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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
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.
C. Port au Port 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.
D. St. George’s Bay 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.
E. Codroy 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.
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.
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