Associated Forest Cover
provided by Silvics of North America
Red maple is a major or an associated species in 56 of the 88
nontropical forest cover types recognized for the eastern United
States (13). Red maple forms a pure cover type (Society
of American Foresters Type 108) because it makes up at least 80
percent of the stand basal area. The species is also at least 20
percent of Gray Birch-Red Maple (Type 19), White Pine-Northern
Red Oak-Red Maple (Type 20), Black Cherry-Maple (Type 28), and
Black Ash-American Elm-Red Maple (Type 39).
The red maple is most common in New England, Middle Atlantic
States, upper Michigan, and northeast Wisconsin. It is rare
farther west and south. Recognition of red maple as a separate
cover type generally is attributed to disturbances that allowed
red maple residuals to respond rapidly. The elimination of elm
(Ulmus americana and U. thomasii) by Dutch elm
disease and of the American chestnut (Castanea dentata) by
the blight, and selective removal of yellow birch (Betula
alleghaniensis) and sugar maple (Acer saccharum) have
contributed to increasing the proportion of red maple stocking in
many stands (13,40,48).
Throughout its range, red maple is associated with more than 70
different commercial tree species (26). Its more common
associates from the north to the south include red spruce (Picea
rubens), balsam fir (Abies balsamea), white pine (Pinus
strobus), sugar maple, beech (Fagus grandifolia), yellow
birch, paper birch (Betula papyrifera), gray birch (B.
populifolia), sweet birch (B. lenta), eastern hemlock
(Tsuga canadensis), eastern hophornbeam (Ostrya
virginiana), striped maple (Acer pensylvanicum), northern
white-cedar (Thuja occidentalis), aspen (Populus
grandidentata and P. tremuloides), black ash (Fraxinus
nigra), pin cherry (Prunus pensylvanica), black
cherry (P serotina), northern red oak (Quercus
rubra), American elm, chestnut oak (Q. prinus), Virginia
pine (Pinus virginiana), yellow-poplar (Liriodendron
tulipifera), silver maple (Acer saccharinum), black
gum (Nyssa sylvatica), swamp white oak (Quercus
bicolor), and loblolly pine (Pinus taeda) (13).
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Climate
provided by Silvics of North America
The northern extent of the red maple range coincides with the -40°
C (-40° F) mean minimum isotherm in southeastern
Canada (11). The western range is limited by the dry
climate of the Prairie States. Of all the maples, it has the
widest tolerance to climatic conditions. The absence of red maple
in the Prairie Peninsula does not seem to be related to
precipitation amount because the tree grows elsewhere with
similar or less annual precipitation.
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Damaging Agents
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Red maple is generally considered
very susceptible to defect. Especially on poor sites, red maple
often has poor form and considerable internal defect.
Discoloration and decay advance much faster in red maple than in
sugar maple (43). In northeastern Pennsylvania, average
cull ranged from 13 percent in 30 cm (12 in) diameter red maple
trees to 46 percent in 61 cm (24 in) diameter trees. Only
associated beech and black birch were more defective (26).
Sprout clumps present some serious problems. More defects
originate from branch stubs on the sprout stems than from the
parent stump (43). Inonotus glomeratus can infect branch
stubs and wounds above the butt in red maple. Nevertheless, a red
maple sprout with only a slightly defective base and small and
well-healed branch stubs has a potential for high future value.
Criteria for selecting red maple sprouts for thinning are (1)
select only stems with small, well-healed branch stubs, (2)
reject sprout clumps with defective bases, and (3) cut all but
one or two of the best dominant stem sprouts (50).
Many trunk rot fungi and stem diseases attack red maple. Inonotus
glomeratus infects branch stubs and wounds on the stem and is
most important. Second in importance is Oxyporus populinus,
which forms a small, white fruit body that often has moss
growing on top. Phellinus igniarius is another leading
heart rot of red maple. Red maple may also be cankered by species
of Nectria, Eutypella, Hypoxylon, Schizoxylon, Strumella,
and others (48).
Red maple is susceptible to many leaf diseases, generally of minor
importance. It is seldom or seriously damaged by root diseases,
although Armillana mellea can enter through root or butt
wounds. However, A. mellea kills only trees already
weakened from other causes (18).
