Hamilton Conservation Authority City of Hamilton Bruce Trail Conservancy


Clappison Escarpment Woods

General Summary

The study area encompasses a 2.6 km segment of the Niagara Escarpment that straddles the City of Hamilton and Halton Region. The bedrock exposures in the abandoned quarry on the escarpment brow are of scientific interest. The upland woods along the escarpment slopes constitute a link in the corridor of natural greenspace along the Niagara Escarpment. As one of the few southerly-facing sections of the Niagara Escarpment, the warmer micro-climate present in this area results in an unusual forested talus slope community association with many rare and uncommon plant species. Though a portion of the area has been acquired as public open space, residential development is encroaching on parts of the study area.


Ontario Ministry of Natural Resources Designation:
• Provincial Earth Science ANSI (Area of Natural and Scientific Interest)
• Regional Life Science ANSI (Area of Natural and Scientific Interest)

City of Hamilton Environmentally Significant Area (ESA) Criteria:
• Significant Earth Science Feature

- the area encompasses provincially significant bedrock exposures

• Significant Ecological Function
- the area contains significant species
- the area contains interior forest habitat (100-200m from forest edge)
- the area contains a high diversity of native plant species
- the area contains rare biotic communities
- the area helps to provide a continuous corridor along the Niagara Escarpment and serves as a link between natural areas in the Halton Region

• Significant Hydrological Function
- the area helps to maintain water quality in Grindstone Creek

Physical Description

The escarpment here is comprised of a steep rock cliff with a forested talus slope beneath. The elevation of the rim ranges from 215 m to 230 m within the study area. Two notable bedrock exposures are present in the study area: the typical upper escarpment stratigraphy from the Reynales Formation to the Ancaster chert beds (Goat Island Member of Lockport Formation) can be viewed in the roadcut along Highway 6; at the King City Quarry, designated a provincially significant earth science site, the siltstone of the Thorold Formation can be seen on the quarry floor, while the Reynales, Irondequoit, Rochester, and Gasport Formations (of the Clinton Group), and the overlying Lockport Formation are exposed in the quarry face.

Above the escarpment, clayey Halton Till has been deposited as a group of small moraines known as the Waterdown Moraines, which parallel the escarpment brow. Several small, unnamed streams arise along the escarpment face in this portion of the Grindstone Creek watershed, and drain southeasterly in a system of ravines cut into the till and shales of the escarpment slope.

Ecological Land Classification

A variety of terrestrial communities associated with the Niagara Escarpment are present, including mature upland woods and successional communities of various ages. Sugar Maple (Acer saccharum ssp. saccharum) covers the steep south facing talus slope, while a light covering of Wild Ginger (Asarum canadense), Blue Cohosh (Caulophyllum thalictroides), Herb Robert (Geranium robertianum), Zig-zag Goldenrod (Solidago flexicaulis) and Tall Bellflower (Campanula americana) can be found in the rocky ground layer. Above the escarpment, the rocky substrate supports a mature forest remnant dominated by Sugar Maple, along with White Ash (Fraxinus americana), Shagbark Hickory (Carya ovata) and Black Cherry (Prunus serotina). Scattered Black Maple (Acer saccharum ssp. nigrum) and Chinquapin Oak (Quercus muehlenbergii) thrive in areas with exposed bedrock.

Flora and Fauna Summary

Vascular Plants

A total of 415 species were documented between 1987 and 1991, including 34 significant species and 28 Carolinian species. Nature Counts surveyors recorded 126 species in 2002, including nine (7%) non-native species.


In 2001, Nature Counts surveyors documented 25 species including two locally uncommon species and one COSEWIC special concern species, the Monarch (Danaus plexippus).


Fish community sampling has not been conducted within the ESA.


A total of seven species were recorded between 1984 and 1991. Nature Counts surveyors recorded two of these same species in 2002.

Breeding Birds

Nature Counts surveyors recorded 39 species in 2001 and 2002, of which eight are locally uncommon species. One, Sharp-shinned Hawk (Accipiter striatus), is a locally rare species and four are interior forest species.


Nature Counts surveyors recorded five common species in 2001 and 2002, including the four species previously documented in 1991.



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