Thompson Creek Flood Study Report - City of Peterborough

Thompson Creek Detailed Flood Reduction Study
City of Peterborough
3.3.2 Terrestrial Features: Wetlands, Vegetation and Wildlife
3.3.2.1 Vegetation
The natural vegetation within the study area was documented by a reconnaissance level
field survey conducted on 5-6 June 2006. The types of vegetation present were
classified and described with reference to the Ecological Land Classification for
Southern Ontario (Lee et al. 1998). The conservation status of observed vascular plants
was determined with reference to the Species at Risk Ontario List (30 June 2006)
(OMNR 2006), the Ontario Plant List (Newmaster et al. 1988), and the Checklist of the
Vascular Plants of Peterborough County (Oldham 1999). The conservation status of
observed vegetation types was determined with reference to Southern Ontario
Vegetation Communities (Bakowsky 1997) and to consultation with Wasyl Bakowsky,
Community Ecologist, Natural Heritage Information Centre.
The natural vegetation within the study area is composed of forests, wetlands,
hedgerows, thickets, regenerating woodlands, old-field meadows and conifer plantation.
Coniferous, mixed and deciduous forests have established on fresh to moist mineral
soils on the upland margins of Thompson’s Creek, whereas mixed swamps, deciduous
swamps, thicket swamps, meadow marshes and shallow marshes have established on
the flooded margins of the large beaver pond and on moist to wet soils on the lowland
margins of Thompson’s Creek. Hedgerows, thickets, patches of regenerating forest,
and old-field meadows have established on former farm fields and field margins. A
conifer plantation has been planted on tableland adjacent to the Otonabee River.
Twenty-five vegetative types (Lee et al. 1998) were observed during the ecological land
classification of the study area (Figure 3.3.2). The most common forest types were
Fresh-Moist Manitoba Maple Lowland Deciduous Forest (FOD7-7) and Fresh-Moist
Lowland Ash Deciduous Forest (FOD7-2). The most common wetland types were
Willow Mineral Thicket Swamp (SWT2-2), Alder Mineral Thicket Swamp (SWT2-1),
Cattail Mineral Shallow Marsh (MAS2-1), Green Ash Mineral Deciduous Swamp
(SWD2-2), and White Cedar – Hardwood Mineral Mixed Swamp (FOM1-1). The most
common cultural vegetation types were Fresh-Moist Old Field Meadow (CUM1-1),
Ash-Elm-Basswood Cultural Woodland (CUW) and Crabapple-Hawthorn-Buckthorn
Cultural Thicket (CUT1-7). None of the observed vegetation types is rare in Ontario
(Bakowsky 1995). The conservation status of Silky Dogwood Mineral Thicket Swamp
(S3/S4) warrants review and is expected to be downgraded to S4 status (W. Bakowsky,
personal communication, July 2006).
Two-hundred-and-eleven species of vascular plants were recorded during the level
botanical survey (Appendix E). Five species are rare in Peterborough County (Burke et
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