Description
This is a re-entrant valley in the Niagara Escarpment. The area is characterized by many forest types on the wide variety of slopes, exposures and moisture regimes. Significant wildlife populations. Various portions known as Spencer Gorge Escarpment Valley (ca. 56 ha), Mineral Springs Forest (ca. 38 ha) and Sulphur Creek Forest (ca. 180 ha) (Eagles & Beechey, 1985).
Vegetation
Spencer Gorge Escarpment Valley (Eagles & Beechey, 1985):
The vegetation patterns here appear to be transitional in character between those of the valleys of the Niagara and Halton Sections of the escarpment associated features. The slope forests are reported to be a mixture of Acer-Quercus-Tilia-Pinus and Tsuga-Acer-Betula (?) communities; the valley bottom canopy includes elements of either as well as very local terraced forests of Acer-Fagus. |
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Mineral Springs Forest (Eagles & Beechey, 1985):
It reputedly has a relatively mature and rich forest which includes several Carolinian species as well as many other species that are typically associated with this habitat and its vegetation. The western half of the area appears to be disturbed and plantains occur all around the area, but its eastern half indeed presents a well developed forest.
Sulphur Creek Forest (Eagles & Beechey, 1985):
It has generally intermediate to young aged forests on the dry mesic ridge crests (Quercus-Acer-Carya), the mesic valley slopes (Acer-Tilia-Fraxinus) and wet mesic valley bottoms (Acer-Betula-Fagus). There are representative southern plant species such as Sassafras, Hamamelis, and Symplocarpus with a good nesting avifauna.
Dundas Valley (Eagles & Beechey, 1985):
The Valley contains many species that are found in Canada only within the Carolinian life zone. The varied topography and the resultant soils, slope, moisture and incident sunlight variations, the southern location and the land use history has produced an area with very high biological diversity. Some of the distant communities include: upland deciduous forest, upland (north-facing) coniferous forest, river, floodplain deciduous forest, upland conifer plantation, working and abandoned orchards, farms plus all ages of ecological succession, on a variety of sites, ranging from grass fields, through old fields, young forest to climax forest. There are forests that may never have been logged. As a result of these conditions and the extensive size of the natural forests many otherwise rare and endangered species still survive and prosper in the valley.
Representation
Spencer Gorge Escarpment Valley (Eagles & Beechey, 1985):
Any talus slope forest patterns do not appear to be well developed; however, there are representative and often well developed escarpment face and rim groves. Unfortunately there is severe disturbance of the escarpment plain communities except in very local and small portions. This valley provides a deep, natural contrast to the surrounding areas; not only scenic splender is here, but also a significant geomorphological feature and a well developed community pattern.
Landform
Spencer Gorge Escarpment Valley (Eagles & Beechey, 1985):
This escarpment associated feature in an excellent development of an incised escarpment valley which has two branches behind the escarpment face. It is located to the north of and adjacent to Dundas and is managed by the Hamilton Region Conservation Authority as a natural Conservation Area: The "Spencer Gorge Wilderness Area". The geomorphology of the area consists of a bifurcating, incised, stream cut escarpment valley of the East and West Spencer Creeks. The former branch presents the more typical pattern for the vicinity: that of a small, steep sided water cut valley directly penetrating the escarpment face of limestone and shale bedrocks. The latter stream, however, has a spur from this valley and has meandered to the west producing a varied complement of meander patterns that occur only very locally elsewhere along the escarpment in the Niagara Peninsula. Both of these branches have excellent water falls at their heads that provide excellent displays of the bedrock strata. Mineral Springs Forest (Eagles & Beechey, 1985):
This site contains one of the most mature silty loam till slope and valley forests in the Dundas Valley. The physiography presents one small valley with a permanent stream and some seepage which is reported to present a local exposure of the Dolomitic bedrock.
Sulphur Creek Forest (Eagles & Beechey, 1985):
This site is the most extensive forested silty loam till valley pattern in the Dundas Valley. It encompasses the crest and a major portion of the slope including a series of valleys, permanent and intermittent streams, seepage slopes, bottomlands; no escarpment exposures are evident.
Dundas Valley (ESA) (Eagles & Beechey, 1985):
The Valley resulted from pre-glacial erosion which cut deeply into the Niagara Escarpment. Later the glaciers eroded the surface further and rocky, unstratified material was deposited by the advancing and retreating ice lobes covering the area. The oscillating ice margin created glacial lakes between ice lobes and exposed land spillways, glaciolacustrine deposits and shoreline features in the Valley are part of these depositions of glacial waters. The lower section of the Valley is part of a glacial end moraine with gravelly depositions and intermittent proglacial lake terraces. Stream bank erosion and slippage can be seen in various areas. The middle part of the Valley is a rough area of glacial deposits with a kame and kettle land form, and drainage is blocked in places. The upper section of the Valley is characterized by glaciolacustrine land forms. The sides of the Valley are defined by the Niagara Escarpment which disappears under the deep glacial deposits. The major soil of the area is the well drained Ancaster silt loam, which formed on the ridges and moraines surrounding and separating the ravines of the Dundas Valley. It developed from silty, clay, loam till. Small areas of well-drained Oneida clay loam developed from clay till also occur. In the upper portion of the valley, adjacent to Spring Creek a complex of Grimsby sandy loam and Brant silt loam developed from water-deposited material.
References
- Allen, G.M., P.F.J. Eagles and S.D. Price (eds.) 1990. Conserving Carolinian Canada: Conservation Biology in the Deciduous Forest Region. University of Waterloo Press, Waterloo. 346 pp.
- Eagles, P.F.J. and T.J. Beechey (eds.) 1985. Critical Unprotected Natural Areas in the Carolinian Life Zone of Canada. Final Report, Identification Subcommittee, Carolinian Canada. The Nature Conservancy of Canada, The Ontario Heritage Foundation and World Wildlife Fund (Canada). 400 pp.
- Ecologistics Limited. 1976. Hamilton-Wentworth Region Environmentally Sensitive Areas Study. Hamilton Region Conservation Authority, Ancaster; Grand River Conservation Authority, Cambridge; Halton Region Conservation Authority, Milton; Niagara Peninsula Conservation Authority, Allanburg.
© Natural Heritage Information Centre, 1998
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