Bigleaf Maple
Acer
macrophyllum
From:
Washington State Department of
Ecology
Massive Maple
The bigleaf maple is the largest species of maple along
Puget Sound. Thick limbs arch up to 100 feet, spreading
over 60 feet at the crown. Leaves fan out to 15 inches
wide.
Erosion Control
A large, fast-growing tree, bigleaf maple needs plenty of
space to grow. It thrives in poor gravelly soils and makes
a massive root system on slopes, which makes it excellent
for erosion control.
Bigleaf Maple Basics
• Broad-leaved deciduous tree.
• Can live over 200 years.
• Leaves leak a milky, sticky juice when broken.
• Graceful greenish-yellow flowers, April through May.
• Paired winged seeds "helicopter" to the ground.
• Fall leaves turn golden yellow.
Moss
On Maple
The bigleaf maple often wears a shaggy green coat of moss,
lichen, and ferns. Thick mats of moss and lichen can create
"soil" right on the bark. Bigleaf maple make special roots
which tap this soil for nutrients. The heavy weight of wet
moss can also break branches.
Maples
Make Habitat
Fragrant yellow spring flowers are favored by honeybees and
butterflies. The seeds or samaras are eaten by squirrels,
chipmunks, and a variety of birds including finches and
Evening Grosbeaks. Black-tailed deer, mule deer, and elk
nibble on fresh leaves, twigs, and saplings. Leaning over
beaches and nearshore waters, bigleaf maples make important
shade for developing fish such as surf smelt.
Bigleaf Maple: Concerns & Conservation
• Avoid planting bigleaf maple near septic system
drainfields or water lines. The fast-growing root system
can block lines.
• Bigleaf maple can drop leaves and large limbs.
Consider removing branches that are hazardous to your home.
Check with a qualified arborist for advice. Be sure to
explain any concerns about slope hazards on your property.
• Avoid topping. Topping will not make a bigleaf maple
safer. In fact, a "topped" bigleaf maple can develop unsafe
top-heavy growth. Consult an arborist for pruning advice.
• Bigleaf maple is valuable to preserve on wooded
sites, moist hillsides, and slopes with poor soil. In many
cases, the wildlife and erosion control benefits outweigh
the drawbacks.
Bigleaf Maple
Acer
macrophyllum Pursh
Aceraceae - Maple family
by
Don Minore & John C. Zasada
Bigleaf
maple
(Acer macrophyllum), also
called broadleaf maple or Oregon maple, is one of the few
commercial hardwood tree species on the Pacific Coast. It
is small compared with its conifer associates. Most mature
bigleaf maples are about 15 m (50 ft) tall and 50 cm (20
in) in d.b.h. (5). Large trees often reach heights of 30 m
(100 ft) and diameters of 90 to 120 cm (36 to 48 in). True
to its common name, bigleaf maple usually bears leaves up
to 30.5 cm (12 in) across, and exceptionally large leaves
may attain widths of 61 cm (24 in)
(2). They
are borne on rounded crowns supported by short, branching
boles if open-grown, but trees growing in dense stands are
often well formed and free of branches for half to
two-thirds of their height. Bigleaf maple is an excellent
shade tree. The wood is used for furniture, especially
piano frames, and the sap can be made into syrup.
Habitat
Native Range
The
native range of bigleaf maple extends from latitude
33° to
51° N.,
always within 300 km (186 mi) of the Pacific Ocean. This
maple is not found in southeastern Alaska or on the Queen
Charlotte Islands (34), but it does grow on Vancouver
Island at least as far north as Port Hardy
(25). On
the mainland, the range is a continuous belt from near
Sullivan Bay, BC, to within 16 km (10 mi) of San Francisco
Bay, CA-a belt that includes the western slopes of the
Coast Ranges of British Columbia, the Olympic Peninsula in
Washington, the Coast Ranges of Oregon and California, and
the western slopes of the Cascade Range in Oregon and
Washington. The species is less common south of San
Francisco Bay, but extensive stands are found in the Santa
Cruz and Santa Lucia Mountains. Isolated groves are
scattered along the southern California coast to San Diego
County. Bigleaf maple is common on the western slopes of
the Sierra Nevada north of the Yuba River and is present in
less abundance as far south as Sequoia National Park
(11).
