Life History and Disturbance Response of Salix nigra (black willow)
Family: Salicaceae
Guild: pioneer, moist-site, shade intolerant
Functional Lifeform: large deciduous tree
Ecological Role: common on floodplains and other wet soils; usually forms dense, pure stands; profuse rooting helps stabilize streambanks
Lifespan, yrs (typical/max): 70/85
Shade Tolerance: very intolerant
Height, m: 30-40
Canopy Tree: yes
Pollination Agent: insects, some wind
Seeding, yrs (begins/optimal/declines): 10/25/75
Mast Frequency, yrs: 1
New Cohorts Source: seeds or sprouts
Flowering Dates: early spring
Flowers/Cones Damaged by Frost: yes, but rare
Seedfall Begins: late spring -- early summer
Seed Banking: seasonal, < 1 month
Cold Stratification Required: no
Seed Type/Dispersal Distance/Agent: plumed/ > 200 m/ wind, water
Season of Germination: spring
Seedling Rooting System: shallow
Sprouting: root collar sprouts common
Establishment Seedbed Preferences:
Substrate: mineral soil
Light: open areas only
Moisture: moist/wet required
Temperature: neutral
Disturbance response:
Fire: Fires are rare in the bottomland areas where black willow typically occurs. Thin-barked and shallow-rooted, black willow is very susceptible to fire damage and typically decreases following fire (particularly seedlings and saplings). High-intensity fires can kill entire stands, and lower intensity fires often damage surviving trees. Damaged trees are highly susceptible to insects and decay organisms. Black willow sprouts from the root crown following fire. Fires that expose bare mineral soil may create a favorable seedbed for black willow establishment. Seedling establishment may occur from seeds of surviving trees onsite or from offsite seeds carried by wind and water. However, seed viability is greatly reduced by dry conditions, and establishment on burned sites depends on season of the burn, moisture availability, and amount of mineral soil exposed. Burning is useful in maintaining tallgrass prairies by inhibiting the invasion of black willow and other woody species.
Air pollution: Black willow is sensitive to sulphur dioxide.