Cawthra - Eglinton 1
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CAWTHRA - EGLINTON 1 Region of Peel NAI Area # 3710, 3754, Toronto and Region 4417 Conservation Authority City of Mississauga Size: 49 hectares Watershed: Etobicoke Creek Con 2 NDS, Lots 9, 10 Ownership: 67% Subwatershed: private, 33% public Little Etobicoke Creek (City of Mississauga, Province of Ontario) General Summary This is an urban site comprised predominantly of deciduous forest, with cultural woodland, marsh and a small amount of swamp. This natural area has good connectivity to other regional corridors via an adjacent cultural meadow and along a hydro corridor. This area is highly disturbed by trash dumping and invasive species but little disturbed in other respects, particularly factors relating to direct human impacts such as trampling and trails. TRCA ELC surveyors, botanists and ornithologists have provided complete data coverage for the core NAI inventories (vegetation communities, plant species, breeding birds) plus incidental observations of other fauna over the delineated area (Table 1). Table 1: TRCA Field Visits Visit Date Inventory Type 25 June 2002 Fauna 24 Oct. 2002 Flora 01 Aug. 2003 ELC Physical Features This area is in the South Slope physiographic region characterized by low-lying ground moraines. The topography at this site is relatively flat. Soils of this region tend to be clay loams with pore sizes between soil particles so small that flow of groundwater to aquifers is slow. This site drains into Etobicoke Creek. It is located close to the watershed boundary between Etobicoke Creek (TRCA jurisdiction) and Cooksville Creek (CVC jurisdiction). While a stream is not evident at the site, the wetlands filter into a swale and the drainage ditches associated with the surrounding highways. Human History The former community of Pucky Huddle was located nearby at the intersection of Tomken Rd. and Burnhamthorpe Rd. One of Mississauga’s oldest remaining structures, the Copeland House was built here in 1837. This village was reputedly a rough-and-tumble place centred around the Pucky Huddle tavern. The tavern was frequented by local farmers. Pucky Huddle also had a brick maker (City of Mississauga, Undated; Mair, 2009). From this it can be deduced that the much of the land around the village was agricultural and that clay was quarried in the vicinity. Although a good portion of the natural area is in public ownership, it is not developed for recreation or other public usage. The area is bordered on two sides by roads, one a highway (Hwy. 403) and the other by busy arterial roads (Cawthra Rd., Eglinton Ave.). Date of this Site Summary: October 2011 CAWTHRA - EGLINTON 2 Surrounding land use includes a small private school, an agricultural field, some commercial use, a few single-unit residences and a hydro substation. A hydro transmission corridor extends from the substation, across the cultural meadow, south of the currently delineated area. Vegetation Communities The general community types present here are deciduous forest (20%), meadow marsh (4%), shallow marsh (6%), deciduous swamp (0.4%), cultural meadow (65%) and cultural woodland (4%). Twenty-four plant communities were mapped for this area, comprised of 11 different vegetation types, none of which are provincially rare (Table 2). One of the community types present here, White Ash Mineral Deciduous Swamp (SWD2-A, L-rank L4), is a TRCA regional Community of Urban Conservation Concern. Seven of the communities, the Purple Loosestrife Mineral Meadow Marshes, are dominated by an invasive species. The deciduous forest communities are mid-aged. Table 2: ELC Vegetation Communities Map Vegetation type Size in % of natural reference * hectares area FOD5-8 Dry-Fresh Sugar Maple - White Ash Deciduous Forest 1.33 2.68 FOD7-2 Fresh-Moist Ash Lowland Deciduous Forest 6.68 13.51 FOD7-c Fresh-Moist Exotic Lowland Deciduous Forest 1.78 3.60 MAM2-2 Reed Canary Grass Mineral Meadow Marsh 0.58 1.18 MAM2-B Purple Loosestrife Mineral Meadow Marsh (5 1.49 3.00 communities) MAS2-1b Narrow-Leaved Cattail Mineral Shallow Marsh 3.10 6.27 (7 communities) MAS2-a Common Reed Mineral Shallow Marsh 0.08 0.17 SWD2-A White Ash Mineral Deciduous Swamp (3 communities) 0.19 0.39 CUM1-A Native Forb Old Field Meadow 10.09 20.39 CUM1-b Exotic Cool-season Grass Old Field Meadow 22.00 44.47 CUW1-A3 Native Deciduous Cultural Woodland 2.14 4.33 TOTAL AREA INVENTORIED 49.46 * Note: The map reference code refers to the vegetation type shown on mapping for this area and also to the Appendix list of species typically encountered in this vegetation type. Species Presence Vascular Plants At least 38 species of vascular plants were observed at this natural area, of which 27 (71%) are native. None are Species At Risk, provincially or regionally rare. One of the plant species is a TRCA regional Species of Conservation Concern and an additional six species are TRCA regional Species of Urban Conservation Concern (Table 3). Breeding Birds At least seven species of breeding birds occur in this area, all of which are native. None are at risk or provincially rare. One of the breeding