Emory Oak

Quercus emoryi reportedly hybridizes with Q . graciliformis (= Q . × tharpii C. H. Muller).

Trees or shrubs , evergreen, to 15 m. Bark dark brown to black, deeply fissured. Twigs dark reddish brown, 1-3 mm diam., pubescent. Terminal buds reddish brown, ovoid to subconic, 2.5-6.5 mm, glabrous except for tuft of hairs at apex, occasionally hairy on distal 1/2. Leaves: petiole 3-7(-10) mm, pubescent. Leaf blade ovate to narrowly oblong to obovate, planar, 28-95 × 15-45 mm, base cordate, margins entire or spinose, with up to 13 awns, apex blunt to acute; surfaces abaxially glabrous except for tuft of tomentum on each side of midrib at base of blade, rarely completely glabrous, adaxially not rugous, glabrous or with a few hairs along midrib. Acorns annual; cup cup-shaped, 5-7.5 mm high × 7-12 mm wide, covering 1/4-1/2 nut, outer surface pubescent to sparsely puberulent, inner surface pubescent to floccose, scale tips appressed, blunt; nut ellipsoid to oblong, 10-18 × 6-10 mm, glabrous to puberulent, especially at apex, scar diam. 3-5.5 mm.

Ariz., N.Mex., Tex.; n Mexico.

Flowering spring.

Foothills and slopes; 1000-2200m.

Quercus hastata Liebmann

Emory oak
blackjack oak
bellota

More info for the term: cover

Emory oak is a member of oak-chaparral and pinyon-oak-juniper
associations.  These associations provide cover for black bear,
white-tailed deer, antelope squirrel, mice, gray fox, and raccoon [30,81].

More info for the terms: monoecious, shrub, tree

Emory oak is a native, monoecious shrub or medium-size tree that can
reach 65.6 feet (20 m) tall and 2.5 feet (0.7 m) in diameter
[18,23,50,57,64].  It has a spreading, rounded crown with bark that is 1
to 2 inches (2.5-5.5 cm) thick [35].  The drought-deciduous leaves are
thick and 1.2 to 3 inches (3-8 cm) long [23,102,104].  Pistillate
catkins are one to two flowered [23,121].  Acorns are solitary or
paired, 0.4 to 0.8 inch (1-2 cm) long [35].

The range of Emory oak extends from central Arizona eastward through
southern New Mexico into western Texas [23,57,64,96,104].  Its range
continues southward through northern Mexico from Chihuahua west to
Sonora and south to Durango [35,48,96,103].

More info for the terms: cover, fire frequency, fire regime, forest, frequency, grassland, root crown, woodland

Emory oak is adapted to recurrent fires [92].  It sprouts from the root
crown or stump and grows vigorously following fire [18,20,26,59,75,108].

Madrean evergreen forests and woodlands are usually bordered by desert
grassland below and coniferous forest above [8].  Historically, fires
probably occurred every 10 to 20 years in oak woodlands adjacent to
semidesert grasslands [5,125].  Mean fire return interval for pine
communities above oak woodlands has been estimated at every 7 years
[75].  Historical fires in oak-pine woodlands in the Chiricahua National
Monument in Arizona occurred every 1 to 38 years [110].  Burned
ponderosa pine snags in evergreen oak woodlands in Arizona suggest
localized severe fires [85].

FIRE REGIMES have been estimated for different oak cover types.  Mexican
(Madrean) oak-pine woodland is probably a fire-tolerant, fire-maintained
community [109].

Emory oak is common at low elevations in open oak woodlands; fire
frequency is important in determining the structure of these communities
[8].

Interior chaparral is scattered throughout the oak-pine woodlands [110].
Emory oak replaces Pringle manzanita (Arctostaphylos pringlei) in
interior chaparral stands that have not recently burned [91].  Emory oak
and Arizona white oak dominate many communities in Arizona that have not
burned since about 1910 [8].

