Livestock Grazing in the Chihuahuan Desert

Rex D. Pieper

New Mexico State University

Introduction

Domestic livestock have been in the Chihuahuan Desert for more than five

centuries. Domestic cattle, sheep, and goats did not evolve on the semidesert grasslands

and opposition to their grazing stems largely from real or perceived detrimental impacts

to plants, animals, soil conditions and overall watershed condition (Fleischner 1994 and

Jacobs 1991).

The foundation for livestock grazing is based on the conversion of herbage to

food suitable for humans through the ruminant animal. Livestock grazing can be

ecologically as well as economically sustainable (Holechek 1992). Many livestock

operators insist that it is in their best interests to maintain productive rangelands since

their livelihoods and that of their heirs depend upon it (McSweeney 1995). Ranching

communities form the economic back bone of many rural communities throughout the

western United States.

While grazing and browsing is nearly universal in all ecosystems, livestock play a

unique role since they are nearly completely under human control. Their impacts can

range from almost undetectable removal of plant material to severe depletion of

vegetational resources and extensive erosion.

Since livestock can have such diverse impacts on rangelands, it is necessary to

include their role in any large scale management program aimed at maintaining

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maximum biodiversity while considering existing economic, social and political realities

in the Chihuahuan Desert. The intent of this paper is to review the historical

developments, and the socio-economics of livestock grazing. The paper will also review

the current status of livestock production in the U. S. portions of the Chihuahuan Desert,

and the ecological role of livestock in the Chihuahuan Desert.

History of Livestock Industry in the Chihuahuan Desert

Early Spanish Exploration and Settlements

Livestock were introduced into the New World through Mexico. Large land

holdings or haciendas were formed as the main component of livestock operations from

1530 to the 1920s (Jordan 1993, Molinar-Holguin et al. 1998, LaBaume and Dahl 1986,

Wagoner 1952). The number and distribution of livestock throughout the New World

during this 500 year period is poorly documented. The Mexican Revolution of 1910

resulted in a series of land reforms whereby the haciendas were broken up and communal

farms, called ejidos, were formed. Under the ejido system several families were assigned

to the ejido and their support was dependent on agricultural income from the land. In

spite of the various land reforms since the 1920s, some Mexican families were able to

maintain fairly large, private land holdings.

Spanish explorers such as Cortez and Coronado brought livestock into what is

now the U.S. portion of the Chihuahuan Desert during the 1500s (Schickedanz 1982).

Father Eusebio Kino is credited with introducing livestock into what is now southeastern

Arizona, in 1691, to support the missions he established (Bahre 1995). By 1680, over

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9,000 head of cattle grazed along the Rio Grande near El Paso (Jordan 1993). These

cattle were probably associated with the Spanish missions of the area. Only 5,000 head

of cattle were reported in the entire state of New Mexico in 1850. Livestock numbers in

New Mexico were never as high as during the expansion of the industry following the

Civil War, approximately 1862-1893 (Schickedanz 1980). In Texas, most livestock

operations prior to 1820 were present in eastern Texas and the productive coastal areas

on the Gulf of Mexico. Texans from these regions eventually expanded into the Big

Bend and Trans Pecos regions (Jordan 1993). Expansions into southern New Mexico and

Arizona occurred later (around 1850 and again, following the Civil War, in 1862).

Westward Expansion After Civil War

The major expansion of livestock into the Chihuahuan Desert in the U. S.

occurred after 1862 (Schickedanz 1980 and Wagoner 1952). Development of the

livestock industry in southern Arizona and New Mexico was fueled by gold discoveries

in California, the need for beef to feed soldiers in military forts built to protect settlers

from native Americans, and the development of the rail system which provided access to

eastern beef markets. By 1879, cattle prices were as high as $15.39.per head and had

increased to $23.52 by 1884 (Crouch 1989).

