|FEIS Home Page|
|Photos courtesy of Virginia Tech, Department of Forestry.|
Reports of hybridization with Pinchot juniper (J. pinchotii) have been refuted by use of numerous chemical and morphologic characters. The two species have nonoverlapping pollination seasons [2,42].
Because research focused specifically on oneseed juniper is not abundant,
some information in this report is drawn from studies and reviews that pertain to
multispecies Southwestern juniper or pinyon (Pinus spp.)-juniper
(Juniperus spp.) woodlands. In this report "oneseed juniper" is used
where the study discussed focused on that species. "Juniper" or "pinyon-juniper"
describes studies broader in scope, but where oneseed juniper was usually
identified as component. When the pinyon species was identified it is included.
FEDERAL LEGAL STATUS:
No special status
of North America also provides distribution information on oneseed juniper
for North America.
FRES21 Ponderosa pine
FRES30 Desert shrub
FRES33 Southwestern shrubsteppe
FRES34 Chaparral-mountain shrub
FRES38 Plains grasslands
FRES40 Desert grasslands
In northern Arizona overstory associates include Utah juniper (J. osteosperma) and Colorado pinyon (P. edulis). Associated plants include winterfat (Krascheninnikovia lanata), skunkbush sumac (Rhus trilobata), shrub live oak (Quercus turbinella), broom snakeweed (Gutierrezia sarothrae), rubber rabbitbrush (Chrysothamnus nauseosus), and Russian-thistle (Salsola kali). Associated grasses include galleta (Pleuraphis jamesii), black grama (Bouteloua eriopoda), blue grama (B. gracilis), Fendler threeawn (Aristida purpurea var. fendleriana), sideoats grama (B. curtipendula), tobosa (P. mutica), and bottlebrush squirreltail (Elymus elymoides). Other associated plants include freckled milkvetch (Astragalus lentiginosus), cholla and prickly-pear (Opuntia spp.), [59,74]. Occasionally oneseed juniper grows in extensive pure stands, such as those on the Coconino Plateau in northern Arizona. It is the dominant species in these stands and may exclude all other plants .
In southern Arizona oneseed juniper occurs with alligator juniper (J. deppeana), Mexican pinyon (P. cembroides), Emory oak (Q. emoryi), Arizona white oak (Q. arizonica), Mexican blue oak (Q. oblongifolia), and species of mesquite (Prosopis spp.) [12,92].
In New Mexico and western Texas common associates are Colorado pinyon, Pinchot juniper, alligator juniper,broom snakeweed, skunkbush sumac, winterfat, fourwing saltbush (Atriplex canescens), Bigelow sagebrush (Artemisia bigelovii), true mountain-mahogany (Cercocarpus montanus), gray oak (Q. grisea), catclaw mimosa (Mimosa biuncifera), lechuguilla (Agave lechuguilla), prickly-pear, sideoats grama, galleta, and blue grama [3,25,44,47,71,101,102,103].
Oneseed juniper is an indicator in a number of pinyon-juniper shrubland and desert grassland classification systems, including:
New Mexico [3,44,71,73,121]
Oneseed juniper produces small, "berry-like", glaucous, globular staminate cones, and subglobose ovulate cones [42,127]. Mature cones are dark blue to purple or brownish, and succulent, or at least somewhat fleshy [50,127,132]. Seeds are generally 1 per fruit, more rarely 2, reddish-brown and ovoid to globose [50,127]. Juniper seeds are described as having a semipermeable and thick seed coat with a dormant embryo . The cones are often referred to as "berries" in the literature.
Mature oneseed junipers have both tap and lateral root systems. The taproots in 1 study ranged from 18 inches (46 cm) to more than 12 feet (3.7 m) in length. Of 500 trees examined, 347 had well-developed taproots. Lateral roots were widespread, commonly being 2.5 to 3 times as long as the tree was tall. Most lateral roots were in the surface 3 feet (1 m) of the soil, most of those concentrated below the surface 6 inches (15 cm) . The deep root system of mature oneseed junipers is adapted for growth on dry sites [51,64,107]. Foxx and Tierney  reported rooting depths ranging from 16 to 197 feet (5-60 m).
Oneseed juniper is a slow-growing species. Lymbery and Pieper  reported an increase in height of approximately 6.3 inches (16 cm) per decade, with a corresponding increase in stem diameter of 0.5 inch (1.2 cm). Growth rate tends to vary according to site characteristics, however. On a hilly site in southwestern Texas, a oneseed juniper 35 years of age was 14 feet (4.3 m) in height with a diameter of 0.5 inch (1.3 cm) .Oneseed juniper has the ability to stop active growth when moisture is limited but can resume growth when moisture availability improves . This growth pattern may represent an important adaptation allowing junipers to survive on harsh, arid sites. Although small trees may be killed by drought, mature oneseed junipers are resistant to drought, especially in comparison to Colorado pinyon [64,107].
Pollination: No information
Seed production: Trees first produce seed at 10 to 30 years of age, although maximum seed production generally does not occur until 50 to 200 years of age [66,115]. Trees as short as 18 inches (46 cm) in height can produce seed . Oneseed juniper typically produces large seed crops at 2- to 5-year intervals .
Seed dispersal: Dispersal of oneseed juniper seeds may occur through water, gravity, or by any of a number of birds and mammals [10,64]. Animal dispersal may be particularly important, as digestive processes may enhance germination . Most seed cones occur on the outer edges of trees where they are most visible and accessible to birds . The brightly-colored, highly-visible cones persist on the trees for much of the year, providing a continually available food source for animals [13,34]. On some sites in New Mexico, as much as 95% of juniper reproduction could be attributed to bird dispersal . Domestic sheep and cattle may also aid in seed dispersal .
Seed banking: According to Johnsen , "Since the seed is not harmed by long periods of dry storage, drought probably does not affect seed viability. Viable seed in the soil may endure prolonged drought and still germinate when conditions become favorable."
Germination: See Value for Rehabilitation of Disturbed Sites for detailed information about germination experiments with this species.
Seedling establishment/growth: Seedling establishment of oneseed juniper is often very poor even when good germination occurs . The growth rate has been characterized as slow with medium vigor. Researchers in some areas have found that only approximately 3% of juniper seeds develop to the seedling stage. Shade may be important for good early growth of oneseed juniper . Emergence appears to be somewhat greater under trees or shrubs than in interspaces where humidity and temperature fluctuations are more extreme . In some areas, small junipers are particularly numerous under the canopy of pinyon or other trees [60,115]. Most seedlings occur some distance from the parent tree, although most seeds are located beneath the source tree . Seedlings seldom establish beneath mature junipers, and an autopathic effect from litter is suspected .
Although oneseed juniper is usually regarded as a nonsprouter , limited sprouting,
mostly from older trees, has been observed [24,129]. Approximately 10% of living
oneseed junipers sprouted from the base following an Arizona fire .
Oneseed juniper occupies xeric sites in semiarid climatic zones [38,51,102]. A typical Arizona site occupied by oneseed juniper receives 10 to 15 inches (250-380 mm) of precipitation annually, and has an average growing season of approximately 120 days [95,134]. Unlike several related species, the distribution of oneseed juniper does not appear to be limited by temperature inversions .
Oneseed juniper grows on dry, rocky, open flats, and slopes [32,50,52]. It commonly occurs in canyons or on middle-elevation foothills [50,134]. In many areas this juniper occurs in a zone below ponderosa pine (P. ponderosa) or alligator juniper, but above oak (Quercus spp.)-mountain-mahogany (Cercocarpus spp.) shrublands [96,134].
Because soil moisture is limited on many oneseed juniper sites, competition with others species may significantly influence the occurrence of this tree on a particular site. Grasses can compete effectively with oneseed juniper seedlings for moisture and can limit its distribution in some areas [64,135]. Many oaks also compete for soil moisture, although oneseed juniper appears to be capable of outcompeting them on shallow soils . Where oneseed juniper occurs with Colorado pinyon, junipers show much more adaptation to drought stress than do the pines . These observations were based on tissue water potentials and metabolic activity during the hottest part of the day.