FIRE REGIMES :
Find fire regime information for the plant communities in which this
species may occur by entering the species name in the FEIS home page under
"Find FIRE REGIMES".

More info for the terms: fire management, fire suppression, forbs, forest, fuel, fuel moisture, grassland, litter, prescribed fire, shrubs, woodland

Prescribed fire is used to manage the interior chaparral where Emory oak
occurs.  It reduces fuel loads and improves wildlife habitat [28].  In
interior chaparral, prescribed fires must be combined with other
management methods to control Emory oak and other shrubs [18,29].
However, on arid rangelands where Emory oak occurs, prescribed burning
for brush control is not usually effective due to insufficient fuel for
widespread fire [47,92].

The open oak woodland can carry fire [85].  Oaks usually survive quick,
low-intensity fires in the open oak woodlands.  However, fires in
closed-canopy oak woodlands are probably high-intensity, stand
replacement fires [75].

Emory oak should be included in fuel moisture sampling programs.  In the
Chiricahua National Monument of Arizona, where Emory oak can make up a
significant portion of the understory fuels, Emory oak foliage had a
mean live fuel moisture content of 106 percent when sampled during
November 1987.  Live fuel moisture measurement methods are discussed in
the literature [100].

A downed woody material summary is useful for assessing fire potential
and danger.  Downed woody material ranged from 2.8 to 9.2 cubic feet per
acre in pine-oak woodlands and from 40.1 to 81.7 cubic feet per acre in
moist woodlands [33].

Pine-oak woodlands where Emory oak occurs are more open in the Sierra
Madre Occidental of Mexico than in southern Arizona.  Higher amounts of
litter and dead fuel exist in the Arizona pine-oak woodlands due to fire
suppression and increased grazing [69].


FIRE CASE STUDY
SPECIES: Quercus emoryi
FIRE CASE STUDY CITATION :
Pavek, Diane S., compiler. 1994. Prescribed fire effects on Emory oak in Lyle
Canyon, Arizona. In: Quercus emoryi. In: Fire Effects Information System,
[Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain
Research Station, Fire Sciences Laboratory (Producer). Available:
https://www.fs.fed.us
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REFERENCE :
Bock, Jane H.; Bock, Carl E. 1987. Fire effects following prescribed
burning in two desert ecosystems. Final Report on Cooperative Agreement
No. 28-03-278. Fort Collins, CO: U.S. Department of Agriculture, Forest
Service, Rocky Mountain Forest and Range Experiment Station. 20 p. [13].


SEASON/SEVERITY CLASSIFICATION :
spring fire/low- to moderate-severity


STUDY LOCATION :
The study was conducted at the National Audubon Appleton-Whittel
Research Sanctuary in foothills on the west side of the Huachuca
Mountains of Arizona.  The research focused on two areas:  a grassland
and a Madrean evergreen woodland.  This case study presents only the
Madrean evergreen woodland results since Emory oak (Quercus emoryi) did
not occur in the grassland.  Study plots were located in Lyle Canyon,
which is leased by the Sanctuary from the Coronado National Forest.


PREFIRE VEGETATIVE COMMUNITY :
Lyle Canyon is covered by a Madrean evergreen oak woodland.  The
overstory consisted of Emory oak and Arizona white oak.  The burn
treatment study plots had a total of 20 Emory oak and 15 Arizona white
oak; control plots had a total of 20 Emory oak and 10 Arizona white oak.
Common understory shrubs were wait-a-minute bush (Mimosa biuncifera),
velvet-pod mimosa (M. dysocarpa), and yerba de pasmo (Baccharis
pteronioides).  Grasses and forbs most commonly present were sideoats
grama (Bouteloua curtipendula), plains lovegrass (Eragrostis
intermedia), annual goldeneye (Viguiera annua), and Arizona poppy
(Kallstroemia parviflora).


TARGET SPECIES PHENOLOGICAL STATE :
The phenological stages of the plants were not specifically mentioned.
At the time of burning in May, Emory oak would be past flowering, and
fruits would be developing.


