Geology | Fresh Water | Soils | Plants | Animals Cultural Environment | Sites of Interest | Topics & Habitats

This Unit has two subdivisions:
(a) South Mountain
(b) Ten Mile Stream

Geology and Landscape Development
Despite its size, the South Mountain Granite is a rather uniform topographic feature. It presents a level horizon when viewed from North Mountain, and the surface steadily decreases in elevation down to its southern, eastern, and western boundaries, where fairly steep slopes mark the boundary with Meguma strata (see Figure 25).

The soils support young conifers, replacing older Hardwoods Click to enlarge

Across the surface of the granite are many large boulders that were plucked out and then dumped by the ice. Some were carried beyond the granite boundaries and dropped, as erratics, on unrelated rocks further away. Long, prominent eskers occur in the Kejimkujik area and to the west.

The granite terrain in the Ten Mile Stream sub-Unit is typical. The surface is elevated above the greywacke and slate bands on three sides by about 50 m but forms a rather steeper escarpment on the northern side where it is undercut by the West River St. Marys. Here the drop is nearly 100 m in places.

The surface is thinly covered with coarse granite till with some areas of thicker Lawrencetown Till. Some glacial outwash deposits are found on the northern side.

Fresh Water
The South Mountain Granite has a typically deranged drainage pattern, but two chains of lakes have maintained a more or less straight line across it. One extends south of Milford in Annapolis County and the other south from Panuke Lake. These may represent old river courses that were superimposed upon the granite as it was exposed.

This Unit contains the headwaters of some of Nova Scotia's largest rivers, such as the Tusket-Silver, Bear, Mersey, Medway, Nictaux, LaHave, and Avon. Except for the tidal rivers, most tend to be shallow and fast flowing.

In the South Mountain sub-Unit (451a), wetlands are scattered along streams and rivers. The occasional lake occurs in Annapolis, Kings, and Digby counties. These counties also contain many raised bogs. Wetlands tend to become more widely scattered and smaller in the eastern portions of sub-Unit 451a. Halifax County has several long north-south oriented lakes running along fault lines.

In the Ten Mile Stream sub-Unit (451b), surface-water coverage is greater in the western portions. Here the numerous, small irregular lakes tend to be oligotrophic and linked by small streams. Raised bogs can be found in the southwestern part of sub-Unit 451b.

Conductivity tends to be below 35 micromhos/cm throughout the Unit and pH ranges between 5.4 and 6.5.

Soils
The major soil series throughout this large Unit is Gibraltar: a coarse-textured, well-drained gravelly, sandy loam derived from granite - usually shallow, heavily leached, and very acidic. Gibraltar soils are also associated with poorly drained Bayswater and Aspotogan soils, along with many areas of peat. Near the north slope are two large areas of Halifax sandy loam derived from quartzite. Bridgetown soils around Gaspereau Lake and south of Hardwood Lake have developed on tills derived from a mixture of basalt, granite, quartzite, and Carboniferous material. A small number of Wolfville drumlins also occur near these areas. Scattered areas of exposed rock are present throughout the Unit, particularly in Halifax County. Soils in unforested areas have a tendency to form hardpans.

Plants
This Unit basically corresponds to the Fisher Lake-Halifax District in Loucks' Red Spruce,

Kedji Pine & Aspens Click to enlarge

Hemlock, Pine Zone. The characteristic species are Red Spruce, Eastern Hemlock, White Pine, Balsam Fir, and Red Maple, with scattered Red Oak. Warm summer temperatures result in high evapotranspiration, which would normally encourage shade-tolerant deciduous trees, but here it appears to favour Red Spruce and Eastern Hemlock. Fire has played a prominent role, but the regeneration of pine and spruce under Red Maple and Red Oak suggests that the area is returning to a mainly coniferous forest. American Beech was formerly abundant, but has been depleted by fire.

White Pine, Red Spruce, and Eastern Hemlock often occur on sites which have not been burned, while fire stands are commonly Red Oak, Red Maple, and White Birch. American Beech, Sugar Maple, and Red Oak are found on exposed slopes and hilltops. Black Spruce and Balsam Fir occupy poorly drained lands. Barrens and semi-barrens are common. Some old Red Spruce and Eastern Hemlock stands can still be found. Coastal-plain plants occur along water courses in this Unit.