Mechanical injury is a common source of defect in hardwoods, and
red maple is especially sensitive to wounding. Often, large areas
of cambium surrounding the wound will die back. In shade tree
maintenance, wound dressings have not proven effective in
stimulating wound closure or internal compartmentalization of the
damaged area (44). Increment boring causes discoloration
and may lead to decay in red maple. Callus growth, when
established, is reasonably rapid, but an extra year or two often
is needed if cambial dieback has been extensive around the wound
(26). Red maple was rated intermediate with respect to amount of
damage after a severe glaze storm in Pennsylvania. In one study,
major damage was sustained by 41 percent of the black cherry, 16
percent of the red maple, and 5 percent of the hemlock (18).
Many different insects feed on red maple, but probably none of
them kill healthy trees. They do reduce vigor and growth leaving
the tree more susceptible to attack from fungi. Insect feeding
also may hasten the death of weakened trees. Susceptibility to
insect attack is illustrated by a study in the Piedmont. Of 40
species investigated, red maple had the highest percentage (79
percent) of insect attacks. Among the more important borers
attacking red maple were the gallmaking maple borer (Xylotreehus
aceris), the maple callus borer (Synanthedon acerni),
and the Columbian timber beetle (Corthylus columbianus).
The common scale insects included the cottony maple scale
(Pulvinaria vitis), the maple leaf scale (P
acericola), and the oystershell scale (Lepidosaphes
ulmi). The common leaf feeding moths were the gypsy moth (Lymantria
dispar), the linden looper (Erannis tiliaria), the
elm spanworm (Ennomos subsignaria), and the red maple
spanworm (Itame pustularia). The forest tent caterpillar
(Malacosoma disstria) avoids red maple, however (26).
Red maple is very sensitive to fire injury, and even large trees
can be killed by a fire of moderate intensity. The fire-killed
trees sprout vigorously, however, and red maple may become a more
important stand component after a fire than before one (26).
Red maple is a desirable deer food and reproduction may be almost
completely suppressed in areas of excessive deer populations.
Snowshoe hares may also reduce the amount of red maple
reproduction (26).
If sapsuckers attack red maple, ringshake may develop (42).
Sapsucker damage may also result in mortality Healthy as well
as unhealthy trees are attacked and nearly 40 percent of the
trees attacked may be killed (41).
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Genetics
provided by Silvics of North America
As might be expected from its wide range, red maple shows great
variation in height, cold hardiness, straightness, time of
flushing, onset of dormancy, and other traits. In general, red
maples in the north show the most reddish autumn color, earliest
flushing and bud set, and least winter injury. Seeds from the
north-central and east-central range produce the tallest
seedlings. Genetic potential has been found for breeding and
selecting red maple against three major urban stresses:
verticillium wilt, air pollution, and drought (52,53). Red
maple fruits also exhibit geographical variation. The more
northerly sources, from locations with short frost-free periods,
produced samaras that are shorter but heavier than those from
southern sources (51,66).
Experimental crosses of red and silver maple have been made (26).
Also, red maple is known to hybridize naturally with silver maple
(33).
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Growth and Yield
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Red maple is a short- to
medium-lived tree and seldom lives longer than 150 years. It
reaches maturity in 70 to 80 years. Average mature trees are 18
to 27 m (60 to 90 ft) in height and 46 to 76 cm (18 to 30 in) in
diameter (26). The largest registered living red maple is growing
near Armada, MI. It is 38.1 m (125 ft) tall and has a bole
circumference, at breast height, of 4.95 m (16.25 ft) (38).
Although red maple height growth starts relatively early in the
spring, radial growth starts late in the season. Radial growth
then proceeds rapidly, becoming half complete in 50 to 59 days
and fully complete in 70 to 79 days. In a New York study, red
maple total height growth was somewhat better than that of the
other species studied (26).
