Description

A relatively intact, river valley corridor illustrating an excellent variety of typical valley rim, slope, and bottomland communities. It includes an impressive set of upland deciduous forests containing oak, hickory, tulip, and sassafras trees (Eagles & Beechey, 1985).

Roughly halfway from both its source (at the northern border of Norfolk County) and its mouth (near Long Point on Lake Erie), Big Creek cuts a steep-sided valley for about five km between the towns of Delhi and Lynedoch. Many small, srping-fed creeks and continuous seepage along the ravine banks provide Big Creek with a steady source of water. This vast reservoir of spring water is partcularly pure, as it percolates through the deep fine sands of the Norfolk Sand Plain. The eastern slopes of the valley's upland forests are hot and dry with oaks and hickories, while the western slopes are cool and moist with cedars and hemlock. Floodplain depressions -- traces of former stream meanders and channels -- comprised of cedar swamps, flank the creek. Edging the rim of the valley are small prairie remnants with plants such as Little Bluestem, Flowering Spurge, and Round-headed Bush Clover.

The remnants of an early 20th-century power dam remain beside the creek at Croton, within the conservation lands acquired by the Long Point Region Conservation Authority. The majority of land in Delhi Big Creek Valley is privately owned (Long Point Region Conservation Authority also owns 53.8 ha). Natural Heritage Stewardship Agreements negotiated by the conservation authority with eight landowners protect 55% of the area (taken from Carolinian Canada Signature Sites Guide by Lorraine Johnson 2005).

Vegetation

A steep-sided valley dissects the Norfolk sand plain along Big Creek for about 5 km between Delhi and Lynedoch. Near the south end of the valley, the river also cuts through a low moraine ridge which crosses the valley in a northeast-southwest direction. Mixed forests, which vary considerably in relation to slope exposure, soil moisture and stand history, cover the valley slopes (cedar- hemlock- ash- yellow birch- white birch- basswood- elm; sugar maple- beech- ash- hemlock; oak- white pine- sugar maple- hemlock; cedar- white birch- hemlock, etc.). Closed and semi-open associations of cottonwood, willow, black walnut, manitoba maple, blue beech, ash, cedar and elm, along with shrub thickets, characterize floodplain and riverbank habitats along the meandering course of Big Creek. Other bottomland sites consist of drier, more elevated, floodplain terraces and wetter, lower, floodplain depressions (which are indicators of former stream meanders and channels). Stands of white pine; cedar-ironwood-beech-ash; and birch-ash-black maple-poplar-beech-hemlock were noted on floodplain terraces. Cedar swamp composed of cedar-yellow birch-red maple- willow- poplar-white birch-white pine occurs in the floodplain depression, flanking the river. Edging the rim of the valley are young dry oak parklands (oak- pine- large-toothed aspen) and occasional small prairie remnants with Andropogon scoparius, Asclepias tuberosa, Euphorbia corollata, Helianthus strumosus, Lezpedeza capitata, and Polygala senega. Other plants of note, found in the valley are Zigadenus elegans and Viola triloba (Lindsay, 1984 in Eagles & Beechey, 1985).

See Eagles & Beechey, 1985 for the vegetation association and/or complex summary.

Community Description (Eagles 1983, in Eagles & Beechey, 1985):
Upland Deciduous Forest:
This forest is the most abundant community type in the ESA. Tree species vary in abundance with the many microsites present. Many forest types exist due to past land practice, microclimates, varying slope aspect, seepage areas, floodplain, alluvial deposits, bank erosion and soil composition. On dry sites White Pine as well as three species of oak are dominant- Red Oak, White Oak, and Black Oak. Under these trees grow Blue Beech, Witch Hazel etc. Other abundant trees include: Whit Ash and Butternut. In dry openings, Hairy Bush Clover can be found. The upland deciduous forests are representative of the Carolinian forest zone.

Upland Coniferous Forest:
Two types of coniferous forest exist on the cooler east-facing slopes. White cedar grows abundantly on the wetter seepage slopes to form a coniferous swamp. The understory is dominated by Skunk Cabbage, and Bulblet Fern. Canada Moonseed grows up the cedars. Eastern Hemlock grows on the drier slopes. The best example of this type of forest occurs on the west side of the river where a large spring-fed creek flows into the main river by a small waterfall. The sub-dominant of this forest is Sugar Maple. The understory is quite sparse due to the heavy shade. The most frequently herbaceous plants include Wild Ginger, Solomon's Seal, and Toothwort.

Floodplain Forest:
The floodplain has a diversity of forest types due to such factors as slight elevation differences, erosion slopes, alluvial plains and past forest disturbances. It is difficult to typify the floodplain forest, due to the heterogeneity. In spots a mature Black Walnut forest occurs. In other places Cottonwood is dominant with frequent Trembling Aspen. Crack Willow is frequent. Bladdernut and Prickly Ash, two Carolinian shrubs, occur as understory plants. Wild Bean is a frequent vine growing over the heavy thick floodplain growth.

Representation

No individual association in Delhi Big Creek could be considered unique. Rather this area illustrates very representative valley community complexes in the Norfolk sand plain. The really outstanding feature of the ANSI is the intactness of the river valley vegetation complexes along its entire length (approx. 5 km). The valley also displays outstanding example of floodplain terraces of both modern and earlier origin. The continuous seepage along the ravine banks serves to provide Big Creek with a steady source of water. The river valley ravines are a vast reservoir of pure spring water which have percolated through the deep fine sands above and are seeping out where they meet the less pernious clay layers (Eagles & Beechey, 1985).

Landform

A deep river valley dissecting the Norfolk Sand Plain. Deep Glaciolacustrine sands overlie silt till and glaciolacustrine sediments (clay, silt, sand and gravel). For the most part soils are derived form either modern alluvium or older alluvian on the upper terraces. Valley slopes are lacustrine sand and loamy/sands of the Fox series. Clay often exposed where valley slopes have collapsed (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

Visit other Carolinian Canada Signature Sites, Return to the Main Signature Sites Page