SPECIES: Bouteloua eriopoda
Simonin, Kevin A. 2000. Bouteloua eriopoda. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available: http://www.fs.fed.us/database/feis/ .
No special status
Black grama is widely distributed throughout southwestern desert grasslands. Its distribution stretches from Texas to southern California and from Mexico northward to Colorado, Wyoming, and Utah [46,49,60,108].
FRES30 Desert shrub
FRES32 Texas savanna
FRES33 Southwestern shrubsteppe
FRES34 Chaparral-mountain shrub
FRES38 Plains grasslands
FRES40 Desert grasslands
7 Lower Basin and Range
10 Wyoming Basin
11 Southern Rocky Mountains
12 Colorado Plateau
13 Rocky Mountain Piedmont
K023 Juniper-pinyon woodland
K031 Oak-juniper woodland
K054 Grama-tobosa prairie
K058 Grama-tobosa shrubsteppe
K065 Grama-buffalo grass
K085 Mesquite-buffalo grass
K086 Juniper-oak savanna
211 Creosotebush scrub
503 Arizona chaparral
504 Juniper-pinyon pine woodland
505 Grama-tobosa shrub
702 Black grama-alkali sacaton
703 Black grama-sideoats grama
705 Blue grama-galleta
706 Blue grama-sideoats grama
707 Blue grama-sideoats grama-black grama
727 Mesquite-buffalo grass
735 Sideoats grama-sumac-juniper
In desert grasslands and rangelands of the Southwest, black grama is the principal native dominant on upland sandy loam soils . It is the dominant grass within Chihuahuan Desert ranges . Historically black grama occurred in almost pure stands over extensive areas of southeastern Arizona, southern New Mexico, western Texas, and into northern Mexico. Pure stands are less extensive today . Within New Mexico semidesert grassland, black grama forms its own vegetation type . It co-dominates in blue grama (Bouteloua gracilis)-black grama and desert scrub types [15,29,121]. Publications describing plant communities dominated by black grama are:
Vegetative succession in the Prosopis sand dunes of southern New Mexico 
New Mexico vegetation: past, present, and future 
Preliminary habitat types of a semiarid grassland 
Vegetation and community types of the Chihuahuan Desert 
A series vegetation classification for Region 3 
The natural vegetation of Arizona 
Plant communities of Texas (Series level) 
Campbell and Bomberger  provide a detailed summary of a general black grama association. Under favorable rainfall and conservative grazing, 60 to 70% plant density is filled by black grama. Approximately 15% is filled by sand dropseed (Sporobolus cryptandrus), mesa dropseed (Sporobolus flexuosus), Wooton threeawn (Aristida pansa), and red threeawn (Aristida purpurea).
Black grama is the dominant grass of upland areas of the Rio Grande Valley desert plain. Within the Rio Grande Valley a strong association (p = 0.05) was seen with creosotebush (Larrea tridentata) and bush muhly (Muhlenbergia porteri). Associations at the p = 0.01 level of significance were seen with Fendler threeawn (A. fendleriana), galleta (Pleuraphis jamesii), broom snakeweed (Gutierrezia sarothrae), and fluffgrass (Erioneuron pulchellum) .
Black grama is considered the climax type of some southwestern rangelands. Perennial grasses associates in black grama grasslands include red and Wooton threeawn, and sand and mesa dropseed. Important forbs include spectacle pod (Dithyrea wislizeni), woolly paperflower (Psilostrophe tagetina), bladderpod (Lesquerella spp.), globemallow (Sphaeralcea spp.), croton (Croton spp.), and several annuals. This black grama type achieves the best structure on older, stable loamy sand. Dropseeds and threeawns are more abundant when surface soils are sandier and less compact .
Along with tobosagrass (Pleuraphis mutica), black grama is the most common grass within semidesert shrub grasslands. Black grama is a dominant member within grama-galleta (Bouteloua-Hilaria spp.)-creosotebush southwestern shrubsteppe . Common associates in Arizona include threeawns. In New Mexico mesa dropseed, threeawns, and fluffgrass are usually present. In Texas blue grama, sideoats grama, Warnock's grama, and vine mesquite (Panicum obtusum) are commonly associated, along with dropseeds and Wooton threeawn .
Black grama is a principal grass of Arizona chaparral . Within Arizona chaparral, black grama inhabits those areas where chaparral borders on semidesert grassland. Common associates include hairy grama (Bouteloua hirsuta), sideoats grama (B. curtipendula), and threeawns .
Black grama is considered excellent forage for all livestock classes and wildlife .
Cactus wrens in the southern Chihuahua Desert of New Mexico and Arizona use black grama as a minor component of their nests .
Overall, black grama is one of the most nutritious desert winter grasses for livestock . The protein content of perennial grasses is generally high when individuals are developmentally young, and declines rapidly with maturity. In Texas, high protein percentages for black grama were observed in June, with the lowest percentages occurring in February and March . In New Mexico arid ranges, black grama protein content varied little throughout the year. Calcium values were considered adequate throughout the year. Phosphorus varied from 0.07% to 0.12%, with the highest levels occurring from June to October.
Nutritional value (%) of fresh black grama varied seasonally as follows :
|Aerial Part- immature||Aerial Part- early bloom||Aerial Part- mature|
|Protein (N × 6.25)||11.5||7.4||6.4|
Black grama is generally not recommended for reseeding projects due to low seed viability. Obtaining high quality seed is difficult; supplies of good seed are scarce .
Black grama is a poor competitor with perennial snakeweeds (Gutierrezia spp.), although snakeweeds commonly occur in black grama-dominated grasslands .
A "good stand" of black grama was established in the northern Chihuahuan Desert by constructing small dikes on arroyos and then reseeding areas just upland from the dikes with native species. Black grama produced seed 2 years after establishment, in a summer of favorable rains, and floodwaters dispersed the seeds downstream .
Black grama shows variable tolerance to grazing, with several abiotic and biotic factors contributing to overall grazing response. In general, black grama decreases under grazing . Vigor is extremely
impaired by heavy grazing; however, black grama is tolerant of light grazing . Black grama in the Southwest showed better response to light grazing
than moderate grazing .
