Life History and Disturbance Response of Betula alleghaniensis (yellow birch)
Family: Betulaceae
Guild: opportunistic, long-lived intermediate
Functional Lifeform: medium-size to large deciduous tree
Ecological Role: common component of mesic, northern mixed hardwood forests; requires canopy openings for successful establishment and growth; gradually replaced by more tolerant species
Lifespan, yrs (typical/max): 150/300
Shade Tolerance: intermediate
Height, m: 20-30
Canopy Tree: yes
Pollination Agent: wind
Seeding, yrs (begins/optimal/declines): 30/40/70
Mast Frequency, yrs: 1-4
New Cohorts Source: seeds or sprouts
Flowering Dates: late spring
Flowers/Cones Damaged by Frost: yes
Seedfall Begins: early fall
Seed Banking: 1 yr +
Cold Stratification Required: yes
Seed Type/Dispersal Distance/Agent: winged nutlet/ to 200 m/ wind
Season of Germination: late spring
Seedling Rooting System: variable
Sprouting: common
Establishment Seedbed Preferences:
Substrate: mineral soil, moss or rotten wood
Light: open areas only
Moisture: moist required
Temperature: warm
Disturbance response:
Fire: Thriving on disturbance, this species is opportunistic with respect to fire (it increases after fire) but it is not fire-dependent. Usually occurring at intervals of several decades to centuries, fires are typically high-intensity surface or crown fires. A thin-barked species, yellow birch is sensitive to fire, and young trees rarely survive. Older trees may survive low-intensity fires. When wounded, surviving trees are highly susceptible to decay. Yellow birch sprouts poorly following topkill. Seed germination and seedling establishment are enhanced by fire, particularly fires that burn the leaf mat, expose mineral soil, and create canopy openings, but leave some mature trees as seed sources. Yellow birch frequently forms pure patches following fire. Prescribed fire has been used for yellow birch seedbed preparation.
Weather: Yellow birch is subject to windthrow on shallow, poorly drained soils. It is susceptible to damage from ice and heavy snow, and winter sunscald.
Air pollution: Yellow birch is sensitive to sulphur dioxide. No difference was observed in seedlings fumigated with ozone under controlled conditions.