Acer saccharum

Sugar Maple

Sugar Maple
Photo courtesy USDA Plants Database

Flora, fauna, earth, and sky...
The natural history of the northwoods

Name:

• Acer, from the Latin for maple
• saccharum, from the Greek, sakcaron (saccharon), "a sweet juice distilled from bamboo", "sugar"
• Common name from the sweet sap used to make Maple Syrup
• Other common names include Hard Maple
, Rock Maple

Taxonomy:

• Kingdom Plantae, the Plants
  • Division Magnoliophyta, the Angiosperms (flowering plants)
    • Class Magnoliopsida, the Dicotyledons
    • Subclass Rosidae, the Roses
      • Order Sapindales
        • Family Aceraceae, the Maples
          • Genus Acer, the Maples
• Taxonomic Serial Number: 28731
• Known to hybridize with Red Maple (Acer rubrum)

Description:

• A large, native, deciduous forest tree, to 90' - 120' in height.
• Leaves simple, opposite, and palmate (the classic mapleleaf) with 5 lobes (rarely 3) separated by rounded crotches and broad, wavey toothed edges; 3½"-5½" long and nearly as wide.
  • Surface dark green and smooth, paler on underside, and either smooth or hairy along the veins.
  • Leafstalks to 3" long; can be hairy.
  • Fall Color yellow to orange or deep red, generally dropping just after seeds have fallen.
• Stem
  • Trunk relatively short, 30"-36" in diameter, occasionally more
  • Branches numerous and spreading, forming a large, rounded crown.
  • Twigs slender, smooth, and shiny; reddish-brown, with obvious lenticels on younger portions.
  • Buds ¼" long; conical with a pointed tip and numerous scales. Smooth or slightly hairy and reddish-brown to grey with scattered whitish lenticels.
  • Bark light grey to grey-brown and relatively thick, becoming deeply furrowed and rough with age.
• Roots relatively deep, with many extensively-branched laterals.
• Flowers monoecious or dioecious. Male and female flowers borne separately, sometimes on different trees. Drooping, yellowish green, tassel-like clusters of 8-14 flowers appear in early spring when leaves begin to unfold.
• Fruit a paired, papery-winged samara, yellow or green, sometimes brownish, and about 1" long. The two halves of the samara are nearly parallel.
• Sugar maple is long-lived and plants can survive for 300 to 400 years.

Identification:

Distribution:

• Manitoba to Nova Scotia and New Brunswick, south through Minnesota, and eastern Kansas into northeastern Texas. It extends eastward to Georgia and northward through the Appalachian Mountains into New England

Habitat:

• Most commonly rich, mesic woods but also drier upland woods. It grows in level areas or in coves and other sheltered locations on adjacent lower slopes. Often associated with stream terraces, streambanks, valleys, canyons, ravines, and wooded natural levees; occasionally found on dry rocky hillsides. At the western edge of its range, grows as scattered canopy seed trees or as abundant seedlings in protected ravines and relatively mesic north-facing slopes.
• A prominent component of mesic hardwood forests, Great Lakes pine forests, spruce-fir forests, and northern hardwood forests. Forms pure stands but also grows mixed with other hardwoods and scattered conifers.
• Can grow on a wide variety of soils, but typically does best on deep, moist, fertile, well-drained soils. It grows on sand, loamy sand, sandy loam, silty loam, and loam. Commonly associated with alluvial or calcareous soils it will also grows on stabilized dunes. Intolerant of flooded soils, it generally grows poorly on dry, shallow soils. Occurs on strongly acidic (pH=3.7) to slightly alkaline (pH=7.3) soils but grows best where soil pH ranges from 5.5 to 7.3. Soils are derived from a variety of parent materials including shale, limestone, and sandstone.
• Very tolerant of shade and can persist for long periods beneath a dense forest canopy. It is noted for its ability to quickly occupy gaps created in the forest canopy. A bank of abundant seedlings remains suppressed until gaps are created by windfall or other disturbances. Seedlings and saplings typically respond vigorously and rapidly to release and can overtop competitors such as northern red oak. Openings or gaps in the canopy allow more nutrients, light, and water to become available. In many areas, sugar maple is a dominant species in gaps created by dying American elms.
• Generally regarded as a late seral or climax species in many eastern deciduous forests. Throughout much of the Upper Midwest, sugar maple codominates climax stands with American basswood, or yellow birch. In the absence of disturbance, forests composed of jack pine, eastern white pine, eastern hemlock, yellow birch, or red pine are replaced by sugar maple and American basswood. However, it should be noted that disturbances, particularly fire, were common in eastern deciduous forests in presettlement times. In some locations, succession to sugar maple-American basswood stands may have taken as long as 650 years.

