SPECIES: Rhus trilobata
USDA-NRCS PLANTS Database
© 1995 Saint Mary's College of California
AUTHORSHIP AND CITATION:
Anderson, Michelle D. 2004. Rhus trilobata. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available: www.fs.fed.us/database/feis/plants/shrub/rhutri/all.html .
Rhus aromatica var. pilosissima 
= Rhus trilobata var. pilosissima [76,115]
Rhus aromatica var. simplicifolia (Greene) Cronq. 
= Rhus trilobata var. simplicifolia [76,155]
Rhus aromatica Aiton ssp. trilobata (Nuttall) Weber 
= Rhus trilobata
Rhus aromatica var. trilobata (Nutt.) Gray [58,153]
= Rhus trilobata var. trilobata [76,115,155]
NRCS PLANT CODE :
The currently accepted scientific name of skunkbush sumac is Rhus trilobata Nutt. (Anacardiaceae) [47,48,69,71,76,77,115,155]. Infrataxa are as follows:
R. t. var. anisophylla (Greene) Jepson [76,155], skunkbush sumac
R. t. var. pilosissima Engelm. [76,115], pubescent skunkbush sumac
R. t. var. quinata (Greene) Jepson [76,155], Grand Canyon skunkbush sumac
R. t. var. racemulosa (Greene) Barkl. , skunkbush sumac
R. t. var. simplicifolia (Greene) Barkl. [76,155], skunkbush sumac
R. t. var. trilobata, skunkbush sumac
FEDERAL LEGAL STATUS:
|R. t. var. anisophylla||Washington south to California, east to Utah and New Mexico|
|R. t. var. pilosissima||California east to Texas, north to Colorado and Kansas|
|R. t. var. quinata||Washington south to California, east to Nevada and New Mexico|
|R. t. var. racemulosa||Arizona and New Mexico|
|R. t. var. simplicifolia||Washington south to California, east to Colorado, New Mexico, and Oklahoma|
|R. t. var. trilobata||entire range|
Grassland: Common associates in mixed-prairie communities are thickspike wheatgrass (Elymus lanceolatus), needle-and-thread grass (Hesperostipa comata), prairie Junegrass (Koeleria macrantha), western wheatgrass (Pascopyrum smithii), plains reedgrass (Calamagrostis montanensis), Sandberg bluegrass (Poa secunda), sedges (Carex spp.), green needlegrass (Nassella viridula), Indian ricegrass (Achnatherum hymenoides), hairy grama (Bouteloua hirsuta), blue grama (B. gracilis), little bluestem (Schizachyrium scoparium), dropseeds (Sporobolus spp.), big bluestem (Andropogon gerardii var. gerardii), and switchgrass (Panicum virgatum) [1,26]. Woody plant associates include cherry (Prunus spp.), smooth sumac (Rhus glabra), lead plant (Amorpha canescens), golden currant (Ribes aureum), snowberry (Symphoricarpos spp.), American elm (Ulmus americana), and hackberry (Celtis occidentalis) .
Shrubland: Skunkbush sumac is frequently found with sagebrushes (Artemisia spp.) and rabbitbrushes (Chrysothamnus spp.) . In mountain shrub communities, skunkbush sumac is associated with Gambel oak (Quercus gambelii), chokecherry (P. virginiana), true mountain-mahogany (Cercocarpus montanus), bluegrass (Poa spp.), needlegrass (Nassella spp.), Indian ricegrass, and broom snakeweed (Gutierrezia sarothrae) . In Colorado steppe communities, common associates include sleepygrass (Achnatherum robustum), western wheatgrass, blue grama, buffalo grass (Buchloe dactyloides), fourwing saltbush (Atriplex canescens), and rubber rabbitbrush (Chrysothamnus nauseous) .
Skunkbush sumac is a common constituent of Arizona chaparral communities. Associates include shrub live oak (Q. turbinella), Emory oak (Q. emoryi), Palmer oak (Q. dunnii), true and birchleaf mountain-mahogany (Cercocarpus montanus var. glaber, C. betuloides), pointleaf and Pringle manzanita (Arctostaphylos pungens, A. pringlei), desert ceanothus (Ceanothus greggii), catclaw acacia (Acacia greggii), catclaw mimosa (Mimosa biurcifera), Bigelow's nolina (Nolina bigelovii), sugar sumac (Rhus ovata), jojoba (Simmondsia chinensis), redberry buckthorn (Rhamnus crocea), California coffeeberry (R. californica), and Wright and chaparral silktassel (Garrya wrightii, G. congdonii) [25,33,34,68,98,137,150]. Chaparral associates in Baja California include Parry pinyon (Pinus quadrifolia), singleleaf pinyon (P. monophylla), Muller oak (Q. cornelius-mulleri), redberry buckthorn, sugar sumac, flannelbush (Fremontodendron californicum), and desert agave (Agave deserti) .
Forest: Associates in Rocky Mountain forest communities include ponderosa pine (P. ponderosa), limber pine (P. flexilis), Douglas-fir (Pseudotsuga menziesii), Rocky Mountain juniper (Juniperus scopulorum), rubber rabbitbrush, prairie rose (Rosa arkansana), common snowberry (Symphoricarpos albus), true mountain-mahogany, chokecherry, wax currant (Ribes cereum), big sagebrush (Artemisia tridentata), silver sagebrush (A. cana), and antelope bitterbrush (Purshia tridentata) [94,121].
In pinyon-juniper (Pinus spp.-Juniperus spp.) communities, skunkbush sumac is commonly found with Colorado pinyon (P. edulis), oneseed juniper (J. monosperma), Bigelow sagebrush (A. bigelovii), true mountain-mahogany, groundcherry (Physalis spp.), agarito (Mahonia trifoliolata), wolfberry (Lycium spp.), galleta grass (Pleuraphis jamesii), blue grama, and creeping muhly (Muhlenbergia repens) [4,43]. Associates in Rocky Mountain juniper communities are chokecherry, silver buffaloberry (Shepherdia argentea), silver sagebrush, and shrubby cinquefoil (Dasiphora floribunda) .
Classifications listing skunkbush sumac as a plant community dominant include the following:
New Mexico [45,136]
South Dakota [39,132]
Plant community codominants include Arizona white oak (Q. arizonica), Colorado pinyon, oneseed juniper, New Mexico muhly (M. pauciflora) in the Southwest [15,45,136]; narrowleaf cottonwood (Populus angustifolia) in Nevada and southern California ; Rio Grande cottonwood (P. deltoides ssp. wislizeni)  and mountain muhly (M. montana) in Colorado ; bluebunch wheatgrass (Pseudoroegneria spicata) in Montana  and Wyoming ; and true mountain-mahogany , bur oak (Q. macrocarpa), bluebunch wheatgrass, and Idaho fescue (Festuca idahoensis)  in the Black Hills of South Dakota.
