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Quercus taxonomy
Quercus turbinella Greene
EOL Text
This oak is found in the California Desert Mountains (New York Mountains)/ The distribution outside California is east to Colorado and Texas, and south to Baja California, Mexico.
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| Rights holder/Author | C. Michael Hogan, C. Michael Hogan |
| Source | No source database. |
More info for the terms: shrub, tree
Sonoran scrub oak is a clump-forming or clonal evergreen shrub or less commonly a small tree [81,84,94,101]. It typically grows from 3 to 8 feet (0.9-2 m) in height with stem diameters to 8 inches (20 cm) [8,99,101]; however, it can reach 15 feet (5 m) or more [8]. The somewhat leathery leaves are 0.5 to 1.6 inches (1.3-4 cm) in length, 0.3 to 0.9 inch (0.7-2.4 cm) in width [94,101]. Leaves persist through the winter [93]. Fruits of Sonoran scrub oak are slender, annual acorns 0.5 to 1 inch (1.3-2.5 cm) in length, with turbinate cups [94].
Belowground structure: Root depths of over 25 feet (8 m) have been reported in parts of Arizona [81]. Roots and rhizomes may spread 16 feet (4.9 m) or more horizontally [16]. Sonoran scrub oak forms colonies by sprouting from rhizomes [8,100]. Thousands of individual stems may form from a single or only a few individuals [8]. Davis and Pase [16] report "what appears to be a relatively open stand of Sonoran scrub oak aboveground, may actually be a relatively closed system" of overlapping roots and rhizomes. The top foot of soil typically contains a dense network of small surface laterals that aid in the absorption of surface soil moisture. In central Arizona, the greatest accumulation of belowground biomass occurred in the top 2 feet (0.6 m) of soil, with biomass decreasing with depth as follows [16]:
Soil depth (m) Weight (g) 0 - 0.3 7053 0.3 - 0.6 7883 0.6 - 0.9 5068 0.9 - 1.2 3403 1.2 - 1.5 2602 1.5 - 1.8 1575 In an Arizona study, only 1 of 7 Sonoran scrub oak stems died within a 47-year period [69].
More info for the terms: fire intensity, fuel, severity, shrub
Sonoran scrub oak is top-killed by fire [15,18]. The degree of damage and subsequent mortality rate of shrub live oak following fire depends largely on fire intensity and severity, site characteristics that influence fuel levels, and climatic factors [87]. On most sites, Sonoran scrub oak is difficult to kill by burning [70].
More info for the terms: mast, shrub
Sonoran scrub oak generally provides relatively little browse for most species of wildlife and livestock. In many areas it is used heavily only when other more palatable species are lacking [70]; however, Sonoran scrub oak is sometimes an important food source for deer and livestock [8]. In southern and central Arizona, it is considered to be a valuable browse plant because of its abundance and evergreen leaves [94]. Sonoran scrub oak can be a valuable emergency winter food when snow is deep or when preferred foods are scarce [8]. Sonoran scrub oak also provides an excellent source of emergency browse during droughts when other plants become desiccated and unpalatable [94]. Sonoran scrub oak can survive heavy browsing and may remain as "almost the only forage" on deteriorated ranges in Arizona [35].
The foliage of Sonoran scrub oak is utilized to at least some degree by a number of big game species. New, succulent growth is the most palatable and is readily consumed [8,65]. New growth is described as "fair" forage for deer in Arizona. In some areas, deer may consume considerable amounts of foliage [65,94]. Use of Sonoran scrub oak by mule deer in the southern Rocky Mountains is described as "moderate" in winter and "light" in summer [46]. Use of Sonoran scrub oak by desert mule deer is described as "low to high" in winter, "low" in spring, "moderate to high" during summer, and "low" in the fall [44]. Desert bighorn sheep feed on Sonoran scrub oak in Arizona [82].
Cattle, domestic sheep [94], and domestic goats use Sonoran scrub oak at least moderately [7]. In some Arizona locations, shrub live oak may become too dense for livestock and big game use [70].
Acorns of Sonoran scrub oak and related species constitute an important source of mast for many small birds and mammals in the Southwest. Acorns are utilized by the collared peccary, wild turkey, numerous rodents such as Abert's squirrel, geese, grouse, quail, scrub jays, and many other birds [8,63,97]. Scrub jays and many rodents collect and cache acorns of Sonoran scrub oak, thereby aiding in seed dispersal [63]. Mule deer, white-tailed deer, and cattle also consume acorns during the fall [8,50,63,96].
In the Southwest, scrub live oak cambium is eaten by sapsuckers, porcupines eat the bark, and beavers consume the twigs [97].
