Bur Oak

Pollinator Value

🔑 Keystone: Quercus is the top keystone genus in eastern North America, supporting 401 lepidoptera species in the Ottawa-Gatineau ecoregion. Bur oak anchors prairie-forest ecotones and oak savannas, providing critical canopy structure and mast resources that sustain food webs from caterpillars to cavity-nesting birds.
S13 401 lepidoptera; S41 prairie-forest ecotone role; S10 high wildlife value
🐛 Larval Host: Acronicta retardata, Dryocampa rubicunda, Furcula borealis, Haploa clymene, Hypercompe scribonia, Limenitis archippus, Ceratomia amyntor, Lochmaeus manteo, Orgyia definita, Acronicta interrupta, Limenitis arthemis, Papilio glaucus, Acronicta funeralis, Callosamia promethea, Campaea perlata
S13+S15 15 verified Eastern NA
❄️ Winter Food Source: Large acorns persist from September through fall and are consumed by Blue Jay, Wild Turkey, Ruffed Grouse, Wood Duck, Red-headed Woodpecker, and Common Grackle among 24 bird species. Mammals including Gray Squirrel, Fox Squirrel, White-tailed Deer, Black Bear, Raccoon, and Eastern Chipmunk rely heavily on the mast crop through winter.
S57 24 bird species on Quercus; S10 mammal list; S41 acorns eaten by red squirrels, wood ducks, deer

Proximity Score: 0
Native Status: ✅ Outaouais ✅ Ottawa ✅ QC ✅ ON
Closest Direction: Local
CEC Eco-Regions: 5 – Northern Forests, 5.2 – Mixed Wood Shield, 5.2.3 – Algonquin/Southern Laurentians
Rarity Notes: Globally secure (G5) with no SARA or COSEWIC listing. Ranked S5 in Ontario and S4 in Quebec, reflecting somewhat sparser distribution on the Quebec side of the Ottawa River. In the Outaouais, bur oak is common along the Ottawa and Gatineau river corridors but less frequent in the Shield uplands.
S22 G5, S5 ON, S4 QC; S26 not SARA listed; S63 common ON, sparse QC
Rarity Ranks: QC S4 – Apparently Secure, ON S5 – Secure
Migration: Stable
Ecological Context: Bur oak is the quintessential prairie-forest ecotone species, anchoring oak savannas and open woodlands on calcareous soils, sandy plains, and fertile bottomlands across the Ottawa-Gatineau region. Its thick, fire-resistant bark and deep taproot allow it to pioneer dry upland sites and persist through disturbance regimes that exclude less tolerant hardwoods.
S41 prairie-forest pioneer, calcareous soils; S10 bottomlands and savannas; S63 common in Ottawa-Hull

Roles: Fire Retardant, Fortress/Barrier, Insectary Plant, Living Mulch, Nutrient Accumulator, Shelterbelter, Wildlife Habitat
S73/S29/S72 Evidence: Fire Retardant: S73 [MEDIUM]: S11 Fire Tolerance = High (not definitional)] | Fortress/Barrier: S61 keyword match: thorns? (supporting signal only)] | Insectary Plant: S72 Hemenway (tables: 6-2, appendix_a, 10-1, pp. 96, 149, 186)] | Living Mulch: S10 keyword match: forms? colon(?:y|ies) (supporting signal only)] | Nutrient Accumulator: S72 Hemenway (tables: 6-2, appendix_a, 10-1, pp. 96, 149, 186)] | Shelterbelter: S72 Hemenway (tables: 6-2, appendix_a, 10-1, pp. 96, 149, 186); S72 Hemenway (tables: 6-2, appendix_a, 10-1, pp. 96, 149, 186)] | Wildlife Habitat: S72 Hemenway (tables: 6-2, appendix_a, 10-1, pp. 96, 149, 186)]
Notes: As a canopy guild anchor, bur oak provides deep-rooted nutrient cycling, heavy mast production, and structural complexity for multi-layered plantings. Its open crown admits enough light for a productive understory of hazelnuts, viburnums, and shade-tolerant herbs. In designed food forests, pair with nitrogen-fixers like Elaeagnus umbellata at the shrub layer and mycorrhizal-compatible ectomycorrhizal associates.
S72 Hemenway canopy guild design; S41 associated cover types; S53 EM mycorrhizal

Category: Analgesic, Antidiarrheal, Antispasmodic, Astringent, Dermatological Aid, Gastrointestinal Aid, Heart Medicine, Pulmonary Aid, Tonic
S28 Chippewa, Iroquois, Meskwaki, Ojibwa uses; S29 bark astringent and tonic
Notes: Chippewa used decoctions of root or inner bark for cramps and lung ailments, and a compound ceremonial decoction for heart trouble. Iroquois employed bark chip infusions for diarrhea. Ojibwa applied bark as an astringent and orthopedic bandage. Oak galls, rich in tannins, were used to treat hemorrhages and dysentery. The bark is considered astringent and tonic.
S28 12 medicinal uses across 6 nations; S29 astringent, tonic, diarrhoea treatment

✅ Edible

Foraging Notes: Acorns were a significant food source for many Indigenous peoples including Chippewa, Dakota, Ojibwa, Lakota, Omaha, Ponca, Pawnee, and Winnebago. Tannins were leached using basswood ashes or boiling, and acorns were roasted, boiled as a vegetable, mashed with grease, or ground into flour for bread and dumplings. Among white oaks, bur oak acorns are considered the most palatable, with some trees producing sweet seeds low in tannins that can be eaten raw.
S28 11 food uses across 9 nations; S29 seed to 5cm, most palatable of oaks