Most
of the estimated volume of standing sawtimber is found in
Washington (about 19.6 million m³ or 3.43 billion fbm) and
Oregon (about 18.0 million m³ or 3.16 billion fbm). Almost
half this timber is in Lewis and Whatcom Counties in
Washington and Douglas and Lane Counties in Oregon
(17). The
estimated 1.1 million m³ (200 million fbm) of bigleaf maple
in British Columbia is found on the south coast and
Vancouver Island
(16).
Climate
Bigleaf
maple grows over a wide range of temperature and moisture
conditions, from the cool, moist, marine climate of coastal
British Columbia to the warm, dry, growing seasons of
southern California. Springs, streams, and other permanent
sources of water are often associated with bigleaf maple in
southern California, but it also grows on eastern and
northern slopes in California where more than 600 mm (24
in) of annual rainfall occurs
(15). It
receives abundant moisture in the coastal redwood region of
northern California (36). Bigleaf maple is not, however,
limited to moist sites in southwestern Oregon, where it is
found from moist stream bottoms to dry hillsides. Nocturnal
moisture stresses of more than 2.0 M Pa (20 bars) have been
recorded on some of those hillsides in southwestern Oregon.
This maple also grows on hot, dry sites in the
central-western Cascade Range in Oregon and does not seem
to be limited by moisture deficiencies there
(40). Moisture
deficiencies seldom occur in western valleys of the Olympic
Peninsula or in coastal British Columbia (25,32).
Temperature probably limits the northern distribution of
bigleaf maple (29).
Soils
and Topography
Well
drained alluvial and colluvial soils are well suited to
bigleaf maple. Abundant moisture and a deep, gravelly
profile produce the best growth-usually on river terraces,
flood plains, and seepage sites (25). Growth is poorer on
shallow, rocky soils, but bigleaf maple is frequently found
on such soils. In the Coast Ranges of Oregon and the north
Cascade Range in Washington, it even grows on steep talus
slopes
(1,5).
Bigleaf
maple is associated with many soil groups
(5,25). On
upland sites, these groups include the moist but well
drained Brown Soils (Haplumbrepts and Dystrochrepts);
Reddish Brown Lateritic soils (Haplohumults); Podzols
(Haplorthods); both fine-and coarse-textured dry soils
(Haploxerolls and Xeropsamments); and shallow, dry soils
(Lithic Xerumbrepts). Soil groups associated with bigleaf
maple in lowland areas include flood plain alluvium
(Udifluvents); alluvial pumice deposits (Vitrandepts); wet,
gley soils (Aqualfs); and cool, acid, well-drained soils
(Boralfs). These soil great groups and suborders are found
in the soil orders Inceptisols, Ultisols, Spodosols,
Mollisols, Entisols, and Alfisols.
Bigleaf maple does not require high concentrations of soil
nutrients (36), but it is very sensitive to toxic
concentrations of soil boron (9). Litterfall weights are
greater under bigleaf maple than under Douglas-fir, and
bigleaf maple leaves and litter contain high concentrations
of potassium, calcium, and other macro-and micro-nutrients
(6,33). Bigleaf maple is a soil-building species that
benefits the sites on which it grows.
Bigleaf maples grow at low elevations on the north side of
Santa Cruz Island (27) but are usually found on riparian
sites above 915 m (3,000 ft) in southern California, where
the maximum elevation at which they grow is 2135 m (7,000
ft). Farther north in California, maximum elevations
decrease to 1675 m (5,500 ft) in the Sierra Nevada and 1035
m (3,400 ft) in the Coast Ranges (29). In central and
northern California, bigleaf maple becomes less riparian
and more widely distributed
(11), sometimes
growing as shrubby clumps on the steepest north-facing
canyon walls
(15). This
maple does not grow in the Central Valley of
California
(11). It
is found above 310 m (1,017 ft) in steep-sided ravines and
on mesic slopes in the Klamath Mountains
(31) and
at elevations of 1220 m (4,000 ft) on the Cascade Range in
southern Oregon.