Skunkbush sumac is a deciduous, flowering native shrub [22,34,74,75,76,86,131]. It grows 2 to 12 feet (0.6-3.6 m) tall, averaging 4 feet (1.2 m) tall [34,40,56,105,107,115,144,150]. Taller shrubs are found on more favorable habitats [22,56]. Growth form is erect to spreading with a dense crown [40,74,107,135]. Shrub width may reach 6.5 feet (2 m) . Skunkbush sumac has many irregularly branched stems, and leaves are formed by 3 leaflets . The fruit of skunkbush sumac is a 1-seeded drupe .
Skunkbush sumac has a taproot  and a fibrous root system [74,75]. Roots
are deep and extensively branched with somewhat shallow, spreading woody
rhizomes . Individual shrubs and patches of skunkbush sumac may be
connected by underground structures that can exceed 20 feet (6 m) in length
and 30 years in age . It sprouts readily from the root crown [74,107].
RAUNKIAER  LIFE FORM:
Skunkbush sumac propagates by seed and root sprouts . It sprouts readily from the root crown after severe disturbance [74,107] but is unlikely to reproduce vegetatively in the absence of disturbance . Skunkbush sumac reproduces only rarely from seed [74,94].
Breeding system: Skunkbush sumac has been reported as dioecious  and as polygamomonoecious .
Pollination: Skunkbush sumac is animal-pollinated , presumably by small mammals.
Seed production: Skunkbush sumac reportedly has low seed production . It was estimated that only 5 to 15% of skunkbush sumac flowers in a North Dakota shrub community actually produced fruit. Branches from 6 to 10 years of age produced the most viable fruit .
Seed dispersal: Seeds are eaten and dispersed by birds and animals [107,110,134].
Seed banking: No information is available on this topic.
Germination: Skunkbush sumac seeds have both seed coat impermeability and embryo dormancy [18,89,131,151]. They germinate poorly without scarification which is necessary to crack or soften the hard seed coat. Little evidence exists that skunkbush sumac seeds are physiologically dormant. Breaking embryo dormancy may require a cold stratification [18,107,151]. High temperatures (>180 oF (82oC)) associated with fire have been shown to break seed dormancy in greenhouse experiments . Some laboratory experiments have demonstrated that neither temperature or light stratification affects germination rates . However, Keeley  found that germination of skunkbush sumac was significantly decreased (p<0.001) by the absence of light.
A study of skunkbush sumac seeds found seeds ingested by bears and deposited in scat had much higher germination rates than noningested seeds. Furthermore, chilling the seeds resulted in even lower germination rates. Prewarming of seeds, on the other hand, significantly increased germination of seeds (p<0.05) .
Skunkbush seeds remain viable in cool storage (37-41 oF/3-5 oC) for 5 years .
Seedling establishment/growth: Seedling establishment may be rare in established skunkbush sumac stands [74,107,123]. Seedlings are very susceptible to damping-off fungus .
The primary means of short-range skunkbush sumac dispersal is vegetative [40,123,150];
shrubs in North Dakota up to 20 feet (6 m) apart were found to be connected
. Skunkbush sumac may form thickets as large as 30 feet (9 m) in diameter
[123,131,143,150]. Undisturbed plants produce few sprouts, while those subject to
browsing, trampling or burning produce many sprouts [40,94,150].
Skunkbush sumac grows on dry, rocky hillsides and sandhills, as well as along streams, canyon bottoms, and wetlands [40,56,75,76,91,105,131,135,137,144,150,153]. It is found in grassy flats and openings in woodland areas [63,74,75,76,94].
Elevation: Skunkbush sumac grows principally from 3,500-9,000 feet (1,065-2,740 m), though it also occurs at lower elevations [75,144]. The following table gives the elevation range of skunkbush sumac by state:
|Arizona||2,500-7,500 feet (760-2,285 m)||[34,77,137]|
|California||500-6,000 feet (152-1,830 m)||[40,74]|
|Montana||<6,000 feet (1,830 m)|||
|Southern New Mexico and southern Texas||4,220-6,000 feet (1,286-1,830 m)|||
|Utah||2,900-7,700 feet (885-2,350 m)||[110,153]|
The relationship between skunkbush sumac and slope aspect is ambiguous. It is reportedly more prevalent on north slopes in the mixed-prairie, where it is protected from prevailing winds and receives more water from wind-drifted snow . It is also more abundant on north-facing slopes in pinyon-juniper communities in the Southwest . In Alberta coulees, however, skunkbush sumac is largely restricted to south-facing slopes . In Montana, it is also found more often on south slopes, with slope gradients between 40 and 80% . In another study, skunkbush sumac in the North Dakota badlands had higher relative densities on steep southwest slopes; however, it was denser and larger on northeast slopes .
Climate: Skunkbush sumac is adapted to a wide range of climates, particularly the 10 to 20 inches (254-508 mm) annual precipitation zones [144,150]. In Montana, sites supporting skunkbush sumac have an average January temperature of 20 oF (-6.7 oC) and average July temperature of 64 oF (18 oC). Average annual precipitation is 14 inches (355 mm) per year, with 50% falling from May through July. The growing season varies from 50 to 130 days, with moderate to high density stands found on sites having 120 or more frost-free days . The climate in North Dakota has January temperatures averaging 11 oF (-11 oC) and July temperatures averaging 69 oF (20 oC). Average annual precipitation is 15.6 inches (396 mm), with 80% falling between April and September .
In contrast, the Arizona chaparral climate has cool, wet winters extending into March, followed by warm, dry weather for 2 or 3 months. Following summer rains, dry weather returns in October and persists until winter rains in December. Average annual precipitation ranges from 16 to 25 inches (406-635 mm), generally increasing with elevation. Average monthly temperatures range from less than 40 oF (4 oC) in January to more than 80 oF (26 oC) in July .
Skunkbush sumac is moderately drought tolerant [60,131,143,150], though seedlings may be severely affected by drought conditions . Acute drought may shorten twig growth and prevent fruit production .
Soils: Skunkbush sumac may grow to 2 to 3 feet (0.6-0.9 m) on dry sites,
and 10 to 12 feet (3-3.6 m) with more favorable moisture availability .
Skunkbush sumac is tolerant of most soil textures but prefers well-drained sites
[94,120,131,139,150,150]; it may be found in higher density at mid-slope
positions than at the bottom of slopes . Skunkbush sumac prefers deep
soil [74,94] or thin soils with a gravel base. Extensive stands have been
reported on steep slopes where topsoils were thin or absent . Soil pH is
often mildly alkaline [94,116]; in Montana, large stands were found on soil pH
of 7.4 . Soils may be high in potassium and low in organic matter,
phosphorus, and salt . Skunkbush sumac is intolerant of flooding and high
water tables .
