The American beech dominates northern hardwood forests, according to the Hubbard Brooks Ecosystem Study. Distinguished by its wide-spreading branches and golden leaves that often linger through the winter, as well as a distinct growth pattern, the growth of the American beech allows it to survive in conditions where other trees find it difficult to take hold.
The growth of a new beech tree begins in two ways. Beech trees are flowering plants and offspring grow from the seeds. Beech trees begin producing seed when they are 40 years old and drop seeds every 2 to 8 years thereafter, according to the U.S. Forest Service. Beech trees also grow from root suckers--new plant growth that arises from existing beech root systems. As the Hubbard Brook Ecosystem Study points out, this growth habit gives the new tree the advantage of an existing extensive root system.
Young beech trees grow out as well as up, an adaptation that allows them to make use of the limited light available to them on the forest floor. The canopies of large, older trees can choke off light supplies to new seedlings, but by spreading its branches over a larger area, the beech tree grabs its share of sunlight, using the energy produced from the light to grow to a height where it can compete with larger trees.
The beech tree reaches heights of 50 to 70 feet at maturity, according to the University of Connecticut's Plant Database. It retains its sprawling shape even into maturity, and mature trees may grow to widths of 120 feet, twice the height of the tree. In crowded conditions, however, the beech doesn't sprawl as wide.
By examining tree rings from a cut beech, the Hubbard Brook Ecosystem Study learned that beech trees grow quickly at the beginning of their lives, with growth beginning to slow after about 6 years. Beech trees are among the slowest growing hardwood trees, likely because both their shade tolerance and their immunity to deer browsing doesn't necessitate quickly achieving great heights. A study conducted on beech trees in the Great Lakes area found that trees as old as 100 years still added a foot of growth every few decades.
The beech tree's heavy reliance on root suckering helps the tree to regenerate, even after seed-producing adults have been killed by disease or fire. However, as the U.S. Forest Service points out, because the beech grows so slowly, it tends to dominate in areas with a high survival rate of adult trees.