In addition, land disposal acts such as the Homestead Act (1862), and later the

Enlarged Homestead Act (1909) and the Stockraising Homestead Act (1916) provided

individuals with title to the land provided prescribed conditions were met such as making

improvements and living on the land (Holechek et al. 1998). In most cases these acreages

were insufficient to provide an economically viable livestock operation due to low

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producing soils and climate conditions. Consequently, it was necessary to combine

several homesteads to include sufficient land for a family to make a living.

Concern About Heavy Livestock Grazing

The influx of cattle to the U.S. portion of the Chihuahuan Desert after the Civil

War often resulted in heavy grazing pressure on these fragile rangelands. There were

several reasons for heavy stocking during this period. Much of the range was “open”, not

fenced or controlled, and restrictions were few. The range was grazed as a commons and

there was little incentive for conservative grazing: forage went to those who had their

livestock there first (Hardin 1968 and Hardin and Baden 1977). In addition, early

ranchers were accustomed to more productive areas of east Texas or the mid West and

probably overestimated the productive capacity of desert rangelands. There was little

experience or knowledge of the long-term consequences of heavy stocking in this region

of unpredictable rainfall. In New Mexico, cattle numbers peaked in the late 1800s and

again about 1920 (Figure 1). In the southern counties of Arizona, cattle numbers also

peaked at these two times (Figure 2). Bahre (1995) showed that cattle numbers peaked in

1900 in Pima, Cochise, and Santa Cruz Counties in Arizona. He reported that 150,000

head of cattle likely grazed in Pima County, Arizona in 1890 compared to less than

60,000 after World War II.

Early botanists and foresters became alarmed about rangeland conditions in

southern New Mexico and Arizona near the turn of the century. Wooton (1908) wrote

that "Examination of the range shows it to be run down and not nearly as productive as it

might be and as it once was”. Thornber (1910) warned of dire consequences of heavy

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stocking in Arizona. He estimated that stocking was about double the appropriate

carrying capacity of the rangeland. Many range scientists recognized that considerable

range deterioration occurred during this period of uncontrolled grazing (Blaisdell and

Sharp 1979, Krueger 1988, Laycock 1994, and Miller 1994). Rangeland deterioration

due to heavy cattle grazing was probably not evenly distributed across the landscape,

however, specific case studies in the Chihuahuan Desert from this period are lacking..

.

Conservation Movements

Concern over deteriorating conditions of many western rangelands convinced the

U.S. Congress to investigate. The result was a comprehensive study conducted by

knowledgeable scientists and managers and publication of Senate Document 199, titled

"The Western Range." This document led to passage of the Taylor Grazing Act whereby

remaining portions of the public domain came under control of the Bureau of Land

Management in the Department of Interior (Fairfax 1984). To foster sustainable grazing

practices, both the BLM and the U.S. Forest established seasons of grazing and stocking

rates for those granted grazing permits.

Setting and Background for Livestock Production

Ecological Setting

Several characteristics of the Chihuahuan Desert influence livestock production

practices in major ways. First, the climate is extremely variable in time and space.

Range vegetation (grasses and other herbaceous plants) grows mainly during the summer

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hot season when precipitation reaches a peak. During other times some plant species

provide forage for livestock, but they are less reliable than perennial grasses. Long-term

precipitation records (50-60 years) at several locations in southern New Mexico varied

from 5.9 to 23.2 inches annually. In southern Arizona the documented variation ranges

from 4 to 21.4 inches annually (Nichols et al. 1996) (Fig. 3). Interspersed within these

yearly variations are periodic droughts. Tree-ring records indicate droughts from 1667-

81, 1730-1750, and the recent drought of the 1950s (Betancourt et al. 1993). After the

drought of the 1950s, perennial grasses recovered on shallow soils but did not recover on

deep, sandy soils (Herbel et al. 1972 and Herbel and Gibbens 1996).