Skunkbush sumac is commonly found on disturbed sites [18,24]. It prefers full sun or partial shade .
Annual growth of skunkbush sumac occurs primarily in spring and early summer [86,94,137,150]. In a North Dakota study, growth of new twigs was complete by July 9 . Skunkbush sumac flowers in early spring, 1 to 3 weeks before leaves appear [40,75,94,105,115,135,150]. Fruit matures July through October [18,22], and persists into winter . Seeds are dispersed from August through the following summer . Leaf drop occurs in October .
Fire regimes: No information is available regarding fire regimes in plant communities where skunkbush sumac is dominant, and little is known about its response to different fire regimes. Frequent or severe fires will restrict skunkbush sumac to protected sites or to areas of light fuel loadings, even though vigorous sprouting occurs after fire. The absence of fire allows seedling establishment on favorable microsites, and may result in an increase of skunkbush sumac on a site .
Skunkbush sumac grows in a wide variety of plant communities, where fire return intervals range from less than 10 years up to hundreds of years. Fire return intervals for plant communities and ecosystems in which skunkbush sumac occurs are summarized below. 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)|
|California chaparral||Adenostoma and/or Arctostaphylos spp.||< 35 to < 100 |
|bluestem prairie||Andropogon gerardii var. gerardii-Schizachyrium scoparium||< 10 [83,109]|
|Nebraska sandhills prairie||Andropogon gerardii var. paucipilus-Schizachyrium scoparium||< 10|
|coastal sagebrush||Artemisia californica||< 35 to < 100 |
|silver sagebrush steppe||Artemisia cana||5-45 [67,117,156]|
|sagebrush steppe||Artemisia tridentata/Pseudoroegneria spicata||20-70 |
|basin big sagebrush||Artemisia tridentata var. tridentata||12-43 |
|mountain big sagebrush||Artemisia tridentata var. vaseyana||15-40 [6,32,97]|
|Wyoming big sagebrush||Artemisia tridentata var. wyomingensis||10-70 (40**) [147,157]|
|desert grasslands||Bouteloua eriopoda and/or Pleuraphis mutica||5-100 |
|plains grasslands||Bouteloua spp.||< 35 [109,156]|
|blue grama-needle-and-thread grass-western wheatgrass||Bouteloua gracilis-Hesperostipa comata-Pascopyrum smithii||< 35 [109,122,156]|
|blue grama-buffalo grass||Bouteloua gracilis-Buchloe dactyloides||< 35 [109,156]|
|grama-galleta steppe||Bouteloua gracilis-Pleuraphis jamesii||< 35 to < 100|
|blue grama-tobosa prairie||Bouteloua gracilis-Pleuraphis mutica||< 35 to < 100 |
|cheatgrass||Bromus tectorum||< 10 [111,154]|
|California montane chaparral||Ceanothus and/or Arctostaphylos spp.||50-100 |
|curlleaf mountain-mahogany*||Cercocarpus ledifolius||13-1,000 [8,127]|
|mountain-mahogany-Gambel oak scrub||Cercocarpus ledifolius-Quercus gambelii||< 35 to < 100|
|blackbrush||Coleogyne ramosissima||< 35 to < 100|
|western juniper||Juniperus occidentalis||20-70|
|Rocky Mountain juniper||Juniperus scopulorum||< 35 |
|cedar glades||Juniperus virginiana||3-22 [61,109]|
|wheatgrass plains grasslands||Pascopyrum smithii||< 5-47+ [109,117,156]|
|pinyon-juniper||Pinus-Juniperus spp.||< 35 |
|Mexican pinyon||Pinus cembroides||20-70 [102,140]|
|Rocky Mountain lodgepole pine*||Pinus contorta var. latifolia||25-340 [13,14,141]|
|Colorado pinyon||Pinus edulis||10-400+ [53,57,78,109]|
|Jeffrey pine||Pinus jeffreyi||5-30 |
|interior ponderosa pine*||Pinus ponderosa var. scopulorum||2-30 [5,10,87]|
|Arizona pine||Pinus ponderosa var. arizonica||2-15 [10,41,128]|
|galleta-threeawn shrubsteppe||Pleuraphis jamesii-Aristida purpurea||< 35 to < 100 |
|mesquite||Prosopis glandulosa||< 35 to < 100 [96,109]|
|mesquite-buffalo grass||Prosopis glandulosa-Buchloe dactyloides||< 35|
|Texas savanna||Prosopis glandulosa var. glandulosa||< 10 |
|Rocky Mountain Douglas-fir*||Pseudotsuga menziesii var. glauca||25-100 [5,6,7]|
|California oakwoods||Quercus spp.||< 35 |
|oak-juniper woodland (Southwest)||Quercus-Juniperus spp.||< 35 to < 200 |
|canyon live oak||Quercus chrysolepis||<35 to 200|
|blue oak-foothills pine||Quercus douglasii-P. sabiniana||<35 |
|California black oak||Quercus kelloggii||5-30 |
|bur oak||Quercus macrocarpa||< 10 |
|oak savanna||Quercus macrocarpa/Andropogon gerardii-Schizachyrium scoparium||2-14 [109,149]|
|shinnery||Quercus mohriana||< 35 |
|post oak-blackjack oak||Quercus stellata-Q. marilandica||< 10|
|blackland prairie||Schizachyrium scoparium-Nassella leucotricha||< 10 |
|little bluestem-grama prairie||Schizachyrium scoparium-Bouteloua spp.||< 35 |
Skunkbush sumac typically increases after fire, though average plant size is reduced in the short-term. The following table describes the impact of a 1979 prescribed fire on skunkbush sumac in a Black Hills ponderosa pine forest :
|1979 - preburn||1980||1981|
|Total # of plants||48||19||57||23||65||23|
|Mean max. height||28.2 cm||39.9 cm||28.6 cm||17.9 cm||30.6 cm||25.4 cm|
|Mean max. crown width||31.0 cm||33.2 cm||31.5 cm||17.7 cm||30.6 cm||25.4 cm|
Response of vegetation to prescribed burning in a Jeffrey pine-California black oak woodland and a deergrass meadow at Cuyamaca State Park, California, provides information on prescribed fire use and postfire response of many mixed-conifer woodland species including skunkbush sumac.FIRE MANAGEMENT CONSIDERATIONS:
Skunkbush sumac is also browsed by small mammals. Porcupines utilize it , and it is also browsed, sometimes heavily, by jackrabbits and cottontail [28,44], particularly after heavy snow when branches extend above drifts .
Skunkbush sumac fruit is an important winter food source for birds, including songbirds, prairie chickens, Merriam turkeys, ring-necked pheasants, sage-grouse, ruffed grouse, sharp-tailed grouse, and bobwhite, valley, Gambel, and scaled quail [107,135,138,139]. Fruit is also eaten by black bears , and occasionally, white-tailed deer .
