Acer Saccharum - Ecology

Ecology

The sugar maple is an extremely important species to the ecology of many forests in North America. Pure stands are common, and it is a major component of the northern and central U.S. hardwood forests. In the north, it forms associations of beech-maple and sugar maple-yellow birch, which is most important beyond the northern limit of beech. Sugar maple-American basswood, sugar maple-white ash and sugar maple-ironwood--red oak are also common forest associations.

Sugar maple is among the most shade tolerant of large deciduous trees. Among North American maples, its shade tolerance is exceeded only by the striped maple, a smaller tree. Like other maples, its shade tolerance is manifested in its ability to germinate and persist under a closed canopy as an understory plant, and respond with rapid growth to the increased light formed by a gap in the canopy. The sugar maple can grow comfortably in any type of soil, except sand.

Sugar maples engage in hydraulic lift, drawing water from lower soil layers and exuding that water into upper, drier soil layers. This not only benefits the tree itself, but also many other plants growing around it.

Human influences have contributed to the decline of the sugar maple in many regions. Its role as a species of mature forests has led it to be replaced by more opportunistic species in areas where forests are cut over. The sugar maple also exhibits a greater susceptibility to pollution than other species of maple. Acid rain and soil acidification are some of the primary contributing factors to maple decline. Also, the increased use of salt over the last several decades on streets and roads for deicing purposes has decimated the sugar maple's role as a "street-front" tree.

In some parts of eastern North America, particularly near urbanized areas, the sugar maple is being displaced by the Norway maple. The Norway maple is also highly shade tolerant, but is considerably more tolerant of urban conditions, resulting in the sugar maple's replacement in those areas heavily disturbed by human activities.