Oneseed juniper grows on a variety of soil textures including gravelly, rocky, or sandy soils . Parent materials include basalt, limestone, and sandstone . Soil characteristics, combined with temperature, moisture and topography influence the upper and lower elevational extent of oneseed juniper [18,134]. Elevational ranges of oneseed juniper reported in the literature are:
Arizona 3,000 to 7,000 feet (914-2,130 m) [32,72]
Colorado 4,000 to 7,600 feet (1,220-2,315 m) 
New Mexico > 5,000 to 7,500 feet (1,525-2,285 m) 
Populations of oneseed juniper have been classified as climax [54,113], seral , late seral , and postclimax . Schott and Pieper [113,115] examined secondary succession in pinyon-juniper several decades following cabling and concluded that re-established stands of pinyon and oneseed juniper were climax. Johnsen  concluded that within northern Arizona grasslands are numerous postclimax oneseed juniper stands with soil and microclimate conditions different from adjacent grasslands. The oneseed junipers maintain themselves on these areas but are not invading the surrounding grassland. Francis  described 4 seral phyto-edaphic community types in northwestern New Mexico where oneseed juniper is a codominant indicator species.
According to Gottfried  junipers are the 1st to return in secondary succession but are often followed and replaced by pinyon. "Habitat type affects the successional pathway following a disturbance. Succession on a site is influenced by the severity and size of the disturbance, and by the composition, longevity, and density of any surviving plants and propagules within the disturbed area and the characteristics of plant communities in adjacent undisturbed areas. Climatic conditions also influence the nature and speed of succession."
See Other Management Considerations for an analysis of a drought-induced ecotone shift of oneseed junipers into a declining ponderosa pine forest in Arizona.
New Mexico studies comparing plant growth in zones extending out from the boles of
oneseed juniper and pinyon pine showed differences between the zones and also between the
two tree species [6,112]. Grasses and other plants were consistently sparser beneath the
tree canopies. The author's review of possible explanations includes allelopathy,
shade, precipitation interception by the canopy, and litter cover forming a physical
barrier to germinating plants. Other explanations offered to explain the reduced
under-canopy vegetation include root competition for soil moisture, and possible
chemical properties of oneseed juniper litter [9,62].
Based on a study conducted near Flagstaff Arizona, annual leader elongation of oneseed juniper generally begins in April . Detailed phenological development from that study is:
|bark begins to slip||March 25|
|pollen shedding and female flowers open||March 25|
|approximate start of leader elongation||April 20|
|1st conspicuous formation of male flowers||April 19|
|leader elongation ceases||October 26|
Flowering generally occurs in March or April [50,66], but can occur as early as January or as late as June, depending on geographic location . Fruit matures in 1 season, ripening from August through November [64,66]. Seed may remain on the tree for 1 to 2 years . Lymbery and Pieper  reported that in the northern Sacramento Mountains, flowering occurred from March to April, fruit ripening from August to September, and seed dispersal from October to November.
In some areas, juniper is protected from fire by site factors. For example, junipers frequently grow on rocky breaks or escarpments where fire frequency is low. Wright  reported that nonsprouting juniper species often occupy isolated topographic breaks which may be surrounded by grasslands that are more susceptible to fire.
Fire adaptations: Postfire reestablishment is primarily through seed and is relatively slow . Most establishment is from seed dispersed from off-site by birds and mammals, but some establishment may occur from seeds buried on-site and protected from the heat of fire by overlying soil layers. Establishment may be relatively poor even when good germination occurs, and growth is typically very slow .Oneseed juniper is usually regarded as a nonsprouter , but older trees have been known to sprout infrequently after fire [24,128]. This mode of regeneration appears to be relatively unimportant, however.
Fire regimes: Past fire regimes in southwestern pinyon-juniper woodlands were mixed, having both surface and crown fires, and are a reflection of variable intensity and frequency depending on site productivity [48,98]. "Productive sites could sustain patchy fires at intervals of 10 to 50 years, and could have attained densities sufficient to carry crown fires at intervals of 200 to 300 years. In open stands, where grass cover was continuous, fire intervals might have been 10 years or less, and probably maintained grasslands and savannas ."
According to a 1962 review of oneseed juniper by Johnsen  (and references therein), fires were reported to have been widespread and destructive before the juniper woodlands were heavily used by settlers. A 1904 publication cited by Johnsen reported that 5% of the junipers on the Coconino National Forest had been struck and killed by lightning. Johnsen indicated that "lightning strikes are still common, but fires started in this way are usually confined to the tree struck, for only in the very dry hot periods with strong winds in the late spring will a fire carry through even a dense juniper stand".
The following table provides some fire return intervals for communities where oneseed juniper may occur. Find further 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".
|Community or Ecosystem||Dominant Species||Fire Return Interval Range (years)|
|desert grasslands||Bouteloua eriopoda and/or Pleuraphis mutica||5-100|
|grama-galleta steppe||Bouteloua gracilis-Pleuraphis jamesii||< 35 to < 100|
|cheatgrass||Bromus tectorum||< 10 |
|basin big sagebrush||Artemisia tridentata var. tridentata||12-43 |
|mountain big sagebrush||Artemisia tridentata var. vaseyana||15-40 [8,21,88]|
|juniper-oak savanna||Juniperus ashei-Quercus virginiana||< 35|
|Ceniza shrub||Larrea tridentata-Leucophyllum frutescens-Prosopis glandulosa||< 35|
|pinyon-juniper||Pinus-Juniperus spp.||< 35 |
|Mexican pinyon||Pinus cembroides||20-70 [91,123]|
|Colorado pinyon||Pinus edulis||10-49 |
|Arizona pine||Pinus ponderosa var. arizonica||2-10 |
|mesquite||Prosopis glandulosa||< 35 to < 100|
|mesquite-buffalo grass||Prosopis glandulosa-Buchloe dactyloides||< 35|
|oak-juniper woodland (Southwest)||Quercus-Juniperus spp.||< 35 to < 200 |
Average mortality following a low-severity June wildfire in oak-juniper woodlands of Arizona was 76% . Researchers observed 92% mortality after a stand of small, bushy oneseed juniper were burned . Springfield  noted 70 to 100% of oneseed junipers less than 4 feet (1.2 m) in height were killed by fire. Mortality ranging from 30 to 100% has been reported in trees 5 to 6 feet (1.5-1.8 m) in height.
Researchers have found that 100% juniper mortality results when 60%
of the crown is scorched . Temperatures lethal to oneseed
juniper tissue are also related to the degree of desiccation, and
thus season of burn may also influence the amount of damage the plant
sustains. Laboratory experiments have shown that temperatures lethal to oneseed
juniper ranged from 140 degrees Fahrenheit to 176 degrees Fahrenheit
(61.8o to 80oC). Lethal temperatures
tend to be lowest during late spring and summer .
DISCUSSION AND QUALIFICATION OF FIRE EFFECT:
PLANT RESPONSE TO FIRE:
Regeneration of oneseed juniper is usually from seed when aboveground vegetation has been killed or seriously damaged by fire. Older oneseed junipers can occasionally sprout from the base after fire. In a southern Arizona burn, 10% of oneseed junipers resprouted. In contrast 42% of alligator juniper resprouted . However, in most cases, sprouting appears to be a relatively unimportant mode of regeneration.
The length of time required for postfire recovery of oneseed juniper has
not been well documented. Oneseed juniper did not become prominent after a
severe wildfire in Utah until postfire year 40. This species did not regain
dominance on this site until 70 years after the fire . Evidence
suggests that factors such as soil type and preburn community
composition may significantly influence the length of time required for recovery
. Seedling establishment may be favored in the shade of
dead vegetation, including other oneseed junipers . Once established,
oneseed juniper can bear seed as early as 10 years of age on some sites
DISCUSSION AND QUALIFICATION OF PLANT RESPONSE:
FIRE MANAGEMENT CONSIDERATIONS:
Historically, periodic fire is believed to have played an important role in maintaining juniper savannas [64,98,132]. Mueggler  reported that a fire-free period of 85 to 90 years was required for formation of a "well-developed" juniper woodland. Recent decades of fire suppression have probably contributed to encroachment of juniper into grasslands [78,94].