Population increases for black grama are greatest under grazing exclusion, due to reliance upon stoloniferous regeneration . Stolons growing horizontally outward from tufts are very susceptible to grazing and trampling damage , and intense grazing pressure may shift regeneration of black grama from stoloniferous expansion to tillering . Stoloniferous expansion of black grama can be successful with careful grazing management, however. To encourage vegetative reproduction, grazing removal of 30 to 35% of total annual production is recommended. Herbage removal of more than 65% of annual production is not recommended .
The season of grazing influences black grama tolerance. In general, black grama is readily damaged under summer grazing. Fall, winter, and spring grazing produce less damage . Defoliating black grama continuously throughout the growing season produces less forage the following year compared to defoliating during culm expansion . Season of grazing also affects black grama regeneration. Protection from summer grazing favors successful black grama regeneration by allowing stolons to root .
A simulated grazing study was conducted in the Jornada Experimental Range of New Mexico. Clippings left 1-inch (2.5 cm) and 2-inch (5 cm) black grama stubble heights. After 11 years, neither 1-inch nor 2-inch clipping treatments produced as much as 4% the original tuft area, and there were severe declines in stolon regeneration. The decreased tuft area allowed for wind erosion of the upper loose soil mulch, which is required for successful stolon rooting .
All other factors aside, there is a correlation between degree of grazing intensity and black grama regrowth. Black grama vigor was greater on lightly and moderately grazed plots during both below normal and above-normal precipitation during the growing season. Results over a 9-year period comparing a light1, moderate2, and recommended (for maintaining and increasing black grama on range land) 3 grazing regimes are summarized below .
|Grazing||Seedstalk height (in.)||Stolons/plant||Stolon length (in.)||Rooted sets/plant|
Black grama is a solid-stemmed [27,96], long-lived , native perennial [45,61]. It has wiry, spreading stems that reach 8 to 24 inches (20-60 cm) in length [45,46].
The growth habit is generally caespitose but occasionally stoloniferous.
It has smooth, narrow , flexuous and pointed, mostly basal leaves . Leaf blades are 1 to 3 inches (2-7cm) long [91,108] and 0.08 to 0.02 inch (0.5-2 mm) wide . Crown foliage is compact, producing dense ground shade . The
inflorescence is a panicle consisting of 3 to 8 spicate, unilateral branches [96,108].
Black grama possesses a well-developed, finely divided root system, with the greatest concentration of roots found within the uppermost 10 inches (25 cm) of soil . In sand, roots may extend 4 feet (1.2 m) or more vertically . At low soil moisture levels (1/4th field capacity), the greatest concentration of roots is found near the soil surface. At intermediate levels of soil moisture (1/3rd field capacity), roots are arranged evenly throughout the soil column. When moisture levels are high, greater concentrations of roots are found toward the bottom of the soil profile .
Once established black grama is tolerant of short droughts. Under prolonged periods of water stress black grama tufts dry out from the center breaking into smaller tufts. With good rainfall, broken tufts may coalesce . The water-regulating physiology and root morphology of black grama place it in the 'intensive exploiter' classification. Intensive exploiters are plants that derive the majority of moisture through dense rooting networks situated within the shallower soil horizons. Periodic rainfalls are exploited with rapid root growth and water absorption. Intensive exploiters are good competitors for limited, shallow soil moisture and recover rapidly from stress or damage with readily available soil moisture .
Vegetative: Black grama primarily regenerates asexually through tillering, layering, and stoloniferous expansion, all of which are effective under arid conditions [59,64,85,91,108]. Parent plants provide support to new plants during establishment. Stoloniferous expansion  and tillering  increases black grama coverage slowly; therefore, black grama does not show quick colonization into adjacent areas. Black grama's reliance upon vegetative reproduction does not promote extensive migration .
Successful production of newly rooted stolon sets is directly related to the current and upcoming growing season. A year of favorable growth is required for stolon production, followed by another favorable year for rooting to take place . Surface
soil layers consisting of loose sand that is high in organic matter provide good conditions for
stolons to successfully root . Once established, plants may survive several decades through
stoloniferous reproduction .
Layering is another form of regeneration used by black grama. Layering occurs when flowerstalks or vegetative stems bend to the ground and produce nodal roots. Small clusters of leaves form at axillary buds, nodes, or joints and take root under favorable environmental conditions, growing into new plants .
Seeding: Black grama does not seed well because the majority of spikelets produce sterile florets . A 53-year study monitored black grama seed regeneration; black grama seedlings were produced in only 7 of the 53 years . Germination of black grama under different summer growing conditions was monitored in New Mexico for 9 years (1917-1926). Results are summarized below .
|Year||Summer growing conditions||Germination (%)|
|1920||excellent, poor seed maturity||2.0|
|1926||intermittently good and poor||2.0|
Black grama is a major grass within western desert grassland areas receiving 12 to 18 inches (300-457 mm) mean annual precipitation . It occurs on rocky or sandy mesas and dry, open ground with well-drained sandy and gravelly soils [40,61,108]. Black grama is rarely found on clay loams or adobe flats . The majority of precipitation (> 50%) within sites dominated by black grama occurs from July to September . In desert grasslands of New Mexico, black grama sites usually receive low rainfall , occupying the 8- to 17-inch (200-430 mm) precipitation belt . Low rainfall is often accompanied by high temperatures and extreme winds .
Several studies have evaluated black grama distribution in relation to edaphic factors. Black grama prefers sandy but firm soils [14,40]. Good stands are rarely found on shifting soils . In California, black grama occupies sandy to rocky slopes . In desert grasslands of New Mexico, greatest coverage is achieved on coarse soil of low clay and high sand content . Black grama is common on sandy soils possessing a lower caliche profile of a few inches to depths of 6 to 7 feet (1.8-2.1 m) [9,28,58]. An association between percent organic matter and nitrogen was observed for black grama in the Chihuahuan Desert. Greatest coverage was achieved in areas with relatively higher organic matter and nitrogen . In southern Arizona higher frequencies of black grama were found where nitrate was readily available in conjunction with trace amounts of organic matter .
