Life History and Disturbance Response of Betula papyrifera (paper birch)
Family: Betulaceae
Guild: opportunistic, short-lived intolerant
Functional Lifeform: medium-size deciduous tree
Ecological Role: pioneer on disturbed areas forming nearly pure stands; common associate in conifer-hardwood mixtures on cool, moist sites
Lifespan, yrs (typical/max): 100/140
Shade Tolerance: intolerant
Height, m: 12-21
Canopy Tree: yes
Pollination Agent: wind
Seeding, yrs (begins/optimal/declines): 15/40/70
Mast Frequency, yrs: 2
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/ to 200 m/ wind
Season of Germination: spring
Seedling Rooting System: shallow
Sprouting: common; profuse on fire-damaged stems
Establishment Seedbed Preferences:
Substrate: mineral soil or humus
Light: overstory shade
Moisture: moist required
Temperature: neutral
Disturbance response:
Fire: Paper birch is well-adapted to disturbance and is opportunistic with respect to fire but it is not fire-dependent. In mixed stands, it burns at intervals of several decades and in pure stands, it burns only during unusually dry conditions at longer intervals. The bark of paper birch is both thin and highly flammable, which renders trees highly susceptible to topkilling. However, in trees <50 years old it sprouts from the root collar prolifically and vigorously. Paper birch is an abundant producer of lightweight, wind-dispersed seeds which readily germinate on mineral seedbeds created by fire. Prescribed fire has been used to prepare seedbeds for paper birch regeneration.
Weather: Paper birch stems are susceptible to breakage in high winds.
Air pollution: Paper birch is sensitive to sulphur dioxide. No differences were observed in seedlings fumigated with ozone under controlled conditions.