WWF Chihuahuan Desert Ecoregion Notes

• Chihuahuan Desert Ecoregion Program World Wildlife Fund-Mexico - WWFBinaryitem2774.pdf


• Spain 1550-1821


• [wild] bison, wild boar and hares, rabbits [moved from USA/Mexico b/c no borders and no degradation yet. Only turkey, goose and hairless dog was domesticated for a small group of families (Saucedo, 1984).


• 1521 start cattle industry. Monopoly by 1523.


• began the breeding of horses, mules and sawhorses for hard work


• principal uses of this kind of cattle was transporting people, mining and cattle management (Saucedo, 1984). Near 1555 it is said that were about 60 estancias with more than 150,000 beef cattle and mares (Esparza, 1988).


• all the settler wanted was to increase the number of animals, not to improve the breed [make gold]


• By 1542 or 1545 the pressure of animals in central México was very hard


• 1777 pacify and evangelize indians, with this the subdue of indians to make toil labor were easy and they can own land for missions.


• mining activity in Zacatecas, the use ofhorses and mules


• the trail of Fresnillo and Sombrerete he could observe good grasses, and in the Haciendas of Los Muleros and El Ojo had breeding of cattle, horses and about 60,000 sheeps. In 1736 only in onedistrit of the Curato of Sagrario grazed 80,000 beef cattle, 2,000 herds of mares, that anualy brought2,000 mules and horses, and 5,000 bulls and cows and 150,000 sheeps. In the time Morfi arrived, he just could see trace of that land.


• Beef catttle decrease by the XVII century and the sheep develop extraordinarily (Esparza, 1988). In the 18th and 19th century cattle and horses were essentially feral animals looking after themselves on vast expenses of semiarid rangelands (Young et al., 1979).


• 1570 to 86 - branded about 37,000 -42,000 bull calfs annually. about 50 or 60 thousands of breeding cows (Esparza, 1988).


• 1800s - Establecimiento de infraestructura necesaria para la explotación de la tierra


• Comercialización de sus productos en los centros urbanos y poblaciones dedicadas a actividades económicas diversas, como la minería.


• México 1821-1914 La monarquía española ejerció una presión que iba en aumento y produjo una fuerte reacción de todas las clases sociales que habitaban el país, esto se tradujo en el movimiento de independencia que derrocó al régimen colonial (Saucedo, 1984).


• México 1914 to present By 1991 with the reform of Art. 27, exists in México 27,410 ejidos that occupied more than half of México's arable land and nominally provide employment for 3.1 million of ejidatarios. The reforms of Art. 27 may have a more far reaching and enduring impact than any other economic reforms introduced in México by technocratic governments sinse 1982 (Cornelius &Myhre, 1998). The reform of Art. 27 came a part of a package of neoliberal reforms. These include the North American Free trade Agreement (NAFTA), privatization of states enterprises, desregulation of agricultural produce markets, and the privatization of irrigation water management.


• with NAFTA, for the ejidatario household, these changes brought a heightened sense of vulnerability, withtwo consequences. First, households were more inclined to rent out their land while they diversified household income through migration to the United States and nearby Mexican cities. Second, the renting of land to nonejidatarios, created a shadow social structure, interests outside of ejido organizations can teke control of land and possibly water resources.


• In the process, ejidatarios will create new organizations, both formal and informal, as they redefine their own identity and their relationship to the state (Cornelius & Myhre, 1998).


• By 1500, before European settlers came to North America, between 60 million and 125 million of grass eating american bison roamed the plain, prairies, and woodlands over most the continent. Single herds covered thousands of square kilometers of land. First american settlers viewed the continent as a hostile wilderness to be conquered, opened up, cleared and used as quickly as possible. This frontier attitude led to enormous resource waste and little regard for future resource needs (Miller,1992).


• By 1840, Ohio settlers had occupied mosto of the prairie land adjacent to rivers and timber, and some were moving to Indiana, Missouri and the Lake States, the grasslands were practically untouched (Doanahue et al., 1956).


• During the period of 1850 to 1880, the prairies and plains were effective barriers to westward expansion. For two hundred years agricultural settlement had followed streams, but here a few narrow trails were the only routes into the vast tall-grass paririe and short-grass plains beyond. Indians were a constant threat to the settlement of the west. Population pressure on the east forced settlers to establish new communities on the prairies from Ohio to Mississippi and from Canada to Texas. A few years later the steel plow proved to be an effective implement for reducing manual labor and animal power (Donahue et al., 1956).