SITE DESCRIPTION :
The study site was located in a steep-sided canyon at 4,922 feet (1,500
m) elevation.  Spring months are dry and warm in this semiarid climate.
The average annual precipitation is 16.9 inches (430 mm) and occurs
bimodally.  No information was given on specific topography, slope, or
soils.


FIRE DESCRIPTION :
Ten plots, 65.6 by 98.4 feet (20x30 m), were assigned either to burn or
control treatments.  Plots were paired for physiognomy and vegetation.
Twenty quadrats, 7.9 by 19.7 inches (20x50 cm), were located in each
plot for a total of 200 quadrats.  The fire burned between 10 a.m. and
12 m. on 25 May 1984.  Air temperature was from 90 to 92 degrees
Fahrenheit (32-33 deg C).  The relative humidity ranged from 16 to 18
percent.  Winds were variable and gusted from 5 to 10 mph (8.1-16.1
km/h).  Dead fine fuel moistures were between 5 and 6 percent.

Fires moved slowly (1.6 to 4.9 feet per minute [0.5-1.5 m/min]) with
flame lengths of 0.7 to 1.6 feet (0.2-0.5 m) in four of the five burn
plots.  This was a heat release of 2.3 to 16.8 Btu per second per foot
(8-58 kw/s/m).  The fire moved rapidly (98.4 feet per minute [30 m/min])
with a heat release of 75.2 Btu per second per foot (260 kw/s/m) over
the remaining burn plot.


FIRE EFFECTS ON TARGET SPECIES :
Mature Emory oak were not affected by the fire [12].  Postfire
vegetation was sampled during two growing seasons in 1984 and 1985.
There was no significant (P>0.05) difference in numbers of Emory oak
seedlings on the burn plots compared to the controls.


FIRE MANAGEMENT IMPLICATIONS :
Fire is a part of the historic Madrean evergreen woodland [125].  This
prescribed fire did not have any lasting effects on woody vegetation in
the study area.  Burning had little detectable effect on the seedlings
of Emory oak.  This is probably due to the short duration and low heat
released by the fires.


This study was part of an extensive of body of research on fire effects in semidesert
grassland, oak savanna, and Madrean oak woodlands of southeastern Arizona. See the Research Project Summary of this work for more information on burning conditions,
fires, and fire effects on more than 100 species of plants, birds, small mammals,
and grasshoppers.

More info for the terms: grassland, prescribed fire, woodland

Fire is a part of the historic Madrean evergreen woodland [125].  This
prescribed fire did not have any lasting effects on woody vegetation in
the study area.  Burning had little detectable effect on the seedlings
of Emory oak.  This is probably due to the short duration and low heat
released by the fires.


This study was part of an extensive of body of research on fire effects in semidesert
grassland, oak savanna, and Madrean oak woodlands of southeastern Arizona. See the Research Project Summary of this work for more information on burning conditions,
fires, and fire effects on more than 100 species of plants, birds, small mammals,
and grasshoppers.

More info on this topic.

More info for the term: phanerophyte

  
   Phanerophyte

More info for the terms: mesic, shrub, tree, xeric

Emory oak occurs in arid to semiarid climates with low amounts of
biseasonal rainfall.  The climate has mild, wet winters and hot, wet
summers [34,66,85,109].

Emory oak is found in canyons at the upper edge of deserts or desert
grasslands [35,64].  Emory oak occurs in open oak woodlands from 4,500
to 5,000 feet (1,400-1,700 m) on hills and mountain slopes up through
Arizona cypress canyon forests and pygmy conifer-oak woodlands at 7,000
feet (2,130 m) [66,85].  It occurs as isolated trees in mesic or
riparian habitats and in xeric pine communities [5,66].  Emory oak is
found on alluvial fans, foothills, bajadas, barrancas, high plains, and
mesas [30,39,47,126].