On some sites, cover of black grama may be related to topographical aspect. In New Mexico, basal cover was highest on south- and west-facing slopes . In a grassland valley in southeastern Arizona at the upper limits of black grama's elevational range, black grama showed a preference for low, south-facing slopes .
Elevational range of black grama is as follows:
Arizona - 3,000 to 5,000 feet (914-1524 m) 
California - 2,600 to 6,200 feet (800-1900 m) 
Colorado - 4,400 to 4,800 (1340-1460 m) 
Black grama occurs on both seral and late-successional communities [10,25,96]. It was a dominant component of early succession during a 3-year natural revegetation of mesquite sand dunes in southern New Mexico. The site received light grazing and adequate rainfall . Black grama increased with grazing on arid southeastern Arizona rangelands that were dominated by tall grasses such as plains lovegrass (Eragrostis intermedia), beardgrass (Bothriochloa spp.), and sideoats grama (Bouteloua curtipendula) .
Growth of black grama corresponds with season and amount of precipitation. Precipitation received between July and September is more important than total annual precipitation . Stems remain green throughout the year [15,19,89], with carbohydrate reserves stored in the stem, root, and root crown . Rapid development and growth occur under periods of relatively abundant moisture and high nighttime temperature. Growth is suspended during dry periods until the next saturating rain .
Flowering, fruiting, and seed dispersal occur during late summer and fall rains. Early seedling establishment may also occur after these rains . A general description of black grama phenology
in the Chihuahuan Desert is as follows :
growth begins - late April to early May
flowering - late August to early September
fruiting - late September to early October
In arid ranges of southern New Mexico, the start of the growing season corresponds with the beginning of the summer rainy period (early July, sometimes May or June possibly mid-August). With adequate rainfall, growth continues until the end of September or October. If fall, spring, and winter precipitation is high and temperatures are not too low, leaves may start growth in March and April. With continued moisture, growth may extend into the main summer growing period. Flowering is generally initiated 5 to 7 weeks after summer growth starts, so time of flowering and fruiting varies with the beginning of the growing season. Flowering usually takes place in early August, with fruiting occurring in late September. Dissemination begins in October and extends into November. The possibility for 2 flowering stages exists if adequate moisture is available. High amounts of early spring rains may induce an early flowering, and a second flowering may occur if July rainfall is high .
Development of black grama in relation to precipitation during the growing season was monitored from 1925 to 1935 within the Jornada Experimental Range in New Mexico. Results are summarized below .
|Year||Growth began||Growth ended||Period of Growth (days)||Total rainfall for growth period|
|1925||July 21||Oct 17||89||7.01 (inches)|
|1926||May 18||Nov 9||176||11.95|
|1927||July 25||Oct 1||69||5.58|
|1928||July 20||Oct 5||78||3.75|
|1929||July 22||Oct 14||85||3.91|
|1930||Aug 11||Nov 3||85||3.35|
|1931||July 1||Nov 4||127||5.79|
|1932||Aug 9||Nov 1||85||4.16|
|1933||July 20||Oct 17||120||6.52|
|1934||no growth||no growth||0||1.57|
|1935||Aug 13||Oct 15||64||5.14|
Fire adaptations: Black grama is reported to be fire sensitive [2,21]. It usually recovers from fire slowly, through vegetative spread. However, black grama grows quickly in response to summer moisture, and its postfire recovery can be good if the stand was healthy before fire and there is adequate precipitation in the 1st 2 growing seasons after fire [3,44,64].
Desert grassland fire regime: Knowledge of fire frequency and fire's ecological role in
desert grasslands is uncertain. Grassland fires leave no direct evidence of historical frequency, such as tree scars . Our general understanding comes from knowledge of plant community ecology, the physiology of individual plant species, and historical accounts. Scientific research has generated arguments to both support and contradict the idea that fire was a common disturbance in desert grasslands.
Several researchers suggest a fire frequency of 7 to 10 years for desert grasslands [17,120]. Fires in desert grasslands of the Chihuahuan Desert were probably less frequent than those in the Sonoran Desert . Many researchers view fire as necessary to maintain desert grasslands, mainly due to the current level of invasion by woody species in the absence of fire. It is hypothesized that shrubs would not have achieved the current level of coverage in desert grasslands if stand-replacement fires had occurred at regular intervals . Although fires may kill some grass plants and weaken others, establishment of shrub seedlings requires several years more than establishment of grasses . Honey mesquite, a major invader of southwestern desert grasslands, shows low seedling establishment when subjected to frequent fire. Glendening and Paulsen  found that severe fires were required to kill established honey mesquite plants; honey mesquite seedlings were readily killed by low-severity fire . Fires generally remove only a single year's growth from desert perennial grasses and do not burn deep into root crowns, enabling the grasses to resprout . Most desert shrubs with perennating buds on the root crown cannot sprout until stems are at least 1 cm in diameter. Most shrubs also require several growing seasons before fruiting can occur .
Other research suggests that competition for space and moisture is more important than frequent fire in controlling woody shrub invasion of desert ecosystems . Glendening and Paulsen  observed that competition with annual grasses reduced germination and emergence of honey mesquite seedlings to the 1st true leaf. On healthy desert grassland sites, survival of mesquite seedlings through their 1st spring drought was rare . Grama grasses have also been observed to outcompete snakeweed .
When cured and dried, desert grassland vegetation provides adequate fuel for ignition. Annual dry lightning storms mark the beginning of the southwestern rains, which take place late June or early July . Once ignited, plant density is the limiting factor for fire spread. Annual productivity can vary from almost nothing to 1000 lbs/acre. If fuels are sparse, light winds may carry desert grassland fires [17,65]. Grazing may reduce fuels to the point where fire will no longer carry . The Appleton-Whittell research sanctuary, a 7800-acre (3160 ha) semiarid grassland preserve in southeastern Arizona, experiences frequent wildfires associated with fuel accumulations resulting from domestic livestock exclusion .
Black grama can carry fire if cover is dense and conditions are windy. However, black grama's high reliance upon layering and stolons for expansion, along with its poor seed production, support arguments that historical fires were infrequent in areas dominated by black grama [18,34,120].