Palatability/nutritional value: Skunkbush sumac has poor palatability for domestic livestock throughout most of its range [46,135], but may be fair to good for cattle and domestic sheep in the Southwest and Colorado . It is highly palatable for domestic goats in the Southwest . Skunkbush sumac provides good browse for deer and pronghorn .
The National Academy of Sciences reports the following nutritional information for skunkbush sumac (% dry matter) :
|Ether extract||4.4||Digestible protein:|
A study in the southern Great Plains found the following monthly nutrient content for skunkbush sumac (5-year means, % dry weight) :
Monthly variation in crude protein content of skunkbush sumac from California samples was reported as follows (% oven dry weight) :
Skunkbush sumac provides useful cover and nesting sites for birds [75,139].
It provides poor to fair cover for elk; fair to good cover for white-tailed
deer, mule deer, and pronghorn; good cover for upland game birds, nongame
birds, and small mammals; and poor cover
for waterfowl .
VALUE FOR REHABILITATION OF DISTURBED SITES:
Skunkbush sumac is useful for landscape planting [60,73], wind barriers [75,139], and reclamation of disturbed areas . It is excellent for erosion control [74,143] and survives on untreated mine spoils . Skunkbush sumac is commercially available (e.g. cultivar "Autumn Amber") [73,146] and grows well from seed (especially when planted in fall and winter) or transplants . Skunkbush sumac has an average of 20,300 seeds per pound (44,750 seeds/kg) . For best survival, plant 2-0 container stock  in deep soil and full sun . Excellent transplant success has been reported (100% on 3 out of 4 sites) ; however, a study in the Tahoe Basin found poor transplant establishment and survival .
In laboratory experiments, optimum germination was achieved with both sulfuric
acid treatment and moist prechilling . Acid scarification is useful in encouraging
seed germination due to the impermeable seedcoat [90,151]. Other experiments found that
germination of skunkbush sumac was significantly decreased (p<0.001) by the absence
of light, while the addition of powdered, charred wood significantly increased (p<0.01)
germination rates .
Southwestern Native Americans ate the fruits of skunkbush sumac, either fresh or after being ground to form meal [16,35]. The berries have a distinct lemon flavor and could be mixed with various foods for seasoning  or dried and made into jam [36,49]. Berries were also mixed with water to make a beverage . Leaves of skunkbush sumac were dried and mixed with tobacco for smoking . The leaves were also used for medicinal purposes (stomachache, diuretic, toothache pain, bleeding, head colds, poison ivy rashes) [16,62,112].
Native Americans burned skunkbush sumac to stimulate production of long,
straight sprouts which could be used for making baskets and handcrafted
OTHER MANAGEMENT CONSIDERATIONS:
Reports regarding skunkbush sumac response to grazing are conflicting, with some authors reporting increased growth due to sprouting [94,135,150] and others reporting decreased growth [86,158].
1. Albertson, F. W. 1937. Ecology of mixed prairie in west central Kansas. Ecological Monographs. 7: 483-547. 
2. Allen, Eugene O. 1968. Range use, foods, condition, and productivity of white-tailed deer in Montana. Journal of Wildlife Management. 32(1): 130-141. 
3. Anderson, M. Kat; Moratto, Michael J. 1996. Native American land-use practices and ecological impacts. In: Status of the Sierra Nevada. Sierra Nevada Ecosystem Project: Final report to Congress. Volume II: Assessments and scientific basis for management options. Wildland Resources Center Report No. 37. Davis, CA: University of California, Centers for Water and Wildland Resources: 187-206. 
4. 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. 
5. 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. 
6. 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. 
7. Arno, Stephen F.; Scott, Joe H.; Hartwell, Michael G. 1995. Age-class structure of old growth ponderosa pine/Douglas-fir stands and its relationship to fire history. Res. Pap. INT-RP-481. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Research Station. 25 p. 
8. Arno, Stephen F.; Wilson, Andrew E. 1986. Dating past fires in curlleaf mountain-mahogany communities. Journal of Range Management. 39(3): 241-243. 
9. Auger, Janene; Meyer, Susan E.; Black, Hal L. 2002. Are American black bears (Ursus americanus) legitimate seed dispersers for fleshy-fruited shrubs. American Midland Naturalist. 147: 352-367. 
10. Baisan, Christopher H.; Swetnam, Thomas W. 1990. Fire history on a desert mountain range: Rincon Mountain Wilderness, Arizona, U.S.A. Canadian Journal of Forest Research. 20: 1559-1569. 
11. Baker, William L. 1984. A preliminary classification of the natural vegetation of Colorado. The Great Basin Naturalist. 44(4): 647-676. 
12. Baldwin, Randolph F. 1979. The effects of fire upon vegetation in Joshua Tree National Monument. Senior thesis report. Santa Barbara, CA: University of California. On file with: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory, Missoula, MT. 76 p. 
13. Barrett, Stephen W. 1993. Fire regimes on the Clearwater and Nez Perce National Forests north-central Idaho. Final Report: Order No. 43-0276-3-0112. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Research Station, Fire Sciences Laboratory. 21 p. Unpublished report on file with: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory, Missoula, MT. 
14. Barrett, Stephen W.; Arno, Stephen F.; Key, Carl H. 1991. Fire regimes of western larch - lodgepole pine forests in Glacier National Park, Montana. Canadian Journal of Forest Research. 21: 1711-1720. 
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. Bean, Lowell John; Saubel, Katherine Siva. 1972. Telmalpakh: Chauilla Indian knowledge and usage of plants. Banning, CA: Malki Museum. 225 p. 
17. Beetle, Alan A. 1962. Range survey in Teton County, Wyoming. Part 2: Utilization and condition classes. Bull. 400. Laramie, WY: University of Wyoming, Agricultural Experiment Station. 38 p. 
18. Belcher, Earl. 1985. Handbook on seeds of browse--shrubs and forbs. Technical Publication R8-TP8. Atlanta, GA: U.S. Department of Agriculture, Forest Service, Southern Region. 246 p. In cooperation with: Association of Official Seed Analysts. 
19. 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. 
20. Bissell, Harold D.; Strong, Helen. 1955. The crude protein variations in the browse diet of California deer. California Fish and Game. 41(2): 145-155. 
21. Bock, Jane H.; Bock, Carl E. [n.d.]. Some effects of fire on vegetation and wildlife in ponderosa pine forests of the southern Black Hills. Final Report: Contracts CX-1200-9-B034, CX-1200-0-B018, CX-1200-1-B022. Grant No. RM-80-105 GR. Unpublished report on file with: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory, Missoula, MT. 58 p. 
22. Bohrer, Vorsila L. 1983. New life from ashes: the tale of the burnt bush (Rhus trilobata). Desert Plants. 5(3): 122-124. 
