Index of Species Information

SPECIES:  Parkinsonia microphylla


AUTHORSHIP AND CITATION : Pavek, Diane S. 1994. Parkinsonia microphylla. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available: []. ABBREVIATION : PARMIC SYNONYMS : Cercidium microphyllum (Torr.) Rose & Johnston (Fabaceae) [31,100,106] SCS PLANT CODE : PAMI5 COMMON NAMES : yellow paloverde little-leaf paloverde foothill paloverde TAXONOMY : The currently accepted scientific name of yellow paloverde is Parkinsonia microphylla Torr. [26,52,80,88,107]. Yellow paloverde occasionally forms hybrids throughout its range with blue paloverde (P. floridum) [52]. In Mexico, yellow paloverde hybridizes with P. praecox to form Sonoran paloverde (P. x sonorae) [43,93]. LIFE FORM : Shrub, tree FEDERAL LEGAL STATUS : No special status OTHER STATUS : NO-ENTRY


SPECIES: Parkinsonia microphylla
GENERAL DISTRIBUTION : Yellow paloverde is distributed through central and southwestern Arizona [16,31,43,88].  A few populations occur in southeastern California near the Colorado River in the Whipple Mountains [3,10,26].  The range of yellow paloverde extends southward through Sonora and Baja California, Mexico [37,38,65,78,80,100]. ECOSYSTEMS :    FRES30  Desert shrub    FRES40  Desert grasslands STATES :      AZ  CA  MEXICO BLM PHYSIOGRAPHIC REGIONS :     7  Lower Basin and Range KUCHLER PLANT ASSOCIATIONS :    K041  Creosotebush    K042  Creosotebush - bursage    K043  Paloverde - cactus shrub SAF COVER TYPES :    242  Mesquite SRM (RANGELAND) COVER TYPES : NO-ENTRY HABITAT TYPES AND PLANT COMMUNITIES : Yellow paloverde is an indicator species of the Sonoran Desert floristic region [50].  It is a dominant species in the Arizona upland subdivision of the Sonoran Desert [9,41,43,93].  Codominant species include creosotebush (Larrea tridentata), triangle bursage (Ambrosia deltoidea), brittle brush (Encelia farinosa), ocotillo (Fouqueria splendens), and Berlandier wolfberry (Lycium belandieri) [9].  This assemblage is also called the paloverde, bursage (Ambrosia spp.) desert scrub community type.  It grades into spinose suffrutescent desert scrub [54]. A major climax association found on bajadas and rocky slopes throughout the Sonoran Desert is the paloverde/saguaro (Carnegiea gigantea) association [5,9,42,89,102].  This association grades into adjacent semidesert grasslands and interior chaparral [53,54]. Yellow paloverde is the principal species in the paloverde series [51,61].  This is also called the paloverde-cacti-mixed scrub series and paloverde woodland and succulents association [93,103]. Yellow paloverde is a facultative riparian species.  It may move into riparian areas from surrounding desert and upland positions [1,74,83]. Where precipitation is less than 3 inches (7.6 cm) per year, yellow paloverde is confined to washes and is an obligate riparian species [2]. Yellow paloverde is listed as a dominant or indicator species in the following publications: (1)  A series vegetation classification for Region 3 [51] (2)  A vegetation classification system applied to southern California        [61] (3)  Vegetation of the Santa Catalina Mountains, Arizona: a gradient        analysis of the south slope [99]. Species associated with yellow paloverde but not previously mentioned in DISTRIBUTION AND OCCURRENCE include white burrobrush (Hymenoclea salsola), white ratany (Krameria grayi), organpipe cactus (Lemaireocereus schottii), MacDougal ocotillo (Fouqueria macdougalii), and heart leatherstem (Jatropha cordata) [25,78,97].


SPECIES: Parkinsonia microphylla
WOOD PRODUCTS VALUE : The wood of yellow paloverde is hard and heavy [37]. IMPORTANCE TO LIVESTOCK AND WILDLIFE : Yellow paloverde has limited value as browse for livestock [3,28,87]. Bighorn sheep, mule deer, and feral burros browse yellow paloverde [25,34,63,75,76].  It is important browse for jackrabbits, heteromyid rodents, and other small mammals [16,25,67,96].  Collared peccary consume yellow paloverde fruits from July to September [15].  Yellow paloverde was used significantly (P<0.01) more than other plant species for foraging by birds [58]. Small mammals such as desert shrews and mice use the habitats where yellow paloverde occurs [86]. PALATABILITY : NO-ENTRY NUTRITIONAL VALUE : Several studies have sampled yellow paloverde bimonthly for 1 year.  Its leaves, flowers, and new growth had from 30 to 60 percent dry matter and from 6 to 16 percent crude protein [34,63,76].  Yellow paloverde has large seeds that weigh an average of 0.005 ounce (0.147 g) and contain 733.3 calories per seed [68]. COVER VALUE : Yellow paloverde that are taller than 6.6 feet (2 m) are used for nesting [89].  Verdin and black-tailed gnatcatchers nest in yellow paloverde [58].  Gambel's quail use them for roosts [23].  Yellow paloverde snags are important wildlife habitat because snags occur infrequently in the Sonoran Desert.  In Arizona, nine bird species used one yellow paloverde snag daily [32]. White-throated woodrats use yellow paloverde for shelter or nests [57]. VALUE FOR REHABILITATION OF DISTURBED SITES : Yellow paloverde was used in the revegetation of an open pit copper mine in Arizona.  Yellow paloverde survived significantly (P<0.05) better on the east slope (27 plants/244 sq m) than on the north slope (1 plant/244 sq m) [56]. OTHER USES AND VALUES : Yellow paloverde seeds were ground and used for food by Pima and other Native Americans [37,66]. Yellow paloverde is planted as an ornamental [37]. OTHER MANAGEMENT CONSIDERATIONS : Dimensional analyses that relate fresh biomass to stem diameter and dry matter content are available for yellow paloverde [18]. Yellow paloverde was evaluated as a potential energy-producing crop. During 2 years of sampling, the stems, leaves, and fruits of yellow paloverde yielded moderate amounts of oil and crude protein.  It was not considered a promising species for exploitation [11]. Yellow paloverde spread from residential plantings into surrounding wildlands in Death Valley National Monument, California.  Yellow paloverde does not occur there naturally, and mechanical and herbicide control methods have been proposed to eradicate it [40]. Yellow paloverde and other desert scrub species invade desert grasslands following disturbances such as grazing [40,98]. Yellow paloverde up to 3 inches (7.6 cm) tall may be seriously injured or killed by jackrabbit browsing.  Larger trees are browsed to the extent that a jackrabbit can reach, about 3 feet (1 m) [96]. Yellow paloverde is an alternate host for seed-predating bruchid beetles (Mimosestes spp.).  Yellow paloverde responses are probably similar to those of the beetles' primary host, mesquite (Prosopis spp.), with reduced yields of viable seeds [33]. Yellow paloverde and community associates typical of the Arizona upland subdivision of the Sonoran Desert occur in very few places in southeastern California.  This is a community type with one of the highest priorities in California for rare plant inventories [27]. Yellow paloverde provides canopy cover that reduces maximum soil surface temperatures.  This is important for the establishment of other desert species [20,78].  Yellow paloverde is the primary nurse plant for saguaro [14,30,43,55,84].


