| 200 | Highlands |
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| 210 | Plateau-Fir Forest |
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| 220 | Steep Slopes |
210 Plateau-Fir Forest
The Plateau-Fir Forest District is divided into two sub-Districts:
(a) The Highlands
(b) Gairloch Mountain
Geology and Landscape Development
The undulating plateau crest of the Cape Breton Highlands is dissected by faults into two parts: the Highlands (including part of Kellys Mountain) and Gairloch Mountain (an isolated section on the southern fringe). The plateau surface is tilted to the southeast, and the average elevation drops from about 500 m to about 400 m at
the edge of the Highlands. This may represent the slope of the original upland surface.
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| Valley and Highland Plateau Click to enlarge |
Gairloch Mountain is cut off from the southern part of the Highlands by two major faults. The boundaries of this block are sharp and steep where softer rocks have been eroded away. In the northwest, where metamorphic rocks are faulted against resistant early Carboniferous Horton deposits, no steep scarp slope is present. Similarly, on the south side, where there is a depositional boundary with resistant Devonian-Carboniferous rocks, the contact is not topographically distinctive (see Figure 21). However, on the north side, where easily eroded Windsor deposits are set against the metamorphic rocks, a pronounced scarp slope is found.
The maximum elevation of Gairloch Mountain is almost 430 m, about 100 m less than the highest part of the Highlands. This reflects its more southerly, and therefore lower, position on the tilted planation surface.
Fresh Water
The drainage pattern across the Cape Breton Highlands is
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| Steep valleys offer scenic views and challenging hiking. Click to enlarge |
District 210 contains relatively few glacial lakes. Conductivity averages 33 micromhos/cm. The pH in Warren Lake averages 5.8.
Blanket bogs are typical of sub-District 210a; the systems form concentric patterns with some flow between adjacent bogs. Ribbed fens are associated with this type of formation.
Plants
The vegetation of the Highlands is characterized by largely even-aged boreal forest, with Balsam Fir, White Birch, and White Spruce as the main species. The main successional agents are windthrow and insect damage, particularly Spruce Budworm. Fire influences are mainly restricted to the area behind Neils Harbour, where pure stands of Jack Pine are found. Elsewhere in the District, pine is uncommon.
Typically, in the central and western Highlands, the Balsam Fir is 50-75 years old. White Birch readily colonizes openings caused by windthrow, but fir eventually reasserts itself. White Spruce is scattered through the forest, and often individual trees are much older (150 years) than the surrounding fir. Most of the Balsam Fir has died following Spruce Budworm infestation in the late 1970s and was replaced by a dense growth of raspberries with some Elderberry. The only tree species able to survive this competition are White Birch, Mountain Ash and Pin Cherry. Eventually the birch shades out the raspberry, enabling Balsam Fir to re-establish itself. Ground vegetation in the mature Balsam Fir forest is often luxuriant. Mountain Maple and Hobblebush frequently form a dense shrub canopy, with ferns, Wood-sorrel, and mosses below. South of the South Aspy River an area dominated by crescent-shaped granite ridges produces a vegetation pattern similar to that found in the Plateau-Taiga Region: barrens on the dry ridge tops, bogs in the depressions, and open stands of Balsam Fir in between.
On the broad, flat plain which slopes down to the Atlantic Ocean between Neils Harbour and Broad Cove, the vegetation has been more influenced by fire and cutting, and is therefore at an earlier successional stage. On the shallow granitic soils, Balsam Fir, Black Spruce, Jack Pine, and White Pine form younger stands, with Bracken Fern underneath.
Animals
The fauna found in this District is, for the most part, characteristically boreal. The Snowshoe Hare is common, but it is subject to cyclic population fluctuations. The Highlands provide one of the last significant refugia for its predator, the lynx. The bobcat is rarely found in the area, and unconfirmed sightings of cougar have been reported. Deer and moose are both present. The moose subspecies Alces alces andersoni was introduced to the area and is flourishing. Deer use the area for summer range but generally move to sheltered lower slopes in winter. The brain parasite
Parelaphostrongylus tenuis has been identified in deer, but the seasonal separation of moose and deer during concentration periods has apparently helped retard its transfer between the species.
A small relict population of Pine Marten existed in northern Cape Breton in the 1980s, but no recent reports are available to confirm its continued existence. The boreal forest does not support large or diverse populations of small mammals.
Spruce Budworm has resulted in many dead and dying trees, changing the habitat structure. Birds that bore into dead wood for insects, particularly woodpeckers, are abundant. Nuthatches are also common. Fish species include Brook Trout and Gaspereau.
Scenic Quality
This area can often appear bleak and forbidding, and where the fir forest is unbroken there is little visual diversity. The infestation of Spruce Budworm is still apparent in many areas. Nevertheless, the presence of bogs and barrens adds variety, and the crests overlooking the deeper valleys have great scenic potential. Those areas accessed by the Cabot Trail and Trans-Canada Highway provide some spectacular viewpoints (see Sites of Special Interest).
Cultural Environment
Various parts of the Plateau-Fir Forest have experienced the impact of major fires and heavy Spruce Budworm infestation. Large expanses of affected trees were clearcut as part of a salvage operation in the early 1990s. Although woodlot lumbering has been practised by some residents of these areas, most communities are focused
on the resources of the surrounding sea. Seasonal hunting also characterizes land use. The Cabot Trail and the Cape Breton Highlands National Park are key tourism and recreational attractions. Peat resources underlie large expanses of the Plateau-Fir Forest.
The geological and geomorphological features of most interest in the Cape Breton Plateau-Fir Forest District are:
- the relationships between the metamorphic rocks and intrusive igneous rocks
- the banded schists and gneisses
- faults, fault scarps, and fault valleys
- waterfalls, coastal cliffs, and narrow beaches
- Geological Highway Map of Nova Scotia (1980) references:
- Bras d'Or Lookoff - on Kellys Mountain over-looking Bras d'Or Channel and the Sydney area
- Cabot Trail between Jumping Brook and Pleasant Bay - view of the plateau and an exposure of granite
- North of Chéticamp, near Jerome Mountain - a faulted contact between granite and gneiss
- Cabot Trail, west park entrance - a cliff of Precambrian granite veined with quartz
- Ingonish, Middle Head peninsula - pink granite cutting dark rocks
- Sugar Loaf Mountain - a granite mass rising to more than 460 m
- French Mountain Lake (IBP Proposed Ecological Site 17) - raised and sloping bogs, dystrophic lake
- French Mountain Bog (IBP Proposed Ecological Site 18) - good example of species-rich minerotrophic bog
68 Near Fox Back Lake - Precambrian granitic rocks and a view of intruding gneisses
69 Aspy Fault scarp
71 Green Cove - gneisses intruded by pink and white granites
73 Cape Smokey Lookoff - Precambrian granite intruded by dark-coloured diabase dykes
74 Kellys Mountain Viewpoint (St. Anns Lookoff) - a road cut through Precambrian high-grade gneisses from which one can look across fault-controlled St. Anns Harbour to the main mass of the Highlands
Provincial Parks and Park Reserves
- Kellys Mountain
Proposed Parks and Protected Areas System includes Natural Landscapes 64a, b, c, d, and e and Candidate Protected Areas 1 Pollet Cove-Aspy Fault, 2 Jim Campbells Barren, and 4 French River.
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