Shrubs or small trees , evergreen or subevergreen, to 4 m. Bark light gray or brown, scaly. Twigs brown to gray, 1-3 mm diam., usually tomentulose, sometimes glabrous, becoming glabrate. Buds brown, round to ovoid, 1-2 mm, minutely pubescent. Leaves: petiole 1-4 mm. Leaf blade elliptic or ovate, (1.5-)20-30 × (5-)10-15(-20) mm, thick, leathery, base cordate or rounded, margins planar or slightly crisped-undulate, coarsely 3-5-toothed or very shallowly lobed on each side, teeth spinose with spines 1-1.5 mm, secondary veins 4-8 on each side, apex acute or obtuse; surfaces abaxially yellow or reddish, usually glaucous, minutely stellate-puberulent, adaxially grayish, glaucous, or yellowish glandular, glabrous or sparsely and minutely stellate-pubescent. Acorns solitary or several, on axillary peduncle 10-40 mm; cup hemispheric or shallowly cup-shaped, 4-6 mm deep × 8-12 mm wide, covering 1/4-1/2 nut, scales tightly appressed, ovate, moderately tuberculate, grayish or yellowish puberulent; nut light brown, ovoid, to 20 × 11 mm, minutely puberulent or glabrate. Cotyledons distinct.
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| Rights holder/Author | eFloras.org Copyright © Missouri Botanical Garden |
| Source | http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=233501092 |
More info for the terms: adventitious, initial off-site colonizer, root sucker, tree
Tree with adventitious bud/root crown/soboliferous species root sucker
Initial off-site colonizer (off-site, initial community)
Sonoran scrub oak is rated fair in energy and protein value [20].
Nutrient content (%) of Sonoran scrub oak is as follows [82]:
Date Dry Protein Lignin Cellulose Ether Ash
matter
Jan-Feb 47.35 15.45 6.38 9.00 20.16 8.22
Mar-April 45.51 13.57 6.59 10.03 15.28 6.59
May-June 58.10 12.19 8.38 13.37 15.38 7.70
July-Aug 60.04 12.16 6.90 12.07 15.33 8.12
Sept-Oct 57.99 11.08 6.10 12.02 17.78 8.06
Nov-Dec 50.76 12.62 7.31 11.51 19.46 7.38
Crude fiber is lowest in May and highest during the winter months [76]. Crude
protein levels of Sonoran scrub oaks in California varied seasonally as follows
[4]:
Oven-dry weight (%)
January 7.7
February 7.3
March 7.5
April 6.9
Nutritional value (%) for Quercus spp. forage is as follows [55]:
Acorns Acorn meats Oak leaves
Dry matter 100.0 100.0 100.0
Organic matter 97.5 98.0 ----
Ash 2.5 5.6 2.0
Crude fiber 13.9 2.0 27.4
Ether extract 5.4 8.9 2.5
N-free extract 73.5 80.7 54.3
Protein (N Ã 6.25) 4.8 6.4 10.2
Cattle* 0.5 1.9 5.8
Horses* 1.7 3.1 6.2
Domestic goats* 1.7 3.1 6.1
Domestic sheep* 1.7 3.1 5.7
*digestible protein
Quercus dumosa Nuttall var. turbinella (Greene) Jepson; Q. subturbinella Trelease
| License | http://creativecommons.org/licenses/by-nc-sa/3.0/ |
| Rights holder/Author | eFloras.org Copyright © Missouri Botanical Garden |
| Source | http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=233501092 |
More info for the terms: natural, reburn, root crown
Sonoran scrub oak is well adapted to survive fire. This oak typically sprouts vigorously from the root crown and rhizomes in response to fire or other types of disturbance [16,63,79,100,104,105]. Postfire establishment by seed also occurs. In central Arizona, seedlings generally emerge in summer after the onset of summer rain [65].
FIRE REGIMES: In Arizona chaparral dominated by Sonoran scrub oak, fire return intervals have been estimated at 74 to 100 years. At least 20 years may be required before these sites can reburn [8]. Childers and Piirto [10] note that fire is a natural part of the ecosystem in southern California communities in which Sonoran scrub oak occurs.
Minnich and Chou [52] report the following average fire rotations in communities in which Sonoran scrub oak occurs:
southern California mixed chaparral - 59 years
northern Mexico mixed chaparral - 59 years
desert chaparral/pinyon-juniper woodland - 219 years
Palatability of Sonoran scrub oak to most species of wildlife and livestock
is relatively low in most seasons [8,86]. It is generally used
only lightly by deer in Arizona [65] and most other big
game species throughout its range. New
sprouts are most palatable and are browsed readily [8,65,86]. Domestic
goats, however, frequently use it year-round
[8,43]. In an Arizona chaparral study,
Sonoran scrub oak was the most preferred species of domestic goats
during the first weeks after goats were released onto the
range [43]. Sonoran scrub oak is fairly palatable to cattle and
domestic sheep in some areas [94].
The palatability of Sonoran scrub oak for livestock and wildlife
species for Sonoran scrub oak in Utah is as follows [20]:
Cattle Poor
Domestic sheep Poor
Horses Poor
Pronghorn Fair
Elk Poor
Mule deer Fair
Small mammals Good
Small nongame birds Poor
Upland game birds Good
Waterfowl Poor