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Quercus taxonomy
Quercus gambelii Nutt.
EOL Text
More info for the terms: adventitious, lignotuber, resistance, shrubs, xeric
Gambel oak occurs as clones [65] of shrubs in dense patches 3 to 20 feet (0.91-6.1 m) tall, often with a central thicket rising above the others [13], and as widely dispersed trees [43] up to 75.5 feet (23 m) tall [38]. Clones show uniform characteristics in shape, pubescence, and color [92]. Variability in life form corresponds with relative levels of water stress; stunted shrubs are present on xeric sites with moderate-sized trees found in wetter locations [54,107]. Gambel oak bark ranges from 0.5 to 0.75 inch (1.2-1.9 cm) thick. The bark is deeply divided into broad, irregular, often connected, flat ridges. Branches are slender and coated with short, pale, rust-colored hairs when 1stappearing [13]. Leaves of Gambel oak are highly variable, differing in outline, texture, lobing [13,92], pubescence, and size. Acorns are sessile or pedunculate [92], with an oval shape, usually 0.75 inch (1.9 cm) long and 0.63 inch (1.6 cm) broad [13].
The underground system of Gambel oak consists of a lignotuber with deep-feeding roots [33]. Lignotubers possess many scattered adventitious buds [213] .Clones are interconnected with rhizomes [198] that intertwine with lignotubers. Root grafting is common; root-endomycorrhizal associations may also occur [213].
Gambel oak possesses morphological and physiological adaptations to drought [1,116]. Deep roots, xeromorphic leaves and efficient water transport contribute to effective drought tolerance [1].
The growth rate of Gambel oak may vary with age. Barger and Ffolliott [14] report Gambel oak grows rapidly in height and diameter at early stages of life, with growth rates steadily declining with age. In contrast, in central Utah study Wagstaff [206] observed little change in growth rate of Gambel oak diameter during the 1st 100 years of life.
Ecological characteristics compiled by Loehle [132], are summarized below:
Typical age of mortality (years) | Maximum Longevity (years) | Specific gravity | Relative growth rate | Relative Decay Resistance |
90 | 120 | 0.62 | Medium | High |
Montane conifer, oak-maple, and higher margins of pinyon-juniper woodlands; 1000-3030m.
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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=233501032 |
Rounded Global Status Rank: T1 - Critically Imperiled
Reasons: Quercus gambellii var. bonina is known from several sites in only one plant community on the eastern side of Lake Powell in San Juan County, Utah (Welsh et al. 1993).
Gambel oak
scrub oak
Shrubs or trees , deciduous, shrubs sometimes clumped and spreading, trees small or moderately large. Bark gray or brown, scaly. Twigs brown or reddish brown with few, inconspicuous lenticels, 1.5-2.5 mm diam., glabrous or stellate-pubescent. Buds brown, ovoid, ca. 3 mm, apex acute or obtuse, sparsely pubescent, becoming glabrate. Leaves: petiole l0-20 mm. Leaf blade elliptic to obovate or oblong, deeply to shallowly 4-6-lobed, (40-)80-120(-160) × (25-)40-60(-100) mm, membranous, base truncate to cuneate, margins entire or coarsely toothed, lobes oblong, rounded or subacute, sinuses acute or narrowly rounded at base, reaching more than 1/2 distance to midrib, secondary veins 4-6 on each side, each passing into lobe, branched, apex broadly rounded; surfaces abaxially dull green, sometimes glaucous, densely velvety with erect 4-6-rayed hairs, sometimes glabrate or persistently villous only near midribs, secondary veins prominent, adaxially lustrous dark green, appearing glabrate, microscopically pubescent, secondary veins slightly raised. Acorns solitary or paired, subsessile or on peduncle to 10(-30) mm; cup deeply cup-shaped, 5-8(-17) mm deep × 7-l5(-25) mm wide, enclosing 1/4-1/2 nut, base round, margin thin, scales closely appressed, ovate, markedly tuberculate, proximally gray-tomentulose; nut light brown, ovoid to ellipsoid, (8-)12-15(-33) × 7-12(-18) mm. Cotyledons distinct.