23. Booth, D. Terrance; Schuman, Gerald E. 1981. Shrub reestablishment research at the High Plains Grasslands Research Station. In: Stelter, Lavern H.; DePuit, Edward J.; Mikol, Sharon A., tech. coords. Shrub establishment on disturbed arid and semi-arid lands: Proceedings of the symposium; 1980 December 2-3; Laramie, WY. Cheyenne, WY: Wyoming Game and Fish Department: 81-88. 
24. Boyd, Steve. 1999. Vascular flora of the Liebre Mountains, western Transverse Ranges, California. Aliso. 18(2): 93-139. 
25. Brady, Ward; Bonham, Charles D. 1976. Vegetation patterns on an altitudinal gradient, Huachuca Mountains, Arizona. The Southwestern Naturalist. 21(1): 55-66. 
26. Breitung, August J. 1954. A botanical survey of the Cypress Hills. Canadian Field-Naturalist. 68: 55-92. 
27. Bromley, Peter T. 1977. Aspects of the behavioural ecology and sociobiology of the pronghorn (Antilocapra americana). Calgary, AB: University of Calgary. 370 p. Dissertation. 
28. Brown, H. Leo. 1947. Coaction of jack rabbit, cottontail, and vegetation in a mixed prairie. Transactions, Kansas Academy of Science. 50(1): 28-44. 
29. Brown, Ray W. 1971. Distribution of plant communities in southeastern Montana badlands. The American Midland Naturalist. 85(2): 458-477. 
30. Bryant, Fred C.; Morrison, Bruce. 1985. Managing plains mule deer in Texas and eastern New Mexico. Management Note 7. Lubbock, TX: Texas Tech University, College of Agricultural Sciences, Department of Range and Wildlife Management. 5 p. 
31. Burcham, L. T. 1974. Fire and chaparral before European settlement. In: Rosenthal, Murray, ed. Symposium on living with the chaparral: Proceedings; 1973 March 30-31; Riverside, CA. San Francisco, CA: The Sierra Club: 101-120. 
32. Burkhardt, Wayne J.; Tisdale, E. W. 1976. Causes of juniper invasion in southwestern Idaho. Ecology. 57: 472-484. 
33. Cable, Dwight R. 1957. Recovery of chaparral following burning and seeding in central Arizona. Res. Note. No. 28. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Forest and Range Experiment Station. 6 p. 
34. Cable, Dwight R. 1975. Range management in the chaparral type and its ecological basis: the status of our knowledge. Res. Pap. RM-155. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Forest and Range Experiment Station. 30 p. 
35. Castetter, Edward F. 1935. Ethnobiological studies in the American Southwest. Biological Series No. 4: Volume 1. Albuquerque, NM: University of New Mexico. 62 p. 
36. 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. 
37. Clarke, Joseph W., DePuit, Edward J. 1981. Analysis of direct seeding methods for establishment of selected native shrub species on minesoils in southeastern Montana. In: Stelter, Lavern H.; DePuit, Edward J.; Mikol, Sharon A., tech. coords. Shrub establishment on disturbed arid and semi-arid lands: Proceedings of the symposium; 1980 December 2-3; Laramie, WY. Cheyenne, WY: Wyoming Game and Fish Department: 89-103. 
38. Cole, G. F. 1956. The pronghorn antelope--its range use and food habits in central Montana with special reference to alfalfa. Technical Bulletin 516. Bozeman, MT: Montana State College, Agricultural Experiment Station. 63 p. 
39. Collins, Ellen I. 1984. Preliminary classification of Wyoming plant communities. Cheyenne, WY: Wyoming Natural Heritage Program/The Nature Conservancy. 42 p. 
40. Conrad, C. Eugene. 1987. Common shrubs of chaparral and associated ecosystems of southern California. Gen. Tech. Rep. PSW-99. Berkeley, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Forest and Range Experiment Station. 86 p. 
41. Cooper, Charles F. 1961. Pattern in ponderosa pine forests. Ecology. 42(3): 493-499. 
42. Coxson, Darwyn S.; Looney, John Henry H. 1986. Vegetation patterns within southern Alberta coulees. Canadian Journal of Botany. 64: 2464-2475. 
43. 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. 
44. DeCalesta, David S. 1971. A literature review on cottontail feeding habits. Special Report No. 25. Denver, CO: Colorado Division of Game, Fish and Parks. 15 p. 
45. Dick-Peddie, William A. 1993. New Mexico vegetation: past, present, and future. Albuquerque, NM: University of New Mexico Press. 244 p. 
46. 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. 
47. Dorn, Robert D. 1977. Flora of the Black Hills. [Place of publication unknown]: Robert D. Dorn and Jane L. Dorn. 377 p. 
48. Dorn, Robert D. 1988. Vascular plants of Wyoming. Cheyenne, WY: Mountain West Publishing. 340 p. 
49. Elmore, Francis H. 1944. Ethnobotany of the Navajo. Monograph Series: 1(7). Albuquerque, NM: University of New Mexico. 136 p. 
50. Everett, Richard L.; Meeuwig, Richard O.; Butterfield, Richard I. 1980. Revegetation of untreated acid spoils: Leviathan mine, Alpine County, California. California Geology. 32(1): 8-10. 
51. Eyre, F. H., ed. 1980. Forest cover types of the United States and Canada. Washington, DC: Society of American Foresters. 148 p. 
52. Flora of North America Association. 2000. Flora of North America north of Mexico. Volume 2: Pteridophytes and gymnosperms, [Online]. Flora of North America Association (Producer). Available: http://hua.huh.harvard.edu/FNA/ [2004, October 27]. 
53. Floyd, M. Lisa; Romme, William H.; Hanna, David D. 2000. Fire history and vegetation pattern in Mesa Verde National Park, Colorado, USA. Ecological Applications. 10(6): 1666-1680. 
54. 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. 
55. Gehlbach, Frederick R. 1967. Vegetation of the Guadalupe Escarpment, New Mexico-Texas. Ecology. 48(3): 404-419. 
56. George, Ernest J. 1953. Tree and shrub species for the Northern Great Plains. Circular No. 912. Washington, DC: U.S. Department of Agriculture. 46 p. 
57. Gottfried, Gerald J.; Swetnam, Thomas W.; Allen, Craig D.; [and others]. 1995. Pinyon-juniper woodlands. In: Finch, Deborah M.; Tainter, Joseph A., eds. Ecology, diversity, and sustainability of the Middle Rio Grande Basin. Gen. Tech. Rep. RM-GTR-268. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Forest and Range Experiment Station: 95-132. 
58. Great Plains Flora Association. 1986. Flora of the Great Plains. Lawrence, KS: University Press of Kansas. 1392 p. 
59. Green, Lisle R.; Newell, Leonard A. 1982. Using goats to control brush regrowth on fuelbreaks. Gen. Tech. Rep. PSW-59. Berkeley, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Forest and Range Experiment Station. 13 p. 