Not only is precipitation in the Chihuahuan Desert extremely variable, it is also

low, resulting in low plant production. Comparative studies of North American

grasslands reveal that Chihuahuan Desert grasslands have the lowest plant productivity of

any U. S. grassland except for some Palouse grasslands in the state of Washington

(Lauenroth 1979, Sims and Singh 1978). Paulsen and Ares (1962) reported that biomass

of perennial grass never exceeded 700 lbs/acre and was as low as 150 lbs/acre on the

Jornada Plain between 1939 and 1953. Pieper and Herbel (1982) reported that plant

standing crop varied from 582 lbs/acre during a year with high precipitation to 281

lbs/acre during a year with low precipitation. Low production means that livestock

operators need extensive rangeland holdings for an economic unit and must maintain a

flexible operation. Part of the flexibility probably means conservative stocking to

minimize financial emergencies, such as purchasing hay, during drought (Martin 1975).

Stocking rates of about three animal units yearly per “section” (which is 640

acres, or 1 mile x 1 mile) in southern New Mexico resulted in average utilization of 25%

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of the perennial grasses (Beck 1978). This is a conservative stocking rate and seems to

cause minimal impacts to soils, plants, and other animal species. An animal unit is

usually a 1000 pound cow or her equivalent, such as 5 sheep or 8 goats). In southern

Arizona, Reynolds and Martin (1968) reported that a stocking rate of 4 animal units per

section on a year-round basis resulted in 40% utilization of grass species. The higher

utilization caused by one cow indicates that the carrying capacity, or grass production, in

the Arizona site, was substantially less than the New Mexico site.

The basic vegetational change during the past 150 years has been one of

increasing shrublands at the expense of grasslands. Grasslands shifted into shrublands on

the Jornada Experimental Range from 1958 through 1963 (Table 4). A number of factors

may be involved in these changes: direct effect of defoliation by livestock on perennial

grasses, which leaves the grasses vulnerable to competition from shrubs; dispersion of

shrub fruits and seeds by livestock in their feces; influence of native small grazing

mammals such as jackrabbits; climatic change and variability; increasing atmospheric

CO2 concentrations; reduction in wildfire frequency and intensity; and several other

possible mechanisms (Allred 1996, Archer 1994, Betancourt et al. 1993, Brown and

Heske 1990 Buffington and Herbel 1965, Conley et al 1992, Gibbens et al. 1993, Grover

and Musick 1990, Humphrey 1958, Johnson et al. 1993, Neilson 1986, Paulsen and Ares

1962, York and Dick-Peddie). It is likely that several factors were involved in these

change from grassland to shrubland, and perhaps different ones occurred at different

times and places (Pieper 1996a, 1996b).

The ecological characteristics of the Chihuahuan Desert might suggest that

livestock grazing is not a viable use here. However, these environments offer certain

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advantages for livestock production if sufficient area is available to support economic

units (sufficient income to support a family). Desert rangelands provide nutritious forage

on an annual basis. Because some green feed is usually available throughout the year,

supplemental feeding can be minimized. Snow cover does not prevent livestock from

reaching forage. Parasites and disease are not important constraints for livestock

production as in more humid climates. In addition, conservative livestock grazing

appears to be ecologically sustainable for relatively long periods of time (Pieper et al.

1992). Long-term studies on the Jornada Experimental Range and the Chihuahuan

Desert Rangeland Research Center shows that herbage production could be maintained

for periods as long as 50 years under conservative stocking.

While a number of factors shaped the current status of Chihuahuan Desert

rangeland, a comprehensive evaluation of range conditions is not available. In the United

States, range condition has traditionally been evaluated on an ecological basis - how far

the present vegetation deviates from the perceived “climax” which is the vegetation

composition before settlement by Europeans (Dyksterhuis 1949). No comprehensive

survey of rangeland conditions or status has been made for the Chihuahuan Desert using

this ecological basis, however, the Society for Range Management (1989) summarized

the data available for the states of Arizona, New Mexico, and Texas. These data indicate

that rangelands are in several ecological categories. Much of the BLM, private and

Indian Land is below excellent condition, but this classification does not indicate how

well the present condition meets needs of specific uses (Table 1).