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=233501032 |
More info for the terms: cover, density, fire intensity, frequency, fuel, fuel moisture, litter, top-kill, wildfire
In mature Gambel oak stands ( > 60 years), severe fires top-kill all or most of the stand; low-severity fires create openings for sprouts [144].
Gambel oak leaf moisture content varies greatly from year to year. Moisture content decreases from May to August [160]; August foliage has less than half the moisture of May foliage [161]. Within Waterton Canyon, Colorado, the moisture content of Gambel oak leaves decreased significantly (p < 0.001) in both the upper and lower canopy from May to August. This was true regardless of aspect and elevation. Ogle [160] constructed a model to predict fire behavior in relation to fuel moisture in Gambel oak.
Gambel oak produces a large amount of leaf litter that contributes, in most cases, 70% of total stand litter. In Utah, accumulated litter biomass of approximately 33,335 pounds per acre (37,348 kg/ha) was about equivalent to the bole biomass of 36,328 pounds per acre (40,702 kg/ha) [38].
The distribution of belowground nitrogen (kg/ha) and the percent of total belowground nitrogen was evaluated in a Gambel oak stands near Ephraim, Utah [199]:
Aboveground | kg/ha | % of N capital |
Leaves | 43 | 0.45 |
Live Branches |
19 | 0.20 |
Stem |
124 | 1.3 |
Dead branches | 40 | 0.43 |
Dead down | 30 | 0.30 |
Standing dead | 55 | 0.60 |
Litter | 582 | 6.2 |
Belowground | ||
Soil | 8455 | 87.9 |
Roots | 240 | 2.6 |
Based on this data, harvest followed by broadcast burning may result in a 10% loss in nitrogen capital depending upon fire intensity [199].
Fire alters the plant community in which Gambel oak occurs. Gambel oak communities are usually tolerant of fire, but herbage yields of associated species do not appear to improve [25]. Frequency and cover of major plant species on Gambel oak-dominated sites in oak brush near Wasatch Mountains State Park, Utah, were evaluated 1 year after an August wildfire [166]:
Unburned | Cover | Burn | ||
Species | Frequency (%) | (%) | Frequency (%) | Cover (%) |
Gambel oak | 100 | 51.12 | 92.8 | 38.36 |
pale agoseris (Agoseris glauca) | 11.8 | 1.06 | 0.90 | < 0.01 |
bluebunch wheatgrass | 29.40 | 0.59 | 0 | 0 |
Saskatoon serviceberry (Amelanchier alnifolia) | 23.50 | 1.09 | 8.1 | 0.95 |
big sagebrush | 17.60 | 1.09 | 0 | 0 |
China aster (Callistephus chimensis) | 5.90 | 0.03 | 0 | 0 |
cheatgrass | 23.5 | 4.17 | 18.90 | 0.16 |
lambsquarters (Chenopodium album) | 0 | 0 | 24.30 | 1.24 |
narrowleaf goosefoot (C. leptophyllum) | 5.90 | 0.03 | 19.8 | 0.39 |
maiden blue-eyed Mary (Collinsia parciflora) | 29.40 | 0.15 | 27.9 | 0.32 |
tapertip hawksbeard (Crepis acuminata) | 47.10 | 1.38 | 3.60 | 0.02 |
stickywilly | 11.80 | 0.21 | 24.30 | 0.69 |
Brown's pea (Lathyrus spp.) | 58.80 | 2.59 | 7.20 | 0.30 |
biscuitroot (Lomatium triternatum) | 35.30 | 0.77 | 1.8 | 0.01 |
tansyaster (Machaerantera canescens) | 0 | 0 | 0.9 | 0.03 |
Kentucky bluegrass | 52.90 | 16.81 | 17.1 | 1.23 |
bushy knotweed (Polygonum ramosissimum) | 0 | 0 | 6.3 | 0.03 |
chokecherry | 29.40 | 8.38 | 10.80 | 0.84 |
threeawn goldenrod (Solidago velutina) | 0 | 0 | 2.7 | 0.19 |
mullein (Verbascum thapsus) | 0 | 0 | 19.8 | 1.2 |
goldeneye (Heliomeris multiflora) | 0 | 0 | 24.3 | 0.86 |
Control: Fall burning provides the least amount of Gambel oak control. Gambel oak is dormant in the fall and total nonstructural carbohydrate reserves are at their peak [137]. Gambel oak is most severely harmed by successive fires when carbohydrate reserves are low. Top-killing Gambel oak in the summer may produce resprouts within 6 weeks. However, by fall, resprouts are still immature and carbohydrate recovery cannot begin until the following spring leaf-out, producing a 9- to 10-month period without carbohydrate replacement. Control may occur though carbohydrate stress imposed by 2 summer burns. However, effective burning may require biennial treatments due to light litter accumulation within a single growing season [94].