SPECIES: Parkinsonia microphylla
GENERAL BOTANICAL CHARACTERISTICS : Yellow paloverde is a native, monoecious, spiny shrub or small tree that may grow to 26 feet (8 m) tall [3,37,52,88].  The trunk may be 1 foot (0.3 m) in diameter; it branches about 8 inches (20 cm) from the ground into four to six major stems [57].  The crown spreads 12 to 18 feet (3.7-5.5 m) [32].  The bark is thin and photosynthetic [91].  Yellow paloverde has numerous flowers in 1 inch (2.5 cm) long clusters [16,37]. It has pinnately compound leaves about 1 inch (2.5 cm) long with minute leaflets and is drought-deciduous [37,100].  Fruits are 2 to 3 inches (4-8 cm) long and have one to five seeds with constrictions between the seeds [16,37,80]. Yellow paloverde lives longer than 72 years [22]. Yellow paloverde is susceptible to freezing [90]. RAUNKIAER LIFE FORM :       Phanerophyte REGENERATION PROCESSES : Yellow paloverde reproduces sexually and asexually.  Yellow paloverde has fair to poor ability to produce sprouts after top removal [11]. Photoperiod initiates fruit and flower production of yellow paloverde. Subsequent local weather conditions determine whether flowering or seed set occurs [91].  A seed crop is produced when the spring is wet or very cool [105]. Yellow paloverde is insect pollinated [44,82]. McAuliffe [47] stated that yellow paloverde pods rapidly abscise as a mechanism to avoid seed predation by bruchid beetles.  The constricted fruits of yellow paloverde do not open before dispersing [37]. Seeds germinate during a rainy season after 1 year in the soil. Seedlings are very susceptible to drought during the first 2 to 3 months following germination.  During a 9-year study in Arizona, 1.6 percent of all seedlings that germinated survived [105]. Recruitment of yellow paloverde is very slow.  Additions as low as two individuals over 30 years or longer have been recorded [22,79]. Herbivory limits yellow paloverde distribution [45].  Bruchid beetles are seed predators of yellow paloverde [47].  Heteromyid rodents rapidly cache yellow paloverde seeds.  The cached seeds occasionally germinate [47,95]. Initial distributions of yellow paloverde seedlings are random. However, after 1 year, a greater proportion of seedlings in open spaces were consumed by rabbits and hares than seedlings beneath triangle bursage.  Recruitment patterns of yellow paloverde show significantly (P<0.001) positive associations with mature triangle bursage and white bursage (Ambrosia dumosa) [45,46].  Because yellow paloverde outlives triangle bursage, large mature yellow paloverde have no association with triangle bursage [46]. Unpredictable water availability causes low, erratic seedling establishment [12].  Mature yellow paloverde maintain deep root contact with wet soil [73,105].  Yellow paloverde self prunes; large branches die during drought [3,105].  Young plants usually survive drought once they drop branches which occurs at variable ages [77,105].  Death of mature yellow paloverde due to drought and subsequent desiccation is uncommon [45,77,92].  Based on water requirement trials, the water-use efficiency of yellow paloverde approaches that of perennial grasses [48]. SITE CHARACTERISTICS : Yellow paloverde occurs in arid to semiarid climates with mild winters and hot summers; precipitation is bimodal, occurring in summer and fall [15,54]. Yellow paloverde is found on lower mountain slopes and alluvial outwash plains [54,97].  In the most arid parts of its range, yellow paloverde occasionally occurs in small washes or arroyos [24,59,64,91,97]. Yellow paloverde occurs from 1,000 to 4,000 feet (305-1,219 m) in elevation throughout its range [19,23,54,97,99].  It grows on very gradual to steep slopes that may face south or north, but it has been reported on all aspects [19,24,28,36,60,101]. The sites on which yellow paloverde occurs are well-drained [28]. Surface soils may be 1.6 to 2.8 inches (4-7 cm) thick and subsoils may be 20 inches (50 cm) thick over caliche [91,101].  The soil temperature regime is thermic (that is, average soil temperatures are between 59 and 72 degrees Fahrenheit [15-22 deg C]) [51].  Soil textures range from sand to sandy loam to loam [24].  They may be underlain by clay loam and clays [23,89].  Parent materials may be basaltic, rhyolitic, granitic, mixed alluvium, and metamorphic [22,49,59,60,91]. The distribution of yellow paloverde is influenced by the continuum of soil textures that occurs from upper to lower bajada [5].  It is found primarily on the upper bajadas [6,7,93,97].  Coarse soil of the upper bajada has one-half the wilting coefficient (which is an estimate of plant stress) of the finer soil of the lower bajada [102].  Yellow paloverde grows infrequently on the middle and lower bajada [97]. SUCCESSIONAL STATUS : Facultative Seral Species Yellow paloverde is a climax species in the Sonoran Desert flora [51,54,61]. Successional sequences have not been completely identified for the desert scrub communities in which yellow paloverde occurs.  Dominants such as yellow paloverde are the first to reappear and replace themselves following disturbance [69]. SEASONAL DEVELOPMENT : Yellow paloverde may not flower every year, depending on adequate moisture availability.  It develops flowers from March to May [24,31,80,91,100].  Leaf production is erratic [24].  Yellow paloverde grows drought-deciduous leaves two or more times during the year following summer and winter rains [77,91].