Growth during early life is rapid but slows after trees pass the
pole stage. Red maple responds well to thinning. In upper
Michigan, thinning was more effective than fertilization for
stimulating red maple growth (49). In the Canadian Maritimes, a
35-year-old coppice red maple stand was thinned by reducing each
sprout clump to one of the better stems. The number of red maple
stems was reduced from 2,610 to 560/ha (1,057 to 227/acre). Ten
years later, these residual trees had more than doubled their
volume to 63.8 m³/ha (911 ft³/acre). In another study,
a partial cutting was made on a 40-year-old stand of Allegheny
northern hardwoods. Of all the species, red maple grew best. In
the 10-year period after cutting, dominant red maple trees grew
an average of 5.7 cm (2.25 in) in diameter. In the north, the
young red maple trees grow faster than sugar maple, beech, or
yellow birch, but slower than aspen, paper birch, or white ash.
In southern bottom lands, the growth rate of red maple compares
favorably with that of other hardwood species. An average
diameter growth of 7.5 to 9 cm (3.0 to 3.5 in) in 10 years is
possible (26).
Early crop tree release of red maple seedlings and sprouts is
feasible in young, even-aged stands. It should be done when the
new stand has crown closure and crown dominance is being
expressed. This occurred on 9- to 12-year-old trees in West
Virginia (56,57). Only 10 percent of red maple sprout
clumps did not have a sprout of potential crop tree quality (29).
Released red maple trees have a low susceptibility to epicormic
sprouting (46).
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Reaction to Competition
provided by Silvics of North America
Red maple is a pioneer or
subclimax species that is more shade tolerant and longer lived
than the usual early successional species, such as poplar (aspen)
and pin cherry. It compares in shade tolerance with sycamore (Platanus
occidentalis), silver maple, American basswood (Tilia
americana), common persimmon (Diospyros virginiana), black
gum, and rock elm (Ulmus thomasii). It is not as tolerant
as sugar maple, American beech, eastern hophornbeam, and
flowering dogwood (Cornus florida) (26). Red maple can
most accurately be classed as tolerant of shade. Seedlings are
more shade tolerant than larger trees and can exist in the
understory for several years. They respond rapidly to release and
can occupy over-story space. Disturbances such as fire, disease,
hurricanes, and harvesting have caused red maple to increase in
stocking where it previously occurred as only scattered trees
(19,31,35,40,48,55). As these stands mature and the
canopy closes, red maple growth slows due to competition for
light (9).
Following a hurricane in central New England, the site was soon
dominated by pin cherry, with red maple, northern red oak, paper
birch, and a few eastern white pine. After 10 years, the pin
cherry was giving way to dominance by red maple. After 40 years,
however, northern red oak and paper birch had assumed dominance
over the now codominant red maple (19). In northern
hardwood types, red maple begins to give way to sugar maple and
more tolerant hardwoods after about 80 years (26), but on
certain wet sites, red maple can probably maintain itself
indefinitely as an edaphic climax (13).
Red maple is generally very resistant to herbicides (28). Also,
diffuse porous species such as red maple are difficult to kill by
girdling. For example, 3 years after treatment, 70 percent of the
girdled trees had live crowns (63). Stem injection, using
cacodylic acid(12) and picloram (61), did
successfully control red maple as did glyphosate applied by
hydraulic sprayer; but not when applied by a mist blower (16).
Generally, if treatment of red maple is planned, it is wise
to consult current labels or experts in the field of chemical
control to determine the latest allowable chemicals and the best
methods of application.
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Rooting Habit
provided by Silvics of North America
Red maple trees grow well and are
generally capable of growing as well as or better than
their associates on sites with less than optimum moisture
conditions, either too wet or too dry. In Michigan, red maple
sprouts grew about twice as fast on wet organic soils as on
mineral soils or drier organic soils (26). Roots of maple
seedlings are capable of developing differently in response to
various environments, so that the seedlings can survive in
situations ranging from swamp to dry upland. This characteristic
root system adaptability is maintained as the trees grow older.
Under flood conditions, many adventitious roots develop, but the
root systems recover quickly upon drainage (24). Red maples seem
to tolerate drought through their readiness to stop growing under
dry conditions (52) and by producing a second growth
flush when conditions improve again, even after growth has
stopped for 2 weeks (27).
