion is subdivided into five subregions.
A. Serpentine Range Subregion
This subregion extends from Blow-Me-Down on the south shore of the Bay of Islands to include the Lewis Hills. The area is mountainous with elevations in excess of 800 m and the vegetation is dominated by rock barrens. The serpentine and ultra basic rock types support numerous rare and endemic species of plants.
B. Corner Brook Subregion
This subregion includes the coastal plain and mountain slopes and river valleys from the southern end of Grand Lake to Robinsons River. Areas of deep undulating till occur locally. These are characterized by orthic podzols on sandy loams with the Dryopteris-Hylocomium-Balsam Fir type occurring in the mid-slope position.
On the steep mountainous slopes, gneiss, granite, sandstone and quartz are the most frequently encountered rock types and the parent material is a shallow, often stony, sandy loam till. The Hylocomium-Balsam Fir forest type occupies the midslope position underlain by orthic or gleyed podzols with seepage over bedrock. The occurrence of seepage waters ensures good forest growth and profuse regeneration after cutting. This landtype is also prevalent in the Corner Brook subregion.
The coastal plain is dominated by numerous coarse textured deposits, such as glacio-fluvial deposits, eskers, drumlins and kames. The generally, low productivity of these site is in stark contrast to most of Western Newfoundland. The Pleurozium-Balsam Fir and Gaulteria-Balsam Fir forest types are the most common in undisturbed landscapes, but these may be replaced by corresponding Black Spruce-Feathermoss types, Kalmia-Black spruce or Kalmia Heath after fire. Orthic podzols dominate these landscapes with gleyed humic podzols in transition to large peatland deposits. This is one of the few landtypes in the Western Newfoundland Ecoregion where serious growth and regeneration problems may be encountered.
C. Port aux Port Subregion
Hilly to undulating terrain from Bonne Bay to Stephenville and east to Grand Lake. The parent materials in this subregion are dominated by slates and limestone till. Areas with calcareous till are distinguished by the occurrence of light coloured marl deposits around ponds and in valleys. The parent material consists of shallow, stony silt loam underlain by limestone bedrock or calcareous basal till. The rugged topography is dominated by the Taxus-Balsam Fir and Dryopteris-Rhytidiadelphus-Balsam Fir forest types.
The hilly, non-calcareous terrain in this subregion is dominated by shallow loamy soils over shale bedrock. However, the shallowness of the till does not adversely affect forest growth since nutrient rich seepage waters are held in the rooting zone by bedrock or a fragipan layer. The steep topography is dominated by the Dryopteris-Balsam Fir forest and supports some of the most productive stands in Newfoundland.
D. St. George’s Bay Subregion
The Codroy Subregion extends from Robinsons River to the Cape Anguille Mountains. Climatically, this area has some of the most favourable conditions for growth in Newfoundland and a large portion of the area has been cleared for agriculture. The forested landscape is dominated by steep slopes.
E. Codroy Subregion
This subregion includes the Port au Port Peninsula. Again the landscape is dominated by rock barren, however, the rock type is dominated by limestone. The Limestone Heaths of the area also support numerous species of rare and endangered plants. Forests are generally unproductive or totally lacking.
F. Bay d’Espoir Subregion
This small outlier of the Western Newfoundland Ecoregion is in a sheltered valley system on the southeast coast. Excellent stands of the Dryopteris Balsam Fir forest type dominate the valley slopes. However, Mountain Maple Thickets and Trembling Aspen are generally lacking in these stands.
Northern Peninsula Ecoregions
This ecoregion differs from most other forested parts of the island by the shortness of the vegetation season, 110-150 days compared to 145-170 days for other areas. The frost-free period is comparable to most other areas and somewhat better than in Central Newfoundland. Precipitation is lower, however, because of low summer temperatures and shorter vegetation season, soil moisture supply is probably adequate at most times.
The soils are comparable to those of Western Newfoundland. Limestone underlies most of the region, with acidic rocks more common on the eastern side of the peninsula.
Balsam Fir is the dominant forest cover except at high elevations (300-400m) on the eastern side of the peninsula where Black Spruce appears to be a natural component of the stands. There is very little fire history in this ecoregion. White Pine, Red Maple, Yellow Birch and Trembling Aspen are conspicuous by their absence. There are approximately 100 species of plants that are excluded from this ecoregion presumably because of the difference of climate (Damman 1965, 1976, and 1983). One of the most conspicuous changes is the replacement of Alnus rugosa by Alnus crispa, Salix pellita and Salix planifolia in swamps. Tall shrubs such as Nemopanthus mucronata, Viburnum cassinoides and Rhododendron canadense are sparse or lacking in the scrub bog-border forests. Silviculturally, they are similar to Western Newfoundland with hardwoods rather than ericaceous shrubs being the most common brush problem on understocked cutovers. Ribes glandulosum, Ribes triste and Cornus stolonifera appear to be a much more conspicuous component of seral vegetation on cutovers. Raspberry is also very abundant in the early years of succession.
This Ecoregion is further subdivided into four sub ecoregions.
A. Coastal Plain Subregion
This includes the western side of the Great Northern Peninsula to the lower slopes of the Long Range Mountains. Most of the coastal plain is dominated by bogs and scrub forest. The area around Hawkes Bay and the foothills of the mountains are important exceptions to this generalization.
B. Beaver Brook Limestone Subregion
This subregion occupies the central lowlands north of the Highlands of St. John on the Great Northern Peninsula. This sheltered outlier maintains the most productive forests in the ecoregion, comparable in productivity to parts of Western Newfoundland. Limestone, shale and sandstone bedrock types occur in this area.
The limestone landtype occurs predominantly on the east side of the peninsula between Roddickton and Main Brook. As in Western Newfoundland, the limestone landtypes are characterized by marl deposits around ponds and in valleys. The soils have a distinct dark greyish brown layer in contact with bedrock, compacted till or large boulders. The landscape is gently rolling with Rubus-Balsam Fir and Taxus-Balsam Fir the most common forest types and Pleurozium-Balsam Fir occurring on shallow till.
On the western side of the peninsula, east and south of Ten Mile Pond, the till is formed from sandstone. The landscape is undulating to hilly in the extreme west. The Dryopteris-Balsam Fir and Clintonia-Balsam Fir types are most common on moderate to deep tills. On shallow tills the Pleurozium-Balsam Fir and Black Spruce-Feathermoss on bedrock are dominant. Soil textures in these types are generally sandy loam to loamy sand.
In the centre of the peninsula, between Route 432 and Salmon River, shale is the dominant bedrock type and the gently rolling topography is formed from till with a loam to silt loam texture. Rubus-Balsam Fir and Clintonia-Balsam Fir types are dominant.
C. Northern Coastal Subregion
This subregion is dominated by exposed, rocky dwarf shrub barrens with local areas of unmerchantable forest.
D. Eastern Long Range Subregion
This subregion includes the productive but inaccessible forest on the eastern slopes of the Long Range Mountains up to 450m in elevation. The forests tend to be somewhat open Balsam Fir-Black Spruce mixtures. Treeline decreases towards the northern end of the subregion.
Strait of Belle Isle Barrens
This ecoregion is dominated by an almost treeless tundra vegetation. White Spruce and Balsam Fir occur as krummholz interspersed with arctic-alpine plants even near sea level. The soils are generally very shallow and outcrops of calcareous bedrock are common throughout. Large stone polygons created by freeze-thaw cycles are common on shallow-exposed mineral soil. Rare and endangered species of calciphillic plants are numerous in these rock barrens.
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