Site characteristics

Species characteristics (life history)

• Silver maple
• Red maple
• American elm
• Black ash
• Green ash
• Black willow
• Eastern cottonwood
• Other species

Natural and human disturbance

Stand characteristics

Silver maple

Figure 4. The native range of silver maple (from Burns and Honkala 1990). Figure 5. Silver maple bark. Figure 6. Silver maple samaras and leaves.

Silver maple (Acer saccharinum) is one of the most common tree species found in the bottomland hardwood forests of the Upper Midwest. It is a fast growing, shade intolerant species found throughout the Eastern United States and adjacent Canada (figure 4). It reproduces sexually from seed and asexually through stump sprouts. It is characterized by grayish bark that breaks apart and flakes at maturity (figure 5). Its leaves are deeply lobed and loosely serrated at the margin (figure 6). Mature trees reach 90 to 120 feet and 36 to 47 inches in diameter at breast height.

Silver maple blooms early in the spring with greenish yellow flowers that arrive well before their leaves. They tend to be monoecious with male and female flowers on the same tree although there are dioecious races where male and female flowers are borne on separate trees. Following pollination, fruits develop quickly and are mature within three weeks. This process begins in April and last until June throughout most of its range. At maturity, silver maple samaras are the largest of any maple species in the US (figure 6). The winged seeds are disseminated primary by wind but also by water and animals.

Silver maple seeds are produced in great abundance annually and can germinate immediately at maturity, requiring no stratification or seed coat scarification. Seedling establishment is most successful on moist mineral soils with a large amount of organic matter. Seedling development on such soils is quick, ranging from 12 to 36 inches in the first year. On saturated bottomland sites or on sites which are potassium-deficient, seedling development is much slower. First-year seedling mortality is often high due to light competition. In plantations where there is intense vegetation management, silver maple can average 12.5 feet after five growing seasons. On similar sites with no vegetation control the average height is less than 2 feet.

Silver maple tends to grow well in both pure and mixed species stands although growth is largely a function of site and competition. It is a major component of bottomland hardwood forests of the Central United States and present, to a lesser extent in many other forest types throughout the Eastern US and Canada. Common tree associates include American elm, eastern cottonwood, green ash, sycamore, swamp white oak, sweetgum, and pin oak. Small trees and shrubs often found with silver maple include willow, redberry elder, red-osier dogwood, and river birch. Understory plants include jewelweed, poison-ivy, swamp milkweed, Joe-pye-weed, and cardinal flower.

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Burns, Russell M., and Barbara H. Honkala, tech. coords. 1990. Silvics of North America: 1. Conifers; 2. Hardwoods. Agriculture Handbook 654. U.S. Department of Agriculture, Forest Service, Washington, DC. vol.2, 877 p.