In some instances, forage production has increased after oneseed juniper and other species were removed by fire. On 1 "notable" Colorado pinyon-juniper site, Aro  reported increased forage production from 100 pounds per acre (45 kg/ha) before treatment to 500 pounds per acre (227 kg/ha) following fire. However, in other instances little long-term increase in forage production has been noted. According to Payson and others , most of the control operations failed to meet managers' objectives.
Individual tree burning was used on some pinyon-juniper woodlands [61,118]. Mechanical methods, such as chaining and cabling in pinyon-juniper woodlands, were often followed by the piling and burning of slash. Burning these high fuel concentrations generated high heat levels that damaged soil and site productivity. Surface soils in many of these piled areas were degraded and remained free of vegetation 20 years later [98,125].
Oneseed juniper does not survive in grasslands where fires occur frequently . Broadcast burns may effectively control oneseed juniper if the species is well represented, weather conditions are favorable, and sufficient fuels are present. Dense stands (400 or more/ac (990/ha)) with a flammable understory are most suitable for broadcast burning [59,128]. In areas with a past history of heavy grazing where little fuels remain and few residual grasses occur, burning may be difficult and ineffective. Burns tend to be most successful when carried out in June when temperatures are high and humidity low [11,104]. Unfortunately, risk of escape may be great during this time period , and the window for burning very narrow .
Currently, prescribed fire in pinyon-juniper woodlands is used to reduce accumulations of slash from fuelwood harvesting or to reduce or eliminate tree cover to increase range productivity and biodiversity. Prescribed burning to dispose of slash is less desirable in partially harvested stands because residual trees are damaged and advance regeneration is killed. Established, smaller trees are particularly important for the next rotation because of the difficulty of achieving adequate regeneration of these relatively slow growing trees. Payson and others  provide recommendations relevant to fire management in pinyon-juniper ecosystems.
Parent material: Basic basalt exposed along ridges, covered by cinders 1 to 4 inches (2.5-10.2 cm) deep on uplands and deeper in drainage areas. Calcareous silt tends to cement the cinders.
Moisture patterns: Little surface runoff, low evaporation, subsurface is often moist.
Average annual precipitation: 11.6 inches (300 mm) (60% as summer thunderstorms).
"badly overgrazed" by 1907. Grazing levels reduced in recent years. (Numbers in
parentheses below refer to individual burn sites.) (1) January and (2) March burn sites -
light domestic sheep grazing for at least 20 years prior to the study.
(3) June burn site - lightly grazed by cattle in winter.
(1) January 5 fire:
Air temperature: 49 to 54 degrees Fahrenheit (9-12oC)
Relative humidity: 44% at 49 degrees F (9oC).
Wind: from northeast, gusts to 6 to 8 miles per hour (10-13 km/hr).
Fires were set from 12:45 to 3:45 p.m., burned 60 out of 90 acres (24 out of 36 ha). Fire slowed down or died as it moved toward the junipers.
(2) March 19 fire:
Air temperature: 70 degrees Fahrenheit (21oC).
Relative humidity: 44%.
Wind: from southwest at 15 to 20 miles per hour (24-32 km/hr).
Fire burned close to trees because prevailing winds had piled Russian-thistle and other debris under the larger trees. The southwest wind caused debris to ignite.
(3) June 28 fire:
Wildfire started by lightning, conditions were very dry.
Wind: from the southwest at 10 to 15 miles per hour (16-24 km/hr).
Air temperature: 97 degrees Fahrenheit (36oC).
Relative humidity: 17 to 25%.
FIRE EFFECTS ON TARGET SPECIES:
On the 3 burns, 380 oneseed junipers were examined along randomly located compass lines. Mortality of trees less than 4 feet (1.2 m) tall ranged from 70 to 100% and 30 to 40% in trees 5 to 6 feet tall (1.5-1.8 m). The March and June burns caused the death of 60 to 90% of the oneseed junipers 8 to 10 feet (2.4-3.1 m) tall. Mortality data for this height group in the January burn was not presented. The authors attributed much of the mortality in the taller oneseed junipers to the accumulation of flammable debris around the base of the trees. When the fires moved with the prevailing winds, Russian-thistle ignited and tree mortality was relatively high (60-90%). When fires moved against the prevailing winds, flammable understory debris did not ignite and few (< 10%) large oneseed junipers were killed.
FIRE MANAGEMENT IMPLICATIONS:
The objective of the prescribed burns was to test grass fires as a means of controlling juniper encroachment into grasslands. The amount of flammable material present at a given site and wind conditions greatly influenced mortality in larger junipers. Mortality was relatively high when winds ignited Russian-thistle and other debris accumulated beneath the crowns. A high percentage of smaller oneseed junipers (< 4 feet (1.2 m)) can also be killed by fire. The authors concluded that grass fires at frequent intervals killed oneseed junipers less than 4 feet (1.2 m) tall. Larger trees were much more resistant to fire except where significant flammable material was present beneath the crown.
Slope: 0 to 9%
Elevation: 6,014 to 6,514 feet (1,829-1,981 m)
Average annual precipitation: 15.5 inches (390 mm), with approximately 61.8% occurring from June to October
Soils: Mostly very fine sandy loam "developed on recent alluvium
derived from the San Andres Formation and mixed material of Guadalupe age."
The fire was a 935 acre (378 ha) wildfire that started at 1:45 p.m. on April 10th. It was controlled approximately 3 hours later. The fire did not move through the crowns of the trees. Other conditions were as follows:
Relative humidity: low
Wind: warm, dry, from the south, (speed not recorded)
Soil, litter, and grass fuel: very dry
Rate of spread: 1,250 feet per hour (381 m/hr)
Available fuel in open grasslands: 750 pounds per acre (670 kg/ha)
FIRE EFFECTS ON TARGET SPECIES:
The total number of oneseed junipers in the burn was 120. All those less than 4 feet (1.2 m) tall were killed by fire. The foliage of many of the smaller trees extended close to the ground and ignited readily. Larger junipers were found to be somewhat more resistant to surface fire. Many trees did not show the extent of fire damage until 1 or 2 years after the fire. After 2 years, approximately 24% of oneseed junipers had died (while only 13.5% of the pinyon pines were killed). At that time some of the larger trees that had been defoliated by fire were surviving. Thirteen % of oneseed junipers were unharmed by the fire.
FIRE MANAGEMENT IMPLICATIONS:
The broad objective of data collection following the wildfire was to examine the effects of fire on the grama-pinyon-juniper vegetation type. Reduction in herbage caused by the fire was 30% in October of the same year. Litter production was also reduced following the fire. Small cholla cacti (Opuntia spp.) were also killed by the fire. The findings suggest that low severity surface fires may be effective in reducing numbers of small (< 4 feet (1.2 m)) oneseed junipers and cholla cacti. Larger oneseed junipers and cacti are somewhat resistant to such fires. Fine fuels tended to be sparse under the large junipers, and the authors conclued that more juniper and pinyon would have been killed if more grass fuel had been present.
Browse: Deer utilize the foliage of oneseed juniper [26,59,84]. Mahgoub and others  observed heavy utilization in parts of south-central New Mexico where juniper can represent up to 20% of the annual diet of mule deer. Oneseed juniper foliage is reported to be a major mule deer food item from January through March in parts of southeastern New Mexico . Pronghorns also browse oneseed juniper, and in some areas, winter use may be heavy [20,122]. Bighorn sheep and elk may consume small amounts of juniper browse . The foliage of oneseed juniper is of little value to domestic livestock. Domestic sheep and goats utilize this species to a limited extent [26,59].
Fruit: The succulent, berrylike cones of oneseed juniper serve as an abundant and readily available food source for a wide range of wildlife species. The bright cones tend to remain on the tree and can provide food year-round [34,110], but become dry and leathery by the 2nd winter .