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Grassland might occur under certain environmental conditions, but that when

shrub density became high enough a threshold is passed and grassland would not return

without direct intervention (brush control, grass seeding, etc.) (Archer 1989).

Two independent efforts incorporated these concepts in range condition

classification (Busby et al. 1994 and RISC 1995). These reports suggested the use of

terms such as healthy, at risk, and unhealthy (Busby et al. 1994) and satisfactory and

unsatisfactory (RISC) depending on whether or not the present status of the site met

criteria for the desired situation. These terms replaced the value-laden stages excellent,

good, fair and poor used in the older system.

Federal land management agencies such as the Natural Resource Conservation

Service (formerly SCS), Forest Service, and BLM have embraced these concepts. The

NRCS is in the process of revising their range site guides to conform to ideas of multiple

states for each range site rather than a single climax state.

One study in the Chihuahuan Desert in southern New Mexico indicated that plant

species diversity was often higher under grazing compared to areas inside exclosures

(Table 2). Detailed analyses indicated that plant species diversity is a function of length

of time an area has been subjected to livestock grazing (Milchunas and Lauenroth 1988,

1993). These studies suggest that for semiarid rangelands, with short grazing history,

plant diversity increases slightly as grazing intensity increases and then declines sharply.

On areas with a long history of livestock grazing, plant species diversity declines

gradually as grazing intensity increases.

Data on Mexican rangeland conditions and status are not available. However,

observations by trained observers indicate that heavy livestock grazing has resulted in

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deterioration throughout the Chihuahuan Desert regions (Buller et al. 1960, Soltero-

Gardea and Negrete-Ramos 1997, Molinar et al. 1998). Chapela (1996) stated that "arid

rangelands in Mexico suffer from a degradation process where overgrazing results in less

vegetation cover, less water infiltration and soil runoff, less forage production, more

overgrazing and so on." There is some indication that deterioration may be greater on

ejidos than on private ranches, but exceptions probably occur (Molinar et al. 1998).

Economic Setting

In the western U.S., livestock ranches are generally large, often comprising tens

of thousands acres. Investments for a minimal economic ranch operation (300 unit

breeding herd) is more than $750,000 (Workman and King 1982). In southwestern New

Mexico, average investment per animal unit year was $3,300 (Torell et al. 1998). Often

net returns are negative for a given year depending on feed costs, weather variables, and

livestock prices. For example, in 1996 medium-sized ranches in southwestern New

Mexico showed a -6.44 % return on investments (Torell et al. 1998). Historically, return

on investments has been low for public land ranchers (about 2% without consideration of

land appreciation) (Fowler and Torell 1987 and Workman 1986). Fowler and Gray

(1988) reported negative net returns to operator labor, management, and total capital for

New Mexico ranchers for three out of twenty years between 1950 and 1969. In Texas,

return to land, labor, management and risk was over $11,000 annually for a 100 cow-calf

unit and $15,000 for a 100 cow-yearling operation (Sharp and Boykin 1967).

Many ranchers in New Mexico and Arizona lease grazing land from federal or

state agencies. For example on medium-sized ranches in southwestern New Mexico,

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42% of the grazing land was private, 40% state leased land, and 18% leased from the

Bureau of Land Management (Torrell et al. 1998). In Texas most rangeland is in private

ownership.

In New Mexico, variable costs for medium-sized ranches in the southwestern

portion of the state, were $42,800 annually compared to $23,086 in fixed costs (Torell et

al. 1998). The largest item of fixed costs was equipment depreciation of over $10,000

per year. Purchased feed costs (hay, grain, liquid feed, protein supplements, salt and

minerals) were the largest variable cost items (over $23,000 annually). In contrast,

grazing fees for state and BLM lands were less that $5000 annually. Costs for small and

large ranches were proportionately smaller and larger than those for medium ranches

(Torell et al. 1998).

