Introduction
If you have visited the Lake Erie region of southwestern Ontario, and are interested in ecology or conservation, chances are that you read or heard the term “Carolinian Life Zone”, or “Carolinian Forest” at least once. This interesting term used by botanists to describe the southernmost region of Ontario north of Lake Erie. The region has shorter winters and hotter summers than the rest of the Great Lakes Region, supporting wildlife and vegetation communities typical of the Eastern United States, such as the Carolinas. Many of these “Carolinian” species are found only within this small region of southern Ontario. This small region, encompassing only 0.25% of Canada’s landmass, is home to more species than any other ecoregion in the country.
Geographic scope
The Carolinian Life Zone extends from Grand Bend to Hamilton, and all regions southward. The highest concentrations of Carolinian species are found within a narrow band along the north shore of Lake Erie, including the Long Point Basin, the Niagara Peninsula, Skunk’s Misery (southwest Middlesex County extending into Dawn-Euphemia), the St. Clair River Region (including Walpole Island), the Rondeau Peninsula, Point Pelee National Park, and Pelee Island. Across the eastern United States, the Carolinian Botanical Zone covers a very large area, extending west to Minnesota, southwest to Texas, through the Gulf coast across the Florida Panhandle, and north to Massachusetts. In the U.S., the term Carolinian Forest is analogous to the Eastern Deciduous Forest Region.
Southern species
Carolinian Forests are home to a unique variety of species found nowhere else in Canada. Tuliptree (Liriodendron tulipifera), featured on Long Point Basin Land Trusts logo, is often utilized as a botanical symbol of the Carolinian Life Zone. Tuliptrees usually occur as tall trees within the forests around Lake Erie, abundantly found in Norfolk. Other southern tree species include Sassafras (Sassafras albidum), Black Tupelo (Nyssa sylvatica), Cucumber Magnolia (Magnolia accuminata), Spicebush (Lindera benzoin), Flowering Dogwood (Cornus florida), American Sycamore (Platanus occidentalis), Blue Ash (Fraxinus quadrangulata), Pumpkin Ash (Fraxinus profunda), and Pignut Hickory (Carya glabra).
Many birds are also closely associated with the Carolinian Life Zone – Hooded Warbler (Setophaga citrina), Cerulean Warbler (Setophaga cerulea), Prothonotary Warbler (Protonotaria citrea), Acadian Flycatcher (Empidonax virescens), Yellow-breasted Chat (Icteria virens), Louisiana Waterthrush (Seiurus motacilla), and White-eyed Vireo (Vireo flavifrons). An observation of any one of these Carolinian species while exploring makes for an exciting day for the birders of southwestern Ontario! Mammalian wildlife associated with the Carolinian Life Zone include the Virginia Opossum (Didelphis virginiana) – Canada’s only marsupial, American Badger (Taxidea taxus), an endangered mustelid of open meadows and prairies, and the Southern Flying Squirrel (Glaucomys volans), a nocturnal rodent of dense forests and oak savannas. While the Lake Erie region is well-known for southern species; the severe, typically subzero winters (average highs of -2°C, lows of -10°C occur in both January and February) ensure the persistence of cold-adapted, northerly species. These cold-adapted species comprise most of the vegetation and fauna, with southern species being a minor, but substantial component.
Ontario’s garden
In addition to wildlife and natural biodiversity, the Carolinian Zone is also home to a vibrant farming community. Local farmers grow a diverse variety of food crops, among the most in Canada. Norfolk County, locally known as “Ontario’s Garden”, has sandy soils that are very well-suited for growing many fruit and vegetable crops. Norfolk is Ontario’s No. #1 grower of pumpkins, squash, tart cherries, peppers, asparagus, cabbage, cucumbers, ginseng, rye, and sweet corn. Farmers also produce substantial quantities of tomatoes, apples, pears, peaches, raspberries, blueberries, beans, carrots, potatoes, and grapes – with a few vineyards. Niagara is another well-known area for fruit cultivation, containing orchards for peaches, pears, cherries, and grapes. Essex County, supports North America’s largest greenhouse industry, supporting year-round production of tomatoes, peppers, and cucumbers.
Conserving Carolinian Canada’s wildlife
While southwestern Ontario has very high ecological value, habitat loss has also been extensive. Deforestation occurring in the latter half of the 19th century, where forests were cleared for agriculture and pasture. Forest cover declined from 77% to 19%, and wetland loss exceeded 70% in many areas. In the most deforested areas (Essex and Perth counties, Chatham-Kent), natural vegetation cover is less than 10%. Such extensive habitat destruction has imperiled many species and ecosystems; conservation actions are much needed to increase their chances of survival. But in the present day, high pressures to transform natural ecosystems to human uses remain – this small region is home to 25% of Canada’s human population, with conversion from rural lands to suburban housing occurring at the periphery of major metropolitan areas. Rural land values have also risen, incentivizing some landowners to destroy woodlots, allowing for the expansion of economically valuable cropland.
Nonetheless, some areas have experienced substantial ecological recovery. The largest has been occurring in Norfolk County’s Long Point Basin, where marginal lands have been reforested, resulting in reconnected woodlots, generating larger forested landscapes – unseen in the region since the mid 1800s. Today, the total conservation network around Long Point encompasses well over 10,000 acres and stands as one of Canada’s best examples of ecological restoration! Conservation efforts are slowly spreading to other high-priority areas in southern Ontario – Pelee Island, Skunk’s Misery and AuSable River Basin. These restored landscapes support sensitive wildlife species that cannot thrive in more fragmented landscapes. Restoration has positively impacted nearly ecosystem type – forests, marshes, swamps, woodland-savannas, and tallgrass prairies, allowing for the proliferation of wildlife, and the safeguarding of Carolinian Life Zone’s rich biodiversity.
Fun facts
- Despite being in Canada, the Carolinian Life Zone in Southern Ontario sits at the same latitude as the northern border of California! This southernly location contributes to its warmer climate compared to the rest of Canada. Both regions can grow wine grapes!
- Collectively, the region supports a higher diversity of reptiles than anywhere else in Canada, including Ontario’s only native lizard – the Eastern Five-lined Skink (Plestiodon fasciatus)!
- Wetlands and coastal forests along Lake Erie provide crucial stopover habitat for many migratory bird species traveling along the Atlantic Flyway and Mississippi Flyways. These forests offer essential food and shelter for birds heading to their breeding grounds further north in the spring and back south in the fall.
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Written by Matthew Palarchio, HBSc in Environmental Sciences, Western University
Photos (L-R): Tuliptree by Matthew Palarchio, Prothonotary Warbler by Matthew Palarchio, Eastern Fox Snake (Pantherophis vulpinus) – Canva Stock Photo, Eastern Tiger Swallowtail (Papilio glaucus) on Butterfly Milkweed (Asclepias tuberosa) by Matthew Palarchio