It is estimated that avian population densities may be 70% greater during years with abundant juniper "berry" crops (generally every 2 to 5 years) . Studies with captive birds have revealed that an average Townsend's solitaire can consume approximately 240 "berries" per day, or 36,000 to 84,000 per winter [13,110]. In some areas at least 97% of the Townsend's solitaire's winter diet may be made up of oneseed juniper "berries" . Robins also consume large numbers of the berrylike cones. An individual bird can eat 220 "berries" per day or 33,000 per winter. Birds and mammals serve as important dispersal agents for seeds of oneseed juniper. Many bird species disperse seed up to 6.3 miles (10 km) or more from the seed source. Sheep and domestic cattle can also facilitate dispersal of oneseed juniper [13,64]. Salomonson  reported the following animals as juniper seed consumers and dispersers:
|northern flicker||desert cottontail|
|Steller's jay||black-tailed jackrabbit|
|mountain chickadee||cliff chipmunk|
|plain titmouse||rock squirrel|
|sage thrasher||golden mantled ground squirrel|
|American robin||deer mouse|
|Townsend's solitaire||Mexican woodrat|
|evening grosbeak||gray fox|
Other wildlife species known to consume oneseed juniper berries include
mule deer, western chipmunk, antelope ground squirrel, squirrels, bear,
javelina, pocket mouse, rabbits, and raccoon [,64,108,119].
The fruits of oneseed juniper are palatable to many birds and mammals . They appear to remain palatable even when dry. The foliage is relatively unpalatable to most species, although it is reported to be somewhat more palatable than that of most other junipers . The palatability of oneseed juniper to livestock and wildlife species in 2 western states has been rated :
|Small nongame birds||-||good|
|Upland game birds||-||good|
|small nongame birds||good||good|
|upland game birds||-||good|
VALUE FOR REHABILITATION OF DISTURBED SITES:
Oneseed juniper is rated as having low overall value for short-term rehabilitation but high value for long-term rehabilitation . It was not widely used in the past for rehabilitation projects because of unreliable seed germination. Fertilizers, wood chips, straw mulch, plastic mesh protection against rodents, and drip irrigation can all contribute to increased survival on disturbed sites. Oneseed juniper has been successfully planted on surface coal and uranium mines in the Southwest. Improved techniques have resulted in survival rates as high as 99% [40,41].
In a New Mexico study of planted seed, drip irrigation was more effective than mulch, while triple-superphosphate aided growth more than slow-release fertilizers. On these sites, July planting dates produced best results at higher elevations, whereas August plantings were most successful on low elevation sites .
Transplanting containerized seedlings onto disturbed sites has also been a successful technique [39,40,41]. In New Mexico, survival is best when trees are planted after the June drought but before the ground freezes. Survival of transplants is heavily dependent on moisture availability. Mulch aids in water conservation and can enhance survival on dry sites. Drip irrigation may be necessary on the most arid sites. Researchers suggested that fertilizer may improve survival on some sites particularly when combined with irrigation [40,41]. In another New Mexico study of rehabilitation of surface-mined land, survival of transplanted containerized seedlings was improved by wood chip mulch and animal protection using rigid mesh. In this study, fertilizer provided no benefit and decreased oneseed juniper survival where seeded grasses were able to outcompete. Competition from weeds also reduced juniper growth and survival .
Germinating juniper seeds is difficult. Seeds may require a period of afterripening . Pack  found that high temperatures, alternating temperatures, freezing and thawing, removal of the seed coat, application of hydrogen peroxide, dilute acids, carbon dioxide, or light had little influence on germination of juniper seeds. Cold stratification may improve germination in oneseed juniper . Fischer and others  found that germination improved when seeds were leached 48 hours with hydrogen peroxide, or treated with ethephon or hydrogen peroxide plus gibberellic acid followed by cold stratification .
Experiments suggest that exposure to sunlight may have relatively little effect on
germination. Johnsen  observed average germination of 44% for seeds grown
in the dark, and 52% for seeds exposed to sunlight. Soil moisture may be an important
factor influencing germination. Germination appears to be best in moist but not saturated
soil. Seeds of oneseed juniper do not germinate well on the soil
surface which is subject to rapid desiccation. Juniper seeds appear to be
resistant to drought when buried in the soil [63,64]. Buried seeds can often retain
viability and germinate when moisture conditions become favorable. Approximately
54% of oneseed juniper seed stored for 21 years germinated .
Oneseed juniper is used locally for fuel, fenceposts, poles, and Christmas trees . Native Americans relied on oneseed juniper for many purposes. Wood was used for bows and arrows by the Kiowa, Comanche, Cheyenne, and Apache . The "berries" were eaten whole or ground into flour for bread [22,31]. Prayer sticks were made from wood, and dye, fibrous mats, and saddles were fashioned from the bark [,31]. Parts of the tree were also used as building materials and for medicinal purposes . Foliage was used as domestic sheep food during extreme winters . Oneseed junipers were used by settlers for fenceposts, fuel, and mine timbers. Oneseed juniper has also been used in the production of cellulose and chemical products [34,64]. Springfield  noted that many species of juniper may have potential value for the production of charcoal, pulp, particleboard, chip products, fiber, or in certain chemicals. Oneseed juniper was first cultivated in 1900 .
OTHER MANAGEMENT CONSIDERATIONS:
In parts of the Southwest, juniper species including oneseed juniper have encroached into adjacent grasslands, or increased in stand density [48,59,78,93,133]. Explanations include fire suppression, a decrease in light fuels from overgrazing, reduction of grass competitiveness by overgrazing, spread of seed by livestock, and climatic change [4,64,78,89,106,132]. Past management efforts focused on halting the juniper invasion through mechanical or chemical means.
Mechanical control: A number of methods of mechanical removal were tried with limited success. Cabling, chaining, bulldozing, and various means of hand removal were used in attempts to convert pinyon-juniper woodlands to grasslands. Neither the single chaining nor double chaining method effectively eliminated trees less than 10 feet (3.1 m) in height. In treatment areas heavily stocked with young trees, reinvasion may be rapid [11,65,104,114,118].
Chemical control: The foliage of junipers tends to be resistant to herbicides, and leaves have little surface area for absorption , though juniper can be killed with chemicals. See Springfield  and Johnsen  for details.
Production: Herbage production values are variable in pinyon-juniper woodlands. Springfield  reported an inverse relationship between tree canopy and average herbage production:
|tree canopy||average herbage production|
|0%||600 lbs per acre|
|20%||300 lbs per acre|
|80%||50 lbs per acre|
Fertilization: The diameter of oneseed juniper was found to be largely unaffected by the addition of nitrogen fertilizer in a New Mexico study, although growth of lateral branches and apex was enhanced .
In a 1998 study in northern New Mexico, Allen and Breshears  concluded that the ecotone between a semiarid ponderosa pine forest and Colorado pinyon-oneseed juniper woodland shifted extensively (1.2 miles (2 km)) and rapidly (within < 5 years) through drought-induced ponderosa pine mortality and associated expansion of the pinyon-juniper population. The Bandelier Wilderness site was chosen in part for its minimal history of human disturbance and extensively documented fire history. They used a Geographic Information System and a series of aerial photographs taken from 1935 to 1975. Their analysis showed that the shift coincided with the culmination of a 1950s drought, which was one of the most severe of the past 500 years. The shift has persisted for at least 40 years. The authors acknowledge that fire suppression since the 1800s allowed the Colorado pinyon and oneseed juniper to become more densely established in proximity to the ponderosa pines prior to the 1950s drought. They also note that the shift was amplified by bark beetle mortality in the ponderosa pine and more efficient water use in pinyon and juniper. They assert drought was the driving factor in the shift, in part because widespread ponderosa pine mortality ceased when the drought broke.
A number of other studies and reviews have examined the relatively recent changes in stand density or areal extent of juniper or pinyon-juniper woodlands [33,48,55,67,89]. Evidence and arguments are presented for both expansion and reduction of the woodlands. The studies do not focus on oneseed juniper specifically, but provide relevant perspectives.
In a recent discussion of the problem of pinyon-juniper expansion, Lanner  provided the following perspective: "Despite the decades old alarm occasioned by juniper encroachment into rangelands, very little research has been undertaken to establish its cause or causes... The lumping of pinyon pines with junipers, despite their very different biologies, is a further confusing factor in understanding the behavior of these coniferous woodlands in which the species may occur together, or singly... At present woodland eradication in the pinyon-juniper zone is nearly an abandoned practice, partly because it is controversial, but mainly because it is almost always a prohibitively expensive way to grow grass."