Emory oak occurs on slopes that vary from flat to steep.  Often these
slopes have northern or western aspects [17,31,76,102,117].  Emory oak
may occur on drier sites than codominants Arizona white oak or Graves
oak [31,83,99,123].  Emory oak is a shrub in the Arizona interior
chaparral, where topography is often rough and highly dissected, with
very rocky loam soils [58].  Emory oak is more abundant and grows to
tree size in deeper soils, often in bottomlands where it forms dense
stands.  Reduced amounts of water prevent typical riparian communities
from forming in these areas [18,64,108].

Emory oak occurs in various soil textures derived from a variety of
parent materials.  Soils may be deep with moderately fine to very fine
textures.  The soils can be acidic and may be old alluvium from mixed
sedimentary and igneous rocks [76,83,105,117,122].  More often Emory oak
is reported on shallow soil with weak profiles, along drainages, or on
rocky slopes with textures of very gravelly sandy loams [25,39,47,85,99].

More info on this topic.

This species is known to occur in association with the following cover types (as classified by the Society of American Foresters):

   210  Interior Douglas-fir
   235  Cottonwood - willow
   237  Interior ponderosa pine
   239  Pinyon - juniper
   240  Arizona cypress
   241  Western live oak

More info on this topic.

This species is known to occur in the following ecosystem types (as named by the U.S. Forest Service in their Forest and Range Ecosystem [FRES] Type classification):

   FRES20  Douglas-fir
   FRES21  Ponderosa pine
   FRES28  Western hardwoods
   FRES35  Pinyon - juniper

More info on this topic.

This species is known to occur in association with the following plant community types (as classified by Küchler 1964):

More info for the terms: forest, woodland

   K018  Pine - Douglas-fir forest
   K019  Arizona pine forest
   K023  Juniper - pinyon woodland
   K031  Oak - juniper woodlands

More info for the terms: root crown, severity

Small-sized Emory oak may be top-killed by fire.  Large trees survive
fires of low severity [12].  Well-developed root systems of mature Emory
oak buffer the effects of drought and allow rapid regeneration by
sprouting vigorously from root crown and stump after top-damage [19,28].
It recovers quickly from the effects of burning [92].  Unless covered by
an insulating layer of soil, acorns are probably killed by fire.

More info for the terms: tree, woodland

Emory oak acorns are valuable food for cattle, mule and white-tailed
deer, wild turkey, band-tailed pigeon, other birds, and small mammals
[35,53,54,96,101].  Collared peccary infrequently consume Emory oak
acorns from July through September [34].  Emory oak is used extensively
by neomigratory birds for foraging during the breeding season [11].
Diverse amphibians, reptiles, and small mammals have been recorded in
the woodland communities where Emory oak occurs [113].

Pronghorn, white-tailed deer, and mule deer browse Emory oak [17,35,96,106].
Reports of Emory oak usage vary.  Humphrey [53] stated that Emory oak
has forage value only when young, and then it is only slightly browsed.
Emory oak was ranked as the most important food item in rumen analyses
of 20 white-tailed deer in Arizona in 1983.  It ranked third in
abundance in white-tailed deer fecal analyses from 1987 to 1989 [106].
However, during late winter in south-central Arizona, Emory oak made up
an average of only 1 percent of the food volume in white-tailed deer
stomachs [73].  In another study, pellet analyses from both white-tailed
and mule deer showed that Emory oak leaves were a minor food item
[106,119].

Emory oak is one of the major tree species in oak and oak-pine habitats
used by the acorn woodpecker.  The acorn woodpecker uses telephone poles
erected in these habitats for nesting sites; few cavity sites are
available to the birds due to the limited availability of snags and the
hardness of the wood in trees present [88].

More info for the terms: codominant, forest, habitat type, series, shrub, tree, woodland

Emory oak occurs in many communities along diverse elevational and
moisture gradients from pine-oak (Pinus spp.-Quercus spp.), Madrean
evergreen, and open oak woodlands to interior chaparral, semidesert
grasslands, and savannas [15,32,67,78,123].