Observations made in 1912 by C.D. Howe give some historical insight into the development of present-day forests: "The slopes, facing the Annapolis valley, are abrupt with relatively short streams flowing from them, while the southerly facing slopes are gentle, and their streams have worn rather wide valleys separated by low rounded ridges. In the portion draining northward the forests are of the mixed type with red spruce and hemlock predominating over the hardwoods, but there are frequently hills of pure over-mature and decrepit hardwoods, half composed of beech, 40 per cent hard maple and the rest yellow birch. In going southward, especially between the LaHave and Port Medway rivers, hemlock is of more common occurrence than the red spruce, in some places reaching as high as eighty percent of the stand. Frequent barren and semi-barren areas are scattered through the county, doubtless, in most cases, the result of repeated fires. One type, however, approaches the character of a natural barren, that is, a low rocky ridge, usually ten to fifty feet above its surroundings, covered chiefly with scrubby red oak and red maple. The largest areas of these latter barrens are found east and northeast of the Milford lakes and south of the Molly Upsum and McGill lakes. The very numerous lakes and ponds usually have at their upper ends, extensive peat bogs and black spruce and fir swamps. The cut of the mills in the western portion of the county [Kings] consists of approximately 50 per cent hemlock, 40 per cent red spruce and 10 per cent white pine, and these species form from 75 per cent to 80 per cent of the forest. In the eastern portion of the county, the ridges are broader and higher; the hardwoods become more prevalent, and finally dominate. Along the basin of the St. Croix lakes the larger percentage of the stands is hemlock. Eastward to the headwaters of Ingram river, red spruce prevails over the hemlock. These areas are near the centre of the granite mass. Both eastward and westward to the limits of the granite in the county, the forest is mixed hardwoods and softwoods, with spruce mostly predominating. Southwest of Ingram river and east of Island lake the forest is second growth, paper birch and red spruce being the most common species, with fir and yellow birch next in abundance. Northwest near the Hants County line, hardwood hills compose about one-fifth of the stand, between which red spruce and hemlock prevail, with the spruce in the lead. The granite area in the north-western corner of Guysborough county is about one-fourth burned and barren. The soil on the rest is deep, and hardwoods prevail, with frequent patches of pure red spruce and fir."

Animals
The second-growth mixed forests support only sparse wildlife populations. Small-mammal diversity is low to moderate. High concentrations of White-tailed deer occur in sub-Unit 451a. Aquatic environments are acidic and have low productivity, providing poor waterfowl habitat. The area sustains substantial populations of Smallmouth Bass. The south basin of Sherbrooke Lake also supports a relict population of Lake Trout.

Cultural Environment
Forestry activities are the dominant land use in this sparsely inhabited area. Mining has also taken place at various localities. Recreational use of the land includes hunting, fishing, hiking, and boating activities.

Sites of Special Interest

• Kejimkujik National Park (part) - eskers and Southern Flying Squirrel (sub-Unit 451a)
• Hollahan Lake (IBP Proposed Ecological Site 41) - Jack Pine forest (sub-Unit 451a)
• Shady Brook (IBP Proposed Ecological site 67) - Red Spruce, Eastern Hemlock forest (sub-Unit 451a)
• Wight Nature Preserve, Hubbards (sub-Unit 451a)

Ecological Reserve

• Panuke Lake Nature Reserve

Provincial Parks and Park Reserves
(All are in sub-Unit 451a, except for Cox Lake.)

• Falls Lake
• Lake George
• Lumsden Pond
• Holden Lake
• Card Lake
• Simms Settlement
• Hollahan Lake
• Halifax Watershed
• Lewis Lake
• Upper Tantallon
• Cox Lake (sub-Unit 451b)

Proposed Parks and Protected Areas System includes Natural Landscape 7a and Candidate Protected Areas 26 Cloud Lake and 27 McGill Lake.

Associated Topics T2.3 Granite in Nova Scotia T3-2 Ancient Drainage Patterns T3-3 Glaciation, Deglaciation and Sea-level Changes T3-4 Terrestrial Glacial Deposits and Landscape Features T4-2 Post-glacial Colonization by Plants T4-3 Post-glacial Colonization by Animals T8.2 Freshwater Environments T8.3 Freshwater Wetlands T10.12 Rare and Endangered Plants T11.18 Rare and Endangered Animals

Associated Habitats H3 Freshwater H4.1 Bog H4.2 Fen H4.3 Swamp H5.1 Barren H6.1 Hardwood Forest (Maple, Oak, Birch Association) H6.2 Softwood Forest (Spruce, Hemlock, Pine Association; Black Spruce, Larch Association) H6.3 Mixedwood Forest (Spruce, Fir, Pine-Maple, Birch Association)