• In 1849 the gold rush to California temporarily diverted the efforts to conquer the prairies. Easter farmers who had been accostumed to high rainfall soon found thattheir crops and methods were not adapted to the Great Plains. The settlement of the Great Plains was the beginning of dry farming in the United States.The natural vegetation was the main factor in the development of the range-cattle industry. Such native grasses as the gramas, buffalograss and mesquite grass provided goor grazing in the states to which they were adapted. Mixtures of warm-season and cool-season grasses were a dependable source of forage from early spring to late fall, and the dry vegetation which consisted of standing grasses that had notbeen heavily grazed was good winter pasture (Donahue, et al., 1956).


• By 1854 the steam railroad not only made the grassland a grain-growing area, but also provided the structure for its livestock economy. It made also possible the marketing of the Pacific Coast products and the Northwest populations at the population centers of the East (Malin, 1956).


• In 1883 the Texas Pacific Railroad was built through the heart of the range country. Owners, agents of land and investors were seeking to acquire free range and free grass. The native grasses would support 300 head of stock per square mile. New comers thourht that this richness of vegetation was normal. The result was graped an exhausting overstocking. The best grasses were eaten down to their very roots. Every green thing was eaten down, they could neither ripen seed and thus preservate its kind.


• The grazing capacity has been reduced within a period of twenty years, from one head to 2-5 acres to 1 head to 20-25 acres (in annex 2 show thw list of the replies received from stock and rangeownerr in the State of Texas in 1894). Such denuded areas occur in New Mexico and Arizona. The chief cause of overstocking was the free range system.


• Southern prairies, the stockmen seen the change with grasses only at intervals and prickly pear near so thick to drive cattle (Smith, 1899)


• Because the grassland possessed environmental peculiarities quite unlike the conditions of the forest, European-American culture with its forest background approached it with an unconscious ecological outlook quite foreign to the requirements oflife under the strange conditions thathad produced a grassland. The grassland was characteristically a "sawed house", not a "sod house", country and still remains so (Malin, 1956).


• According Miller (1992) after the Civil War, the federal government turned its attention to expanding the frontier westward. That meant displacing the Native Americans- mostlyApaches, Comanches, Arapahos, Kiowas, and Sioux.- who were obstacles to settling the plains this involved the mass killing of these indigenous people and of the american bison, which served as a major source of food and another resources for these dwellers en the land. In 1850, about the 85% of the total land area of the United States was government owned. Most of this land had been taken from indigenous Native Americans, who had lived on it sustainability for thousands of years. By 1876 remaining Native Americans had been pushed onto a few government-managed reservations. As railroad spreads westward, in the late 1860's, railroad companies hired professional bison hunters to supply construction crews with meat. The well known bison hunter "Buffalo Bill" Cody killed an estimated4,280 bison in only 18 months.


• ten years after the destruction of the buffalo herds, before the number of cattle and sheep on any portion of the ranges equaled the great herds of game. These years, from 1874 to 1884 may be called the "golden period" of the southwestern stockman. During this decade there were fewer head of stock, abundant rain and the seasons were favorable to the development of the grasses.It is common twestimony of the older stockmen that in the early eighties the grass was often as high as a cow's back, not only along the river bottoms, but also in uplands far from creeks and rivers( changes inbison population are shown graphically in annex 2) (Smith, 1899).


• In 1862 The first homestead law opened the west to agricultural settlement. Was designed to give settlers a chance to establish permanent homes on land which had been the public domain (Donahue et al., 1956).


• In 1916 The Stock-raising Homestead Act for land not adapted to cultivation, gave stockmen 640 acres (260 has.) to carry 50 head of cattle, this principle had followed for fifty four years (Stoddart et al., 1975; Donahue et al., 1956).


• About 73 percent of all public land in the contiguous 11 western states is grazed by domestic livestock (Nielsen and Workman, 1971). The percentage of privately owned land in the 11 western states that is grazed is probably even higher. Why is this land grazed by livestock rather than used in some other way? Range forage is a ¨ flow ¨3 resource that with present technology can be converted on a large scale to produts useful to man only throurgh livestock grazing.


• mayores incrementos en la producción de carne en relación con el crecimiento de la población humana los cuales han ocurrido en los Estados Unidos, Argentina y Australia.