Emory oak is a codominant or subdominant species in all community types
of the pine-oak woodlands of higher elevations [8,27,85].  It is an
indicator species in ponderosa pine (Pinus ponderosa), Apache pine (P.
engelmannii), and Chihuahua pine (P. leiophylla var. chihuahuana) habitat
types and border pinyon (P. discolor) community types [1,76,82,116].

In pinyon-juniper (Pinus spp.-Juniperus spp.) woodlands, Emory oak is a
codominant or an indicator species [17,47,51,74,80].  It is an important
understory species in pinyon-juniper stands [94].

Emory oak is dominant or codominant with Arizona white oak (Q.
arizonica), Mexican blue oak (Q. oblongifolia), and juniper in Madrean
evergreen and open oak woodland series [6,16,42,79,85,98].  Emory oak is
the most characteristic tree of encinal or oak woodlands in the border
region of Mexico and the United States [57,64,66].  In the Chihuahuan
Desert, Emory oak is codominant with gray oak (Q. grisea), Graves oak,
and Mexican pinyon (Pinus cembroides) [24,46,116].

Emory oak is occasionally present in the interior chaparral as a
subdominant shrub or as one of the taller evergreen oaks.  These
interior chaparral communities occur discontinuously and extend into the
wetter Madrean evergreen woodland [40,58,59,91,124].

Emory oak, gray oak, and Chisos oak (Q. chisoensis) form savannas at the
periphery of grama (Bouteloua spp.)-bluestem (Andropogon spp.)
associations [30,32].  Emory oak is a minor species in open savannas of
velvet mesquite (Prosopis velutina)-turpentine bush (Ericameria
laricifolia)-burroweed (Isocoma tenuisecta) associations [122].

Emory oak is known as an upland species but also occurs in riparian
associations.  It is a codominant to infrequent tree in Arizona sycamore
(Platanus wrightii) and Arizona walnut (Juglans major) community types
[61,65,112,115].  Emory oak occurs in mixed broadleaf community and
vegetation types with Arizona cypress (Cupressus arizonica) [98].

Some of the publications in which Emory oak is listed as a dominant or
indicator species are:

(1)  Classification of the forest vegetation on the National Forests of
       Arizona and New Mexico [1]
(2)  Forest and woodland habitat types (plant associations) of Arizona
       south of the Mogollon Rim and southwestern New Mexico [6]
(3)  Forest habitat types south of the Mogollon Rim, Arizona and New
       Mexico [31]
(4)  Classification of mixed broadleaf riparian forest in Tonto
       National Forest [61]
(5)  A forest habitat type classification of southern Arizona and its
       relationship to forests of the Sierra Madre Occidental of Mexico [82]
(6)  Plant communities of Texas (Series level): February 1992 [116].

Succulent species associated with Emory oak but not previously mentioned
in Distribution and Occurrence include Echinocereus ledingii,
Mammillaria viridiflora, and Opuntia spinosior [56].

More info for the terms: shrub, tree

Tree, Shrub

More info for the terms: codominant, cover, forest, fuel, grassland, litter, root collar, shrubs, wildfire, woodland

Emory oak stands have been managed under pinyon-juniper silvicultural
systems [51].  On a fuelwood management area in the Huachuca Mountains
of Arizona, three areas in oak woodland were cut at different times and
intensities to assess harvest effects.  Emory oak was codominant with
Arizona white oak.  Harvests of 50 and 80 percent occurred 7, 15, and 20
years prior to assessment.  Structural changes to the overstory, such as
shrublike trees that originated from prolific stump sprouting, persisted
after 20 years [102].