The topography occupied by bigleaf maple in Oregon and
Washington includes flat interior valleys, gently sloping
stream bottoms, and moderate to steep slopes. It grows on
both moist, fertile stream bottoms and arid, precipitous,
south-facing rock outcroppings with slopes greater than 100
percent in the Coast Ranges of northwestern Oregon
(1). On
the Olympic Peninsula in Washington, the maximum elevation
at which it grows is 455 m (1,500 ft). Bigleaf maple is
seldom found above 305 m (1,000 ft) in coastal British
Columbia, but it has been observed above 350 m (1,150 ft)
on the east coast of southern Vancouver Island (25).
Associated
Forest Cover
Characteristic
trees, shrubs, and herbs associated with bigleaf maple in
five portions of its native range are listed in table 2.
Douglas-fir, Pacific madrone, Pacific dogwood, swordfern,
and prince's-pine grow with bigleaf maple in most
environments. Bigleaf maple communities often present on
moist sites include willow-black cottonwood-bigleaf maple
and red alder-bigleaf maple/salmonberry. The bigleaf
maple/snowberry
(Symphoricarpos albus) community
is found on dry sites (5). Bigleaf maple is present but is
not a dominant species in several other plant
communities-western hemlock/western swordfern/ Oregon
oxalis and Douglas-fir/oceanspray (western Washington and
Oregon), Sitka spruce/devilsclubstink currant
(Ribes bracteosum) (British
Columbia), and white fir/Oregongrape (California), for
example.
Bigleaf maple is present in the following forest cover
types (3): Red Alder (Society of American Foresters Type
221), Black Cottonwood-Willow (222), Sitka Spruce (223),
Western Hemlock-Sitka Spruce (225), Pacific Douglas-Fir
(229), Douglas-Fir- Western Hemlock (230),
Port-Orford-cedar (231), Redwood (232), Oregon White Oak
(233), Douglas-Fir-Tanoak-Pacific Madrone (234), Pacific
Ponderosa Pine-Douglas-Fir (244), and Pacific Ponderosa
Pine (245).
Bigleaf maple supports several epiphytic plants in moist
climates. This support is particularly evident in the "rain
forest" on the west side of the Olympic Peninsula, where
epiphytes weigh nearly four times as much as the leaves of
host bigleaf maples
(19). Some
of those maples, heavily laden with rain-soaked epiphytes,
are more susceptible to windthrow than trees with less
luxuriant epiphytic growth (32). A club moss
(Selaginella oregana) and
the mosses
Hylocomium splendens, Leucolepis menziesii, Isothecium
stoloniferum, and
Neckera menziesii are
the most abundant epiphyte species, but lichens
(Cladonia, Nephroma, and
Crocynia spp.)
and the licorice fern
(Polypodiuni glycyrrhiza) are
also common (5,32).
Life
History
Reproduction and Early Growth
Flowering and Fruiting- Bigleaf
maple begins to produce seed at about 10 years of age and
continues every year thereafter (23). It is polygamous, and
both staminate and perfect flowers are mixed in the same
dense, cylindrical racemes. Flowers are greenish yellow and
scented, and they appear before the leaves-from March, at
low elevations and in the southern part of the range, to
June, at high elevations and in the north. Pollination by
insects usually occurs within 2 to 4 weeks after the buds
burst
(29). Pubescent
double samaras result, with 3.5- to 5-cm (1.4- to 2-in)
wings that diverge at less than a 90° angle. They ripen in
September and October.
Seed
Production and Dissemination- Seeds
are abundant almost every year, but production by
individual trees and stands can vary from year to year (7).
Although most of the seeds are dispersed by the wind
between October and January, some seeds can be found on
trees as late as March. Bigleaf maple seeds are large and
generally triangular or oval. They are 4 to 12 mm (0.16 to
0.47 in) long and 4 to 9 mm (0.16 to 0.35 in) thick. At
field moisture content, filled-seed weights range from
5,200 to 7,900 seeds/kg (2,400 to 3,600 seeds/lb) for
individual trees in the Oregon Coast Range. Seed coat
comprises 60 to 70 percent of the seed weight (39).
Seed moisture content reaches a minimum of 10 to 20 percent
(dry weight basis) before the autumn rains begin in western
Oregon. After the rains begin, seed moisture content varies
among individual trees, but it increases by 140 to 200
percent. The pubescent seed coat appears to be effective in
holding water and raising seed moisture content quickly.