Red maple roots are primarily horizontal and form in the upper 25
cm (10 in) of soil. After germination, a taproot develops until
it is about 2 to 5 cm (1 to 2 in) long, then it turns and grows
horizontally. As the woody roots extend sideways, nonwoody fans
of feeder roots extend upward, mostly within the upper 8 cm (3
in) of mineral soil. The woody roots may be 25 m (80 ft) long
(34). Although red maple trees and seedlings tolerate flooding,
they can be damaged if silt and sand layers 7.6 cm (3 in) or more
are deposited over their roots (6).
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Seed Production and Dissemination
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A seed crop occurs
almost every year, and on an average, a good to bumper crop
occurs once in every 2 years (14). Red maple is generally
very fruitful. Trees 5 to 20 cm in d.b.h. (2 to 8 in) can yield
seed crops of 12,000 to 91,000 seeds. A 30-cm (12-in) tree
yielded nearly a million seeds (1). It is possible to
stimulate red maple seed production through fertilization. The
stimulation often lasts 2 years and may yield up to 10 times more
seeds than an unfertilized stand (4).
The fruit, a double samara, ripens from April to June before leaf
development is complete. After ripening, seeds are dispersed for
a 1- to 2-week period during April through July. The seed does
not require pregermination treatment and can germinate
immediately after ripening. The fruits are among the lightest of
the maple fruits, averaging about 51,000 cleaned seeds per
kilogram (23,OOOflb). In general, fruits are heavier in northern
latitudes. Red maple fruit from Canada, Wisconsin, and Michigan,
where the normal growing season is 80 to 150 days, averaged 23 gr
(1.5 g)/100 fruits. On the other hand, in Rhode Island, Kentucky,
and South Carolina, with a frost-free period of 180 to 240 days,
the weight averaged 17 gr (1.1 g)/100 fruits. Because the fruits
are small and winged, they disperse efficiently in the wind.
Germination may be 75 to 80 percent in 2 to 6 days. Total
germination is often 85 to 91 percent (59,66).
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Seedling Development
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Red maple has few
germination requirements. The seed can germinate with very little
light (26), given proper temperature and some moisture.
Most seeds generally germinate in the early summer soon after
dispersal. Shading by a dense overstory canopy can depress
first-year germination; then second-year germination is common
(36). Germination is epigeal (59).
Moist mineral soil seems the best seedbed for red maple,
and a thin layer of hardwood leaf litter does not hinder
germination and early survival. Many red maple seeds germinate
each year in abandoned old fields, in cutover areas and burns,
and in the forest. Reproduction has also been observed on
strip-mine Spoil banks in Pennsylvania, West Virginia, and Ohio
(26). Not many new seedlings can survive under a closed
forest canopy, but enough do survive to perpetuate the species in
abundance.
Presently, red maple is important in many stands where it was
formerly a limited associate; it is enabled to increase by
disturbances such as disease, windthrow, fire, and harvesting
(5,15,19,3740). In southeastern Ohio, 6 years after
clearcutting a 3.4 ha (8.5 acre) mature oak-hickory stand, the
new stand contained more than 2,200 red maple seedlings per
hectare (900/acre) taller than 1.4 m (4.5 ft), together with many
yellow-poplar and oak seedlings (Unpub. data, Vinton Furnace
Experimental Forest, McArthur, OH). The original stand on the
plot contained no red maple. There were occasional red maples in
nearby stands. Red maple does not show a strong affinity for
either northern or southern exposures (48), but its best
growth form is often found on northeast slopes (40). The
young seedlings are shade tolerant, and abundant 1- to 4-year-old
seedlings are often found under the canopy of older stands. Many
of these seedlings die each year if they are not released by
opening of the main crown canopy, but new ones replace them.
Thus, a reservoir of seedlings and ungerminated seed is available
to respond to increased sunlight resulting from disturbance.
Pre-existing red maples in a cut stand add greatly to the new
stand stocking through stump sprouts (21). In some
species, disturbances of small areas often restrict development
of new age classes because the canopy over small areas closes in
from the side too quickly. Red maple, however, is sufficiently
shade tolerant to respond and may increase in prominence after
small disturbances (20,37).