Emory oak is harvested for fuel with alligator juniper (Juniperus
deppeana) from the oak woodlands on the Coronado National Forest in
Arizona.  Restrictions to ensure sustained yield are discussed in the
literature [7].  Coppice thinning for Emory oak in Emory oak/sideoats
grama (Bouteloua curtipendula) habitat types is recommended 5 years after
harvest.  Growth and yield of sprouts depend on number and age of
sprouts after thinning.  Time to harvest depends on diameter of root
collar.  Approximately 20 to 30 years after thinning, root collar
diameters of 6 to 8 inches (15.2-20.3 cm) are possible [117].

Equations for volume, biomass, net primary productivity, and mortality
of the oak woodlands to which Emory oak belongs are discussed in the
literature [21,22,38,43,44].  Emory oak stands with different management
histories, harvests, and merchantable volumes are also discussed [38].
Equations are available to predict Emory oak regeneration following
cutting [77].

In a ponderosa pine forest on Big Bug Mesa, Arizona, two burned and two
unburned plots were treated at three levels (clearcut, partial cut, and
uncut) and seeded with grass.  Emory oak occurred on unburned
partially-cut and uncut sites at 6.5 trees per acre (16 trees/ha) and
9.7 trees per acre (24 trees/ha), respectively [10].

Emory oak and the other codominant oaks usually do not comprise more
than 10 to 20 percent canopy cover in open oak woodlands.  However,
where it is the dominant species, Emory oak can comprise 50 percent of
the canopy cover [14].  In pygmy conifer (Pinus spp.)-oak scrub, shrubby
Emory oak, other oaks, and manzanita (Arctostaphylos spp.) make up 60 to
70 percent of the canopy cover [85].

In the Dos Cabezas Mountains of southeastern Arizona, the mixed oak
woodland-interior chaparral community is heavily browsed by white-tailed
and mule deer.  Emory oak is dominant but has a skewed age distribution.
Emory oak is not recruiting; seedlings have not survived.  Of the
standing Emory oak, 83 percent were greater than 7.9 feet (2.4 m) tall;
17 percent were dead.  Anthony and Smith [2] attributed this lack of
recruitment to poor reproduction by over-mature trees or gradual climate
change to hotter and drier conditions.

Cattle graze on most encinal woodlands where Emory oak is an important
component [71].  Emory oak grows in pinyon-juniper woodlands and
interior chaparral stands that have been converted to grassland through
fire, mechanical, and chemical methods to increase forage production
[3,18,26,29,47,49,89].  Currently, such single-use management of these
habitats is declining [51].  Several projects converted interior
chaparral into grassland and riparian habitat on the Three Bar Game
Management Area on the Tonto National Forest in central Arizona since
grazing stopped in 1947.  In June 1959, a wildfire killed all shrubs,
and herbicide applications prevented them from reestablishing.  One
hundred Emory oak trees had established in the riparian study area 21
years later [111].

Young Emory oak leaves have higher concentrations of tannin and phenolic
compounds than older leaves [70].  A flash flood flushed double the
normal load (0.15 pounds per square foot [750g/sq m]) of Emory oak
litter into Pena Blanca Lake, Arizona.  The elevated levels of soluble
tannins and phenolic compounds did not harm invertebrates, monitored as
environmental indicators, after 20 to 30 days of exposure [72].

Emory oak resists damage from pests and many diseases [90].  However, it
is susceptible to the wood decay fungus Inonotus andersonii [37].

Sampling methods for classification of riparian communities to which
Emory oak belongs are available [114].

From July to September, seasonal estimates of white-tailed deer nutrient
intake from Emory oak acorns consisted of 54 percent protein and 52.2
percent acid detergent fiber, having 27 percent in vitro digestibility
[119].  In a study 15 years prior to this, Emory oak acorns had
"intermediate" protein content and low phosphorus [108].

     AZ  NM  TX  MEXICO

Raw Emory oak acorns are sweet, edible, and gathered for commercial
markets [4,54,105].  Emory oak acorns were used for flour and meal by
native Americans [84,96].

Emory oak is one of the most important sources of firewood in Arizona [64].