Seed collection and storage are best done when minimum
moisture content is reached before the start of the autumn
rains. Seeds in this condition can be stored without
further drying for at least 1 year at 1° C (34° F) with
only a slight loss in viability. Seeds collected after the
moisture content has increased are usually killed by
redrying, but they can be stored for up to 6 months at the
field moisture content with a 30- to 40-percent reduction
in viability Seeds stored in this way produce vigorous
seedlings when planted in nursery beds (39).
Seedling
Development- Germination
is epigeal. It begins in late January or early February
under field conditions and is usually completed by April or
May in the Oregon Coast Range. Seeds germinate completely
at 1°
C
(34° F) under laboratory conditions, beginning at about 60
days and completing their germination after 90 to 120 days
(39). Because of this low temperature threshold for
germination, seeds germinate early under natural conditions
if moisture is not limiting. Germination during
stratification can be used as a means of screening seeds
before sowing. If seeds are stratified for 60 days and then
germinated, the optimum temperature for germination is 15°
C (59° F)
(10). Exogenous
gibberellin, cytokinin, or ethylene do not overcome the
stratification requirement
(10). A
small number of seeds have been found germinating on trees
in December before dispersal (39).
Seed germination is excellent on mineral soil and organic
substrates
(7,25,39), and
seedling establishment is best when those substrates do not
dry excessively during the growing season. Bigleaf maple
seedling emergence is not affected by Douglas-fir canopy
density in coastal Oregon under conditions that vary from
young-and-dense to old-and-open stands, but emergence is
better under all of these stand conditions than it is in
clearcut areas (7). An average 30 to 40 percent of the
viable seeds germinate if they are protected from
predators, and occasional seed lots attain 80 percent
germination (7). All bigleaf maple seeds germinate during
the late winter and spring after seed dispersal. Delayed
germination does not occur in subsequent years (7).
Bigleaf maple seedlings have a high juvenile growth
potential, exceeding that of Douglas-fir and other conifers
(38,39). When open-grown under conditions of adequate
moisture and nutrients, seedlings reach heights of 1 to 2 m
(3.3 to 6.6 ft) in one growing season. Competition affects
growth, however; and first-season height is reduced by more
than 50 percent when seedling density is increased from 1
to about 600 seedlings/m² (0.1 to 55.7 seedlings/ft²).
Seedling weight is even more sensitive to competition than
seedling height, and an increase in density from 1 to 60
seedlings/m² (0.1 to 5.6 seedlings/ft²) can result in a
50-percent decrease in seedling dry weight (39).
The morphology of young seedlings is strongly influenced by
density. At low density, branch development begins in the
buds associated with the cotyledons and moves up the stem
as height growth progresses. At high densities, branch
development is suppressed and the few branches that develop
soon die. Internode length is highly responsive to density,
and the longest internodes are produced at intermediate
densities during the first year of growth.
The growth potential of bigleaf maple is rarely achieved in
the field under normal conditions of light, moisture,
competition, and browsing intensity (7). A survey of
bigleaf maple seedlings in western Oregon showed that the
tallest seedlings were 5 m (16.4 ft) tall and 20 to 30
years old. The height distribution of all seedlings in a
stand most commonly resembled an inverted J, with 0 to 25
cm (0 to 10 in) tall, 1- to 4-year-old seedlings, most
numerous. Normal and bimodal height distributions were also
observed in the western Oregon survey. Although these
seedlings were all growing in the understories of
Douglas-fir stands, shapes of the height-distribution
curves did not seem to be associated with stand conditions.
Few seedlings were found in clearcuts (7). Browsing by deer
probably is the most important factor influencing the
height and stem morphology of bigleaf maple seedlings (7).
Temporary flooding is common on riparian sites, and the
seedlings are able to survive short periods of inundation.
Bigleaf maple is not as tolerant of flooding as red alder,
Oregon ash
(Fraxinus latifolia), black
cottonwood, Sitka spruce, and western red-cedar, however;
flooding for 2 months during the growing season kills both
maple seedlings and mature trees (35).