The invasion of shrub and subshrub species (for example, honey mesquite and burroweed) has increased the severity of fire in desert grasslands. Invasive plants such as burroweed provide extra fuel and increase fire temperatures, resulting in "hot spots" [3,22]. Cable  observed increased mortality of perennial grasses located adjacent to burroweed plants due to extra heat provided by the fine-stemmed, resinous burroweed crowns.
Invasive alien grasses have increased fire frequency on some desert grasslands sites. For example, some Sonoran Desert sites have been invaded by Lehmann's lovegrass (Eragrostis lehmanniana), buffel grass (Cenchrus cilaris), and/or red brome (Bromus rubens). These exotics generally increase with frequent fire, producing historically unprecedented fuel loads [2,3]. Exotic grasses are less common in the Chihuahuan than the Sonoran Desert .
The following table describes historic fire regimes for many communities where black grama occurs. For further information on fire regimes and fire ecology of communities and ecosystems where black grama occurs, see the "Fire Ecology and Adaptations" section of the FEIS species summary for the plant community and ecosystem dominant listed below.
|Community or Ecosystem||Dominant Species||Fire Return Interval Range in Years|
|plains grasslands||Bouteloua spp.||< 35|
|blue grama-needle-and-thread grass-western wheatgrass||B. gracilis-Hesperostipa comata-Pascopyrum smithii||< 35|
|blue grama-buffalo grass||B. g.-Buchloe dactyloides||< 35|
|grama-galleta steppe||B. g.-Pleuraphis jamesii||< 35 to < 100|
|blue grama-tobosa prairie||B. g.-P. mutica||< 35 to < 100|
|creosotebush||Larrea tridentata||< 35 to < 100|
|pinyon-juniper||Pinus-Juniperus spp.||< 35|
|mesquite||Prosopis glandulosa||< 35 to < 100|
|mesquite-buffalo grass||P. g.-Buchloe dactyloides||< 35|
|Texas savanna||P. g. var. glandulosa||< 10 |
Black grama is generally top-killed by fire . Fire typically causes little if any mortality in desert grasses . Within the southwestern United States, fire usually consumes black grama to within 0.2 to 0.8 inch (3-19 mm) of the root crown. Culm bases and stolons located near the soil surface are susceptible to damage by fire [73,100]. Fire effects, however, are largely determined by relative levels of humidity and precipitation. Periods of hot, dry weather increase black grama's susceptibility to serious damage [64,72,73]. Hot fires due to relatively large amounts of fine-stemmed, dry herbaceous fuels may result in high mortality for black grama .
Black grama postfire response is variable. Both positive and negative effects are observed. Black grama recovery is best when above-average summer precipitation occurs after fire. Recovery is very slow when plants are subject to drought and grazing after fire, or if plant vigor was low prior to fire . In the long term, stoloniferous expansion may be enhanced by fire
under some conditions .
Studies monitoring postfire recovery potential of black grama in the Southwest suggest a recovery period from 2 to 8 years [47,64]. Postfire drought can lengthen recovery time considerably ; in some extremes, estimated recovery time is 50 years . Allen  reported that black grama populations in the malpais area of the Arizona Sonoran Desert recover from fire faster than lower-elevation populations that receive less precipitation.
In some situations, little or no recovery is observed in the short term [52,74]. A study in the Chihuahuan Desert of southern Arizona found that black grama had not recovered prefire density 4 years after a June 1950 prescribed fire .
Black grama recovered from a summer wildfire than nonnative Lehmann lovegrass (Eragrostis lehmanniana) in Arizona. The study was located 40 miles (64 km) south of Tucson, Arizona, on 6 acres (2.4 ha) at 3,850 feet (1,173 m) within the Santa Rita Experimental Range. The prefire vegetation community consisted of a mesquite (Prosopis spp.) overstory averaging 200 trees/acre with 2 distinct forms of understory. A nearly pure stand of Lehman's love grass made up half of the ground cover. The other half, a mixed native grass stand, was dominated by black grama with lesser amounts of Arizona cottontop (Trichachne californica). The majority of black grama clumps were mostly dried with a few wilted, green leaves from current spring growth. Wilting was the result of 64 previous days without precipitation. The air-dry weight of herbaceous fuel was estimated at 2,200 pounds/acre (998 kg/acre). The study investigated the effects of a wild fire that took place on June 28, 1963, under dry conditions. Relative humidity was estimated at 6%. Wind speed during the fire was estimated at 12 to 15 miles per hour (19-24 km/hr). The fire started at 3:30 p.m. and was controlled by 5:00 p.m. The fire removed all top growth and burned or charred the bases to within 1/8th to 3/4th of an inch (3-20 mm) of the root crown. Resprouting began 3½ weeks after the fire. Black grama started sprouting earlier and continued sprouting longer than Lehmann lovegrass. In September, 3 months after fire, 10% of the burned black grama plants had sprouted. No black grama seedlings were found .
A positive postfire response was observed in mountain shrub
habitats of the Chihuahuan Desert. The frequency of black grama was 2 times that of unburned controls 3 growing seasons after fires . The opposite was seen in a Sonoran Desert shrub range in southern Arizona. Observations of black grama coverage after a June fire in the Sonora Desert are summarized below .
|Prefire cover (%)||Postfire cover (%)|
|Treatment||June 1950||October 1950||October 1951||October 1953||October 1954|
|Percent of Control||167.9||38.3||50.0||62.2||37.1|
On southern plains grasslands and plains grassland-desert grassland transition zones, blue grama may recover from fire more quickly than black grama. Because blue grama is more resistant to grazing, livestock grazing may retard black grama recovery even further. The October after late June prescribed burning or clipping treatments on a Chihuahuan Desert-southern plains grassland transition zone in New Mexico, growth of blue grama exceeded that of black grama on burned, clipped, and control plots. The contrast in plant height was greatest on burned plots. Mean plant height (cm) in the 1st posttreatment growing season was :
In New Mexico black grama had less mean plant height on June-burned plots compared to unburned areas. Biomass was also significantly
(p < 0.05) greater in unburned compared to burned plats .
Following April and May prescribed fires in the Sierrita Mountains of southern Arizona, black grama not occur on burned plots at postfire year 2; however, black grama density on adjacent unburned control plots was also low (mean=0.31 plant/m2) .
