Introducing Long Point’s oak trees 

The Long Point Basin has 8 species of oaks, distributed widely across many different ecosystems, from oak savannas (displayed in the rightmost photo) to swampy woodlands! These oaks are categorized into two major groups – red oaks (Quercus section Lobatae) and white oaks (Quercus section Quecus), with a few notable differences in the fruit structure and leaf morphology. For species in the white oak group, it takes one year for an acorn to fully mature, while red oak acorns require two years to mature. White oak acorns are sweet, and red oak acorns are bitter. All of Ontario’s species in the red oak group have pointed leaf lobes, whereas species of the white oak group have smooth leaf lobes. Black Oak (Quercus velutina), Northern Red Oak (Quercus rubra), and Northern Pin Oak (Quercus ellipsoidalis) are part of the red oak group, whereas White Oak (Q. alba), Bur Oak (Quercus macrocarpa), Swamp White Oak (Quercus bicolor), Chinquapin Oak (Quercus muehlenbergii) and Dwarf Chinquapin Oak (Quercus prinoides) are in the white oak group.

Northern Red Oak description, ecology, and habitat

Red Oak is one of Long Point Basin’s most abundant, widely distributed, and important tree species. It is a large tree, often exceeding 30 m in height on fertile soils. The foliage of Red Oak is typically 10-25 cm long, 8-15 cm broad, with 7-11 pinnate lobes that have bristle-like tips. The sinuses (space between lobes) extend less than halfway to the midrib (Black Oak has more deeply divided lobes). The leaves are deep green above, and a little lighter on the underside. Autumn foliage is scarlet, red, deep orange, or rusty bronze. As typical for oaks, leaf colour change occurs later than other species, regularly in October for even northern regions, and around Lake Erie, usually around October 20th. Red Oak is sometimes confused with Black Oak, but it can be distinguished by it’s bark (smooth vertical ridges which often expose red or white inner bark, compared to Black Oak, which typically has black, squarish ridges on the bark), and fruit (Red Oak has a large, 1.5-3 cm diameter acorn, with a cap covering less than 1/3 of the acorn, whereas Black Oak has a smaller, 1.5 cm acorn with a deep cup covering 1/2 the acorn).

Red Oak can be found in a wide variety of habitats, including oak savannas, dry-mesic forests (where Red Oak is most dominant), moist mesic forests, riparian forests, and swamp margins. Red Oaks are found throughout the entire Great Lakes Region (except for the northernmost areas around Wawa on Lake Superior’s north shore). They are more abundant in some areas though – sand plains and moraines are their most preferred habitat. Red Oak is likely most abundant in the northeastern Lower Peninsula of Michigan, where vast forests are found mostly or entirely of this species, overtop of massive sandy moraines. Smaller areas with a large oak component are found throughout Ontario, such as the Ganaraska Forest on the Oak Ridges Moraine, the Oro Moraine of Simcoe County, and throughout the Lake Erie Region, including the Long Point Basin, and many other regions. However, Red Oak is often in competition with more shade tolerant, mesic forest species such as Sugar Maple (Acer saccharum), Yellow Birch (Betula lutea), and Beech (Fagus grandifolia). Without disturbance, these latter species will rise in proportional abundance compared to oak. Thus, Red Oak is commonly found as scattered individuals within moist forests dominated by maple or beech, restricting Red Oak dominated forests to sandier soils (and contrastingly, those with the most poorly drained lakeplains, such as Bickford Oak Woods and Mosa Forest). It is uncommon the inland lake regions on the Canadian Shield, being scarce in much of the Algonquin Highlands (where Sugar Maple dominates), but in the La Cloche Mountains and Algoma Highlands, Red Oak is often observed on south-facing rock faces and slopes. It is distributed southwards from the Great Lakes Region into Alabama and Mississippi, but does not reach the Gulf Coast.

