Bigleaf maple

Bigleaf maple (Mb) - Acer macrophyllum

Page Index

Geographic Range & Ecological Amplitudes

Bigleaf maple is a medium-sized (<30 m tall), deciduous, broad-leaved tree, at maturity with a broad, rounded crown, often curved stem (in the open, the stem soon divides into a few large spreading and ascending branches), and grayish-brown bark which is shallowly furrowed into narrow scaly ridges. Like sugar maple, bigleaf maple has sweet sap that can be made into syrup. Its wood is used for furniture, flooring, interior paneling, and musical instruments.
Geographic Range  Geographic element:
Western North American/mainly Pacific and less Cordilleran

Distribution in Western North America:
central and south in the Pacific region; (central) in the Cordilleran region
Ecological Amplitudes 

Bigleaf maple
Climatic amplitude:
(subcontinental cool temperate) - cool and warm mesothermal

Orographic amplitude:
submontane - (montane)

Occurrence in biogeoclimatic zones:
(subcontinental IDF), CDF, southern CWH

Edaphic Amplitude

Range of soil moisture regimes:
(moderately dry) - slightly dry - fresh - moist - very moist - (wet)

Range of soil nutrient regimes:
(poor) - medium - rich - very rich

Nutritional requirements of bigleaf maple appear to be high, especially for nitrogen (mainly nitrates), calcium, magnesium, potassium, and phosphorus. As a consequence, (i) its bark is rich in calcium that provides substrate for the establishment of many corticolous calciphytic bryophytes, and (ii) its litter contributes to the nutrient status of forest floor by increasing its nitrogen, calcium, and magnesium concentrations. Thus, the presence of bigleaf maple in coniferous stands will tend to improve humus form quality from Mors to Moders, which have higher decomposition and mineralization rates, and higher levels of plant-available soil nutrients.


Tolerances and Damaging Agents

Root System Characteristics Bigleaf maple has a shallow but wide-spreading root system. Roots are associated with vesicular-arbuscular mycorrhizae.
tolerance to tolerance class comments
low light L moderately shade-tolerant in the early development stage
frost L not a major concern in mesothermal climates
heat M frequent on insolated sites
water deficit L like red alder, responds to drought by shedding its leaves
water surplus H common on wet sites, floodplains, and sites with a strongly fluctuating water table
nutrient (mainly N) deficiency M absent in acid, very poor soils
Damaging Agents
damaging agent resistance class comments
snow L snowfall is low in submontane, maritime, cool mesothermal climates
wind M high winds will break the boles rather than uproot trees
  risk class  
fire L Low risk in pure bigleaf maple stands
insect L Not a major risk
fungi L Not a major risk in undamaged trees
other agents L Browsing by deer and elk is not a major risk
Associated tree species and successional role In British Columbia, bigleaf maple grows occasionally in even-aged, pure stands, but most commonly in early and intermediate stages of secondary succession mixed with conifers or hardwoods. It is a pioneer species (primary succession) on talus and floodplains, and is present in second-growth stands on upland sites. Bigleaf maple may invade gaps created by windthrow of climax tree species, such as western redcedar on floodplains and colluvial sites and retain its presence in old-growth stands. It frequently grows in clumps of 3-5, all originating from a single stump.
tree species
occurance class major area of occurance
red alder L floodplains in southwestern B.C
black cottonwood L floodplains in southwestern B.C
common douglas L southwestern B.C


Silvical Characteristics

characteristic interpretive class comments
reproduction capacity H the minimum age for seed crops is about 10 years
seed dissemination capacity L dispersed by wind for <100 m
potential for natural regeneration in low light L higher, providing the presence of exposed mineral soil and if considering vegetative reproduction
potential for natural regeneration in the open H providing the presence of exposed mineral soil
potential initial growth rate (<5 years) H up to 5 m in one growing season from stump sprouts
response of advance regeneration to release na advance regeneration does not develop in the absence of adequate light and seedbeds
self-pruning capacity in dense stands M dense stands are infrequent
crown spatial requirements H develops a very broad, irregular crown
light conditions beneath closed-canopy, mature stands M associates with well developed moss and herb layers
potential productivity H site index functions are not available; probably similar to red alder
longevity M few trees live >200 years


Genetics and Notes

Genetics Two varieties are recognized: Kimball maple (Acer macrophyllum Pursh var. kimballi Harrar) and Acer macrophyllum Pursh var. rubrum Murray.
Notes In some individuals of bigleaf maple, the grain patterns are unsurpassed, even by walnut, suggesting a potential for use in furniture. Considering its productivity, easy regeneration, and low risk of being affected by damaging agents, bigleaf maple is a suitable species for intensive management on some coastal sites (e.g., skeletal alluvial fans, fragmental colluvial slopes, stream-edge sites, and floodplains). Considering its wildlife and aesthetic values and soil improvement capacity, it is a useful short-term or even a long-term, minor admixture in coniferous stands, such as common douglas stands, in southwestern B.C.

There are two other shrub-sized maple species: vine maple (Acer circinatumPursh) and Douglas maple (Acer glabrum Torr.), the latter of which may attain small tree size. While the range of vine maple is restricted to the southern coastal mainland, Douglas maple occurs throughout central and southern B.C., except the outer coastal region. Both species are shade-tolerant and their litterfall, like that of bigleaf maple, improves humus form quality. More detailed silvics information is given by:

Minore, D. and J.C. Zasada. 1990. Acer macrophyllum. Pp. 33-40 in R.M. Burns and B.H. Honkala (technical coordinators) Silvics of North America, Vol. 2. Agri. Handbook 654, USDA For. Serv., Washington, D.C.