Observations within a ponderosa pine stand in southwestern Colorado at 7,600 feet (2,316 m) suggest frequent burning during mid-August provides control for Gambel oak. Vigorous Gambel oak sprouting was observed regardless of burn season. Twice-burned spring and fall treatments resulted in resprout densities equal to once-burned areas. Twice-burned summer treatments resulted in decreased oak density, frequency, and cover. Resprouts after twice-burned summer treatments were confined to top-killed oak thickets; sprouting after fall and spring burns was not restricted; and previous Gambel oak thicket boundaries were extended[94]. Frischknect and Plummer [76] suggest seeding competitive grasses after fire, but additional studies are required to substantiate findings [92].
United States
Rounded National Status Rank: NNR - Unranked
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Rights holder/Author | NatureServe |
Source | http://explorer.natureserve.org/servlet/NatureServe?searchName=Quercus+gambelii |
Quercus douglasii Hooker & Arnott var. gambelii (Nuttall) A. de Candolle; Q. gambelii var. gunnisonii Wenzig; Q. lesueuri C. H. Muller; Q. marshii C. H. Muller; Q. novomexicana Rydberg; Q. undulata Torrey var. gambelii (Nuttall) Engelmann; Q. utahensis Rydberg
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=233501032 |
More info for the terms: fire severity, prescribed burn, severity, wildfire
Postfire stand recovery time varies according to fire severity, climatic factors, and site characteristics. Recovery after fire is fastest on
warm, south-facing slopes at low elevations [125].
Postfire regrowth was greatest the 1st year following a summer (July) and fall (September to October) fire between 4,600 and 6,400 feet
(1,402-1,950 m) in northern Utah. August 1 postfire growth was 16 to 18 inches (41-46 cm), with 2nd-year growth at 4 to 8 inches (10-20 cm) [13].
Other studies show similar, rapid Gambel oak recovery from fire. New shoots with flowers were produced 26 days after an August fire in Orem Park, Provo Canyon, Utah, on stems
that were defoliated but not killed
[92]. Gambel oak shrublands were nearly half-covered with resprouting oaks 1 year after an August fire in Mesa Verde National Park, Colorado [72].
Also in Mesa Verde National Park, Gambel oak crown sprouted and leafed within a few months after a mid-July to August
lightning-ignited wildfire at 7,500 feet (2,286 m) [61]. Resprouting of Gambel oak after an October prescribed burn in Grand Mesa National Forest, Colorado, was greatest
at the 1st postburn growing season, decreasing the 2nd and following growing seasons.
Rounded Global Status Rank: G5 - Secure
License | http://creativecommons.org/licenses/by-nc/3.0/ |
Rights holder/Author | NatureServe |
Source | http://explorer.natureserve.org/servlet/NatureServe?searchName=Quercus+gambelii |