Throughout the Great Lakes Region, Red Oak is most frequently observed with other oak species, including White Oak, Black Oak, and Chinquapin Oak. It is also found alongside pines, especially White Pine (Pinus strobus) and Red Pine (Pinus resinosa). In addition to these trees, Red Oak occurs with Black Cherry (Prunus serotina), Red Maple (Acer rubrum), Ironwood (Ostyra virginiana), Sassafras (Sassafras albidum), and other oak-dominated forests, also with Shagbark Hickory (Carya ovata), Bitternut Hickory (Carya cordiformis), White Ash (Fraxinus americana), Basswood (Tilia americana), Bigtooth Aspen (Populus grandidentata), Tuliptree (Liriodendron tulipifera), and American Chestnut (Castanea dentata). Red Oak is found in Sugar Maple – American Beech forests at lower abundances. The understory of Red Oak forests are usually dominated by shade-tolerant perennial wildflowers, but on drier, sandier sites, Bracken Fern (Pteridium aquilinum) and Wild Sarsaparilla (Aralia nudicaulis) have especially high abundances. Shrubs with an affinity for Oak Forests include American Witch-Hazel (Hamamelis virginiana), American Hazel (Corylus americana), Flowering Dogwood (Cornus florida), Chokecherry (Prunus virginiana), and in moist forests, Red Elderberry (Sambucus racemosa), Blue-beech (Carpinus caroliniana) and Pagoda Dogwood (Cornus alternifolia).

Ecological importance of Red Oak

Each autumn, Red Oak acorns are consumed by a vast diversity of wildlife, including squirrels (Sciuridae), White-tailed Deer (Odocoileus virginianus), Wild Turkeys (Meleagris gallopavo), grouse, Blue Jays (Cyanocitta cristata), and Black Bears (Ursus americanus). In more northern regions, such as the Algonquin Highlands, these acorns are also consumed by Elk (Cervus canadensis). Oaks also support highly biodiverse insect community, including 534 species of lepidopterans (butterflies and moths). Red Oak is a host plant for the Oak Leafshredder Moth (Croesia semipurpurana), Spiny Oakworm Moth (Anisota stigma), Orange-humped Oakworm Moth (Anisota senatoria), Saddled Prominent Moth (Heterocampa guttivitta), and the Variable Oakleaf Caterpillar (Lochmaeus manteo). The leaves are also consumed by caterpillars of the invasive Spongy Moth (Lymantria dispar), large infestations which can defoliate entire trees. Fortunately, oaks often recover fully from insect infestations during the following growing season.

When marginal lands in the Long Point Basin are restored to natural habitat, especially on recently secured Long Point Basin Land Trust or Nature Conservancy of Canada land, Red Oak is one of the first species to establish. This is due to the species affinity for full sun conditions and sandy soil (which dominates southern Norfolk County), as well as a general tolerance for exposed areas. Red Oak stabilizes these areas, reducing soil erosion. As these trees grow, regenerating Red Oak forests absorb atmospheric carbon dioxide, strengthen forest connectivity, and provide habitat to a wide variety of other plant and animal species.

Oak Wilt 

In the United States, all species in the Red Oak group suffer from Oak Wilt (Bretziella fagacearum). This disease was introduced from Mexico, and as of 2025, there has been a few isolated cases of Oak Wilt in Ontario. This introduced fungal pathogen kills host trees within a few weeks. Luckily, it is not as an effective spreader as other pathogens (such as Chestnut Blight, Cryphonectria parasitica), and Northern Red Oak typically remains a major feature on the landscape. Oak Wilt can be a more severe problem in small areas and ecosystems with a high oak abundance, such as islands and oak savannas.

Fun facts

• The dense canopy of the Northern Red Oak is a wildlife attractant – it provides shelter and nesting sites for a wide variety of songbirds and small mammals throughout the year.
• To ecologists, Red Oak is considered a foundational species in the Great Lakes Region – a species with both high abundance and high importance.
• Northern Red Oak can live over 300 years in old-growth forests and oak savannas.
• Some wildlife species, such as Blue Jays, Grey Squirrels (Sciurus carolinensis), and Chipmunks (Tamias striatus), play a substantial role in distributing acorns, allowing for dispersal to locations distant from the parent tree.

 

Written by Matthew Palarchio, HBSc in Environmental Sciences, Western University.

All photos provided by Matthew Palarchio

 

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To view a directory of all species featured on our website, visit: https://longpointlandtrust.ca/featured-species