Vegetative
Reproduction- Bigleaf
maple sprouts profusely after being cut. The large stumps
produce more and taller sprouts, but all sizes regenerate
vigorously. Sprout clumps have achieved heights of 5 m (17
ft) and crown diameters of 6.5 m (21.5 ft) in 3 years, with
as many as 67 sprouts around a single stump
(28). This
sprouting vigor probably could be used in reproducing pure
stands of bigleaf maple by the coppice method. It creates
undesirable competition for the conifers being managed on
most sites. Unlike vine maple
(Acer circinatum), bigleaf
maple does not appear to reproduce by layering. It can,
however, be propagated from stem cuttings.
Sapling
and Pole Stages to Maturity
Growth and Yield- Rapid
height growth of bigleaf maple continues through the
sapling stage, but it slows as the trees grow from pole to
sawtimber size. Diameter growth is proportional to leaf
area, and trees with large crowns develop more sapwood than
trees with small crowns
(37). The
volume of individual trees ranges from 0.11 m³ (4 ft³) at
15 cm (6 in) in d.b.h. to 6.5 m³ (230 ft³) at 91 cm (36 in)
in d.b.h.
(24). The
largest bigleaf maple known in 1977 grew in western Oregon
and had a circumference of 1064 cm (419 in) at breast
height, a height of 30.8 m (101 ft), and a crown spread of
27.4 m (90 ft) (26). The oldest attain ages of 200 years or
more (2).
Pure, 70-year-old stands of bigleaf maple have yielded
about 315 m³/ha (4,500 ft³/acre). Under intensive
management, rotations of 50 years or less could probably be
used
(16).
Rooting
Habit- Bigleaf
maple has a shallow, widespreading root system well suited
to the shallow or saturated soils on which it often grows.
It probably has a competitive advantage over deeper-rooted
species under such conditions.
Reaction
to Competition- Bigleaf
maple is not a pioneer species that rapidly invades
disturbed areas; however, it is often present in
undisturbed stands and is able to respond with vigorous
sprout growth after disturbance. Maple seedling
establishment is most likely to occur in Douglas-fir stands
after the start of natural thinning and before the dense
understory characteristic of older stands develops. Light
or other factors related to stand density apparently limit
establishment. Increases in light from 0 to 20 percent of
that in the open result in increases of from 0 to 60
percent in survival, but additional increases in light are
not beneficial. Seedlings often occur in clusters, with
various age distributions, suggesting that conditions
favoring establishment vary from year to year
(7). The
presence of bigleaf maple in undisturbed stands and its
potential for rapid growth suggest that it can respond
quickly to gap formation or overstory removal.
Maple seedlings often appear in intermediate or late seral
communities. Bigleaf maple frequently follows willow
(Salix spp.)
or red alder in riparian seres
(4,13), and
sometimes it replaces oaks or Pacific madrone on upland
sites.
Silviculture of bigleaf maple usually involves control
rather than culture. Bigleaf maple does not aggressively
invade clearcut units, but vigorous stump sprouting is a
problem when it occurs in the harvested stand. Sprouting
can be control!ed by applying water-soluble amines or
potassium salts of phenoxy herbicides around the sapwood
perimeter on freshly cut stumps
(21). Girdling
the uncut trees is ineffective, for girdled bigleaf maples
survive for several years and sprout. Aerial spraying of
herbicides and other foliar applications are also
ineffective-herbicide translocation is inadequate and the
roots are not killed
(22). Basal
bark treatments overcome this problem. They are effective
when ester-in-oil formulations of the phenoxy herbicides
are applied
(21).
Dry
sites with bigleaf maple overstories should not be clearcut
if conversion to Douglas-fir is attempted. Seedling
survival will be better if the Douglas-fir is underplanted,
preferably after the overstory maples are killed with a
basal spray of phenoxy ester in oil (20).
When bigleaf maple is harvested as a crop rather than
killed as a weed, often only trees that will yield a
minimum log size (3.7 m by 25 cm, or 12 ft by 10 in) are
harvested
(16). Merchantable
trees are usually scattered, limbing is laborious, and logs
are short. Felling, yarding, and milling costs therefore
tend to be higher for bigleaf maple than for conifers. Mill
waste is also high-as much as 30 percent in slabs, sawdust,
trim, and defect
(16).