Drought lengthens black grama recovery time after fire, and drought in combination with grazing may result in extremely high postfire mortality . Recovery is best if grazing is deferred until plants receive at least 2 consecutive years of above-average summer rainfall . Black grama response was poor, with density reduced by half, following a fall burn in Arizona. The fire was initiated following a summer of average rainfall and a 40-day rain-free period. Results were partly attributed to postburn grazing pressure . According to Gosz and Gosz , infrequent fires in conjunction with light grazing may allow persistence of black grama within New Mexico desert grassland communities on sandy loam or loamy sand soils.
1. Ahlstrand, Gary M. 1982. Response of Chihuahuan Desert mountain shrub vegetation to burning. Journal of Range Management. 35(1): 62-65. 
2. Allen, Larry S. 1996. Ecological role of fire in the Madrean Province. 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: 5-10. 
3. Allen, Larry. 1998. Grazing and fire management. In: Tellman, Barbara; Finch, Deborah M.; Edminster, Carl; Hamre, Robert, eds. The future of arid grasslands: identifying issues, seeking solutions: Proceedings; 1996 October 9-13; Tucson, AZ. Proceedings RMRS-P-3. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station: 97-100. 
4. Anderson, Darwin; Hamilton, Louis P.; Reynolds, Hudson G.; Humphrey, Robert R. 1953. Reseeding desert grassland ranges in southern Arizona. Bulletin 249. Tucson, AZ: University of Arizona, Agricultural Experiment Station. 32 p. 
5. Arnold, Joseph F.; Schroeder, W. L. 1955. Juniper control increases forage production on the Fort Apache Indian Reservation. Station Paper No. 18. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Forest and Range Experiment Station. 35 p. 
6. Barrow, Jerry R.; Havstad, Kris M. 1995. Natural methods of establishing native plants on arid rangelands. In: Roundy, Bruce A.; McArthur, E. Durant; Halley, Jennifer S.; Mann, David K, compilers. Proceedings: wildland shrub and arid land restoration symposium; 1993 October 19-21; Las Vegas, NV. Gen. Tech. Rep. INT-GTR-315. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Research Station: 44-45. 
7. 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. 
8. Bock, Carl E.; Bock, Jane H. 1990. Effects of fire on wildlife in southwestern lowland habitats. In: Krammes, J. S., technical coordinator. Effects of fire management of southwestern natural resources: Proceedings of the symposium; 1988 November 15-17; Tucson, AZ. Gen. Tech. Rep. RM-191. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Forest and Range Experiment Station: 50-64. 
9. Bock, Carl E.; Bock, Jane H. 1993. Cover of perennial grasses in southeastern Arizona in relation to livestock grazing. [Journal name unknown]. 7(2): 371-377. 
10. Bock, Carl E.; Bock, Jane H. 1998. Factors controlling the structure and function of desert grasslands: a case study from southeastern Arizona. In: Tellman, Barbara; Finch, Deborah M.; Edminster, Carl; Hamre, Robert, eds. The future of arid grasslands: identifying issues, seeking solutions: Proceedings; 1996 October 9-13; Tucson, AZ. Proceedings RMRS-P-3. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station: 33-44. 
11. Bock, Carl E.; Bock, Jane H.; Grant, Michael C.; Seastedt, Timothy R. 1995. Effects of fire on abundance of Eragrostis intermedia in a semi-arid grassland in southeastern Arizona. Journal of Vegetation Science. 6: 325-328. 
12. Bock, Jane H.; Bock, Carl E. 1986. Habitat relationships of some native perennial grasses in southeastern Arizona. Desert Plants. 8(1): 3-14. 
13. Bridges, J. O. 1941. Reseeding trials on arid range land. Bulletin 278. Las Cruces, NM: New Mexico State University, Agricultural Experiment Station. 48 p. 
14. Bridges, J. O. 1942. Reseeding practices for New Mexico ranges. Bull. 291. Las Cruces, NM: New Mexico State University, Agricultural Experiment Station. 48 p. 
15. Brown, David E. 1982. Plains and Great Basin grasslands. In: Brown, David E., ed. Biotic communities of the American Southwest--United States and Mexico. Desert Plants. 4(1-4): 115-121. 
16. Brown, Dwight A.; Gersmehl, Philip J. 1985. Migration models for grasses in the American midcontinent. Annals of the Association of American Geographers. 75(3): 383-394. 
17. Brown, James K.; Smith, Jane Kapler, eds. 2000. 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. 257 p. 
18. Buffington, Lee C.; Herbel, Carlton H. 1965. Vegetational changes on a semidesert grassland range from 1858 to 1963. Ecological Monographs. 35: 139-164. 
19. Burgess, Tony L. 1995. Desert grassland, mixed shrub savanna, shrub steppe, or semidesert scrub?: The dilemma of coexisting growth forms. In: McClaran, Mitchel P.; Van Devender, Thomas R., eds. The desert grassland. Tucson, AZ: The University of Arizona Press: 31-67. 
20. Cable, Dwight R. 1961. Small velvet mesquite seedlings survive burning. Journal of Range Management. 14: 161-161. 
21. Cable, Dwight R. 1965. Damage to mesquite, Lehmann lovegrass, and black grama by a hot June fire. Journal of Range Management. 18: 326-329. 
22. Cable, Dwight R. 1967. Fire effects on semidesert grasses and shrubs. Journal of Range Management. 20(3): 170-176. 
23. 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. 
24. Cable, Dwight R.; Martin, S. Clark. 1975. Vegetation responses to grazing, rainfall, site condition, and mesquite control on semidesert range. Res. Pap. RM-149. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Forest and Range Experiment Station. 24 p. 
25. Campbell, R. S. 1929. Vegetative succession in the Prosopis sand dunes of southern New Mexico. Ecology. 10(4): 392-398. 
26. Campbell, R. S.; Bomberger, E. H. 1934. The occurrence of Gutierrezia sarothrae on Bouteloua eriopoda ranges in southern New Mexico. Ecology. 15(1): 49-61. 