SPECIES: Parkinsonia microphylla
FIRE ECOLOGY OR ADAPTATIONS : The thin-barked photosynthetic stems of yellow paloverde are killed by fire [13].  Yellow paloverde may sprout from the root crown following top-kill [39]. The temperatures of desert fires are variable due to fluctuations in kinds and quantities of available fuel [104].  Heavy grazing in some upland sites has eliminated the grass understory beneath paloverde species and saguaro.  Grass species were replaced with bursage, burroweed (Haplopappus tenuisectus), and snakeweed (Gutierrezia spp.). This has lowered the fire frequency because there is insufficient fuel to carry fires [70].  However, introduced annuals in other areas may have increased both the frequency and the severity of fire [71,72]. Fires in the Sonoran Desert are generally infrequent and are low severity due to low fuel loads [49].  However, fires can be relatively common in the Sonoran Desert under appropriate conditions, especially during the summer [39].  Two consecutive wet winters are probably needed to develop fuel loads adequate to sustain fire.  Fire is frequent in desert grasslands on the eastern edge of the Sonoran Desert [49]. The Sonoran savanna grasslands are subtropical, fire-climax grasslands. Most of these communities were destroyed through grazing and other land management practices by the 1940's.  Yellow paloverde grows in remnants of these communities at their northern limits [8]. POSTFIRE REGENERATION STRATEGY :    Tree with adventitious-bud root crown/soboliferous species root sucker    Tall shrub, adventitious-bud root crown    Secondary colonizer - off-site seed FIRE REGIMES : Find fire regime information for the plant communities in which this species may occur by entering the species name in the FEIS home page under "Find Fire Regimes".


SPECIES: Parkinsonia microphylla
IMMEDIATE FIRE EFFECT ON PLANT : Although entire yellow paloverde trees are rarely consumed during a fire, they are top-killed or killed.  Surviving yellow paloverde rootstocks sprout following fire.  Sprouting plants are susceptible to death from repeated fires [39]. A fire on a southern Arizona rangeland during the 1900's burned for 2 days and killed paloverde species.  Postfire recovery of the vegetation was not mentioned in the article [29]. PLANT RESPONSE TO FIRE : During May 1981 in the Tonto National Forest, Arizona, the prefire mean density of yellow paloverde was 30 plants per acre (75 plants/ha). Following a controlled fire of moderate severity during June 1981, yellow paloverde mean density was 24.8 plants per acre (62 plants/ha). Heat-damaged plants subsequently died.  Nine months after the fire, yellow paloverde mean density was 17.2 plants per acre (43 plants/ha) [13]. Yellow paloverde was completely eliminated by fire at one site on the Tonto National Forest, Arizona [13]. Yellow paloverde may require 20 years to return to prefire plant densities and community species composition following fires in paloverde-saguaro communities [13,39,72]. Wildfire during June 1979 in Arizona top-killed 83 percent of yellow paloverde present.  Twenty-five percent of top-killed plants sprouted about 2 years following the fire.  There was 63 percent mortality for yellow paloverde after about 3 years [49]. Fire burned during June 1974 in two desert scrub communities of south-central Arizona.  Before the fires, yellow paloverde had not sprouted; no seedlings were present on one site (Dead Man Wash Site), and five seedlings were present at the other site (Saguaro Site). Prefire data concerning yellow paloverde were not given.  Fire killed 78 percent of the photosynthetic tissue on the Dead Man Wash Site and 92 percent on the Saguaro Site.  For both sites, approximately 10 percent of the yellow paloverde present after fire were not top-killed; approximately 14 percent were top-killed and sprouted.  Five seedlings were found on the Saguaro Site in postfire year 1 [71,72]. Yellow paloverde occurred in two different communities that were prescribed burned during different years, one in 1983 and the other in 1985.  Control and prefire communities were similar in composition.  No information specific to yellow paloverde was given.  The fires consumed 70 percent of the perennial vegetation.  Plants were two-thirds less dense immediately after than before the fire.  In 1986, plant densities were still below prefire levels [39]. Yellow paloverde was codominant with triange bursage and buckhorn cholla (Opuntia acanthocarpa) on rocky slopes on the Tonto National Forest.  A prescribed fire during June 1985 burned 9.9 acres (4 ha).  The fire burned vigorously in washes and on lower slopes.  But fire decreased on the upper slopes due to a lack of fuel between the shrubs; vegetation patches were ignited with flares.  The spotty burning reduced shrub cover by 49 percent.  No specific effects on yellow paloverde response to fire were given in the article [81]. The Research Project Summary Ibarra-F and others 1996 provides information on mortality of yellow paloverde after prescribed fires in buffelgrass (Pennisetum ciliare) pastures in Sonora, Mexico. FIRE MANAGEMENT CONSIDERATIONS : Introduced annuals in desert habitats may create sufficient fuel to increase fire frequency and severity [71].  Native annuals probably provided less fuel [39,71]. In the soils on which yellow paloverde occurs, nutrients are quickly translocated following fire.  Two years after fire, soil nitrogen levels can drop below prefire levels [13,101].