Damaging
Agents- Fungi
are responsible for much of the defect in bigleaf maple.
Decay is seldom a serious problem in young undamaged trees,
but stem and branch wounds are invaded by wood-rotting
fungi such as
Heterobasidion annosum, Fomitopsis pinicola, Polyporus
berkeleyi, and
Inonotus dryadeus that
can reduce the tree to a hollow shell. Overmature bigleaf
maples are often decayed by root rot
(Armillaria spp.)
and butt rots
(Ganoderma applanatum and
Oxyporus populinus). Verticillium
wilt
(Verticillium albo-atrum) occasionally
kills forest trees, but it is most serious on ornamental
bigleaf maples
(14).
The
carpenter worm
(Prionoxystus robiniae) may
seriously damage living maples. It attacks trees of all
sizes, particularly those that are open-grown. The
resulting larval tunnels degrade the lumber cut from
affected stems. Dead trees and maple products are damaged
by powderpost beetles
(Hemicoelus, Melalgus, Polycaon, Ptilinus,
Scobicia, and
Xestobium spp.),
and a roundheaded borer
(Synaphaeta guexi) makes
large burrows in dead or dying trees
(8).
Bigleaf
maple twigs and young stems are browsed by deer and elk.
They are also clipped by mountain beavers. The roots are
sometimes attacked by nematodes
(Meloidogyne spp.)
(14). A
high percentage of seedling mortality also results from
predation by rodents and grazing by slugs and other
invertebrates
(7).
Seed
predation by small mammals is high, and it may be related
to overstory condition. Seedling emergence on artificially
seeded plots in the Oregon Coast Range is from 7 to 100
times greater on plots protected from birds and rodents
than on unprotected plots. The highest rate of predation is
in young (20- to 40-year-old) and old (80- to 250-year-old)
stands with lower rates in clearcuts and in pole-size
stands (40 to 80 years old) (7).
Special
Uses
Bigleaf
maple is an excellent shade tree. Its wood is used in the
furniture industry, but it is neither as hard nor as strong
as the wood of sugar maple
(Acer saccharum) (16). Like
sugar maple, it has sweet sap that can be made into syrup.
The flow of sap is adequate for syrup production in January
and February, but the syrup is of a lower quality than that
made from sugar maple
(30).
Bigleaf
maple is a preferred wood for piano frames. It is excellent
for decorative face veneer and makes good container
material but is not suitable for flooring
(16). The
amounts of bigleaf maple being marketed for fuelwood are
increasing as the use of wood stoves increases. Bigleaf
maple has about 70 percent of the fuel value of Oregon
white oak and 115 percent of the fuel value of red alder
wood.
Bigleaf maple is usually harvested in conifer stands along
with the conifers. These trees generally originate from
sprouts and are of poor quality. Higher quality trees could
be produced by managing maple stands that originate from
seed or planted seedlings.
Genetics
The
Kimball maple
(Acer macrophyllum Pursh
var.
kimballi Harrar),
a rare variety of bigleaf maple, occurs in the Washington
counties of Snohomish, Cowlitz, and Pierce. It differs
from
Acer maerophyllum var.
macrophyllum in
having much more deeply lobed leaves, often tricarpellate
flowers, and frequent triple samaras
(12).
Acer macrophyllum Pursh
forma
rubrum Murray
is an even rarer form of bigleaf maple. First noticed at
Berkeley, CA, in 1968 and later found in the Coast Ranges
north of San Francisco, it has red leaves
(18). The
young leaves of an early German cultivar, 'tricolor,' are
also red. Tricolor leaves are rose-red, however, and they
later become marked with white.
Literature
Cited
1
Bailey, Arthur W., and Charles E. Poulton. 1968. Plant
communities and environmental interrelationships in a
portion of the Tillamook Burn, northwestern Oregon. Ecology
49(1):1-13.
2 Black, Marvin E. 1981.
Acer macrophyllum: Hills
of gold. University of Washington Arboretum Bulletin
44(4):35-38.
3 Eyre, F.H., ed. 1980. Forest cover types of the United
States and Canada. Society of American Foresters,
Washington, DC. 148 p.