27. Canfield, R. H. 1934. Stem structure of grasses on the Jornada Experimental Range. Botanical Gazette. 95: 636-648. 
28. Canfield, R. H. 1939. The effect of intensity and frequency of clipping on density and yield of black grama and tobosa grass. Tech. Bull. 681. Washington, DC: U.S. Department of Agriculture. 32 p. 
29. Canfield, R. H. 1948. Perennial grass composition as an indicator of condition of Southwestern mixed grass ranges. Ecology. 29: 190-204. 
30. Canfield, R. H. 1957. Reproduction and life span of some perennial grasses of southern Arizona. Journal of Range Management. 10(5): 199-203. 
31. Clary, Warren P.; Jameson, Donald A. 1981. Herbage production following tree and shrub removal in the pinyon-juniper type of Arizona. Journal of Range Management. 34(2): 109-113. 
32. Cronquist, Arthur; Holmgren, Arthur H.; Holmgren, Noel H.; [and others]. 1977. Intermountain flora: Vascular plants of the Intermountain West, U.S.A. Vol. 6. The Monocotyledons. New York: Columbia University Press. 584 p. 
33. Daniel, Alipayou; Holechek, Jerry L.; Valdez, Raul; [and others]. 1993. Range condition influences on Chihuahuan Desert cattle and jackrabbit diets. Journal of Range Management. 46(4): 296-301. 
34. Dick-Peddie, William A. 1993. New Mexico vegetation: past, present, and future. Albuquerque, NM: University of New Mexico Press. 244 p. 
35. Dwyer, Don D.; DeGarmo, Harlan C. 1970. Greenhouse productivity and water-use efficiency of selected desert shrubs and grasses under four soil-moisture levels. Bulletin 570. Las Cruces, NM: New Mexico State University, Agricultural Experiment Station. 15 p. 
36. Eyre, F. H., ed. 1980. Forest cover types of the United States and Canada. Washington, DC: Society of American Foresters. 148 p. 
37. Fletcher, Rick. 1984. Burning improves Southwestern ranges. Forestry Research West. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Forest and Range Experiment Station. June: 1-3. 
38. Francis, Richard E.; Aldon, Earl F. 1983. Preliminary habitat types of a semiarid grassland. 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: 62-66. 
39. Gardner, J. L. 1950. Effects of thirty years of protection from grazing in desert grassland. Ecology. 31(1): 44-50. 
40. Gardner, J. L. 1951. Vegetation of the creosotebush area of the Rio Grande Valley in New Mexico. Ecological Monographs. 21: 379-403. 
41. 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. 
42. Gibbens, Robert P.; Beck, Reldon F. 1988. Changes in grass basal area and forb densities over a 64-year period on grassland types of the Jornada Experimental Range. Journal of Range Management. 41(3): 186-192. 
43. Glendening, George E.; Paulsen, Harold A., Jr. 1955. Reproduction and establishment of velvet mesquite as related to invasion of semidesert grasslands. Tech. Bull. 1127. Washington, DC: U.S. Department of Agriculture, Forest Service. 50 p. 
44. Gosz, Rusty J.; Gosz, James R. 1996. Species interactions on the biome transition zone in New Mexico: response of blue grama (Bouteloua gracilis) and black grama (Bouteloua eripoda) to fire and herbivory. Journal of Arid Environments. 34((1): 101-114. 
45. Gould, Frank W. 1978. Common Texas grasses. College Station, TX: Texas A&M University Press. 267 p. 
46. Gould, Frank W. 1979. The genus Bouteloua (Poaceae). Annals of the Missouri Botanical Garden. 66: 348-416. 
47. Gould, Walter L. 1982. Wind erosion curtailed by controlling mesquite. Journal of Range Management. 35(5): 563-566. 
48. Graves, Robbie G. 1971. Effects of redberry juniper control on understory vegetation. Lubbock, TX: Texas Tech Univeristy. 86 p. Thesis. 
49. Great Plains Flora Association. 1986. Flora of the Great Plains. Lawrence, KS: University Press of Kansas. 1392 p. 
50. Haque, Zahoorul; Younga, Amade; McDaniel, Kirk C.; Pieper, Rex D. 1991. Two-phase pattern in mesquite-herbland vegetation in southern New Mexico. The Southwestern Naturalist. 36(1): 54-59. 
51. Harrington, H. D. 1964. Manual of the plants of Colorado. 2d ed. Chicago: The Swallow Press Inc. 666 p. 
52. Havstad, K. M. 1998. An overview of arid grasslands in the northern Chihuahuan Desert. In: Tellman, Barbara; Finch, Deborah M.; Edminster, Carl; Hamre, Robert, eds. The future of arid grasslands: identifying issues, seeking solutions: Proceedings; 1996 October 9-13; Tucson, AZ. Proceedings RMRS-P-3. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station: 11-20. 
53. Hennessy, J. T.; Gibbens, R. P.; Tromble, J. M.; Cardenas, M. 1983. Vegetation changes from 1935 to 1980 in mesquite dunelands and former grasslands of southern New Mexico. Journal of Range Management. 36(3): 370-374. 
54. Henrickson, James; Johnston, Marshall C. 1986. Vegetation and community types of the Chihuahuan Desert. In: Barlow, J. C.; [and others], eds. Chihuahuan Desert--U.S. and Mexico, II. Alpine, TX: Sul Ross State University: 20-39. 
55. Herbel, C. H.; Steger, R.; Gould, W. L. 1974. Managing semidesert ranges of the Southwest. Circular 456. Las Cruces, NM: New Mexico State University, Cooperative Extension Service. 48 p. 
56. Herbel, Carlton H.; Abernathy, George H.; Yarbrough, Clyde C.; Gardner, David K. 1973. Rootplowing and seeding arid rangelands in the Southwest. Journal of Range Management. 26(3): 193-197. 
57. Herbel, Carlton H.; Ares, Fred N.; Wright, Robert A. 1972. Drought effects on a semidesert grassland range. Ecology. 53: 1084-1093. 
58. Herbel, Carlton H.; Nelson, Arnold B. 1966. Species preference of Hereford and Santa Gertrudis cattle on a southern New Mexico range. Journal of Range Management. 19: 177-181. 