bird species is a TRCA regional Species of Conservation Concern and the remaining six of these bird species are TRCA regional Species of Urban Conservation Concern (Table 3). The grassland communities in this area are sufficiently large enough to provide nesting habitat for two species of grassland birds, Willow Flycatcher (Empidonax traillii) and Savannah Sparrow (Passerculus sandwichensis). Of these, Savannah Sparrow is area-sensitive. Date of this Site Summary: October 2011 CAWTHRA - EGLINTON 3 Invertebrates Although invertebrates were not targeted in inventories, one notable species present here is the Chimney Crayfish (Fallicambarus fodiens). This native species is a TRCA regional Species of Conservation Concern. Table 3: Regionally Rare Species (shown in bold), TRCA Regional Species of Conservation Concern (L1-L3) and TRCA Regional Species of Urban Conservation Concern (L4) (Kaiser, 2001; Toronto and Region Conservation Authority, 2007) Scientific name Common name S rank G rank L-rank VASCULAR PLANTS Acer rubrum Red Maple S5 G5 L4 Carex crinita Fringed Sedge S5 G5 L3 Fagus grandifolia American Beech S4 G5 L4 Crategeus macrantha Long-spined Hawthorn S5 GNR L4 Quercus macrocarpa Bur Oak S5 G5 L4 Thelypteris palustris var. pubescens Marsh Fern S5 G5T5 L4 Thuja occidentalis Eastern White Cedar S5 G5 L4 BIRDS Scolopax minor American Woodcock S4B G5 L3 Geothlypis trichas Common Yellowthroat S5B G5 L4 Dumetella carolinensis Gray Catbird S5B G5 L4 Colaptes auratus Northern Flicker S4B G5 L4 Passerculus sandwichensis Savannah Sparrow S4B G5 L4 Actitis macularia Spotted Sandpiper S5B G5 L4 Empidonax traillii Willow Flycatcher S5B G5 L4 INVERTEBRATES Fallicambarus fodiens Chimney Crayfish S4 G5 L2 Site Condition and Disturbances This natural area is moderately to highly affected by its urban surroundings. Each of the three largest forest communities has a number of trash dumps, creating a moderate level of disturbance. Invasive species, some of them problematic, are widespread throughout the natural area. Four of the eight vegetation communities at this site have invasive species as community dominants. Particularly widespread are Common Buckthorn (Rhamnus cathartica) and Garlic Mustard (Alliaria petiolata) in the forest communities, and Purple Loosestrife (Lythrum salicaria) and Narrow-leaved Cattail (Typha angustifolia) in the wetland communities. Human traffic in the natural area is not evident. However, the cultural meadow communities under the hydro transmission towers show tracks from off-road vehicles criss-crossing the meadow and wetland. Thus, this site offers a refuge away from regular human disturbance (dumping disturbance is episodic) for sensitive wildlife that are tolerant to the presence of invasive species. Ecological Features and Functions With forest communities greater than 2 ha and wetlands over 0.5 ha in size this natural area has the potential to support and sustain biodiversity, healthy ecosystem functions and to provide long-term Date of this Site Summary: October 2011 CAWTHRA - EGLINTON 4 resilience for the natural system. The adjacent cultural meadow in the hydro corridor is over 10 ha in size and thus also contributes to the health, function and stability of this natural area. By containing a relatively wide variety of habitat types, this natural area supports biodiversity, particularly for species that require more than one habitat type for their life needs. This area has good connectivity via the hydro corridor with other natural areas and corridors. In urban areas, hydro corridors are useful movement corridors, particularly suitable for species that do not require forests. Hydro corridors tend to have substantial width and are relatively permanent features. Wetlands are compatible with this type of land use although succession to treed communities is not permitted. Habitat in hydro corridors is maintained as meadow or low thicket, by periodic mowing and/or treatment with herbicides. At this location, the hydro corridor intersects with the vegetated corridor of Little Etobicoke Creek valley, a short distance to the east, connecting this natural area with a major regional corridor. The relatively close proximity of other areas of natural habitat creates above-average potential for wildlife movement between natural areas, species dispersal and recovery from disturbance, creating additional resilience for the ecosystem. This area supports two grassland bird species, one of which is area-sensitive. Opportunities The linkage between this natural area, the hydro corridor and the Little Etobicoke Creek valley should be maintained and enhanced where possible. When the hydro corridor is scheduled for mowing, if would be most advantageous if the timing of mowing could be delayed until after the young of grassland-nesting birds have fledged. Elsewhere, a beetle bio-control for Purple Loosestrife has been successful in dramatically reducing this wetland invasive species. Introductions of the control beetle into wetlands at this site could be beneficial in allowing re-establishment of native community structure in the wetland currently dominated by Purple Loosestrife.