SPECIES: Parkinsonia microphylla
FIRE CASE STUDY CITATION : Pavek, Diane S. 1994. Effects of prescribed fire on yellow paloverde on the Tonto National Forest, Arizona. In: Parkinsonia microphylla. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available: []. REFERENCE : Cave, George Harold, III. 1982. Ecological effects of fire in the upper Sonoran Desert. Tempe, AZ: Arizona State University. 124 p. Thesis. [13]. SEASON/SEVERITY CLASSIFICATION : summer fire/low-severity STUDY LOCATION : The study was located in Bulldog Canyon on the Tonto National Forest, Arizona, at 33 degrees 15 minutes north latitude and 111 degrees 22 minutes west longitude. PREFIRE VEGETATIVE COMMUNITY : A yellow paloverde-saguaro (Parkinsonia microphylla-Carnegiea gigantea) community covered Bulldog Canyon.  Standing dead biomass was assessed in April before the fire.  Three microhabitats were evaluated:  (1) open shrubless interspaces which covered 70 percent of the ground, (2) yellow paloverde covered 8 percent, and (3) triangle bursage (Ambrosia deltoidea) covered 15 percent. Total perennial plant cover was measured prefire in April and immediately postfire in June.  Twenty-three 12x26 feet (4x8 m) random quadrats were located along parallel transects systematically placed every 32.8 feet (10 m) throughout the study area.  Prefire mean total perennial plant cover was 30.7 with a standard error of 3.4 percent. TARGET SPECIES PHENOLOGICAL STATE : Phenological stages of the plants were not specifically mentioned.  At the time of burning in June, yellow paloverde would be past flowering, and fruits would be developing. SITE DESCRIPTION : The study site was located in a desert canyon at 1,477 feet (450 m) elevation.  Spring months are dry and warm in this semiarid climate.  No appreciable precipitation was reported from the April prefire assessments to the June prescribed fire.  No information was given on specific topography, slope, or soils. FIRE DESCRIPTION : Plots were placed to assess prefire surface fuels such as dead litter and annual plants.  Twenty 7.9x7.9 inch (20x20 cm) plots were randomly located in both the open and the triangle bursage microhabitats. Thirty-two similar plots were located under eight yellow paloverde, one at each of the four cardinal directions.  Average fuels are given in the following table:          microhabitat                   mean (standard error)g/sq m         open                                     69.9 ( 7.5)         triangle bursage                        143.3 (32.6)         yellow paloverde                        319.4 (56.5) The fire burned 12 June 1981.  Air temperatures ranged from 104 degrees Fahrenheit (40 deg C) in the shade to 132.8 degrees Fahrenheit (50 deg C) at 0.39 inch (1 cm) above an unshaded soil surface.  The relative humidity remained at 29 percent during the fire.  Mean air movement during the fire was low at 0.003 foot per second (0.001 m/sec) with gusts up to 9 feet per second (2.75 m/sec).  Mean soil moisture in the top 2 inches (5 cm) of soil was 0.61 and 0.80 percent for open and shaded areas, respectively, with standard errors less than 0.1 percent. Maximum temperatures for each microhabitat were estimated with temperature sensitive pellets placed 0.39 and 0.78 inch (1 and 2 cm) below the soil surface and 0.39 and 11.8 inches (1 and 30 cm) above the soil surface.  Additional measurements were made with thermocouples at 0.39 inch (1 cm) below soil surface, at the soil surface, and 11.8 inches (30 cm) above the soil surface in the three microhabitats. Temperatures were lowest in open microhabitats and highest in triangle bursage areas (see table below).  Temperatures beneath yellow paloverde were intermediate.  Fire had little influence on soil temperatures at 0.39 and 0.79 inch (1 and 2 cm) below the soil surface.  Temperatures at 0.39 inch (1 cm) above the soil surface burned the hottest. Temperatures 0.39 inch (1 cm) above soil surface were significantly (P<0.05) higher from temperatures 0.79 inch (2 cm) below the soil surface for yellow paloverde and triangle bursage microhabitats.                         mean maximum temperatures (deg C) during fire*                                 (standard error in parentheses) vertical                                 microhabitat location (cm)            open    yellow paloverde    triangle bursage    30                  76(76)ax     167(33)abx         210(54)abx     1                  88(51)ax     299(17) bxy        405(16) b y   - 1                  61( 5) x      63( 7)  x          90( 9)  x   - 2                  60( 0)ax      57( 2)a x          60( 2)a x *Means not significantly different (P<0.05) within each vertical location   are indicated by the same letter (a,b) and within microhabitats (x,y). As fire moved through yellow paloverde microhabitats, it burned lightly leaving some litter and duff unburned.  Additionally, the thick litter and duff beneath yellow paloverde insulated the soil from the fire. The increase in soil surface albedo after the fire was not significant (P=0.08).  A small increase in water repellency was not expected to create erosion or runoff problems. FIRE EFFECTS ON TARGET SPECIES : No fire effects information specific to yellow paloverde was given. Fires were low severity and did not consume all litter and duff below yellow paloverde.  However, yellow paloverde has thin bark and photosynthetic trunks that make it susceptible to top-kill by fire. FIRE MANAGEMENT IMPLICATIONS : Desert fire temperatures are variable due to interactions of microhabitats and fuel.  This prescribed fire did not alter physical site characteristics such as albedo, soil water repellency, and long-term microsite temperatures.  Perennial plant cover was significantly (P=0.001) reduced which may lead to soil erosion.  Yellow paloverde is very susceptible to fire, but no mortality data were given.


