Swamp White Oak - Quercus bicolor

Swamp White Oak - Quercus bicolor
Family: Fagaceae - Beeches, Chinkapins and Oaks
Swamp white oak is a medium-sized tree of the north central and northeastern mixed forests. It is found in lowlands, along edges of streams, and in swamps subject to flooding. It is rapid growing and long lived, reaching 350 years.
[Fagaceae Table of Contents] [Tree Encyclopedia] [Trees Alphabetic Table of Contents] [Family Fagaceae]

Throughout its range, swamp white oak is typically found on hydromorphic soils. These may be mineral soils that are imperfectly to poorly drained, as evidenced by high water tables and the presence of glei subsurface layers, or both; organic soils ranging from mucks (well decomposed) to peats (poorly decomposed) in which high water levels have favored organic accumulation; or alluvial soils underlain by a glei layer. These kinds of soils are associated with lands that are periodically inundated, such as broad stream valleys, low-lying fields, and the margins of lakes, ponds, or sloughs. Swamp white oak is not found where flooding is permanent.

The tree is classed as intermediate in tolerance to shade, and seedlings become established under moderate shade. Lowland forests in which swamp white oak grows are characterized by instability and successional uncertainty because of the variable effects of flooding, together with the presence of saturated soils. Swamp white oak may achieve dominance on the better drained lowland soils together with basswood, northern red oak (Quercus rubra), American beech (Fagus grandifolia), and sugar maple (Acer saccharum). Once established, it is able to compete effectively with American elm, green ash, and black willow. Limited current evidence indicates clearcutting to be an adequate silvicultural system, particularly on the better sites. In forest stands swamp white oak has a straight bole with ascending branches and a narrow crown. However, open-grown trees are generally poorly formed and often have persistent lower branches.

Swamp White Oak
This specimen was started from seed 23 years ago. It is about 25 feet tall.

Several insects attack oak trees. They are usually not important but may become epidemic and kill weakened trees. Economically, the most important are the wood borers. These may damage the wood of standing trees and cause log and lumber defects. White oak is attacked by several leaf eaters including the gypsy moth (Lymantria dispar), orange-striped oakworm (Anisota senatoria), variable oakleaf caterpillar (Heterocampa manteo), several oak leaf tiers and walking stick.

The Cynipid wasps cause galls to develop on the leaves, in the acorn or on the cup. White oak also hosts various scale insects, gall-forming insects, and twig pruners, but most of these are of minor importance. White oak acorns are commonly attacked by insects, in some cases affecting half the total acorn crop. Weevils of the genera Curculio and Conotrachelus cause most acorn damage. Light acorn crops usually are more heavily infested than heavy ones. Two moths damage acorns, the filbert worm (Melissopus latiferreanus) and Valentinia glandulella.

This swamp white oak is approximately 40 years old.

Windthrow may be a problem especially in recently thinned stands. (In forestry, windthrow refers to trees uprooted by wind, or to other phenomena that cause uprooting. When tree bole breakage occurs instead of uprooting it is called windsnap.) Disease and insects affecting swamp white oak are essentially the same as those found on white oak. Oak anthracnose can be damaging to individual trees but is generally not fatal. Swamp white oak is susceptible to the oak wilt fungus (Ceratocystis fagacearum) and in Illinois Phomopsis canker and oniothyrium dieback were found on this oak. In addition, an titleernaria fungus was found on blighted petioles.

The acorns are sweet, like others in the white oak group, and are eaten by squirrels and other rodents. In a study in Wisconsin, swamp white oak acorns were found to make up 27 percent of the diet of wild ducks. Several nongame bird species include these acorns in their diet.
(United States Department of Agriculture NRCS Plant Fact Sheet)

swamp white oak foliage

[Cirrus Home] [Tree Encyclopedia] [Trees Table of Contents] [Family Fagaceae] [Fagaceae Table of Contents] [Tree Encyclopedia]

Custom Search