1. Adams, R. P. 1972. Chemosystematic and numerical studies of natural populations of Juniperus pinchotii Sudw. Taxon. 21(4): 407-427. 
2. Adams, Robert P. 1975. Numerical-chemosystematic studies of infraspecific variation in Juniperus pinchotii. Biochemical Systematics and Ecology. 3: 71-74. 
3. Aldon, Earl F.; Scholl, David G.; Fresquez, P. R.; Francis, Richard E. 1988. Natural production potential of some Rio Puerco soils in New Mexico. Res. Note RM-481. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Forest and Range Experiment Station. 4 p. 
4. Allen, Craig D.; Breshears, David D. 1998. Drought-induced shift of a forest-woodland ecotone: rapid landscape response to climate variation. Proceedings, National Academy of Sciences of the United States of America. 95(25): 14839-14842. 
5. Allen, Rogert B.; Peet, Robert K. 1990. Gradient analysis of forests of the Sangre de Cristo Range, Colorado. Canadian Journal of Botany. 68: 193-201. 
6. Armentrout, Susan M.; Pieper, Rex D. 1988. Plant distribution surrounding Rocky Mountain pinyon pine and oneseed juniper in south-central New Mexico. Journal of Range Management. 41(2): 139-143. 
7. Arno, Stephen F. 2000. Fire in western forest ecosystems. In: Brown, James K.; Smith, Jane Kapler, eds. Wildland fire in ecosystems: Effects of fire on flora. Gen. Tech. Rep. RMRS-GTR-42-vol. 2. Ogden, UT: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station: 97-120. 
8. Arno, Stephen F.; Gruell, George E. 1983. Fire history at the forest-grassland ecotone in southwestern Montana. Journal of Range Management. 36(3): 332-336. 
9. Arnold, J. F. 1964. Zonation of understory vegetation around a juniper tree. Journal of Range Management. 17: 41-42. 
10. Arnold, Joseph F.; Jameson, Donald A.; Reid, Elbert H. 1964. The pinyon-juniper type of Arizona: effects of grazing, fire and tree control. Production Research Report No. 84. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Intermountain Forest and Range Experiment Station. 28 p. 
11. Aro, Richard S. 1971. Evaluation of pinyon-juniper conversion to grassland. Journal of Range Management. 24(2): 188-197. 
12. Bahre, Conrad J. 1998. Late 19th century human impacts on the woodlands and forests of southeastern Arizona's sky islands. Desert Plants. 14(1): 8-21. 
13. Balda, Russell P. 1987. Avian impacts on pinyon-juniper woodlands. In: Everett, Richard L., compiler. Proceedings--pinyon-juniper conference; 1986 January 13-16; Reno, NV. Gen. Tech. Rep. INT-215. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Research Station: 525-533. 
14. Barnes, Fairley J.; Cunningham, G. L. 1987. Water relations and productivity in pinyon-juniper habitat types. In: Everett, Richard L., compiler. Proceedings--pinyon-juniper conference; 1986 January 13-16; Reno, NV. Gen. Tech. Rep. INT-215. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Research Station: 406-411. 
15. Bassett, Dick; Larson, Milo; Moir, Will. 1987. Forest and woodland habitat types (plant associations) of Arizona south of the Mogollon Rim and southwestern New Mexico. 2nd edition. Albuquerque, NM: U.S. Department of Agriculture, Forest Service, Southwestern Region. Variously paginated. 
16. Bernard, Stephen R.; Brown, Kenneth F. 1977. Distribution of mammals, reptiles, and amphibians by BLM physiographic regions and A.W. Kuchler's associations for the eleven western states. Tech. Note 301. Denver, CO: U.S. Department of the Interior, Bureau of Land Management. 169 p. 
17. Blackburn, Wilbert H.; Bruner, Allen D. 1975. Use of fire in manipulation of the pinyon-juniper ecosystem. In: The pinyon-juniper ecosystem: a symposium: Proccedings; 1975 May; Logan, UT. Logan, UT: Utah State University, College of Natural Resources, Utah Agricultural Experiment Station; 1975: 91-96. 
18. Breshears, David D.; Myers, Orrin B.; Johnson, Susan R.; [and others]. 1997. Differential use of spatially heterogeneous soil moisture by two semiarid woody species: Pinus edulis and Juniperus monosperma. Journal of Ecology. 85(3): 289-299. 
19. Brown, David E. 1982. Plains and Great Basin grasslands. In: Brown, David E., ed. Biotic communities of the American Southwest--United States and Mexico. Desert Plants. 4(1-4): 115-121. 
20. Buechner, Helmut K. 1950. Life history, ecology, and range use of the pronghorn antelope in Trans-Pecos Texas. The American Midland Naturalist. 43(2): 257-354. 
21. Burkhardt, Wayne J.; Tisdale, E. W. 1976. Causes of juniper invasion in southwestern Idaho. Ecology. 57: 472-484. 
22. Castetter, Edward F.; Opler, M. E. 1936. Ethnobiological studies in the American Southwest. III. The ethnobiology of the Chiricahua and Mescalero Apache. University of New Mexico Bulletin. 4(5): 1-63. 
23. Cottle, H. J. 1931. Studies in the vegetation of southwestern Texas. Ecology. 12(1): 105-155. 
24. Crane, Marilyn F. 1982. Fire ecology of Rocky Mountain Region forest habitat types. Final report: Contract No. 43-83X9-1-884. Missoula, MT: U.S. Department of Agriculture, Forest Service, Region 1. 272 p. On file with: U.S. Department of Agriculture, Forest Service, Intermountain Research Station, Fire Sciences Laboratory, Missoula, MT. 
25. Cully, Anne C.; Cully, Jack F., Jr. 1989. Spatial and temporal variability in perennial and annual vegetation at Chaco Canyon, New Mexico. The Great Basin Naturalist. 49(1): 113-122. 
26. Dayton, William A. 1931. Important western browse plants. Misc. Publ. 101. Washington, DC: U.S. Department of Agriculture. 214 p. 
27. Diamond, David D.; Riskind, David H.; Orzell, Steve L. 1987. A framework for plant community classification and conservation in Texas. Texas Journal of Science. 39(3): 203-221. 
28. Dittberner, Phillip L.; Olson, Michael R. 1983. The plant information network (PIN) data base: Colorado, Montana, North Dakota, Utah, and Wyoming. FWS/OBS-83/86. Washington, DC: U.S. Department of the Interior, Fish and Wildlife Service. 786 p. 
29. Dwyer, Don D.; Pieper, Rex D. 1967. Fire effects on blue grama-pinyon-juniper rangeland in New Mexico. Journal of Range Management. 20: 359-362. 
30. Edgerton, Paul J. 1983. Response of the bitterbrush understory of a central Oregon lodgepole pine forest to logging disturbance. In: Tiedemann, Arthur R.; Johnson, Kendall L., compilers., Proceedings--research and management of bitterbrush and cliffrose in western North America; 1982 April 13-15; Salt Lake City, UT. General Technical Report INT-152. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Forest and Range Experiment Station: 99-106. 
31. Elmore, Francis H. 1944. Ethnobotany of the Navajo. Monograph Series: 1(7). Albuquerque, NM: University of New Mexico. 136 p. 
32. Emerson, Fred W. 1932. The tension zone between the grama grass and pinyon-juniper associations in northeastern New Mexico. Ecology. 13: 247-258. 
33. Ernst, Reg; Pieper, Rex D. 1996. Changes in pinon-juniper vegetation: a brief history. Rangelands. 18(1): 14-16. 
34. Evans, Raymond A. 1988. Management of pinyon-juniper woodlands. Gen. Tech. Rep. INT-249. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Research Station. 34 p. 