SPECIES: Parkinsonia microphylla
REFERENCES : 1.  Asplund, Kenneth K.; Gooch, Michael T. 1988. Geomorphology and the        distributional ecology of Fremont cottonwood (Populus fremontii) in a        desert riparian canyon. Desert Plants. 9(1): 17-27.  [563] 2.  Bennett, Peter S.; Kunzmann, Michael R.; Johnson, R. Roy. 1989. Relative        nature of wetlands: riparian and vegetational considerations. In: Abell,        Dana L., technical coordinator. Protection, management, and restoration        for the 1990's: Proceedings of the California riparian systems        conference; 1988 September 22-24; Davis, CA. Gen. Tech. Rep. PSW-110.        Berkeley, CA: U.S. Department of Agriculture, Forest Service, Pacific        Southwest Forest and Range Experiment Station: 140-142.  [13516] 3.  Benson, Lyman; Darrow, Robert A. 1981. The trees and shrubs of the        Southwestern deserts. Tucson, AZ: The University of Arizona Press.        [18066] 4.  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.        [434] 5.  Bowers, Michael A. 1988. Plant associations on a Sonoran Desert bajada:        geographical correlates and evolutionary source pools. Vegetatio. 74:        107-112.  [4408] 6.  Bowers, Michael A.; Lowe, Charles H. 1986. Plant-form gradients on        Sonoran Desert bajadas. Oikos. 46: 284-291.  [10864] 7.  Brooks, William H. 1978. Jojoba--a North American desert shrub; its        ecology, possible commercialization, & potential as an introd. into        other arid regions. Journal of Arid Environments. 1: 227-236.  [5162] 8.  Brown, David E. 1982. Sonoran savanna grassland. In: Brown, David E.,        ed.  Biotic communities of the American Southwest--United States and        Mexico. Desert Plants. 4(1-4): 137-141.  [8897] 9.  Burgess, Tony L.; Bowers, Janice E.; Turner, Raymond M. 1991. Exotic        plants at the Desert Laboratory, Tucson, Arizona. Madrono. 38(2):        96-114.  [15362] 10.  Burk, Jack H. 1977. Sonoran Desert. In: Barbour, M. G.; Major, J., eds.        Terrestrial vegetation of California. New York: John Wiley and Sons:        869-899.  [3731] 11.  Carr, Merle E.; Mason, Charles T., Jr.; Bagby, Marvin O. 1986. Renewable        resources from Arizona trees and shrubs. Forest Ecology and Management.        16: 155-167.  [3053] 12.  Castellanos, A. E.; Molina, F. E. 1990. Differential survivorship and        establishment in Simmondsia chinensis (jojoba). Journal of Arid        Environments. 19: 65-76.  [14982] 13.  Cave, George Harold, III. 1982. Ecological effects of fire in the upper        Sonoran Desert. Tempe, AZ: Arizona State University. 124 p. Thesis.        [12295] 14.  Ciesla, Bill. 1993. Cactus condo. American Forests. 99(5&6): 25-28, 58.        [20995] 15.  Eddy, Thomas A. 1961. Foods and feeding patterns of the collared peccary        in southern Arizona. Journal of Wildlife Management. 25: 248-257.        [9888] 16.  Elias, Thomas S. 1980. The complete trees of North America: field guide        and natural history. New York: Times Mirror Magazines, Inc. 948 p.        [21987] 17.  Eyre, F. H., ed. 1980. Forest cover types of the United States and        Canada. Washington, DC: Society of American Foresters. 148 p.  [905] 18.  Felker, Peter; Cannell, G. H.; Clark, Peter R.; [and others]. 1983.        Biomass production of Prosopis species (mesquite), Leucaena, and other        leguminous trees grown under heat/drought stress. Forest Science. 29(3):        592-606.  [4765] 19.  Fernandes, G. Wilson. 1992. A gradient analysis of plant forms from        northern Arizona. Journal of the Arizona-Nevada Academy of Science.        24-25: 21-30.  [18247] 20.  Franco, A. C.; Nobel, P. S. 1989. Effect of nurse plants on the        microhabit and growth of cacti. Journal of Ecology. 77: 870-886.  [9766] 21.  Garrison, George A.; Bjugstad, Ardell J.; Duncan, Don A.; [and others].        1977. Vegetation and environmental features of forest and range        ecosystems. Agric. Handb. 475. Washington, DC: U.S. Department of        Agriculture, Forest Service. 68 p.  [998] 22.  Goldberg, Deborah E.; Turner, Raymond M. 1986. Vegetation change and        plant demography in permanent plots in the Sonoran Desert. Ecology.        67(3): 695-712.  [4410] 23.  Goodwin, John G., Jr.; Hungerford, C. Roger. 1977. Habitat use by native        Gambel's and scaled quail and released masked bobwhite quail in southern        Arizona. Res. Pap. RM-197. Fort Collins, CO: U.S. Department of        Agriculture, Forest Service, Rocky Mountain Forest and Range Experiment        Station. 8 p.  [14970] 24.  Hanley, Thomas A.; Brady, Ward W. 1977. Seasonal fluctuations in        nutrient content of feral burro forages, lower Colorado River Valley,        Arizona. Journal of Range Management. 30(5): 370-375.  [4336] 25.  Hanley, Thomas A.; Brady, Ward W. 1977. Feral burro impact on a Sonoran        Desert range. Journal of Range Management. 30(5): 374-377.  [4337] 26.  Hastings, James R.; Turner, Raymond M.; Warren, Douglas K. 1972. An        atlas of some plant distributions in the Sonoran Desert. Technical        Reports on the Meteorology and Climatology of Arid Regions No. 21.        Tuscon, AZ: University of Arizona, Institute of Atmospheric Physics. 255        p.  [10534] 27.  