Emory oak is highly palatable yearlong to white-tailed and mule deer
[120].  In spring, Emory oak has fair palatability for pronghorn and
poor palatability for cattle and sheep [17].

More info on this topic.

Emory oak gradually drops leaves in the spring as new leaves form
[64,103].  Emory oak acorns mature annually from June through September,
with a peak in midsummer [35,75,87,121].

More info for the terms: fire severity, forest, prescribed fire, severity, tree, wildfire, woodland

Most fires move quickly through oak woodlands that have a continuous
grass understory.  Fire effects on Emory oak depend on tree size, fire
severity, and drought stress, especially after the fire.  A wildfire
during June 1983 burned a Madrean evergreen oak woodland in the Santa
Catalina Mountains of Arizona.  Two years later, 89 percent of the
sampled Emory oak survived, 38 percent with some portion of the original
crown alive.  Significantly (P=0.011) more Emory and Mexican blue oak
sprouted on burned plots (94%) than trees in unburned control plots
(8-16%).  Emory oak produced 15 to 53 sprouts per tree on burned plots
[19].

In a Madrean evergreen woodland in Arizona with an understory of grasses
and herbs, a prescribed fire in May 1984 was of low intensity and short
duration.  The fire did not affect scattered mature Emory oak.  Emory
oak and other oak seedling densities did not differ between burned and
control sites during the first 2 postfire seasons [12,13].

During June 1959, an accidental fire burned an oak-juniper woodland in
the Santa Rita Mountains of Arizona.  The fire moved rapidly over dry
grasses.  Drought stress may have increased tree mortality.  On unburned
controls, 19.7 percent of Emory oak trees died, and 22.3 percent died on
the burned sites.  Only 21 percent of Emory oaks sprouted on the
control, while 47 percent sprouted on the burn [55].

Emory oak seedling establishment and survival were assessed 1 year
following a fall prescribed fire of interior chaparral in the Mazatzal
Mountains of Arizona.  Sites where fire severity was low had more than
twice the number of seedlings (147 seedlings/ha) than the unburned
control (48 seedlings/ha) or sites where fire severity was high (58
seedlings/ha) [18,89].

One or two years following fall prescribed strip fires in interior
chaparral, 47 Emory oak seedlings were tagged.  Three years later, only
13 seedlings had survived.  Nearly half (48%) of tagged seedlings had
died due to drought.  The surviving seedlings stood 3.3 inches (8.4 cm)
high, and roots had penetrated 20 inches (50.8 cm).  Uniform acorn depth
and seedling spacing across the burned areas indicated that scrub jays
probably cached the acorns.  Clustered seedlings, possibly from rodent
caches, were not included in the study [90].

An oak-mountain-mahogany (Cercocarpus spp.) chaparral stand in the
Sierra Ancha Experimental Forest, Arizona, was prescribed burned after
desiccation with herbicides.  Emory oak seedling emergence steadily
dropped from 33 seedlings per acre (13 seedlings/ha) during the first
postfire year to 0 seedlings the fifth postfire year [63,93].

More info for the terms: root crown, root sucker, secondary colonizer, shrub, tree

   Tree with adventitious-bud root crown/soboliferous species root sucker
   Tall shrub, adventitious-bud root crown
   Initial-offsite colonizer (off-site, initial community)
   Secondary colonizer - off-site seed

More info for the terms: grassland, seed, tree, woodland

After top removal by fire or cutting, Emory oak vigorously sprouts from
root crowns or stumps [18].  Following harvest in Arizona, Emory oak
regenerated by stump sprouts; there was low seedling survival [102].  A
higher percentage of Emory oak stumps than Arizona white oak stumps
sprouted following harvest of oak woodlands in southern Arizona.  Emory
oak sprouts also grew faster than Arizona white oak sprouts [77].