4 Fonda, R. W. 1974. Forest succession in relation to river
terrace development in Olympic National Park, Washington.
Ecology 55(5):927-942.
5 Franklin, Jerry F., and C. T. Dyrness. 1973. Natural
vegetation of Oregon and Washington. USDA Forest Service,
General Technical Report PNW-8. Pacific Northwest Forest
and Range Experiment Station, Portland, OR. 417 p.
6 Fried, Jeremy Steven. 1985. Two studies of
Acer macrophyllum: I.
The effects of bigleaf maple on soils in Douglas-fir
forests. II. The ecology of bigleaf maple establishment and
early growth in Douglas-fir forests. Thesis (M.S.), Oregon
State University, Corvallis. 91 p.
7 Fried, Jeremy S., John C. Tappeiner II, and David E.
Hibbs. 1988. Bigleaf maple seedling establishment and early
growth in Douglas-fir forests. Canadian Journal of Forest
Research 18(10): 1226-1233.
8 Furniss, R. L., and V. M. Carolin. 1977. Western forest
insects. U.S. Department of Agriculture, Miscellaneous
Publication 1339. Washington, DC. 654 p.
9 Glaubig, B. A., and F. T. Bingham. 1985. Boron toxicity
characteristics of four northern California endemic tree
species. Journal of Environmental Quality 14( 1):72-77.
10 Goldstein, Julie, and Wayne Loescher. 1981. Germination
requirements for
Acer macrophyllum, bigleaf
maple. Ornamentals Northwest Newsletter (May-June): 1-15.
11 Griffin, James R., and William B. Critchfield. 1972. The
distribution of forest trees in California. USDA Forest
Service, Research Paper PSW-82. Pacific Southwest Forest
and Range Experiment Station, Berkeley, CA. 114 p.
12 Harrar, E. 8.1940. The Kimball maple. Journal of
Forestry 38(9):726-728.
13 Hawk, Glenn Martin. 1973. Forest vegetation and soils of
terraces and floodplains along the McKenzie River, Oregon.
Thesis (M.S.), Oregon State University, Corvallis. 188 p.
14 Hepting, George H. 1971. Diseases of forest and shade
trees of the United States. U.S. Department of Agriculture,
Agriculture Handbook 386. Washington, DC. 658 p.
15 Jepson, Willis Linn. 1901. A flora of western middle
California. Encina Publishing Company, Berkeley, CA. 625 p.
16 Kerbes, E. L. 1968. Broadleaf maple in British Columbia.
Information Report VP-X-38. Forest Products Laboratory,
Vancouver, BC. 23 p.
17 Metcalf, Melvin E. 1965. Hardwood timber resources of
the Douglas-fir subregion. USDA Forest Service, Resource
Bulletin PNW-11. Pacific Northwest Forest and Range
Experiment Station, Portland, OR. 12 p.
18 Murray, Edward. 1969.
Acer macrophyllum forma
rubrum. Kalmia
1(2):5.
19 Nadkarni, Nalini M. 1984. Biomass and mineral capital of
epiphytes in an
Acer macrophyllum community
of a temperate moist coniferous forest, Olympic Peninsula,
Washington State. Canadian Journal of Botany 62(1
1):2223-2228.
20 Newton, Michael: 1963. Success in Douglas-fir
plantations as related to site and method of removal of
bigleaf maple overstory.
In Western
Weed Control Conference, March 1963, Portland, OR. Research
Progress Report. p.17-18. Western Society of Weed Science.
39
21 Newton, Michael. 1964. Herbicide effects on maple trees
according to compound formulation, solvent, and method of
application.
In Western
Weed Control Conference, March 1964, Salt Lake City, Utah.
Research Progress Report. p. 30-31. Western Society of Weed
Science.
22 Norris, L. A., and V. H. Freed. 1966. The absorption,
translocation, and metabolism characteristics of
4-(2,4-dichlorophenoxy) butyric acid in bigleaf maple. Weed
Research 6(4):283-291.
23 Olson, David F., Jr., and W. J. Gabriel. 1974.
Acer L. Maple
In Seeds
of woody plants in the United States. p.187-194. C. S.
