Range and Habitat
Eastern White Oak (Quercus alba) is native to most of the eastern United States, from southern Maine south to the Florida panhandle and west to Minnesota and eastern Texas. The western limit of its range closely parallels the 95th meridian, an approximate demarcation between eastern species and the flora of the Great Plains.
White Oak does well in a variety of habitats, from dry hillsides to moist bottomlands; it is absent only from very dry ridgetops – and at the other extreme – frequently flooded lowlands. In the south it may grow in nearly pure stands; further north, as in New England, it is mostly seen in association with other upland hardwoods, especially Hickories and other Oaks. In the southern Appalachians it will grow at elevations up to 4,500 feet, where it may take a shrubby form. In New England it is not found at higher elevations, being limited to lower slopes and valleys.
Description
White Oak is a medium-sized to large, slow-growing, deciduous tree that reaches 15 to 25 meters tall and typically lives 200 to 300 years. On favorable sites it may attain 30 meters in height and live to be over 500 years old! Trees growing in the open have broad spreading crowns that are often as wide as tall. The strong root system is a foreshortened reflection of the trunk and limbs above, with a deep taproot and many thick horizontal roots. The bark is whitish gray and scaly on young trees, becoming medium gray and furrowed on older trunks.
Leaves are green above, lighter green beneath, with 5 to 9 rounded lobes separated by sinuses of variable depth. The leaves turn a rich burgundy color in autumn. Male and female catkins appear April to May on the same tree; the male pollen is dispersed by wind. The shiny brown acorns fall in September or October, and germinate soon after, ensuring that the seedlings have established roots by the first frost.
Ecology
White Oak is not a seed banker, as the acorns do not lie dormant, and will not survive in the soil for more than one year. Acorn production is variable by year, with bumper crops of acorns occurring every 3 to 6 years. These peaks in acorn abundance are called mast years – from the Old English mæst – referring to the fallen nuts of trees, especially Beech and Oak, that carpet the forest floor in autumn. A large, healthy White Oak can produce 10,000 acorns in a season, with numbers declining in drought years and increasing in mast years. That kind of output is a boon to the birds and mammals that feed on the seed crop, and the majority becomes food for wildlife – from mammals, such as Mice, Squirrels, Foxes, and Black Bear – to birds, including Bobwhite, Pheasant, Ruffed Grouse, and Turkey.
The main seed dispersers are Gray Squirrels, who bury more nuts than they retrieve, and Blue Jays, who may carry the acorns some distance from the parent tree. White Oaks provide habitat for many insects, which in turn provide sustenance for a host of bird species. This is especially evident in the spring, when migratory Warblers, Vireos, and other passerines crowd the branches of the Oaks seeking their insect prey.
White Oak is generally a hardy species, but like all plants is subject to a variety of pests and pathogens. One of the most interesting and noticeable of these are galls – odd growths that appear on the leaves and twigs. Oaks as a group are especially susceptible, with over 500 different kinds of oak galls described. Most galls are due to the presence of tiny wasps, midges, and mites (although some are caused by microorganisms). The adult arthropods lay eggs that hatch into larvae that begin to release chemicals – the plant response is a gall – plant tissue that provides a safe home for the unwanted guest! This is a fine-tuned evolutionary relationship best described as a mild form of parasitism, because in most cases, despite their tumor-like appearance, the galls do no great harm to the host. Some observers bemoan the unsightly presence of the galls, while others admire their colors and patterns.
Wood
The wood of White Oak is heavy, strong, and rot-resistant; it is harvested for flooring, furniture, paneling, and wooden shipbuilding. The hull of the famous heavy frigate USS Constitution, launched in Boston in 1797 and the oldest commissioned warship in the world still afloat, is of White Oak. The U. S. Navy maintains a large tract of land in Indiana that contains Constitution Grove, many acres of old White Oaks whose wood is designated for future maintenance and repair of the renowned ship!
White Oak has been used in cooperage for centuries, and has always been the preferred wood for whiskey barrels, giving characteristic color and flavor during the ageing process. White Oak also makes the finest firewood, providing as much heat as Hickory, while being easier to split than Black Locust.
The following two excerpts, from A Natural History of Trees by Donald Culross Peattie, depicts White Oak’s worth:
If Oak is the king of trees, as tradition has it, then White Oak is the king of kings. The Tuliptree can grow taller, and the Sycamore more massive, but no other tree in our sylva has so great a spread…. Indeed, the fortunate possessor of an old White Oak owns a sort of second home, an outdoor mansion of shade and greenery and leafy music.
For this is the best all-around hardwood in America. True, White Pine warps less, Hickory is more resilient, Ironwood is stronger, and Black Locust more durable; but White Oak would stand second to all these trees in each property in which they excel, and combining all these good qualities in a single species, it comes out as the incomparable wood for nearly every purpose for which wood can be used!
References
Peattie, Donald Culross. 1950. A Natural History of Trees of Eastern and Central North America. Houghton Mifflin, Boston.
Tirmenstein, D.A. 1991. Quercus alba. In: USDA. Fire Effects Information System. [Online] (www.feis-crs.org).