Red maple shows an early tendency to develop root system
characteristics according to soil conditions, enabling it to grow
on greatly different sites ranging from swamp to dry upland (62).
On wet sites, red maple seedlings produce short taproots with
long, well-developed laterals. On dry sites, they develop long
taproots with much shorter laterals (26). Red maple seedlings are
classified as moderately tolerant of soil saturation. In one
study, their growth was only slightly retarded after 60 days in
saturated soils (24). Red maple seedlings were very tolerant of
flooding, showing no sign of stem or leaf damage after 60 days of
flooding (7). This capacity to withstand conditions of wetness or
dryness enables survival and growth on a wide variety of site
conditions where red maple grows naturally.
Throughout the northern portion of its range, with respect to
shade, red maple seedlings are rated moderately tolerant to
tolerant and are often abundant in the understory advance
reproduction. In the Piedmont, red maple seedlings were found to
be shade intolerant however; and, in the lower Mississippi Basin,
red maple seedlings grow well only in openings. The species was
found to be more shade tolerant on good sites than on poor sites.
Overall, it ranks more shade tolerant than yellow birch or white
ash (Fraxinus americana) but less so than sugar maple,
American beech, or eastern hophornbeam (26).
Sugar maple is one of the first species to start stem elongation
in the spring, and red maple starts only a few days later. In one
study, red maple stem elongation was one-half completed in 1
week. Growth then slowed and was 90 percent completed in 54 days
(27). Under favorable light and moisture, red maple seedlings can
grow 0.3 m (1 ft) the first year and as much as 0.6 m (2 ft) each
year for the next few years. Some sprouts can grow 0.9 m (3 ft)
or more the first year (26), but they soon slow to about the same
rate as seedlings.
Although red maple naturally germinates and becomes established on
many types of seedbeds, direct seeding in an old field failed.
Survival was only 37 percent after the first year (2). Planting
of seedlings has not succeeded on strip-mine spoil banks (26) or
old fields (45). First year survival generally is low and
survivors may show poor growth rate and form. Planted red maple
infected with mycorrhizae may grow somewhat better, especially on
strip-mine spoil banks (10). In the nursery, red maple
seedling growth was increased when 4 hours of supplemental light
and an aluminum foil soil mulch were provided, and when the soil
was treated with the insecticide Disulfoton. In 1 year, these
seedlings compared favorably with 2- to 3-year-old seedlings
grown by conventional methods (8). If planting of red
maple is desired, container-grown stock seems to offer some
promise. Ninety-eight percent of the red maple tubelings planted
in a New Hampshire forest clearcutting during August survived.
The stock had been grown for 8 weeks in containers. Two container
sizes-41 cm³ (2.5 in³) and 125 cm³ (7.6 in³)
were compared, with no difference in results (17).
Red maple is a common associate in second-growth cherry-maple
Allegheny hardwood stands. But after clearcutting, red maple
seedlings often grow poorly, whereas the black cherry seedlings
do well. A chemical from black cherry, perhaps benzoic acid, may
interfere with red maple development (22). Black cherry
leaves have been identified as a source of benzoic acid and as a
potential allelopathic inhibitor of red maple (23).
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Soils and Topography
provided by Silvics of North America
Red maple can probably thrive on a wider range of soil types,
textures, moisture, pH, and elevation than any other forest
species in North America (18). Its range covers soils of
the following orders: Entisols, Inceptisols, Ultisols, Alfisols,
Spodosols, and Histosols. It grows on both glaciated and
nonglaciated soils derived from granite, gneisses, schists,
sandstone, shales, slates, conglomerates, quartzites, and
limestone (26).
Red maple grows on diverse sites, from dry ridges and southwest
slopes to peat bogs and swamps. It commonly grows under the more
extreme soil-moisture conditions either very wet or quite dry.
The species does not show a strong affinity for either a north or
a south aspect (48). Although it develops best on
moderately well-drained, moist sites at low to intermediate
elevations, it is common in mountainous country on the drier
ridges and on south and west exposures of upper slopes. It is
also common, however, in swampy areas, on slow-draining flats and
depressions, and along small sluggish streams (26). In
upper Michigan and New England, red maple grows on ridge tops and
dry sandy or rocky upland soils and in almost pure stands on
moist soils and swamp borders (13,40). In the extreme
south, red maple is almost exclusively a swamp species.
