Description

A river valley complex and neighbouring sand plain forest with excellent examples of open floodplain communities including wet meadow, marshes, shrub carr, and oxbow ponds (Eagles & Beechey, 1985).
The South Walsingham Sand Ridges and Big Creek Floodplain "Area of Natural and Scientific Interest" (ANSI) and Carolinian Canada Site contains one of the most significant and biologically diverse forests remaining in the Carolinian Zone of southwestern Ontario. A multitude of private, public, and non-profit landowners are responsible for the stewardship of this natural area. Several years ago, the ANSI's largest land owner, the Long Point Region Conservation Authority, asked Bird Studies Canada and the Ministry of Natural Resources to devise a management strategy for the ANSI.

This strategy document -- prepared in partnership by the Ontario Ministry of Natural Resources, the Long Point Region Conservation Authority, Bird Studies Canada, and landowner representatives -- provides a synthesis of the efforts of a steering committee, technical planning committee and commenting landowners to conserve natural heritage values through wise forest management practices and long term planning, while at the same time allowing an economic return from the forest.

This represents one of the first projects in Ontario to study the relationship between forest characteristics, such as the proportion of different sized trees, and forest bird community representation. This has resulted in new recommendations in provincial forest management guidelines and has provided some direction for further studies on forest management and its impact on forest bird communities.

An Adobe Acrobat PDF file is available for downloading from BSC's website

Vegetation

Big Creek Floodplain: Excellent examples of open floodplain communities remain along Big Creek at this location. The rather broad floodplain holds stranded meander pools with submerged, floating and emergent aquatic vegetation, wet forb and shrub meadows, cattail swards, buttonbush-willow-dogwood thickets, and seasonally inundated groves of deciduous floodplain forest (willow, sycamore, black walnut) situated on riverbank levees or raised portions of the floodplain. The north-facing valley slopes and tributary ravines support mixed forests of hemlock with white pine, yellow birch, red maple and beech in good condition. The south and east-facing slopes are wooded with sugar maple and some beech and hemlock. Portions of these slopes have been recently disturbed by selective logging. Dry oak-pine sandland forests occur along the valley rim (Lindsay, 1984 in Eagles & Beechey, 1985).

South Walsingham Sand Ridges: Within this area, a combination of undulating sand ridges (from 3 to 7m in height) and wetter, lowlying plains creates a varied landscape. The dry to dry mesic slopes and crests of the ridges are wooded with oak and white pine. Deciduous lowlands and swamps (silver maple, red maple, yellow birch, ash, bitternut and tulip-tree) stretch between the ridges. Carolinian species such as sassafras, black oak, tulip-tree and flowering dogwood are well represented. A few plots of coniferous reforestation are scattered through the forest. Parts of this site are various disturbed by selective cutting, forest management and forest access roads (Eagles & Beechey, 1985). See Eagles and Beechey, 1985 for complete lists of vegetation associations or complexes in these two sites.

Representation

Big Creek Floodplain: This candidate nature reserve was chosen to represent the open floodplain communities of river valley systems; habitats which are disappearing rapidly throughout the Norfolk sand plain region as drainage projects facilitate the conversion of floodplains to agricultural land. It is a large natural unit with a diversity of habitats and wildlife. On the south it connects with another candidate nature reserve, the South Walsingham Sand Ridges (Lindsay, 1984 in Eagles & Beechey, 1985). South Walsingham Sand Ridges: This site is a large, diverse area offering representation of a sand ridge and lowland forest tract typical of the Norfolk sand plain (Eagles & Beechey, 1985).

Landform

Big Creek Floodplain: Floodplain terraces are less pronounced than the former Big Creek Site. Glaciolacustrine sands overlie silty clay till and glaciolacustrine clay. Heavy clay deposits are prevalent along the steep valley slopes especially is the extreme north and south of the study area. Eolian find sand of the Plainfield series occurs along the western valley slope, rim and tablelands. Lacustrine silt loam and silty clay loam till predominate on the eastern valley slope and rim and at the extreme south end of the western slopes. Sharp changes in soil type and texture occur between fine sand, and silty clay. Bottomland areas are a composite of silt, clay, sand and muck. Seasonal flooding occurs over most of the floodplain complex. Shallow depressions and old oxbows retain surface water well into mid-summer. Standing water in shrub thickets and floodplain meadows may often persist into late June and early July (Eagles & Beechey, 1985).

South Walsingham Sand Ridges: The entire study area consists of a complex of large and smaller dunes on the Norfolk sand plain. These dunes form a roughly parallel series, oriented in a NE-SW fashion. The resulting topography is a continuous and rather complex set of sand ridges and hollows. The ridge and hollow topography is smooth and undulating. With the exception of the largest dune ridges, slopes are gently to moderately steep. Eolian fine sands of the Plainfield and Walsingham series form the dominant soil types. The sand ridges and large dunes are represented by Plainfield sands, soils characterized by rapid drainage and deep parent material. The deep fine sands encourage rapid infiltration of surface moisture along dune ridges and slopes. Groundwater is frequently at the surface in the larger depressions between the sand ridges (Eagles & Beechey, 1985).

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.

* Lindsay, K.M. 1984. Life Science Areas of Natural and Scientific Interest in Site District 7-2 West of the Haldimand Clay Plain: A Review and Assessment of Significant Natural Areas in Site District 7-2 West of the Haldimand Clay Plain. Ontario Ministry of Natural Resources, Central Region, Richmond Hill, and Southwestern Region, London. SR OFER 8403. viii + 131 pp. + map.

© Natural Heritage Information Centre, 1998

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