• The small farmer-feeder, with a feedlot having a capacity of less than 1,000 head of cattle, owned 98% of all cattle feedlots in 1980, (Palme, 1983)


• 1980, commercial feedlots accounted for only 2% of all cattle feedlots, but they produced 72% of the fed cattle marketed


• For grazing private livestock on federal lands are currently st under a formula in the Public Rangelands Improvement Act of 1978. PRIA, s minimum fee of $ 1.35 per Animal Unit Month (AUM) - - the amount of forage needed to sustain one animal unit (one cow and calf, one horse, or five sheep or goats) for one month. 1996 grazing fees were the minimum $1.35 per AUM. The 1995 fee was $ 1.61 per AUM, and the 1994 fee was $ 1.98 per AUM. The declining fee reflects both falling beef prices and rising production costs (Cody and Baldwin, 1998) .


• The $ 1.35 grazing fee also applies to BLM lands and National Forests in Arizona, California, Colorado, ...New Mexico, etc. The grazing fee for national grasslands administered by the Forest Service in colorado, Kansas, New Mwxico, North Dakota,Oklahoma, South Dakota, Texas and Wyoming is $1.42 per AUM (Polk, 1996).


• When NAFTA took effect Jan. 1, 1994 tariffs on U.S. beef imports dropped from 20-25% to zero, pushing U.S beef trade with Mexico to record highs in 1994, up an estimated 69% over 1993. Similary, U.S. pork exports to Mexico were up an estimated 43% in 1994 over the prior year.


• the Mexican government has set a traget of 4.5 pesos to the U.S. dollar for the end of 1994, which amounts to a cost increase for U.S. meat imports of 21%. (Willis and Manuel, 1995).


• On January 1, 1994, the North American Free Trade Agreement (NAFTA) eliminated import tariffs of 15 and 20 percent on U.S. beef sales to Mexico. The latest USDA report shows U.S. beef exports up 28 percent in volume and 43 percent in value since NAFTA went into effect (Oates, 1994).


• environmental condition of public ranges deteriorated in the early 1900s because of overgrazing, and improvement since then has been slow and expensive. Taxpayers havepaid for federally supervised and subsidized grazing. Ranchers, the intended beneficiaries, have gained little except debt, insecurity, and mountains of regulations (Hess and Holecheck, 1995).


• discourage rancher stewardship and pay stockmen to overgraze and reward them for poor management practices


• BLM and the Forest Service now spend 10 to 20 percent more on their public-land grazing programs each year than public-land ranchers make in net profits. Moreover, six years of the combined rangeland budgets of the two agencies now equal or exceed the current market value of all federal grazing permits: roughly $1.2 billion. (Hess and Holecheck, 1995)


• First, ranchers, not taxpayers, should shoulder the fiscal burden of private grazing on publiclands. Second, grazing permits should be made marketable to persons other than ranchers and for uses other than livestock. Third, control over federal lands should be decentralized in selected areas on a trial basis. Fourth, range reform should be taken to its limits, extending local control and opening debate on partial or full divestiture of public lands.


• First, the deficit-ridden federal grazing program mustbe made fiscally sound to relieve taxpayers of an unnecessary burden. That means streamlining the operations of the BLM and the Forest Service. Second, economically and ecologically failed multiple-use policies must be replaced with market policies. That means shifting power over federal resources from bureaucrats and special-interest groups to the tens of millions of Americans who use the public lands each year. Third, control over federal rangelands must be decentralized and diversified. That means changing the laws and regulations that rule the federal estate and transferring powers once reserved to bureaucracies to new, locally elected governing councils. Fourth, more fundamental and sweeping reforms must be examined to prepare public grazing lands for the 21st century. That means far-reaching yet sustainable changes in the nature of stewardship, control, accountability, responsability, and ultimately, ownership on the nation´s vast federal grazing estate


• decentralizes management of and decision making about federal lands has the potential of yielding an arry of fiscal, civic, and environmental benefits. Devolution of federal authority to local, self-governing resource councils will reduce federal expenditures on resource management, expand opportunities for more effective public participation inland-use decision making