Schopmeyer, tech. coord. U.S. Department of Agriculture,
Agriculture Handbook 450. Washington, DC.
24 Pacific Northwest Forest and Range Experiment Station
1953. Volume tables for permanent sample plots as
recommended by the Puget Sound Research Center advisory
committee for use in western Washington. USDA Forest
Service, Portland, OR. Unpaged.
25 Packee, Edmond Charles. 1976. An ecological approach
toward yield optimization through species allocation.
Thesis (Ph.D.), University of Minnesota, St. Paul. 740 p.
26 Pardo, Richard. 1978. National register of big trees.
American Forests 84(4): 18-45.
27 Philbrick, Ralph N., and J. Robert Haller. 1977. The
southern California islands.
In Terrestrial
vegetation of California. p. 893-906.Michael 0. Barbour and
Jack Major, eds. John Wiley and Sons, New York.
28 Roy, D. F. 1955. Hardwood sprout measurements in
northwestern California. USDA Forest Service, Forest
Research Note 95. California Forest and Range Experiment
Station, Berkeley. 6 p.
29 Ruth, Robert H., and Gerhard F. Muerle. 1958. Silvical
characteristics of bigleaf maple. USDA Forest Service,
Silvical Series 13. Pacific Northwest Forest and Range
Experiment Station, Portland, OR. lOp.
30 Ruth, Robert H., J. Clyde Underwood, Clark E. Smith, and
Hoya Y. Yang. 1972. Maple syrup production from bigleaf
maple. USDA Forest Service, Research Note PNW-181. Pacific
Northwest Forest and Range Experiment Station, Portland,
OR. 12 p.
31 Sawyer, John 0., and Dale A. Thornburgh. 1977. Montane
and subalpine vegetation of the Klamath Mountains.
In Terrestrial
vegetation of California. p.699-732. Michael G. Barbour and
Jack Major, eds. John Wiley and Sons, New York.
32 Sharpe, Grant William. 1956. A taxonomical-ecological
study of the vegetation by habitats in eight forest types
of the Olympic rain forest, Olympic National Park,
Washington. Thesis (Ph.D.), University of Washington,
Seattle. 313 p.
33 Tarrant, Robert F., Leo A. Isaac, and Robert F.
Chandler, Jr. 1951. Observations on litter fall and foliage
nutrient content of some Pacific Northwest tree species.
Journal of Forestry 49(12):914-915.
34 Viereck, Leslie A., and Elbert L. Little, Jr. 1972.
Alaska trees and shrubs. U.S. Department of Agriculture,
Agriculture Handbook 410. Washington, DC. 265 p.
35 Walters, M. Mice, Robert 0. Teskey, and Thomas M.
Hinckley. 1980. The impact of water level changes on woody
riparian and wetland communities. Vol.8. Pacific Northwest
and Rocky Mountain Regions. U.S. Department of the Interior
Fish and Wildlife Service, Biological Services Program
7894. University of Missouri, School of Forestry,
Fisheries, and Wildlife, Columbia. 57 p.
36 Waring, R. H., and J. Major. 1964. Some vegetation of
the California coastal redwood region in relation to
gradients of moisture, nutrients, light, and temperature.
Ecological Monographs 34:167-215.
37 Waring, R. H., H. L. Gholz, C. C. Grier, and M. L.
Plummer. 1977. Evaluating stem conducting tissue as an
estimator of leaf area in four woody angiosperms. Canadian
Journal of Botany 55(11):147-1477.
38 Zaerr, J. B., D. P. Lavender, M. Newton, and R. K.
Hermann. 1981. Natural versus artificial forest
regeneration in the Douglas-fir region. p. 177-185.
In Woodpower,
new perspectives on forest usage. James J. Talbot and
Winfield Swanson, eds. Pergamon Press, New York.
39 Zasada, John C., and John C. Tappeiner II. Unpublished
data on file at the USDA Forest Service Forestry Sciences
Laboratory, Corvallis, OR.
40 Zobel, Donald B., Arthur McKee, Glenn M. Hawk, and C. T.
Dyrness. 1976. Relationships of environment to composition,
structure, and diversity of forest communities of the
central western Cascades of Oregon. Ecological Monographs
46:135-156.