Fire:

• Sugar maple typically increases in the absence of fire. Seedlings occasionally sprout, but postfire establishment occurs primarily through an abundance of wind-dispersed seed.
• Shade-tolerant species, such as sugar maple, commonly assume dominance in the absence of fire in Great Lake's hardwood forests. Where fire frequencies are high, aspen and paper birch (Betula papiryfera) are common dominants. In presettlement times, sugar maple was typically absent from portions of the North Woods which burned at frequent intervals.
• Sugar maple is sensitive to fire. The thin bark is easily damaged by even light ground fires. Curtis reported that "cambial injury occurs even in trees that show little external damage." Large trees occasionally survive light fires and may exhibit visible fire scars. Hot fires can kill existing regeneration.
• Commonly occurs in mesic closed canopy forests that are relatively resistant to ground fires, particularly during the winter and spring when litter is usually moist. In the summer, flammable litter (generally deciduous leaves) is often scarce or absent. Greatest fire hazard occurs in dry years during October, after the leaves have fallen. Fires which occur during this time period are occasionally severe and can kill the entire stand.
• Sprouts poorly after fire. Mature trees that have been top-killed by fire do not sprout, small saplings occasionally sucker. Although sprouting is common in young sugar maples following mechanical disturbances, it is relatively uncommon after fire. Sugar maple reestablishes through seedling sprouts and seedlings.

Associates:

• Trees: American Basswood, Yellow Birch (Betula alleghaniensis), Black Cherry (Prunus serotina), White Spruce (Picea glauca), beech, White Pine (Pinus strobus), Eastern Hemlock (Tsuga canadensis), Northern Red Oak (Quercus rubra), white oak (Q. alba)
• Shrubs: Beaked Hazel (Corylus cornuta), Atlantic leatherwood (Dirca palustris), Redberry Elder (Sambucus pubens), Alternate-leaf Dogwood (Cornus alternifolia), Dwarf Bush-Honeysuckle (Diervilla lonicera), Canada Yew (Taxus canadensis), Red Raspberry (Rubus idaeus), and Blackberries (Rubus spp.).
• Herbs: Springbeauty (Claytonia caroliniana), Large-flowered Trillium (Trillium grandiflorum), Anemone (Anemone spp.) Marsh Blue Violet (Viola cucullata), Downy Yellow Violet (Viola pubescens), Solomons-seal (Polygonatum pubescens), False Solomons-seal (Smilacina stellata), Sweet Cicely (Osmorhiza spp.), Adderstongue (Ophioglossom vulgatum), Jack-in-the Pulpit (Arisaema atrorubens), clubmosses (Lycopodium spp.), and Largeleaf Aster (Aster macrophyllus)
• Mammals: Sugar maple is commonly browsed by white-tailed deer, moose, and snowshoe hare. The red squirrel, gray squirrel, and flying squirrels feed on the seeds, buds, twigs, and leaves of sugar maple. The porcupine consumes the bark and can, in some instances, girdle the upper stem.
• Birds: Numerous species of songbirds nest in sugar maple. Cavity nesters such as the black-capped chickadee excavate nest cavities or utilize preexisting cavities. The common flicker, pileated woodpecker, and screech owl also nest in maples

History:

• During the last Ice Age retreated with other hardwoods to the relative shelter of the lower Mississippi Valley, moving north after the pioneering conifers as the ice sheets melted.
• State Tree of West Virginia and Wisconsin.

