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COSEWIC Assessment and Status Report on the Eastern Flowering Dogwood in Canada


Habitat Requirements

 Cornus florida typically occurs as an understory or edge tree of open dry-mesic oak-hickory to mesic maple-beech deciduous or mixed forests. It often occurs in drier aspects of its habitats, such as the top of slopes or on a southern exposure. Occasionally it is found in moist or lowland sites within its forest habitat, but not areas that are periodically flooded. It occurs on sand to sandy loam or occasionally on clay loam soils. Forests where it occurs are commonly mid-age to mature. There may be a light to moderate amount of disturbance within occupied habitats, such as where sustainable forest harvesting practices have taken place. This tends to promote seedling establishment in habitats with closed canopies. Cornus florida is less tolerant of more severe practices resulting in major forest openings or clearings. It does not appear to be dependent on other specific species.

Suitable habitat often appears to occur through more of a site than is occupied. The species typically occurs in clusters of individuals within larger areas of habitat that are apparently equally suitable but unoccupied. On a landscape level, suitable forest habitat is highly fragmented in the Carolinian Zone; in Chatham-Kent and Essex County the forest cover reaches an extreme low; only a few percent of the landscape is forested.

Other woody Species at Risk that occur in the same habitats include: American chestnut (Castanea dentata) and butternut (Juglans cinerea). The following species with restricted distribution in the Carolinian Zone occur with Cornus florida: dwarf chinquapin oak (Quercus prinoides), tulip tree (Liriodendron tulipifera), winged sumac (Rhus copallina), black oak (Quercus velutina), black walnut (Juglans nigra), pignut hickory (Carya glabra), American witch-hazel (Hamamelis virginiana), black gum (Nyssa sylvatica) and pin oak (Quercus palustris).

Habitat Trends

Historically, this species occurred through much of the Carolinian Zone, an area that has been severely cleared for its productive agricultural lands and related settlements and industry. Thus, the historical trend is a significant reduction and fragmentation of forest cover and suitable habitat. In the last twenty-five years renewed efforts have been made to document and map significant areas and provide them with protection through designation, acquisition or other securement devices such as conservation easements and stewardship agreements, culminating in efforts to reverse the trend of habitat degradation and loss. Local habitat restoration projects have attempted to turn around the past loss in several areas of southern Ontario. Nevertheless, forest cover and important habitat continue to decline in some areas.

Habitat Protection/Ownership

Some of the sites with Cornus florida habitat are protected as provincial parks (Wheatley, Short Hills), conservation areas, (Balls Falls, Rock Glen, Backus Woods), county forests (Norfolk County), or designated environmentally significant areas but not necessarily with strong local planning protection. However, many municipalities are adding natural heritage mapping to their planning tools; the future looks brighter for these.