35. Everett, Richard L.; Sharrow, Steven H. 1983. Response of understory species to tree harvesting and fire in pinyon-juniper woodlands. In: Monsen, Stephen B.; Shaw, Nancy, compilers. Managing Intermountain rangelands--improvement of range and wildlife habitats: Proceedings of symposia; 1981 September 15-17; Twin Falls, ID; 1982 June 22-24, Elko, NV. General Technical Report INT-157. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Forest and Range Experiment Station: 62-66. 
36. Eyre, F. H., ed. 1980. Forest cover types of the United States and Canada. Washington, DC: Society of American Foresters. 148 p. 
37. Ferry, Gardner W.; Clark, Robert G.; Montogmery, Roy E.; [and others]. 1995. Altered fire regimes within fire-adapted ecosystems. In: LaRoe, Edward T.; Farris, Gaye S.; Puckett, Catherine E.; [and others], eds. Our living resources: A report to the nation on the distribution, abundance, and health of U.S. plants, animals, and ecosystems. Washington, DC: U.S. Department of the Interior, National Biological Service: 222-224. 
38. Ffolliott, Peter F.; Thorud, David B. 1974. Vegetation for increased water yield in Arizona. Tech. Bull. 215. Tucson, AZ: University of Arizona, Agricultural Experiment Station. 38 p. 
39. Fisher, James T.; Fancher, Gregory A. 1990. Factors affecting establishment of one-seed juniper (Juniperus monosperma) on surface-mined lands in New Mexico. Canadian Journal of Forestry Research. 20: 880-886. 
40. Fisher, James T.; Fancher, Gregory A.; Neumann, Robert W. 1986. Survival and growth of containerized native juniper (Juniperus monosperma) on surface-mined lands in New Mexico. Forest Ecology and Management. 16: 291-299. 
41. Fisher, James T.; Fancher, Gregory A.; Neumann, Robert W. 1987. Germination and field establishment of juniper in the Southwest. In: Everett, Richard L., compiler. Proceedings--pinyon-juniper conference; 1986 January 13-16; Reno, NV. Gen. Tech. Rep. INT-215. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Research Station: 293-299. 
42. Flora of North America Association. 2004. Flora of North America: The flora. [Online]. Flora of North America Association (Producer). Available: http://www.fna.org/FNA. 
43. Foxx, Teralene S.; Tierney, Gail D. 1987. Rooting patterns in the pinyon-juniper woodland. In: Everett, Richard L., compiler. Proceedings--pinyon-juniper conference; 1986 January 13-16; Reno, NV. Gen. Tech. Rep. INT-215. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Research Station: 69-79. 
44. Francis, Richard E. 1986. Phyto-edaphic communities of the Upper Rio Puerco watershed, New Mexico. Res. Pap. RM-272. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Forest and Range Experiment Station. 73 p. 
45. Frischknecht, Neil C. 1975. Native faunal relationships within the pinyon-juniper ecosystem. In: The pinyon-juniper ecosystem: a symposium: Proceedings; 1975 May; Logan, UT. Logan, UT: Utah State University, College of Natural Resources, Utah Agricultural Experiment Station: 55-56. 
46. Garrison, George A.; Bjugstad, Ardell J.; Duncan, Don A.; Lewis, Mont E.; Smith, Dixie R. 1977. Vegetation and environmental features of forest and range ecosystems. Agric. Handb. 475. Washington, DC: U.S. Department of Agriculture, Forest Service. 68 p. 
47. Gehlbach, Frederick R. 1967. Vegetation of the Guadalupe Escarpment, New Mexico-Texas. Ecology. 48(3): 404-419. 
48. Gottfried, Gerald J. 1999. Pinyon-juniper woodlands in the southwestern United States. In: Ffolliott, Peter F.; Ortega-Rubio, Alfredo, eds. Ecology and management of forests, woodlands, and shrublands in the dryland regions of the United States and Mexico: perspectives for the 21st century. Co-edition No. 1. Tucson, AZ: The University of Arizona; La Paz, Mexico: Centro de Investigaciones Biologicas del Noroeste, SC; Flagstaff, AZ: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station: 53-67. 
49. Gottfried, Gerald J.; Severson, Kieth E. 1994. Managing pinyon-juniper woodlands. Rangelands. 16(6): 234-236. 
50. Great Plains Flora Association. 1986. Flora of the Great Plains. Lawrence, KS: University Press of Kansas. 1392 p. 
51. Hall, Marion T.; Carr, Claudia J. 1968. Variability in Juniperus in the Palo Duro Canyon of western Texas. The Southwestern Naturalist. 13(1): 75-98. 
52. Harrington, H. D. 1964. Manual of the plants of Colorado. 2d ed. Chicago: The Swallow Press, Inc. 666 p. 
53. Herman, F. R. 1956. Growth and phenological observations of Arizona junipers. Ecology. 37: 193-195. 
54. Hoffman, George R.; Alexander, Robert R. 1983. Forest vegetation of the White River National Forest in western Colorado: a habitat type classification. Res. Pap. RM-249. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Forest and Range Experiment Station. 36 p. 
55. Huebner, Cynthia D.; Vankat, John L.; Renwick, William H. 1999. Change in the vegetation mosaic of central Arizona USA between 1940 and 1989. Plant Ecology. 144(1): 83-91. 
56. Humphrey, Robert R. 1953. Forage production on Arizona ranges: III. Mohave County: A study in range condition. Bulletin 244. Tucson, AZ: University of Arizona, Agricultural Experiment Station. 79 p. 
57. Humphrey, Robert R. 1955. Forage production on Arizona ranges: IV. Coconino, Navajo, Apache counties: A study in range condition. Bulletin 266. Tucson, AZ: University of Arizona, Agricultural Experiment Station. 84 p. 
58. Jameson, Donald A. 1961. Heat and desiccation resistance of tissue of important trees and grasses of the pinyon-juniper type. Botanical Gazette. 122: 174-179. 
59. Jameson, Donald A. 1962. Effects of burning on a galleta-black grama range invaded by juniper. Ecology. 43(4): 760-763. 
60. Jameson, Donald A. 1965. Arrangement and growth of pinyon and one-seed juniper trees. Plateau. 37: 121-127. 
61. Jameson, Donald A. 1966. Juniper control by individual tree burning. Research Note RM-71. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Forest and Range Experiment Station. 4 p. 
62. Jameson, Donald A. 1970. Juniper root competition reduces basal area of blue grama. Journal of Range Management. 23(3): 217-218. 
63. Johnsen, Thomas N., Jr. 1959. Longevity of stored juniper seeds. Ecology. 40(3): 487-488. 
64. Johnsen, Thomas N., Jr. 1962. One-seeded juniper invasion of northern Arizona grasslands. Ecological Monographs. 32(3): 187-207. 
65. Johnsen, Thomas N., Jr. 1987. Using herbicides for pinyon-juniper control in the Southwest. In: Everett, Richard L., compiler. Proceedings--pinyon-juniper conference; 1986 January 13-16; Reno, NV. Gen. Tech. Rep. INT-215. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Research Station: 330-334. 
66. Johnsen, Thomas N., Jr.; Alexander, Robert A. 1974. Juniperus L. juniper. In: Schopmeyer, C. S., tech. coord. Seeds of woody plants in the United States. Agric. Handb. 450. Washington, DC: U.S. Department of Agriculture, Forest Service: 460-469. 
67. Johnson, Alan R.; Milne, Bruce T.; Hraber, Peter. 1996. Analysis of change in pinon-juniper woodlands based on aerial photography, 1930's-1980's. Albuquerque, NM: University of New Mexico, Department of Biology; Final report to the USDA Forest Service. Cooperative Agreement No. 28-C4-860. 12 + p. 
68. Johnson, Donald E.; Mukhtar, Hashim A. M.; Mapston, Raymond; Humphrey, R. R. 1962. The mortality of oak-juniper woodland species following a wild fire. Journal of Range Management. 15: 201-205. 
69. Johnston, Barry C. 1987. Plant associations of Region Two: Potential plant communities of Wyoming, South Dakota, Nebraska, Colorado, and Kansas. 4th ed. R2-ECOL-87-2. Lakewood, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Region. 429 p. 