• Transformation ecology, which is founded on basic ecology, agronomy and physical sciences, should be a specialized branch of range sciencia. New approaches are necessary and renewed interests in the roll of organic matter and soil surface management providethe potential for a significant advancement in transformation ecology in finding new ways to solve the riddle. (Reynaga, 1994). Before we can rehabilitate rangeland ecosystems, we must understand their structure and function and its dynamics. If physicians are trained to treat sick human bodies, ecologists must be trained to treat sick land (Burges 1992). The capacity of rangelands to produce commodities and to satisfy values on a sustained basis depends on internal, self-sustaining ecological processes such as soil development,nutrient cycling, energy flow, and the structure and dynamics of the plant communities. (Reynaga, 1994)


• Cuando nuestros problemas con los arbustos y las malas hierbas se vuelven muy grandes, de tal forma que necesitamos controlarlos o cuando nuestros pastizales se deterioran tanto que debemos revegetarlos, ningún nivel de manejo del pastoreo mejorará la condición de nuestros pastizales. En este caso debemos dirigirnos hacia alguna forma de controlar los arbustos y malas hierbas o implementar un programa de resiembras. Podemos encontrar muchas exclusiones en pastizales áridos y semiáridos en todo el suroeste de los Estados Unidos, algunos de los cuales alcanzan entre 50 y 60 años, la vegetación deseable en esas exclusiones no produce más biomasa ni es de mejor calidad que la vegetación fuera de esas exclusiones y que ha sido sometida al pastoreo. Si queremos rehabilitar estos pastizales y regresarlos a un mayor estado de producción, necesitamos reconocer su potencial y hacer un gran esfuerzo para poder rehabilitarlos adecuadamente. Es imperativo que aprendamos más a cerca de la ecología del área que será rehabilitada, nuestras decisiones acerca de cómo, cuándo, y qué rehabilitaremos nuestros pastizales deberán estar basados en principios ecológicos y no en emocionalismos. Si tomamos nuestras decisiones basada en principios ecológicos podremos conservar nuestra rica herencia de recursos naturales para quepuedan ser utilizados por muchas generaciones que están por venir (Sosebee, 1994).


• The addition of shrubs and broadleaf herbs to native grasslands has greatly improved forage resources for livestock and game animals. In one earlier mentioned project, important increases in forage production were achieved through alternate row planting of shrubs and forbs with grasses in northern Utah. Adding fourwing saltbush to grass mixtures markedly increased the yield of herbage for cattle and big game on arid lands in Utah and Idaho. This shrub along with a shorter growing shrub, prostrate kochia, has provided important forage during the fall and winter grazing periods. Only one pound of fourwing saltbush seed per acre (0.18 Kg/ha) interplanted with Fairway wheatgrass on a cheatgrass burn in southern Idaho produced about 300 pounds of air-dry forage per acre (55 Kg/ha). Between 70 and 80 percent of the annual twig growth has been browsed each year by cattle. However, the plants have persisted and increased in stature over a 10-year period. (Monsen & Plummer, 1978)


• The importance of woody species for production of browse, protection of animals and soil, snow accumulation, stream-channel stability, and habitat suggested the research "to develop guidelines for the establishment or reestablishment of woody species adaptable to draws and upland sites". Other research at the Rapid City Research Unit pertains to rehabilitation of coal and bentonite mine spoils, and management of mine water impoundments. Rehabilitacion research focuses on the reestablishment of shrubs, trees, and forbs, while the water research concentrates on water quality for waterfowl, aquatic, plants, and aquatic invertebrate animals. (Bjugstad, 1978)


• Reclamation of Mine Spoils: Reseach shows that dryland techniques for reestablishment of shrub and tree species-such as green ash, Russian olive, poderosa pine, Rocky Mountain juniper, silver buffaloberry, American plum, and Siberian peashrub-on bentonite and low-salt coal spoils in northeastern Wyoming hace been moderately successful (Orr 1975). Green ash has the highest survival rate, 44 percent at the start of the third growing season. Rocky Mountain juniper and Russian olive are next with 24 percent; buffaloberry, Siberian peashrub pine, and American plum show survival rate of 7 percent or less. (Bjugstad, 1978)


• Dentro de las prácticas de fehabilitación se pueden utilizar resiebras,como en el caso del zacate Buffel común (Cenchrus ciliaris) es una gramínea perenne, amacollada de estación cálida. Fue introducido con éxito a la parte sur de Texas en 1947 y a México en 1954. Es de fácil establecimiento, altamente productivo, muy apetecible y digestible por el ganado, tolera el pastoreointensivo y es realativamente resistente a las sequías. (Hanselka & Johnson, 1991)


• publicados oficialmente; determinó también coeficientes de agostadero en 47% de la propiedad ganadera privada para la expedición de certificados de inafectabilidad; además de su función principal, COTECOCA ha incursionado en otros terrenos afines según Claverán (1993):


• A great deal of practical knowledge concerning rangeland conditions resides in the collective minds of ranchers (Downing and Folliott, 1981).