60. Gutknecht, Kurt W. 1989. Xeriscaping: an alternative to thirsty landscapes. Utah Science. 50(4): 142-146. 
61. Guyette, Richard; McGinnes, E. A., Jr. 1982. Fire history of an Ozark glade in Missouri. Transactions, Missouri Academy of Science. 16: 85-93. 
62. Hart, Jeffrey A. 1981. The ethnobotany of the northern Cheyenne Indians of Montana. Journal of Ethnopharmacology. 4: 1-55. 
63. Hayward, Herman E. 1928. Studies of plants in the Black Hills of South Dakota. Botanical Gazette. 85(4): 353-412. 
64. Heit, C. E. 1967. Propagation from seed. Part 7: Germinating six hardseeded groups. American Nurseryman. 125(12): 10-12; 37-41; 44-45. 
65. Hellgren, Eric C. 1993. Status, distribution, and summer food habits of black bears in Big Bend National Park. The Southwestern Naturalist. 38(1): 77-80. 
66. Hendricks, Paul; Allard, Herbert F. 1988. Winter food habits of prairie porcupines in Montana. Prairie Naturalist. 20(1): 1-6. 
67. Heyerdahl, Emily K.; Berry, Dawn; Agee, James K. 1994. Fire history database of the western United States. Final report. Interagency agreement: U.S. Environmental Protection Agency DW12934530; U.S. Department of Agriculture, Forest Service PNW-93-0300; University of Washington 61-2239. Seattle, WA: U.S. Department of Agriculture, Pacific Northwest Research Station; University of Washington, College of Forest Resources. 28 p. [+ Appendices]. Unpublished report on file with: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory, Missoula, MT. 
68. Hibbert, Alden R.; Davis, Edwin A.; Scholl, David G. 1974. Chaparral conversion potential in Arizona. Part I: water yield response and effects on other resources. Res. Pap. RM-126. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Forest and Range Experiment Station. 36 p. 
69. Hickman, James C., ed. 1993. The Jepson manual: Higher plants of California. Berkeley, CA: University of California Press. 1400 p. 
70. Hill, Ralph R. 1946. Palatability ratings of Black Hills plants for white-tailed deer. Journal of Wildlife Management. 10(1): 47-54. 
71. Hitchcock, C. Leo; Cronquist, Arthur. 1973. Flora of the Pacific Northwest. Seattle, WA: University of Washington Press. 730 p. 
72. Hoffman, Donald M. 1965. The scaled quail in Colorado: Range--population status--harvest. Tech. Publ. No. 18. Denver, CO: Colorado Department of Game, Fish, and Parks. 47 p. 
73. Hooks, R. F.; Oaks, W. R. 1986. `Autumn amber' fragrant sumac. HortScience. 21(6): 1465-1466. 
74. Horton, Jerome S. 1949. Trees and shrubs for erosion control of southern California mountains. Berkeley, CA: U.S. Department of Agriculture, Forest Service, California Forest and Range Experiment Station; California Department of Natural Resources, Division of Forestry. 72 p. 
75. Johnson, Kendall L. 1977. Skunkbush sumac: Rhus trilobata. Wyoming Range Plants B-636.4. Laramie, WY: University of Wyoming, Agricultural Extension Service. 2 p. 
76. 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]. 
77. Kearney, Thomas H.; Peebles, Robert H.; Howell, John Thomas; McClintock, Elizabeth. 1960. Arizona flora. 2d ed. Berkeley, CA: University of California Press. 1085 p. 
78. Keeley, Jon E. 1981. Reproductive cycles and fire regimes. In: Mooney, H. A.; Bonnicksen, T. M.; Christensen, N. L.; [and others], technical coordinators. Fire regimes and ecosystem properties: Proceedings of the conference; 1978 December 11-15; Honolulu, HI. Gen. Tech. Rep. WO-26. Washington, DC: U.S. Department of Agriculture, Forest Service: 231-277. 
79. Keeley, Jon E. 1987. Role of fire in seed germination of woody taxa in California chaparral. Ecology. 68(2): 434-443. 
80. Kittams, Walter H. 1973. Effect of fire on vegetation of the Chihuahuan Desert region. In: Proceedings, annual Tall Timbers fire ecology conference; 1972 June 8-9; Lubbock, Texas. No. 12. Tallahassee, FL: Tall Timbers Research Station: 427-444. 
81. Kittams, Walter H.; Evans, Stanley L.; Cooke, Derrick C. 1979. Food habits of mule deer on foothills of Carlsbad Caverns National Park. In: Genoways, Hugh H.; Baker, Robert J., eds. Biological investigations in the Guadalupe Mountains National Park: Proceedings of a symposium; 1975 April 4-5; Lubbock, TX. Proceedings and Transactions Series No. 4. Washington, DC: U.S. Department of the Interior, National Park Service: 403-426. 
82. Komarkova, Vera. 1986. Habitat types on selected parts of the Gunnison and Uncompahgre National Forests. Final report: Contract No. 28-K2-234. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Forest and Range Experiment Station. 270 p. 
83. Kucera, Clair L. 1981. Grasslands and fire. In: Mooney, H. A.; Bonnicksen, T. M.; Christensen, N. L.; [and others], technical coordinators. Fire regimes and ecosystem properties: Proceedings of the conference; 1978 December 11-15; Honolulu, HI. Gen. Tech. Rep. WO-26. Washington, DC: U.S. Department of Agriculture, Forest Service: 90-111. 
84. 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. 
85. Kufeld, Roland C.; Wallmo, O. C.; Feddema, Charles. 1973. Foods of the Rocky Mountain mule deer. Res. Pap. RM-111. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Forest and Range Experiment Station. 31 p. 
86. Lacey, John; Mosley, John. 2002. 250 plants for range contests in Montana. MONTGUIDE MT198402 AG 6/2002. Range E-2 (Misc.). Bozeman, MT: Montana State University, Extension Service. 4 p. 
87. Laven, R. D.; Omi, P. N.; Wyant, J. G.; Pinkerton, A. S. 1980. Interpretation of fire scar data from a ponderosa pine ecosystem in the central Rocky Mountains, Colorado. In: Stokes, Marvin A.; Dieterich, John H., technical coordinators. Proceedings of the fire history workshop; 1980 October 20-24; Tucson, AZ. Gen. Tech. Rep. RM-81. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Forest and Range Experiment Station: 46-49. 
88. Lawrence, Donna L.; Romo, J. T. 1995. Tree and shrub communities of wooded draws near the Matador Research Station in southern Saskatchewan. The Canadian Field Naturalist. 108(4): 397-412. 