70. Kartesz, John T.; Meacham, Christopher A. 1999. Synthesis of the North American flora (Windows Version 1.0), [CD-ROM]. Available: North Carolina Botanical Garden. In cooperation with the Nature Conservancy, Natural Resources Conservation Service, and U.S. Fish and Wildlife Service [2001, January 16]. 
71. Kaufmann, Merrill R.; Huckaby, Laurie S.; Regan, Claudia M.; Popp, John. 1998. Forest reference conditions for ecosystem management in the Sacramento Mountains, New Mexico. Gen. Tech. Rep. RMRS-GTR-19. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station. 87 p. 
72. Kearney, Thomas H.; Peebles, Robert H.; Howell, John Thomas; McClintock, Elizabeth. 1960. Arizona flora. 2d ed. Berkeley, CA: University of California Press. 1085 p. 
73. Kennedy, Kathryn L. 1983. A habitat type classification of the pinyon-juniper woodlands of the Lincoln National Forest, New Mexico. In: Moir, W. H.; Hendzel, Leonard, tech. coords. Proceedings of the workshop on Southwestern habitat types; 1983 April 6-8; Albuquerque, NM. Albuquerque, NM: U.S. Department of Agriculture, Forest Service, Southwestern Region: 54-61. 
74. Kruse, William H.; Balda, Russell P.; Simono, Michael J.; [and others]. 1979. Community development in two adjacent pinyon-juniper eradication areas twenty-five years after treatment. Journal of Environmental Management. 8: 237-247. 
75. Kuchler, A. W. 1964. Manual to accompany the map of potential vegetation of the conterminous United States. Special Publication No. 36. New York: American Geographical Society. 77 p. 
76. Kuchler, A. W. 1964. United States [Potential natural vegetation of the conterminous United States]. Special Publication No. 36. New York: American Geographical Society. 1:3,168,000; colored. 
77. Lanner, Ronald M. 1975. Pinyon pines and junipers of the Southwestern woodlands. In: The pinyon-juniper ecosystem: a symposium: Proceedings; 1975 May; Logan, UT. Logan, UT: Utah State University, College of Natural Resources, Utah Agriculture Experiment Station: 1-17. 
78. Lanner, Ronald M.; Van Devender, Thomas R. 1998. The recent history of pinyon pines in the American Southwest. In: Richardson, David M., ed. Ecology and biogeography of Pinus. Cambridge, United Kingdom: The Press Syndicate of the University of Cambridge: 171-182. 
79. Little, Elbert L., Jr. 1979. Checklist of United States trees (native and naturalized). Agric. Handb. 541. Washington, DC: U.S. Department of Agriculture, Forest Service. 375 p. 
80. Lymbery, Gordon A.; Pieper, Rex D. 1983. Ecology of pinyon-juniper vegetation in the northern Sacramento Mountains. Bulletin 698. Las Cruces, NM: New Mexico State University, Agricultural Experiment Station. 48 p. 
81. Lyon, L. Jack; Stickney, Peter F. 1976. Early vegetal succession following large northern Rocky Mountain wildfires. In: Proceedings, Tall Timbers fire ecology conference and Intermountain Fire Research Council fire and land management symposium; 1974 October 8-10; Missoula, MT. No. 14. Tallahassee, FL: Tall Timbers Research Station: 355-373. 
82. Mahgoub, El Fatih; Pieper, Rex D.; Holechek, Jerry L.; [and others]. 1987. Botanical content of mule deer diets in south-central New Mexico. New Mexico Journal of Science. 27(1): 21-27. 
83. Martin, William C.; Hutchins, Charles R. 1981. A flora of New Mexico. Volume 2. Germany: J. Cramer. 2589 p. 
84. McDonald, Fred Wayne. 1974. Response of oneseed juniper to nitrogen fertilization. Las Cruces, NM: New Mexico State University. 38 p. Thesis. 
85. McPherson, Guy R.; Wright, Henry A. 1987. Factors affecting reproductive maturity of redberry juniper (Juniperus pinchotii). Forest Ecology and Management. 21: 191-196. 
86. Meeuwig, Richard O.; Bassett, Richard L. 1983. Pinyon-juniper. In: Burns, Russell M., compiler. Silvicultural systems for the major forest types of the United States. Agriculture Handbook No. 445. Washington, DC: U.S. Department of Agriculture, Forest Service: 84-86. 
87. Miller, Melanie. 2000. Fire autecology. In: Brown, James K.; Smith, Jane Kapler, eds. Wildland fire in ecosystems: Effects of fire on flora. Gen. Tech. Rep. RMRS-GTR-42-vol. 2. Ogden, UT: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station: 9-34. 
88. Miller, Richard F.; Rose, Jeffery A. 1995. Historic expansion of Juniperus occidentalis (western juniper) in southeastern Oregon. The Great Basin Naturalist. 55(1): 37-45. 
89. Miller, Richard F.; Wigand, Peter E. 1994. Holocene changes in semiarid pinyon-juniper woodlands. Bioscience. 44(7): 465-474. 
90. Moir, W. H.; Carleton, J. O. 1987. Classification of pinyon-juniper (p-j) sites on national forests in the Southwest. In: Everett, Richard L., compiler. Proceedings--pinyon-juniper conference; 1986 January 13-16; Reno, NV. Gen. Tech. Rep. INT-215. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Research Station: 216-226. 
91. Moir, William H. 1982. A fire history of the High Chisos, Big Bend National Park, Texas. The Southwestern Naturalist. 27(1): 87-98. 
92. Morino, Kiyomi A.; Baisan, Christopher H.; Swetnam, Thomas W. 2000. Historical fire regimes in the Chiricahua Mountains, Arizona: an examination of fire along an elevation gradient and in mixed-conifer forest. Final report. USFS Cooperative Agreement #28-C4-858: Sub-project IV/Amendment 6. On file with: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Lab, Missoula, MT. 82 p. 
93. Mueggler, Walter F. 1976. Ecological role of fire in western woodland and range ecosystems. In: Use of prescribed burning in western woodland and range ecosystems: Proceedings of the symposium; 1976 March 18-19; Logan, UT. Logan, UT: Utah State University, Utah Agricultural Experiment Station: 1-9. 
94. Neary, Daniel G.; Klopatek, Carole C.; DeBano, Leonard F.; Ffolliott, Peter F. 1999. Fire effects on belowground sustainability: a review and synthesis. Forest Ecology and Management. 122(1-2): 51-71. 
95. Neilson, Ronald P. 1987. On the interface between current ecological studies and the paleobotany of pinyon-juniper woodlands. In: Everett, Richard L., compiler. Proceedings--pinyon-juniper conference; 1986 January 13-16; Reno, NV. Gen. Tech. Rep. INT-215. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Research Station: 93-98. 
96. Nichol, A. A. [revisions by Phillips, W. S.]. 1952. The natural vegetation of Arizona. Tech. Bull. 68 [Revised]. Tucson, AZ: University of Arizona, Agricultural Experiment Station: 189-230. 
97. Pack, Dean A. 1921. After-ripening and germination of Juniperus seeds. Botanical Gazette. 71: 32-60. 
98. Paysen, Timothy E.; Ansley, R. James; Brown, James K.; [and others]. 2000. Fire in western shrubland, woodland, and grassland ecosystems. In: Brown, James K.; Smith, Jane Kapler, eds. Wildland fire in ecosystems: Effects of fire on flora. Gen. Tech. Rep. RMRS-GTR-42-volume 2. Ogden, UT: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station: 121-159. 
99. Pieper, Rex D. 1977. The southwestern pinyon-juniper ecosystem. In: Aldon, Earl F.; Loring, Thomas J., technical coordinators. Ecology, uses, and management of pinyon-juniper woodlands: Proceedings of the workshop; 1977 March 24-25; Albuquerque, NM. Gen. Tech. Rep. RM-39. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Forest and Range Experiment Station: 1-6. 
100. Pieper, Rex D. 1983. Overstory-understory relationships: pinyon-juniper and juniper woodlands. In: Bartlett, E. T.; Betters, David R., eds. Overstory-understory relationships in western forests. Western Regional Research Publication No. 1. Fort Collins, CO: Colorado State University Experiment Station: 35-37. 