Uses:

• Wood Characteristics
  • Tough, strong, durable, and hard as oak.
  • Heavy at 44 pounds per cubic foot, with a specific gravity of .56.
  • Generally straight grained but famous for curly or wavy figure (tiger maple, birdseye maple, and curly maple, for example).
  • Sapwood is white to pinkish-white in color, changing abruptly to the pinkish-brown heartwood.
  • Accepts all finishes very well.
• Wood Uses
  • Commonly used to make furniture, paneling, flooring, and veneers.
  • Also where durability is important, such as gunstocks, tool handles, cutting blocks, sporting goods, bowling pins
  • Musical instruments.
• Landscape Uses
  • Widely planted as a shade tree and an ornamental. Its leaves turn vivid shades of yellow and red in the fall.
• Other Uses
  • Primary source of maple sugar and syrup. Maple sugar and syrup were used as trade items by many Native American peoples.

Reproduction:

• Seed: Sugar maple possesses extremely effective outbreeding mechanisms, and flowers are readily wind pollinated. Minimum seed-bearing age is 30 to 40 years. Forty- to sixty-year-old trees with 8" d.b.h. produce light crops, whereas 70- to 100-year-old trees with d.b.h. of 10"-14" produce moderate seed crops. Large fluctuations in annual seed crops have been reported. Seed production is partly dependent on genetic factors, and some trees produce an abundance of flowers nearly every year.
• Seed is primarily dispersed by wind, which can carry the relatively large seeds for up to 330'. However, most seeds do not travel more than 50' from the forest edge. Some seed may also be dispersed by water.
• Few seeds persist in the seed bank for more than 1 year, and sugar maple is not considered an important seed banker.
• Vegetative regeneration
  • a prolific sprouter in the northern part of its range, but at the southern edge of its range, it sprouts less vigorously than associated hardwoods.
  • Stump-sprouting and root-sprouting are moderately common.
  • Layering occasionally occurs.
• Growth initiation of sugar maple varies geographically. Flower buds generally begin to swell prior to the development of vegetative buds and generally emerge 1 to 2 weeks before the leaves appear. Male and female flowers mature at slightly different rates, which promotes cross-pollination. Fruit ripens approximately 12 to 16 weeks after the flowers appear. Fruit begins to fall approximately 2 weeks after ripening.

Propagation:

• Most commonly by seed, it can also be propagated vegetatively by budding, grafting, air-layering, or by rooting stem cuttings.

Cultivation:

• Hardy to USDA Zone 3 (average minimum annual temperature -40ºF)
• Cultural Requirements
• Full sun to part shade; shade tolerant
• Prefers fertile, slightly acidic soil.
• pH 3.7 - 7.3
• Medium wet, well-drained soil
• Size 30'-60'W x 40'-80'H
• Growth rate slow
• Excellent specimen tree for the lawn or parks. May be used as a street tree as long as it can be located on a street and in a location where road salt, soil compaction and pollution will not be significant problems.
• Cultivars and species available by mail order from specialty suppliers or at local nurseries.
• Damage: Susceptible to wind damage and to damage caused by ice storms and winter freezes. De-icing salts often damage sugar maples which grow along roadways. Individuals within the overstory are susceptible to air pollutants such as sulfur oxides, nitrogen oxides, chlorides, and fluorides. Sugar maple is susceptible to logging injuries which frequently permit the entrance of decay.
• Insects/disease: Host to numerous insects including bud miners, aphids, borers, and defoliators such as the gypsy moth, tent caterpillar, linden looper, and cankerworms. Cankers, root rot (Armillaria spp.), and verticillium wilt also affect sugar maple. Leaf scorch may be a problem in drought conditions. Has been frequently used as a street tree, but is generally intolerant of road salt, soil compaction and pollution. Since the early 1900's, this species has been periodically affected by a condition known as maple decline. Increases in die-back have been observed in many parts of the Northeast since 1982. Causes of maple decline are unknown, but acid rain and other pollutants are possible contributors. Trees already weakened by pollutants may be increasingly susceptible to root rot and tent caterpillar infestations. Maple decline may be accentuated by a series of unusual climatic events; large diameter trees are most susceptible.

Links:

• Fire Effects Information System

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