Holland, Robert F. 1986. Preliminary descriptions of the terrestrial        natural communities of California. Sacramento, CA: California Department        of Fish and Game. 156 p.  [12756] 28.  Humphrey, R. R. 1950. Arizona range resources. II. Yavapai County. Bull.        229. Tucson, AZ: University of Arizona, Agricultural Experiment Station.        55 p.  [5088] 29.  Humphrey, Robert R. 1958. The desert grassland: A history of        vegetational change and an analysis of causes. Bull. 299. Tucson, AZ:        University of Arizona, Agricultural Experiment Station. 61 p.  [5270] 30.  Hutto, Richard L.; McAuliffe, Joseph R.; Hogan, Lynee. 1986.        Distributional associates of the saguaro (Carnegiea gigantea).        Southwestern Naturalist. 31(4): 469-476.  [1229] 31.  Kearney, Thomas H.; Peebles, Robert H.; Howell, John Thomas; McClintock,        Elizabeth. 1960. Arizona flora. 2d ed. Berkeley, CA: University of        California Press. 1085 p.  [6563] 32.  Kennedy, Charles E. 1983. A palo verde snag in the Sonora Desert. In:        Davis, Jerry W.; Goodwin, Gregory A.; Ockenfeis, Richard A., technical        coordinators. Snag habitat management: proceedings of the symposium;        1983 June 7-9; Flagstaff, AZ. Gen. Tech. Rep. RM-99. Fort Collins, CO:        U.S. Department of Agriculture, Forest Service, Rocky Mountain Forest        and Range Experiment Station: 165-166.  [17832] 33.  Kingsolver, J. M.; Johnson, C. D.; Swier, S. R.; Teran, A. 1977.        Prosopis fruits as a resource for invertebrates. In: Simpson, B. B., ed.        Mesquite: Its biology in two desert ecosystems. US/IBP Synthesis 4.        Stroudsburg, PA: Dowden, Hutchinson & Ross, Inc: 108-122.  [5193] 34.  Krausman, Paul R.; Ordway, Leonard L.; Whiting, Frank M.; Brown, William        H. 1990. Nutritional compostition of desert mule deer forage in the        Picacho Mountains, Arizona. Desert Plants. 10(1): 32-34.  [7259] 35.  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.  [1384] 36.  Leitner, Lawrence A. 1987. Plant communities of a large arroyo at Punta        Cirio, Sonora. Southwestern Naturalist. 32(1): 21-28.  [1439] 37.  Little, Elbert L., Jr. 1950. Southwestern trees: A guide to the native        species of New Mexico and Arizona. Agriculture Handbook No. 9.        Washington, DC: U.S. Department of Agriculture, Forest Service. 109 p.        [20330] 38.  Little, Elbert L., Jr. 1976. Atlas of United States trees. Volume 3.        Minor western hardwoods. Misc. Publ. 1314. Washington, DC: U.S.        Department of Agriculture, Forest Service. 13 p. 290 maps.  [10430] 39.  Loftin, Samuel Robert. 1987. Postfire dynamics of a Sonoran Desert        ecosystem. Tempe, AZ: Arizona State University. 97 p. Thesis.  [12296] 40.  Loope, Lloyd L.; Sanchez, Peter G.; Tarr, Peter W.; [and others]. 1988.        Biological invasions of arid land nature reserves. Biological        Conservation. 44: 95-118.  [3263] 41.  Lowe, Charles H., Jr. 1961. Biotic communities in the sub-Mogollon        region of the inland Southwest. Arizona Academy of Science Journal. 2:        40-49.  [20379] 42.  Lowe, Charles H.; Holm, Peter A. 1991. The amphibians and reptiles at        Saguaro National Monument, Arizona. Technical Report No. 37. Tucson, AZ:        University of Arizona, School of Renewable Natural Resources,        Cooperative National Park Resources Study Unit. 20 p.  [18335] 43.  MacMahon, James A. 1988. Warm deserts. In: Barbour, Michael G.;        Billings, William Dwight, eds. North American terrestrial vegetation.        Cambridge; New York: Cambridge University Press: 231-264.  [19547] 44.  McArthur, E. Durant. 1989. Breeding systems in shrubs. In: McKell, Cyrus        M., ed. The biology and utilization of shrubs. San Diego, CA: Academic        Press, Inc.: 341-361.  [8039] 45.  McAuliffe, Joseph R. 1986. Herbivore-limited establishment of a Sonoran        Desert tree, Cercidium microphyllum. Ecology. 67(1): 276-280.  [2756] 46.  McAuliffe, Joseph R. 1988. Markovian dynamics of simple and complex        desert plant communities. American Naturalist. 131(4): 459-490.  [6744] 47.  McAuliffe, Joseph R. 1990. Paloverdes, pocket mice, and bruchid beetles:        interrelationships of seeds, dispersers, and seed predators.        Southwestern Naturalist. 35(3): 329-337.  [14988] 48.  McGinnies, W. G.; Arnold, Joseph F. 1939. Relative water requirement of        Arizona range plants. Technical Bulletin No. 80. Tucson, AZ: University        of Arizona, Agricultural Experiment Station: 167-246.  [4441] 49.  McLaughlin, Steven P.; Bowers, Janice E. 1982. Effects of wildfire on a        Sonoran Desert plant community. Ecology. 63(1): 246-248.  [1619] 50.  Minckley, W. L.; Clark, Thomas O. 1981. Vegetation of the Gila River        Resource Area, eastern Arizona. Desert Plants. 3(3): 124-140.  [10863] 51.  Moir, W. H. 1983. A series vegetation classification for Region 3. 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: 91-95.  [1672] 52.  Munz, Philip A. 1974. A flora of southern California. Berkeley, CA:        University of California Press. 1086 p.  [4924] 53.  Nichol, A. A. [revisions by Phillips, W. S.]. 1952. The natural        vegetation of Arizona. Tech. Bull. 68 [revision]. Tucson, AZ: University        of Arizona, Agricultural Experiment Station: 189-230.  [3928] 54.  Niering, William A.; Lowe, Charles H. 1984. Vegetation of the Santa        Catalina Mountains: community types and dynamics. Vegetatio. 58: 3-28.        [12037] 55.  Niering, W. A.; Whittaker, R. H.; Lowe, C. H. 1963. The saguaro: a        population in relation to environment. Science. 142(3588): 15-23.        [5093] 56.  Norem, M. A.; Day, A. D.; Ludeke, K. L. 1982. An evaluation of shrub and        tree species used for revegetating copper mine wastes in the        south-western United States. Journal of Arid Environments. 5: 99-304.        [1776] 57.  Olsen, Ronald W. 1973. Shelter-site selection in the white-throated        woodrat, Neotoma albigula. Journal of Mammalogy. 54: 594-610.  [9886] 58.  Parker, Kathleen C. 1986. Partitioning of foraging space and nest sites        in a desert shrubland bird community. American Midland Naturalist.        115(2): 255-267.  [19258] 59.  Parker, Kathleen C. 1988. Environmental relationships and vegetation        associates of columnar cacti in the northern Sonoran Desert. Vegetatio.        78: 125-140.  [6953] 60.  Parker, Kathleen C. 1991. Topography, substrate, and vegetation patterns        in the northern Sonoran Desert. Journal of Biogeography. 18: 151-163.        [14979] 61.  Paysen, Timothy E.; Derby, Jeanine A.; Black, Hugh, Jr.; [and others].        1980. A vegetation classification system applied to southern California.        Gen. Tech. Rep. PSW-45. Berkeley, CA: U.S. Department of Agriculture,        Forest Service, Pacific Southwest Forest and Range Experiment Station.        33 p.  [1849] 62.  Raunkiaer, C. 1934. The life forms of plants and statistical plant        geography. Oxford: Clarendon Press. 632 p.  [2843] 63.  Rautenstrauch, Kurt R.; Krausman, Paul R.; Whiting, Frank M.; Brown,        William H. 1988. Nutritional quality of desert mule deer forage in King        Valley, Arizona. Desert Plants. 8(4): 172-174.  [2768] 64.  Rea, Amadeo. 1979. Velvet mesquite. Environment Southwest. 486: 3-7.        [2977] 65.  Rea, Amadeo M. 1983. Sonoran desert oases: plants, birds and native        people. Environment Southwest. 503: 5-9.  [2967] 66.  Rea, Amadeo M. 1991. Gila River Pima dietary reconstruction. Arid Lands        Newsletter. 31: 3-10.  [18255] 67.  Reichman, O. J. 1975. Relation of desert rodent diets to available        resources. Journal of Mammalogy. 56(4): 731-751.  [4572] 68.  Reichman, O. J. 1976. Relationships between dimensions, weights,        volumes, and calories of some Sonoran Desert seeds. Southwestern        Naturalist. 20(4): 573-574.  [12326] 69.  Reynolds, Hudson G. 1962. Some characteristics and uses of Arizona's        major plant communities. Journal of the Arizona Academy of Science. 2:        62-71.  [1959] 70.  Robinett, Dan. 1990. Tohono O'odham range history. Rangelands. 12(6):        296-300.  [14968] 71.  Thomas, Renee L.; Anderson, Roger C. 1993. Influence of topography on        stand composition in a midwestern ravine forest. American Midland        Naturalist. 130(1): 1-12.  [1742] 72.  Rogers, Garry F.; Steele, Jeff. 1980. Sonoran Desert fire ecology. 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: 15-19.  [16036] 73.  Roundy, Bruce A.; Dobrenz, Albert K. 1989. Herbivory and plant water        status of jojoba [Simmondsia chinensis (Link) Schn.] in the Sonoran        Desert in Arizona. Journal of Arid Environments. 16: 283-291.  [7865] 74.  Rucks, Michael G. 1984. Composition and trend of riparian vegetation on        five perennial streams in southeastern Arizona. In: Warner, Richard E.;        Hendrix, Kathleen M., eds. California riparian systems: Ecology,        conservation, and productive management: Proceedings of a conference;        1981 September 17-19; Davis, CA. Berkeley, CA: University of California        Press: 97-107.  [5831] 75.  Scarbrough, David L.; Krausman, Paul R. 1988. Sexual segregation by        desert mule deer. Southwestern Naturalist. 33(2): 157-165.  [5250] 76.  Seegmiller, Rick F.; Krausman, Paul R.; Brown, William H.; Whiting,        Frank M. 1990. Nutritional composition of desert bighorn sheep forage in        the Harquahala Mountains, Arizona. Desert Plants. 10(2): 87-90.  [11943] 77.  Shreve, Forrest. 1911. Establishment behavior of the Palo Verde. Plant        World. 14: 289-296.  [11168] 78.  Shreve, Forrest. 1942. The desert vegetation of North America. Botanical        Review. 8(4): 195-246.  [5051] 79.  Shreve, Forrest; Hinckley, Arthur L. 1937. Thirty years of change in        desert vegetation. Ecology. 18(4): 463-478.  [4574] 80.  Shreve, F.; Wiggins, I. L. 1964. Vegetation and flora of the Sonoran        Desert. Stanford, CA: Stanford University Press. 2 vols.  [21016] 81.  Simons, L. H. 1989. Vertebrates killed by desert fire. Southwestern        Naturalist. 34(1): 144.  [7850] 82.  Simpson, B. B.; Neff, J. L.; Moldenke, A. R. 1977. Prosopis flowers as a        resource. In: Simpson, B. B., ed. Mesquite: Its biology in two desert        ecosystems. US/IBP Synthesis 4. Stroudsburg, PA: Dowden, Hutchinson &        Ross, Inc: 84-107.  [5192] 83.  Stamp, Nancy E. 1978. Breeding birds of riparian woodland in        south-central Arizona. Condor. 80: 64-71.  [8079] 84.  