89. Li, Xiaojie; Baskin, Jerry M.; Baskin, Carol C. 1999. Physiological dormancy and germination requirements of seeds of several North American Rhus species (Anacardiaceae). Seed Science Research. 9(3): 237-245. 
90. Li, Xiaojie; Baskin, Jerry M.; Baskin, Carol C. 1999. Seed morphology and physical dormancy of several North American Rhus species (Anacardiaceae). Seed Science Research. 9: 247-258. 
91. Magruder, T. L. 1985. Wind Cave's riparian habitats. South Dakota Conservation Digest. 52(3): 20-23. 
92. 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. 
93. Manning, Mary E.; Padgett, Wayne G. 1995. Riparian community type classification for Humboldt and Toiyabe National Forests, Nevada and eastern California. R4-Ecol-95-01. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Region. 306 p. 
94. Martin, Peter Raymond. 1973. Ecology of skunkbush sumac (Rhus trilobata Nutt.) in Montana with special reference to use by mule deer. Bozeman, MT: Montana State University. 97 p. Thesis. 
95. McCulloch, Clay Y. 1973. Part I: Seasonal diets of mule and white-tailed deer. In: Deer nutrition in Arizona chaparral and desert habitats. Special Report No. 3. Phoenix, AZ: Arizona Game and Fish Department, Research Division: 1-37. In cooperation with: U.S. Department of Agriculture, Forest Service, Rocky Mountain Forest and Range Experiment Station. 
96. McPherson, Guy R. 1995. The role of fire in the desert grasslands. In: McClaran, Mitchel P.; Van Devender, Thomas R., eds. The desert grassland. Tucson, AZ: The University of Arizona Press: 130-151. 
97. 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. 
98. Minckley, W. L.; Clark, Thomas O. 1981. Vegetation of the Gila River Resource Area, eastern Arizona. Desert Plants. 3(3): 124-140. 
99. Minnich, Richard A.; Franco-Vizcaino, Ernesto. 1997. Protecting vegetation and fire regimes in the Sierra San Pedro Martir of Baja California. Fremontia. 25(3): 13-21. 
100. Mohgoub, Elfatih Eltagi. 1984. Seasonal food habits of mule deer in the foothills of the Sacramento Mountains, New Mexico. Las Cruces, NM: New Mexico State University. 89 p. Dissertation. 
101. Moir, William H. 1969. Steppe communities in the foothills of the Colorado Front Range and their relative productivities. The American Midland Naturalist. 81(2): 331-340. 
102. Moir, William H. 1982. A fire history of the High Chisos, Big Bend National Park, Texas. The Southwestern Naturalist. 27(1): 87-98. 
103. Monsen, Stephen B. 1984. Use of shrubs on mine spoils. In: Murphy, P. M., compiler. The challenge of producing native plants for the Intermountain area: Proceedings: Intermountain Nurseryman's Association 1983 conference; 1983 August 8-11; Las Vegas, NV. Gen. Tech. Rep. INT-168. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Forest and Range Experiment Station: 26-31. 
104. Mower, Kerry J.; Smith, H. Duane. 1989. Diet similarity between elk and deer in Utah. The Great Basin Naturalist. 49(4): 552-555. 
105. Mozingo, Hugh N. 1987. Shrubs of the Great Basin: A natural history. Reno, NV: University of Nevada Press. 342 p. 
106. National Academy of Sciences. 1971. Atlas of nutritional data on United States and Canadian feeds. Washington, DC: National Academy of Sciences. 772 p. 
107. Noste, Nonan V.; Bushey, Charles L. 1987. Fire response of shrubs of dry forest habitat types in Montana and Idaho. Gen. Tech. Rep. INT-239. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Research Station. 22 p. 
108. Pase, Charles P. 1971. Effect of a February burn on Lehmann lovegrass. Journal of Range Management. 24: 454-456. 
109. 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. 
110. Pendleton, Rosemary L.; Pendleton, Burton K.; Harper, Kimball T. 1989. Breeding systems of woody plant species in Utah. In: Wallace, Arthur; McArthur, E. Durant; Haferkamp, Marshall R., compilers. Proceedings--symposium on shrub ecophysiology and biotechnology; 1987 June 30 - July 2; Logan, UT. Gen. Tech. Rep. INT-256. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Research Station: 5-22. 
111. Peters, Erin F.; Bunting, Stephen C. 1994. Fire conditions pre- and postoccurrence of annual grasses on the Snake River Plain. In: Monsen, Stephen B.; Kitchen, Stanley G., compilers. Proceedings--ecology and management of annual rangelands; 1992 May 18-22; Boise, ID. Gen. Tech. Rep. INT-GTR-313. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Research Station: 31-36. 
112. Peterson, Dennis. 1977. The effects of Rhus trilobata on poison ivy rash. Quarterly Journal of Crude Drug Research. 15(3): 135-138. 
113. Pieper, Rex D.; Wood, M. Karl; Buchanan, Bruce B. 1988. Ecology of pinyon-juniper vegetation in New Mexico. In: Fisher, James T.; Mexal, John G.; Pieper, Rex D., technical coordinators. Pinyon-juniper woodlands of New Mexico: a biological and economic appraisal. Special Report 73. Las Cruces, NM: New Mexico State University, College of Agriculture and Home Economics: 1-11. 
114. Pond, Floyd W.; Cable, Dwight R. 1960. Effect of heat treatment on sprout production of some shrubs of the chaparral in central Arizona. Journal of Range Management. 13: 313-317. 
115. Powell, A. Michael. 1988. Trees & shrubs of Trans-Pecos Texas including Big Bend and Guadalupe Mountains National Parks. Big Bend National Park, TX: Big Bend Natural History Association. 536 p. 
116. Quarterman, Elsie; Burbanck, Madeline P.; Shure, Donald J. 1993. Rock outcrop communities: limestone, sandstone, and granite. In: Martin, William H.; Boyce, Stephen G.; Echternacht, Arthur C., eds. Biodiversity of the southeastern United States: Upland terrestrial communities. New York: John Wiley & Sons, Inc: 35-86. 
117. Quinnild, Clayton L.; Cosby, Hugh E. 1958. Relicts of climax vegetation on two mesas in western North Dakota. Ecology. 39(1): 29-32. 
118. Raunkiaer, C. 1934. The life forms of plants and statistical plant geography. Oxford: Clarendon Press. 632 p. 
119. Riegel, Andrew. 1942. Some observations of the food coactions of rabbits in western Kansas during periods of stress. Transactions, Kansas Academy of Science. 45: 369-373. 
120. Ross, Robert L.; Hunter, Harold E. 1976. Climax vegetation of Montana: Based on soils and climate. Bozeman, MT: U.S. Department of Agriculture, Soil Conservation Service. 64 p. 
