|Natural range of Quercus gambelii|
Quercus gambeli' (lapsus)
Quercus gambelii, or Gambel oak, is a deciduous small tree or large shrub that is widespread in the foothills and lower mountain elevations of the central southwestern United States and northwestern Mexico. Its range is centered on the states of Utah, Colorado, Arizona and New Mexico, but also extends into Nevada, Wyoming, South Dakota, Kansas, Oklahoma and west Texas. In Mexico, it is mostly confined to northern Sonora and Chihuahua. Gambel oak typically grows at altitudes of 1,000–3,000 meters above sea level, where precipitation averages between 30–60 centimeters (12–24 inches) per year. It is often called scrub oak, oak brush or white oak.
Gambel oak varies significantly in size from one location to another. The average mature height is from 3 to 9 meters (10–30 ft), but occasionally reaches heights of 18 meters (60 ft) in some locations. Dwarf stands of plants under one meter (39 in) tall are common in marginal areas where heavy browsing occurs. The plant reproduces from acorns, but spreads most rapidly from root sprouts that grow from vast underground structures called lignotubers. These reproductive characteristics often result in dense groves or thickets of the trees that often cover entire mountainsides.
Although Gambel oak wood is hard and dense, its branches are irregular and crooked, making them flexible enough to bend without breaking when covered with heavy snow. The bark is rough and brownish-gray. The leaves are generally 7–12 cm (3–5 inches) long and 4–6 cm broad, deeply lobed on each side of the central vein; the upper surface is glossy dark green, the undersurface is paler and velvety. They frequently turn orange and yellow during autumn, creating mountainsides of vivid colors. The flowers are inconspicuous unisexual catkins that occur in the spring. The acorns are 1–2 centimeters (0.75 in) long, and about one-third to one-half enclosed by a cap or cup (cupule); they mature in September, turning from green to golden brown.
Gambel oak flourishes in full sun on hillsides with thin, rocky, alkaline soil where competition from other plant species is limited. It also does well in richer soils, but in those areas it is forced to compete for growing room. It is well-adapted to locations where wet springs and hot, dry summers create conditions conducive to wildfires. After a fire, Gambel oak quickly re-establishes itself from root spouts. The plant is also quite drought tolerant.
Because of its abundance, Gambel oak is an important food source for browsing animals like deer and livestock. Acorns are frequently gathered by squirrels and stored for winter food. Some insects depend on Gambel oak; for example, the Colorado Hairstreak Butterfly uses it as a food source for caterpillars. Historically, acorns from Gambel oak provided a reliable source of food for Native Americans.
Associated plant species include chokecherry, arrowleaf balsamroot, bigtooth maple, mountain mahogany, ponderosa pine and serviceberry. Associated birds and mammals include Western Scrub Jay, black-billed magpie, grouse, deer, chipmunks and squirrels.
|Wikimedia Commons has media related to Quercus gambelii.|
- Flora of North America, Rangemap. Map
- Plants Profile, USDA, Quercus gambelii.