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Special Uses
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Red maple is known in the lumber industry as soft maple. The wood
is close grained and resembles sugar maple but is softer in
texture, not as heavy, lacks the figure, and has somewhat poorer
machining qualities. Red maple in the better grades is
substituted for hard maple, particularly for furniture. Red maple
lumber shrinkage from green to oven-dry moisture content is
slightly more than shrinkage for hard maple in radial,
tangential, and volumetric measurements (60).
Brilliant fall coloring is one of the outstanding features of red
maple. In the northern forest, its bright red foliage is a
striking contrast against the dark green conifers and the white
bark and yellow foliage of the paper birches. Red maple is widely
used as a landscape tree.
Although the hard maples-sugar and black maple (Acer nigrum)
are principally used for syrup production, red maple is also
suitable. When sap and syrup from sugar maple were compared with
those of red and silver maple, boxelder (A. negundo), and
Norway maple (A. platanoides), they were found to be
equal in sweetness, flavor, and quality (30). The buds of
red and silver maple and boxelder break dormancy much earlier in
the spring than sugar maple, however, and the chemical content of
the sap changes, imparting an undesirable flavor to the syrup.
Consequently, the tapping season for red and silver maple is
shorter than that for sugar maple.
Red maple is a highly desirable wildlife browse food. Elk and
white-tailed deer especially use the current season's growth of
red maple and aspen as an important source of winter food
(25). Timber harvesting slash can provide an
important source of browse to help sustain the animals. Red
maple, sugar maple, and paper birch trees cut any time after leaf
fall provide browse as nutritious as, and more acceptable than,
trees cut immediately before leaf fall (3).
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Vegetative Reproduction
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Red maple stumps sprout
vigorously. Inhibited, dormant buds are always present at the
base of red maple stems. Within 2 to 6 weeks after the stem is
cut, these inhibited buds begin to extend (65). Fire can
also stimulate these buds. The number of sprouts per stump
increases with stump diameter to a maximum of 23 to 30 cm (9 to
12 in), and then decreases among larger trees. Stumps of younger
trees tend to produce taller sprouts (39,47). Sprouts grow faster
than seedlings, and leaf and internode size is greater. As
competition increases, growth rates slow (65). Many of
the sprouts have rot and poor form (58). Also, the
attachment of a sprout to the stump is often weak because the
base of the sprout grows over the stump bark and the vascular
connection between them is constricted (65). Regeneration
by seedling sprout may be especially successful (19). Generally,
the species' great sprouting capacity makes it suitable for
coppicing and accounts for its tendency to be found in sprout
clumps.
Red maple is difficult to propagate from cuttings and success
varies considerably. Some rooting has been obtained by treating
cuttings with a concentration of 200 mg per liter (200 p/m) of
indolebutyric acid for 3 hours. Cuttings collected in June seem
to root better than those taken later in the growing season.
Cuttings from the lower part of the crown root better than those
from the upper part, and cuttings from male clones or female
clones, which fruit sparingly, root better. Successful bud
grafting on an experimental basis has been reported with red
maple and with sugar maple on red maple stocks, and layering has
been observed in central Pennsylvania. For the most part,
however, the species is difficult to propagate vegetatively,
except by means of stump sprouts (26).
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Brief Summary
provided by Silvics of North America
Red Maple
Aceraceae -- Maple family
Russell S. Walters and Harry W. Yawney
Red maple (Acer rubrum) is also known as scarlet maple,
swamp maple, soft maple, Carolina red maple, Drummond red maple,
and water maple (33). Many foresters consider the tree inferior
and undesirable because it is often poorly formed and defective,
especially on poor sites. On good sites, however, it may grow
fast with good form and quality for saw logs. Red maple is a
subclimax species that can occupy overstory space but is usually
replaced by other species. It is classed as shade tolerant and as
a prolific sprouter. It has great ecological amplitude from sea
level to about 900 m (3,000 ft) and grows over a wide range of
microhabitat sites. It ranks high as a shade tree for landscapes.
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