Life History and Disturbance Response of Quercus alba (white oak)
Family: Fagaceae
Guild: persistent, large-seeded, advance growth dependent
Functional Lifeform: large deciduous tree
Ecological Role: common upland oak found in mixed forests on dry ridge tops, upper slopes and rich coves; persists for long periods, but shade tolerance declines as trees grow large; responds well to release
Lifespan, yrs (typical/max): 300/600
Shade Tolerance: intermediate
Height, m: 24-30
Canopy Tree: yes
Pollination Agent: wind
Seeding, yrs (begins/optimal/declines): 20/75/200
Mast Frequency, yrs: 4-10
New Cohorts Source: seeds or sprouts
Flowering Dates: late spring
Flowers/Cones Damaged by Frost: yes
Seedfall Begins: early fall
Seed Banking: up to 1 yr
Cold Stratification Required: no
Seed Type/Dispersal Distance/Agent: nut (acorn)/ to 50 m/ gravity, birds, other animals
Season of Germination: fall
Seedling Rooting System: taproot
Sprouting: seedling and stump sprouts common
Establishment Seedbed Preferences:
Substrate: loose soil or humus, with litter cover
Light: overstory shade
Moisture: neutral
Temperature: 10 - 16C favors germination
Disturbance response:
Fire: White oak is well-adapted to periodic fire. It is unable to regenerate beneath the shade of parent trees and relies on periodic fires for its perpetuation. Fire exclusion has inhibited white oak regeneration through much of its range. Periodic fires in upland oak systems promote oak dominance by opening the canopy and reducing competition. Fires in upland forests tend to be low- to moderate-intensity and short in duration. Fires primarily occur during the dormant season at frequent intervals (once or more per decade to several decades). White oak is moderately resistant to fire, possessing thick, rough, scaly bark and deep roots. It becomes more fire resistant with age as bark thickens. When topkilled, seedlings and saplings readily and persistently sprout from the root crown or stump. Small fire scars are rapidly compartmentalized and damage is usually limited. Fire promotes seedling establishment by creating favorable seedbeds and reducing competition. However, acorns present during the fire are usually killed. Seedling establishment may occur from seeds of surviving trees onsite or from offsite seeds carried by birds and other animals. Low-intensity prescribed fire has been used successfully to promote white oak advanced regeneration.
Weather: White oak is moderately resistant to ice breakage, but sensitive to flooding.
Air pollution: White oak is intermediate in sensitivity to sulphur dioxide and sensitive to ozone. Variable foliar injury has been observed under high ambient ozone conditions; no injury was noted under controlled fumigations.
Exotics: Gypsy moth (Lymantria dispar) is a defoliator of eastern hardwood forests, introduced to Massachusetts from France in 1885. It has spread throughout New England into Virginia and Michigan. Defoliation causes growth loss, decline, and mortality. It feeds on many tree species, but Quercus and Populus are the most susceptible taxa, and trees growing on xeric sites are the most vulnerable. Various efforts have been made to control it, with mixed results. A fungus, Entomophaga maimaiga introduced from Japan causes considerable mortality to gypsy moth populations. E. maimaiga levels are promoted by damp weather.