59. Herbel, Carlton H.; Nelson, Arnold B. 1969. Grazing management of semidesert ranges in southern New Mexico. Las Cruces, New Mexico: Agricultural Research Service, U. S. Department of Agriculture, Crops Research Division; Jornada Experimental Range Report No. 1 13 pp. 
60. Hickman, James C., ed. 1993. The Jepson manual: Higher plants of California. Berkeley, CA: University of California Press. 1400 p. 
61. Hitchcock, A. S. 1951. Manual of the grasses of the United States. Misc. Publ. No. 200. Washington, DC: U.S. Department of Agriculture, Agricultural Research Administration. 1051 p. [2nd edition revised by Agnes Chase in two volumes. New York: Dover Publications, Inc.]. 
62. Holechek, Jerry L.; Tembo, Ackim; Daniel, Alipayou; [and others]. 1994. Long-term grazing influences on Chihauhuan Desert rangeland. The Southwestern Naturalist. 39(4): 342-349. 
63. Humphrey, R. R. 1949. Fire as a means of controlling velvet mesquite, burroweed, and cholla on southern Arizona ranges. Journal of Range Management. 2: 175-182. 
64. Humphrey, R. R. 1950. Arizona range resources. II. Yavapai County. Bull. 229. Tucson, AZ: University of Arizona, Agricultural Experiment Station. 55 p. 
65. Humphrey, R. R. 1958. The desert grassland. Botanical Review. 24: 193-253. 
66. Humphrey, Robert R. 1955. Forage production on Arizona ranges, IV. Coconino, Navajo, Apache Counties: A study in range condition. Bulletin 266. Tucson, AZ: University of Arizona, Agricultural Experiment Station. 84 p. 
67. 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. 
68. Humphrey, Robert R. 1970. Arizona range grasses: Their description, forage value and management. Bulletin 298. Tucson, AZ: The University of Arizona, Agricultural Experiment Station. 159 p. 
69. Humphrey, Robert R. 1974. Fire in the deserts and desert grassland of North America. In: Kozlowski, T. T.; Ahlgren, C. E., eds. Fire and ecosystems. New York: Academic Press: 365-400. 
70. Jackson, Carola V. 1928. Seed germination in certain New Mexico range grasses. Botanical Gazette. 86: 270-294. 
71. Jacoby, P. W.; Meadors, C. H.; Foster, M. A.; Hartmann, F. S. 1982. Honey mesquite control and forage response in Crane County, Texas. Journal of Range Management. 35: 424-426. 
72. Jameson, Donald A. 1961. Heat and dessication resistance of tissue of important trees and grasses of the pinyon-juniper type. Botanical Gazette. 122: 174-179. 
73. Jameson, Donald A. 1962. Effects of burning on a galleta-black grama range invaded by juniper. Ecology. 43(4): 760-763. 
74. Julander, Odell. 1937. Utilization of browse by wildlife. Transactions, 2nd North American Wildlife Conference. ?: 276-287. 
75. Kartesz, John T. 1994. A synonymized checklist of the vascular flora of the United States, Canada, and Greenland. Volume I--checklist. 2nd ed. Portland, OR: Timber Press. 622 p. 
76. Kearney, Thomas H.; Peebles, Robert H. 1942. Flourensia. Tarbush, varnishbush. In: Misc. Publ. 423. Flowering plants and ferns of Arizona. Washington, DC: U.S. Department of Agriculture: 957. 
77. Kemp, Paul R. 1983. Phenological patterns of Chihuahuan desert plants in relation to the timing of water availability. Journal of Ecology. 71: 427-436. 
78. Knipe, Duane; Herbel, Carlton H. 1960. The effects of limited moisture on germination and initial growth of six grass species. Journal of Range Management. 13: 297-302. 
79. 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. 
80. MacKay, William P.; Fisher, Fred M.; Silva, Solange; Whitford, Walter G. 1987. The effects of nitrogen, water and sulfur amendments on surface litter decomposition in the Chihuahuan Desert. Journal of Arid Environments. 12: 223-232. 
81. McClaran, Mitchel P.; Anable, Michael E. 1992. Spread of introduced Lehmann lovegrass along a grazing intensity gradient. Journal of Applied Science. 29(1): 92-98. 
82. McDaniel, Kirk C.; Pieper, Rex D.; Loomis, Lyn E.; Osman, Abdelgader A. 1984. Taxonomy and ecology of perennial snakeweeds in New Mexico. Bulletin 711. Las Cruces, NM: New Mexico State University, Agricultural Experiment Station. 34 p. 
83. 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. 
84. 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. 
85. Miller, Richard F.; Donart, Gary B. 1979. Response of Bouteloua eriopoda (Torr.) Torr. and Sporobolus flexuosus (Thurb.) Rhbd. to season of defoliation. Journal of Range Management. 32(1): 63-67. 
86. Milton, Suzanne J.; Dean, W. R. J.; Kerley, G. I. H.; [and others]. 1998. Dispersal of seeds as nest material by the cactus wren. The Southwestern Naturalist. 43(4): 449-452. 
87. 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. 
88. National Academy of Sciences. 1971. Atlas of nutritional data on United States and Canadian feeds. Washington, DC: National Academy of Sciences. 772 p. 
89. Neilson, Ronald P. 1986. High-resolution climatic analysis and Southwest biogeography. Science. 232: 27-34. 
90. Nelson, A. B.; Herbel, H. M.; Jackson, H. M. 1970. Chemical composition of forage species grazed by cattle on an arid New Mexico range. Bulletin 561. Las Cruces, NM: New Mexico State University, Agricultural Experiment Station. 33 p. 
91. Nelson, Enoch W. 1934. The influence of precipitation and grazing upon black grama grass range. Technical Bulletin No. 409. Washington, DC: U.S. Department of Agriculture. 32 p. 
92. 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. 
93. Nicholson, Robert A.; Bonham, Charles D. 1977. Grama (Bouteloua Lag.) communities in a southeastern Arizona grassland. Journal of Range Management. 30(6): 427-433. 
94. Osman, Abdelgader; Pieper, Rex D.; McDaniel, Kirk C. 1987. Soil seed banks associated with individual broom snakeweed plants. Journal of Range Management. 40(5): 441-443. 