121. Roughton, Robert D. 1972. Shrub age structures on a mule deer winter range in Colorado. Ecology. 53(4): 615-625; 1972. 
122. Rowe, J. S. 1969. Lightning fires in Saskatchewan grassland. Canadian Field-Naturalist. 83: 317-324. 
123. Sanford, Richard Charles. 1970. Skunk bush (Rhus trilobata Nutt.) in the North Dakota Badlands: ecology, phytosociology, browse production, and utilization. Fargo, ND: North Dakota State University. 165 p. Dissertation. 
124. 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. 
125. Savage, D. A.; Heller V. G. 1947. Nutritional qualities of range forage plants in relation to grazing with beef cattle on the Southern Plains Experimental Range. Tech. Bull. No. 943. Washington, DC: U.S. Department of Agriculture. 61 p. 
126. Schallenberger, Allen Dee. 1966. Food habits, range use and interspecific relationships of bighorn sheep in the Sun River area, west-central Montana. Bozeman, MT: Montana State University. 44 p. Thesis. 
127. Schultz, Brad W. 1987. Ecology of curlleaf mountain mahogany (Cercocarpus ledifolius) in western and central Nevada: population structure and dynamics. Reno, NV: University of Nevada. 111 p. Thesis. 
128. Seklecki, Mariette T.; Grissino-Mayer, Henri D.; Swetnam, Thomas W. 1996. Fire history and the possible role of Apache-set fires in the Chiricahua Mountains of southeastern Arizona. In: Ffolliott, Peter F.; DeBano, Leonard F.; Baker, Malchus, B., Jr.; [and others], tech. coords. Effects of fire on Madrean Province ecosystems: a symposium proceedings; 1996 March 11-15; Tucson, AZ. Gen. Tech. Rep. RM-GTR-289. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Forest and Range Experiment Station: 238-246. 
129. Shiflet, Thomas N., ed. 1994. Rangeland cover types of the United States. Denver, CO: Society for Range Management. 152 p. 
130. Slayback, Robert D.; Clary, Raymond F., Jr. 1988. Vegetative solutions to erosion control in the Tahoe Basin. In: Rieger, John P.; Williams, Bradford K., eds. Proceedings of the second native plant revegetation symposium; 1987 April 15-18; San Diego, CA. Madison, WI: University of Wisconsin - Arboretum; Society of Ecological Restoration & Management: 66-69. 
131. 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. 
132. Steinauer, Gerald A. 1981. A classification of the Cercocarpus montanus, Quercus macrocarpa, Populus deltoides, and Picea glauca habitat types of the Black Hills National Forest. Vermillion, SD: University of South Dakota. 95 p. Thesis. 
133. 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. 
134. Stiles, Edmund W. 1980. Patterns of fruit presentation and seed dispersal in bird-disseminated woody plants in the eastern deciduous forest. The American Naturalist. 116(5): 670-688. 
135. Stubbendieck, James; Nichols, James T.; Butterfield, Charles H. 1989. Nebraska range and pasture forbs and shrubs (including succulent plants). Extension Circular 89-118. Lincoln, NE: University of Nebraska, Nebraska Cooperative Extension. 153 p. 
136. 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. 
137. Swank, Wendell G. 1958. The mule deer in Arizona chaparral. Wildlife Bulletin No. 3. Phoenix, AZ: State of Arizona, Game and Fish Department. 109 p. 
138. Swenson, Jon E. 1985. Seasonal habitat use by sharp-tailed grouse, Tympanuchus phasianellus, on mixed-grass prairie in Montana. Canadian Field-Naturalist. 99(1): 40-46. 
139. Swenson, W.S. 1957. Squawbush in windbreaks in eastern Colorado. Journal of Soil and Water Conservation. 12: 184-185. 
140. 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. 
141. Tande, Gerald F. 1979. Fire history and vegetation pattern of coniferous forests in Jasper National Park, Alberta. Canadian Journal of Botany. 57: 1912-1931. 
142. Tweit, Susan J.; Houston, Kent E. 1980. Grassland and shrubland habitat types of the Shoshone National Forest. Cody, WY: U.S. Department of Agriculture, Forest Service, Region 2, Shoshone National Forest. 143 p. 
143. U.S. Department of Agriculture, Forest Service, Intermountain Forest and Range Experiment Station. 1976. Some important native shrubs of the West. Ogden, UT. 16 p. On file with: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory, Missoula, MT. 
144. U.S. Department of Agriculture, Forest Service. 1937. Range plant handbook. Washington, DC. 532 p. 
145. U.S. Department of Agriculture, National Resource Conservation Service. 2005. PLANTS database (2004), [Online]. Available: http://plants.usda.gov/. 
146. U.S. Department of Agriculture, Natural Resources Conservation Service, Tucson Plant Materials Center. 2001. Commercial sources of conservation plant materials, [Online]. Available: http://plant-materials.nrcs.usda.gov/pubs/azpmsarseedlist0501.pdf [2003, August 25]. 
147. Vincent, Dwain W. 1992. The sagebrush/grasslands of the upper Rio Puerco area, New Mexico. Rangelands. 14(5): 268-271. 
148. Vogl, Richard J.; Schorr, Paul K. 1972. Fire and manzanita chaparral in the San Jacinto Mountains, California. Ecology. 53(6): 1179-1188. 
149. Wade, Dale D.; Brock, Brent L.; Brose, Patrick H.; [and others]. 2000. Fire in eastern 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: 53-96. 
150. Wasser, Clinton H. 1982. Ecology and culture of selected species useful in revegetating disturbed lands in the West. FWS/OBS-82/56. Washington, DC: U.S. Department of the Interior, Fish and Wildlife Service. 347 p. 
151. Weber, G. P.; Wiesner, L. E.; Lund, R. E. 1982. Improving germination of skunkbush sumac and serviceberry seed. Journal of Seed Technology. 7(1): 60-71. 
152. Weber, William A. 1987. Colorado flora: western slope. Boulder, CO: Colorado Associated University Press. 530 p. 
153. 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. 
154. Whisenant, Steven G. 1990. Postfire population dynamics of Bromus japonicus. The American Midland Naturalist. 123: 301-308. 
155. Wiggins, Ira L. 1980. Flora of Baja California. Stanford, CA: Stanford University Press. 1025 p. 
156. Wright, Henry A.; Bailey, Arthur W. 1982. Fire ecology: United States and southern Canada. New York: John Wiley & Sons. 501 p. 
157. Young, James A.; Evans, Raymond A. 1981. Demography and fire history of a western juniper stand. Journal of Range Management. 34(6): 501-505. 
158. Zacek, Joseph C.; Hunter, Harold E.; Bown, T. A.; Ross, Robert L. 1977. Montana grazing guides. [Washington, DC]: U.S. Department of Agriculture, Soil Conservation Service. 12 p. On file with: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory, Missoula, MT.