101. Pieper, Rex D. 1990. Overstory-understory relations in pinyon-juniper woodlands in New Mexico. Journal of Range Management. 43(5): 413-415. 
102. Pieper, Rex D.; Montoya, James R.; Groce, V. Lynn. 1971. Site characteristics on pinyon-juniper and blue grama in south-central New Mexico. Bulletin 573. Las Cruces, NM: New Mexico State University, Agricultural Experiment Station. 21 p. 
103. Plumb, Gregory A. 1992. Vegetation classification of Big Bend National Park, Texas. Texas Journal of Science. 44(4): 375-387. 
104. Ralphs, Michael H.; Busby, Frank E. 1979. Prescribed burning: vegetative change, forage production, cost, and returns on six demonstration burns in Utah. Journal of Range Management. 32(4): 267-270. 
105. Raunkiaer, C. 1934. The life forms of plants and statistical plant geography. Oxford: Clarendon Press. 632 p. 
106. Richardson, David M.; Bond, William J. 1991. Determinants of plant distribution: evidence from pine invasions. The American Naturalist. 137(5): 639-668. 
107. Rundel, Philip W.; Yoder, Barbara J. 1998. Ecophysiology of Pinus. In: Richardson, David M., ed. Ecology and biogeography of Pinus. Cambridge, United Kingdom: The Press Syndicate of the University of Cambridge: 296-323. 
108. Rushing, Charles Keith. 1977. Growth response of oneseed juniper to three levels of nitrogen fertilization. Las Cruces, NM: New Mexico State University. 39 p. Thesis. 
109. Salomonson, M. G.; Balda, R. P. 1977. Winter territoriality of Townsend's solitaires (Myadestes townsendi) in a pinyon-juniper - ponderosa pine ecotone. The Condor. 79: 148-161. 
110. Salomonson, Michael G. 1978. Adaptations for animal dispersal of one-seed juniper seeds. Oecologia. 32: 333-339. 
111. Sapsis, David B. 1990. Ecological effects of spring and fall prescribed burning on basin big sagebrush/Idaho fescue--bluebunch wheatgrass communities. Corvallis, OR: Oregon State University. 105 p. Thesis. 
112. Schott, M. R.; Pieper R. D. 1985. Influence of canopy characteristics of one-seed juniper on understory grasses. Journal of Range Management. 38(4): 328-331. 
113. Schott, M. R.; Pieper, R. D. 1987. Succession of pinyon-juniper communities after mechanical disturbance in southcentral New Mexico. Journal of Range Management. 40(1): 88-94. 
114. Schott, M. R.; Pieper, Rex D. 1987. Succession in tree pits following cabling in pinyon-juniper communities. The Southwestern Naturalist. 32(3): 399-402. 
115. Schott, Martin R.; Pieper, Rex D. 1986. Succession in pinyon-juniper vegetation in New Mexico. Rangelands. 8(3): 126-128. 
116. Severson, Kieth E. 1986. Small mammals in modified pinyon-juniper woodlands, New Mexico. Journal of Range Management. 39(1): 31-34. 
117. Shiflet, Thomas N., ed. 1994. Rangeland cover types of the United States. Denver, CO: Society for Range Management. 152 p. 
118. Springfield, H. W. 1976. Characteristics and management of southwestern pinyon-juniper ranges: the status of our knowledge. Res. Pap. RM-160. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Forest and Range Experiment Station. 32 p. 
119. Stanton, Frank. 1974. Wildlife guidelines for range fire rehabilitation. Tech. Note 6712. Denver, CO: U.S. Department of the Interior, Bureau of Land Management. 90 p. 
120. Stickney, Peter F. 1989. FEIS postfire regeneration workshop--April 12: Seral origin of species comprising secondary plant succession in Northern Rocky Mountain forests. 10 p. Unpublished draft on file at: U.S. Department of Agriculture, Forest Service, Intermountain Research Station, Fire Sciences Laboratory, Missoula, MT. 
121. Stuever, Mary C.; Hayden, John S. 1996. Plant associations (habitat types) of the forests and woodlands of Arizona and New Mexico. Final report: Contract R3-95-27. Placitas, NM: Seldom Seen Expeditions, Inc. 520 p. 
122. Sundstrom, Charles; Hepworth, William G.; Diem, Kenneth L. 1973. Abundance, distribution and food habits of the pronghorn: A partial characterization of the optimum pronghorn habitat. Bulletin No. 12. Cheyenne, WY: Wyoming Game and Fish Commission. 59 p. 
123. Swetnam, Thomas W.; Baisan, Christopher H.; Caprio, Anthony C.; Brown, Peter M. 1992. Fire history in a Mexican oak-pine woodland and adjacent montane conifer gallery forest in southeastern Arizona. In: Ffolliott, Peter F.; Gottfried, Gerald J.; Bennett, Duane A.; [and others], technical coordinators. Ecology and management of oak and associated woodlands: perspectives in the southwestern United States and northern Mexico: Proceedings; 1992 April 27-30; Sierra Vista, AZ. Gen. Tech. Rep. RM-218. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Forest and Range Experiment Station: 165-173. 
124. Texas Natural Heritage Program. 1993. Plant communities of Texas (Series level). Austin, TX: Texas Parks and Wildlife Department. Unpublished report on file at: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory, Missoula, MT. 26 p. 
125. Tiedemann, Arthur R. 1987. Nutrient accumulations in pinyon-juniper ecosystems--managing for future site productivity. In: Everett, Richard L., compiler. Proceedings--pinyon-juniper conference; 1986 January 13-16; Reno, NV. Gen. Tech. Rep. INT-215. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Research Station: 352-359. 
126. Tueller, Paul T.; Clark, James E. 1975. Autecology of pinyon-juniper species of the Great Basin and Colorado Plateau. In: The pinyon-juniper ecosystem: a symposium: Proceedings; 1975 May; Logan, UT. Logan, UT: Utah State University, College of Natural Resources, Utah Agricultural Experiment Station: 27-40. 
127. U.S. Department of Agriculture, Soil Conservation Service. 1994. Plants of the U.S.--alphabetical listing. Washington, DC: U.S. Department of Agriculture, Soil Conservation Service. 954 p. 
128. Vallentine, John F. 1971. Range development and improvements. Provo, UT: Brigham Young University Press. 516 p. 
129. Vasek, Frank C. 1966. The distribution and taxonomy of three western junipers. Brittonia. 18: 350-372. 
130. Vincent, Dwain W. 1992. The sagebrush/grasslands of the upper Rio Puerco area, New Mexico. Rangelands. 14(5): 268-271. 
131. Welsh, Stanley L.; Atwood, N. Duane; Goodrich, Sherel; Higgins, Larry C., eds. 1987. A Utah flora. The Great Basin Naturalist Memoir No. 9. Provo, UT: Brigham Young University. 894 p. 
132. White, Larry D. 1965. The effects of a wildfire on a desert grassland community. Tucson, AZ: University of Arizona. 107 p. Thesis. 
133. Woodbury, Angus M. 1947. Distribution of pigmy conifers in Utah and northeastern Arizona. Ecology. 28(2): 113-126. 
134. Wright, Henry A. 1972. Shrub response to fire. In: McKell, Cyrus M.; Blaisdell, James P.; Goodin, Joe R., eds. Wildland shrubs--their biology and utilization: Proceedings of a symposium; 1971 July; Logan, UT. Gen. Tech. Rep. INT-1. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Forest and Range Experiment Station: 204-217. 
135. Young, James A.; Evans, Raymond A. 1981. Demography and fire history of a western juniper stand. Journal of Range Management. 34(6): 501-505. 
136. Zanoni, T. A. 1978. The American junipers of the section Sabina (Juniperus, Cupressaceae) -- a century later. Phytologia. 38(6): 433-454. 
137. Zarn, Mark. 1977. Ecological characteristics of pinyon-juniper woodlands on the Colorado Plateau: A literature survey. Tech. Note T/N 310. Denver, CO: U.S. Department of the Interior, Bureau of Land Management, Denver Service Center. 183 p.