• La mayor parte de los suelos de México, estan afectadosen mayor o menor grado por erosión. Los estudios correspondientes estiman que este daño varía en todo el territorio de 71 a 86%, (dependiendo de los autores), pero aún el porcentaje estimado, representa un problema de importancia cardinal para el futuro del país. Desde luego que el sobrepastoreo no es el único culpable de esos porcentajes preocupantes, la agrícultura y la deforestación han contrubuído también generosamente. (Claverán, 1993)


• A study made by Smith et al., (1994)indicate that Chihuahuan desert ranges are in high ecological condition produce more forage that those in an earlier successional stage. Paulsen and Ares (1962) and Tembo (1990) in New Mexico, and Frost and Smith (1991) in Arizonaalso found forage production increased as ecological condition increased on desert ranges. Cattle grazing capacity might be 30 to 40% higher on excellent compared to good condition range


• Encroachment of woody plants into previously brushless areas


• Good grazing management techniques can control the establishment of undesirable woody plants but will not remove established plants unless those techniques, suchas the inclusion of goats for brush control - Brush management, then, is a management problem that must be approached on an ecological basis and within a closely defined economic framework.(Scifres, 1980).


• Savory (1988) contend that the present management techniques are doing long.term damage to range. Holistic Resource Management (HRM) is grounded upon three princeples: 1.- Grazing is good for grasslands, most distinguish between grazing and overgrazing. 2.- Over-grazing can be avoided by herbivore herding (reducing the pasture available to a herd or increasing the cattle density in a larger area).


• Samuel & Hart (1994) founf that.rangeland 10 - 20 years after disturbance may be superior to undisturbed range for cattle grazing. Disturbed range produced more forage in most years and had a much higher percentage of western wheatgrass, which is the most important grass in cattle diets on the Wyoming High Plains. Biological diversity also appears to be higher on disturbed range, which is not dominated by blue grama as is undisturbed range, but has a much higher percentage of forbs and other grasses. Secondary succesion proceeded through usual stages: annual forbs, perennial forbs and annual grasses, short-lived perennial grasses, and long-lived grasses. Western wheatgrass [Pascopyrum smithii (Rydb.) A loved] was an exception beacuse it appearedmuch earlier and in much greaterabundance than other long-lived perennial grasses. Blue grama [Bouteloua gracilis (H.B.K.) Lag ex. Steud.] may be another exception; total recovery of this grass may requiere centuries. Time of appearance in succession seemed to be related to availability of propagules and ease of establishment; (Samuel & Hart, 1994).


• importancia planear el control de arbustos y malas hierbas de acuerdo con la especie que se pretende controlar y del tiempo exacto en el cual esta especie es más suceptible su control con herbicidas.


• standing crop and litter (Kg/ha) for the three pastures in 1979 were(McGinty et al., 1979): Continuous Rotation Exclosure Standing Crop 1270 2257 1907 Litter 1188 2758 3031


• Clearly the rotation grazing did permit accumulation of greater aboveground biomass than the continuously heavily grazed pasture,although it was primarily dominated by shortgrasses at that time. (Amos & Gehlbach, 1988)


• hot, dry environment of the DesertGrasslands offers unique opportunities for the use of municipal biosolids (e.g., increased infiltration, decreasederosion) that are not available in other ecosystems. (Sosebee, 1994)


• Promising natural enemies have been identified on some of these weeds and a few insects are being tested at the USDA´s Biological Control of Weeds Laboratory near Buenos Aires, Argentina, by one of us (Cordo). At the moment, the weed that would seem acceptable to both the U.S. and Mexico for biological control are Gutierrezia, Baccharis, Flourensia,


• Monsen and Plummer (1978) try the addition of shrubs and broadleaf herbs to native grasslands has greatly improved forage resources for livestock and game animals


• prostrate kochia, has provided important forage during the fall and winter grazing periods


• southwestern United States shows a predominance of cattle; northern Mexico has not only cattle, but also a high proportion of sheep and goats. Rangeland management, in many cases, is animal specific, since the grazing patterns, browse preference, herd behavior, are distinct for each species


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