Emory oak acorns mature in one season [35,105].  Germination occurs
during the summer shortly after maturation [87,93].  There is no seed
dormancy.  Most germination occurs within 30 days after acorns drop from
the tree; acorns are viable for about 60 days [75].  In field trials,
Emory oak acorns had lower viability and germination at the soil surface
(5%) than 3 inches (7.5 cm) beneath the soil (29%) [87].  Emory oak
germination is strongly positively correlated with moisture during the
summer rainy season.  Favorable environmental conditions for Emory oak
germination and establishment occur infrequently, about once in a decade
[87,90].

Acorn production is highly variable.  Large acorn crops, up to 15,500
acorns per tree, alternate with several years of low acorn production
[75].  One study demonstrated that Emory oak recruitment in mature oak
woodlands was not limited by germination [87].

Vertebrates consume from 1 to 65 percent of acorns Emory oak produces,
and invertebrates consume from 1 to 50 percent.  While postdispersal
losses can be high, they are also variable.  Seventy-eight percent of
Emory oak acorns escaped predation in a 1978 oak woodland study in
Arizona.  Two years later, only 25 percent of the acorns escaped
predation [75].  Scrub jays and rodents rarely carry Emory oak acorns
very far from seed trees.  Caching of acorns by jays and rodents at 1.5
inches (3.8 cm) or deeper can provide germination opportunities,
depending upon moisture availability [90].

Emory oak topgrowth is slow, especially in seedlings [35,75].  They may
succumb to drought.  Emory oak mortality resulted from drought in a
pygmy conifer-oak woodland in Arizona [85].  A study evaluating seedling
establishment after fire found that drought rather than predation caused
most of the seedling mortality [90].  Acorns dropping directly below the
canopy may experience moisture deficits, since up to 70 percent of
precipitation may be intercepted by the canopy [45].  However, a field
study showed that significantly (P less than 0.05) higher germination and
viability of Emory oak acorns occurred under trees than in the open
grassland between trees [86].

More info on this topic.

This species can be found in the following regions of the western United States (according to the Bureau of Land Management classification of Physiographic Regions of the western United States):

    7  Lower Basin and Range
   12  Colorado Plateau
   13  Rocky Mountain Piedmont

spring fire/low- to moderate-severity

The study site was located in a steep-sided canyon at 4,922 feet (1,500
m) elevation.  Spring months are dry and warm in this semiarid climate.
The average annual precipitation is 16.9 inches (430 mm) and occurs
bimodally.  No information was given on specific topography, slope, or
soils.

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More info for the terms: climax, forb

Facultative Seral Species

Emory oak is a climax species in evergreen oak and encinal woodlands
[62].  It is both a seral and climax species in pine-oak woodlands
[8,27,85].  Emory oak is a minor climax species in Chihuahua pine
forests [62].  Four years after cabling in pinyon-juniper woodlands
where Emory oak is one of several important oak understory species, the
oaks reestablished during the perennial grass and forb stage [95].

The currently accepted scientific name of Emory oak is Quercus emoryi
Torr. It is a member of the oak family (Fagaceae) [23,57]. No
infrataxa are recognized. Where distributions overlap in Texas, Emory
oak hybridizes with graceful oak (Q. graciliformis) to form Tharp oak (Q.
x tharpii C. H. Mull.) and Graves oak (Q. gravesii) to form robust oak
(Q. x robusta C. H. Mull.) [23,96,105,121].

More info for the terms: fuel, refractory

Emory oak is managed and used for fuel and infrequently for furniture
[35,52,87,117].  The wood is close-grained, heavy, strong, and brittle
[64,121].  It has a specific gravity of 0.56 to 0.96 [52,68,121].  Emory
oak is refractory with a tendency to degrade due to surface check, end
split, and honeycomb. [52].

Quercus emoryi, the Emory oak, is a species of oak common in Arizona (including inside Saguaro National Park), New Mexico and western Texas (including inside Big Bend National Park), United States, and northern Mexico (Sonora, Chihuahua, Coahuila (including Parque Nacional Maderas del Carmen), Durango, Nuevo León, and San Luis Potosí). It typically grows in dry hills at moderate altitudes.