95. Parker, Kenneth W.; Martin, S. Clark. 1952. The mesquite problem on southern Arizona ranges. Circular No. 908. Washington, DC: U.S. Department of Agriculture. 70 p. 
96. Paulsen, Harold A., Jr.; Ares, Fred N. 1962. Grazing values and management of black grama and tobosa grasslands and associated shrub ranges of the Southwest. Tech. Bull. No. 1270. Washington, DC: U.S. Department of Agriculture, Forest Service. 56 p. 
97. Pieper, Rex D.; Herbel, Carlton H. 1982. Herbage dynamics and primary productivity of a desert grassland ecosystem. Bulletin 695. Las Cruces, NM: New Mexico University, Agricultural Experiment Station. 43 p. 
98. Potter, Loren D.; Krenetsky, John C. 1967. Plant succession with released grazing on New Mexico range lands. Journal of Range Management. 20: 145-151. 
99. Raunkiaer, C. 1934. The life forms of plants and statistical plant geography. Oxford: Clarendon Press. 632 p. 
100. Reynolds, H. G.; Bohning, J. W. 1956. Effects of burning on a desert grass-shrub range in southern Arizona. Ecology. 37(4): 769-777. 
101. Reynolds, Hudson G.; Martin, S. Clark. 1968. Managing grass-shrub cattle ranges in the Southwest. Agric. Handb. 162. Washington, DC: U.S. Department of Agriculture, Forest Service. 34 p. 
102. Rosiere, R. E.; Beck, R. F.; Wallace, J. D. 1975. Cattle diets on semidesert grasslands: botanical composition. Journal of Range Management. 28: 89-93. 
103. Shiflet, Thomas N., ed. 1994. Rangeland cover types of the United States. Denver, CO: Society for Range Management. 152 p. 
104. Smith, Gretchen; Holechek, Jerry L.; Cardenas, Maual. 1996. Wildlife numbers on excellent and good condition Chihuahuan Desert rangelands: an observation. Journal of Range Management. 49(6): 489-493. 
105. Stein, Rebecca A.; Ludwig, John A. 1979. Vegetation and soil patterns on a Chihuahuan Desert bajada. The American Midland Naturalist. 101(1): 28-37. 
106. Stephens, G.; Whitford, W. G. 1993. Responses of Bouteloua eriopoda to irrigation and nitrogen fertilization in a Chihuahuan Desert grassland. Journal of Arid Environments. 24: 415-421. 
107. 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. 10 p. 
108. Stubbendieck, James; Hatch, Stephan L.; Butterfield, Charles H. 1992. North American range plants. 4th ed. Lincoln, NE: University of Nebraska Press. 493 p. 
109. Texas Parks and Wildlife Department. 1992. Plant communities of Texas (Series level): February 1992. Austin, TX: Texas Parks and Wildlife Department, Texas Natural Heritage Program. 38 p. 
110. Tiedemann, Arthur R.; Klemmedson, James O. 1973. Effect of mesquite on physical and chemical properties of the soil. Journal of Range Management. 26(1): 27-29. 
111. Tiedemann, Arthur R.; Klemmedson, J. O.; Ogden, P. R. 1971. Response of perrenial southwestern grasses to shade. Journal of Range Management. 24: 442-447. 
112. Tschirley, Fred H.; Martin, S. Clark. 1961. Burroweed on southern Arizona range lands. Technical Bulletin 146. Tucson, AZ: University of Arizona, Agricultural Experiment Station. 34 p. 
113. U.S. Department of Agriculture, Soil Conservation Service. 1994. Plants of the U.S.--alphabetical listing. Washington, DC: U.S. Department of Agriculture, Soil Conservation Service. 954 p. 
114. Valentine, K. A. 1970. Influence of grazing intensity on improvement of deteriorated black grama range. Bulletin 553. Las Cruces, NM: New Mexico State University, Agricultural Experiment Station. 21 p. 
115. Wansi, Tchouassi; Pieper, Rex D.; Beck, Reldon F.; Murray, Leigh W. 1992. Botanical content of black-tailed jackrabbit diets on semidesert rangeland. The Great Basin Naturalist. 52(4): 300-308. 
116. Warren, Alan; Holechek, Jerry; Cardenas, Manual. 1996. Honey mesquite influences on Chihuahuan desert vegetation. Journal of Range Management. 49(1): 46-52. 
117. Weber, William A.; Wittmann, Ronald C. 1996. Colorado flora: eastern slope. 2nd ed. Niwot, CO: University Press of Colorado. 524 p. 
118. Whitfield, Charles J.; Anderson, Hugh L. 1938. Secondary succession in the desert plains grassland. Ecology. 19(2): 171-180. 
119. Wierenga, P. J.; Hendrickx, J. M. H.; Nash, M. H.; [and others]. 1987. Variation of soil and vegetation with distance along a transect in the Chihuahuan Desert. Journal of Arid Environments. 13: 53-63. 
120. Wolters, Gale L.; Loftin, Samuel R.; Aguilar, Richard. 1996. Changes in species composition along a Chihuahuan Desert scrub/desert grassland transition zone in central New Mexico. In: West, N. E., ed. Proceedings, 5th international rangeland congress symposium; 1995 July 23-28; Salt Lake City, UT. Denver, CO: Society for Range Management: 323-324. 
121. Wood, John E. 1969. Rodent populations and their impact on desert rangelands. Bulletin 555. Las Cruces, NM: New Mexico State University, Agricultural Experiment Station. 17 p. 
122. Woodmansee, Robert G.; Potter, Loren D. 1971. Natural reproduction of winterfat (Eurotia lanata) in New Mexico. Journal of Range Management. 24(1): 24-30. 
123. Wright, Henry A. 1980. The role and use of fire in the semidesert grass-shrub type. Gen. Tech. Rep. INT-85. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Forest and Range Experiment Station. 24 p. 
124. Wright, Henry A.; Bailey, Arthur W. 1982. Fire ecology: United States and southern Canada. New York: John Wiley & Sons. 501 p. 
125. Wright, R. Gerald; Van Dyne, George M. 1976. Environmental factors influencing semidesert grassland perennial grass demography. The Southwestern Naturalist. 21(3): 259-274.