Life History and Disturbance Response of Oxydendrum arboreum (sourwood)
Family: Ericaceae
Guild: persistent, slow-growing understory tolerant
Functional Lifeform: medium-size deciduous tree
Ecological Role: found on dry open sites and ridgetops;
also occurs on moist uplands and well-drained lowlands; grows as an understory
or midstory associate in oak-hickory and oak-pine forests
Lifespan, yrs (typical/max): 100/120
Shade Tolerance: tolerant
Height, m: 18-24
Canopy Tree: yes
Pollination Agent: insects
Seeding, yrs (begins/optimal/declines): 20/30/100
Mast Frequency, yrs: 2
New Cohorts Source: seeds or sprouts
Flowering Dates: summer
Flowers/Cones Damaged by Frost: no
Seedfall Begins: early fall
Seed Banking: up to 1 yr
Cold Stratification Required: no
Seed Type/Dispersal Distance/Agent: nonwinged/
to 50 m/ wind, gravity
Season of Germination: spring
Seedling Rooting System: variable
Sprouting: prolific, from stumps
Establishment Seedbed Preferences:
Substrate: variable
Light: overstory shade
Moisture: moist required
Temperature: neutral
Disturbance response:
Fire: Sourwood populations tolerate occasional,
but not frequent fire. Following a single fire, sourwood usually increases
in density. It is often topkilled by low-intensity fires, but sprouts prolifically
and persistently from the root collar or from root suckers. Seedling establishment
may occur from seeds of surviving trees onsite, but it seems likely that
fire degrades site requirements for good seedling establishment (overstory
shade and moist seedbeds). Repeated prescribed fires can eliminate sourwood
from areas where it is undesirable.
Air pollution: Symptoms of foliar
injury have been noted in areas of high ambient ozone.