Steenbergh, Warren F.; Lowe, Charles H. 1969. Critical factors during        the first years of the saguaro (Cereus giganteus) at Saguaro National        Monument, Arizona. Ecology. 50(5): 825-834.  [19692] 85.  Stickney, Peter F. 1989. Seral origin of species originating in northern        Rocky Mountain forests. Unpublished draft on file at: U.S. Department of        Agriculture, Forest Service, Intermountain Research Station, Fire        Sciences Laboratory, Missoula, MT; RWU 4403 files. 7 p.  [20090] 86.  Szaro, Robert C.; Belfit, Scott C. 1987. Small mammal use of a desert        riparian island and its adjacent scrub habitat. Res. Note RM-473. Fort        Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky        Mountain Forest and Range Experiment Station. 5 p.  [3843] 87.  Thornber, J. J. 1910. The grazing ranges of Arizona. Bull. No. 65.        Tucson, AZ: University of Arizona, Agricultural Experiment Station. 360        p.  [4555] 88.  Tidestrom, I.; Kittell, T. 1941. A flora of Arizona and New Mexico.        Washington, DC: The Catholic University of America Press. 897 p.        [18145] 89.  Tomoff, Carl S. 1974. Avian species diversity in desert scrub. Ecology.        55: 396-403.  [19307] 90.  Turnage, William V.; Hinckley, Arthur L. 1938. Freezing weather in        relation to plant distribution in the Sonoran Desert. Ecological        Monographs. 8(2): 530-550.  [3789] 91.  Turner, Raymond M. 1963. Growth in four species of Sonoran Desert trees.        Ecology. 44: 760-765.  [9883] 92.  Turner, Raymond M. 1990. Long-term vegetation change at a fully        protected Sonoran Desert site. Ecology. 7(2): 464-477.  [10866] 93.  Turner, Raymond M.; Brown, David E. 1982. Sonoran desertscrub. In:        Brown, David E., ed. Biotic communities of the American        Southwest--United States and Mexico. Desert Plants. 4(1-4): 181-221.        [2375] 94.  U.S. Department of Agriculture, Soil Conservation Service. 1982.        National list of scientific plant names. Vol. 1. List of plant names.        SCS-TP-159. Washington, DC. 416 p.  [11573] 95.  Vander Wall, Stephen B. 1993. Seed water content and the vulnerability        of buried seeds to foraging rodents. American Midland Naturalist.        129(2): 272-281.  [21306] 96.  Vorhies, Charles T.; Taylor, Walter P. 1933. The life histories and        ecology of jack rabbits, Lepus alleni and Lepus californicus ssp., in        relation to grazing in Arizona. Technical Bulletin No. 49. Tucson, AZ:        University of Arizona, Agricultural Experiment Station. 117 p.  [9933] 97.  Warren, Peter L.; Anderson, L. Susan. 1985. Gradient analysis of a        Sonoran Desert wash. In: Johnson, R. Roy; [and others], technical        coordinators. Riparian ecosystems & their mgmt: reconciling conflicting        issues: Proceedings, 1st North American riparian conference; 1985 April        16-18; Tucson, AZ. Gen. Tech. Rep. RM-120. Fort Collins, CO: U.S.        Department of Agriculture, Forest Service, Rocky Mountain Forest and        Range Experiment Station: 150-155.  [17158] 98.  Whitfield, Charles J.; Anderson, Hugh L. 1938. Secondary succession in        the desert plains grassland. Ecology. 19(2): 171-180.  [5252] 99.  Whittaker, R. H.; Niering, W. A. 1965. Vegetation of the Santa Catalina        Mountains, Arizona: a gradient analysis of the south slope. Ecology. 46:        429-452.  [9637] 100.  Wiggins, Ira L. 1980. Flora of Baja California. Stanford, CA: Stanford        University Press. 1025 p.  [21993] 101.  Whysong, Gary L.; Heisler, Michael H. 1978. Nitrogen levels of soil and        vegetation in the upper Sonoran Desert as affected by fire. In: Hyder,        Donald N., ed. Proceedings, 1st international rangeland congress; 1978        August 14-18; Denver, CO. Denver, CO: Society for Range Management:        697-699.  [3990] 102.  Yang, Tien Wei; Lowe, Charles H., Jr. 1955. Correlation of major        vegetation climaxes with soil characteristics in the Sonoran Desert.        Science. 123: 542.  [12226] 103.  Zimmermann, Robert C. 1969. Plant ecology of an arid basin: Tres        Alamos-Redington Area, southeastern Arizona. Geological Survey        Professional Paper 485-D. Washington, DC: U.S. Department of the        Interior, Geological Survey. 51 p.  [4287] 104.  Patten, Duncan T.; Cave, George H. 1984. Fire temperatures and physical        characteristics of a controlled burn in the upper Sonoran Desert.        Journal of Range Management. 37(3): 277-280.  [181] 105.  Shreve, Forrest. 1917. The establishment of desert perennials. Journal        of Ecology. 5: 210-216.  [22785] 106.  Hickman, James C., ed. 1993. The Jepson manual: Higher plants of California.        Berkeley, CA: University of California Press. 1400 p.  [21992] 107.  Kartesz, John T. 1999. A synonymized checklist and atlas with        biological attributes for the vascular flora of the United States,        Canada, and Greenland. 1st ed. In: Kartesz, John T.; Meacham,        Christopher A. Synthesis of the North American flora (Windows Version        1.0), [CD-ROM]. Chapel Hill, NC: North Carolina Botanical Garden        (Producer). In cooperation with: The Nature Conservancy; U.S.        Department of Agriculture, Natural Resources Conservation Service; U.S.        Department of the Interior, Fish and Wildlife Service.  [36715]