Two rather recent changes in ranching in the U.S. portions of the Chihuahuan

Desert have impacts on livestock operations here. The first is change in ownership from

those depending on ranch income for their livelihood to absent owners (termed

“gentlemen ranchers” by Fowler and Torell (1987)) who do not depend upon the ranch

for main income and may only use ranches as an income tax advantage or for recreational

purposes. An example is the purchase of the Ladder and Armendariz Ranches in central

New Mexico by the millionaire Ted Turner. Mr. Turner has removed livestock from

these ranches and introduced bison. These ranches are to be operated on a commercial

basis with bison as the product and not livestock.

The second trend is part-time ranchers. Seventy five percent of small ranches in

New Mexico have people working off the ranch contributing 44% of the family income.

For medium ranches, 55% have family members working off the ranch, contributing 20%

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of the family income (Fowler 1994). Ranch income has declined to the point where it is

not possible to make sufficient income to support a family.

Another factor in livestock ranching has been a recent decline in ranch values

(Torell and Kincaid 1996). Ranch values increased at a steady rate during the 1950s and

60s, accelerated sharply during the 1970s and then declined as much as 30% between

1982 and 1987 in New Mexico (Torell and Doll 1991). Initially ranch values were

determined mostly by estimated grazing capacity with little distinction between private

and leased grazing permits. A ranch was valued based on total grazing capacity. Thus,

ranchers were reluctant to reduce the permitted numbers on their state or federal grazing

lease since this reduced the value of the ranch. However, during the past 10 years leased

state or federal grazing lands have had a ranch market value of about 20 to 40% of

deeded (private) land. In Texas ,with essentially all private land, market forces have

determined ranch value.

Social Setting

Ranching has a long history in the Chihuahuan Desert beginning with the

haciendas established in Mexico in the 1500s and 1600s. In the southwestern U.S.,

ranches were established during the 1800s with major expansion after the 1862. These

ranches represented a rural way of life and often supported local communities. In New

Mexico, the average rancher spends over $16,000 annually for local goods and services

(Fowler 1994). With multiplier effects these expenditures represent substantial

contributions to the economy of these rural communities (Beutler 1992).

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Ranchers contend that they are good stewards of the land, and contribute to

wildlife habitat through water developments and “range improvements” such as grass

seedings or shrub eradication. These ranchers have a strong interest in maintaining

sustainable livestock operations for their heirs.

During the last several decades people without livestock backgrounds have

invested in ranches. The ranch may be a financial investment, or used for tax purposes,

or simply purchased for its open spaces and esthetic values.

In addition to those who use Chihuahuan Desert areas for commercial enterprises,

there are many who have other interests. These include off-road vehicle enthusiasts,

hikers, hunters, and bird watchers. The main concern of some of these groups is access

to the land and restrictions on use of fragile desert areas may not be supported.

While some would argue that ranching in the Chihuahuan Desert is not

economically viable, ranchers would counter that their main concern is not necessarily

economics per se. McSweeney (1995) found, after interviewing 18 ranchers in northern

New Mexico, that the main reason for these ranchers staying in the ranching business

was satisfaction with the life style. The same reason may prevail for Chihuahuan Desert

ranchers. Favorable economic return was secondary.

Political Setting

As mentioned, the Taylor Grazing Act established what was to become the

Bureau of Land Management. In 1976, the U.S. Congress passed the Federal Land

Policy and Management Act, an Organic Act for the management of public lands under

the BLM. FLPMA, as the Act became to be known, provided that "the public lands be

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managed in a manner that will protect the quality of scientific, scenic, historical,

ecological, environmental, air and atmospheric, water resource, and archeological values;

that, where appropriate, will preserve and protect certain public lands in their natural

condition; that will provide food and habitat for fish and wildlife and domestic animals;

and that will provide for outdoor recreation and human occupancy and use.”

Another congressional act in the U.S. was the National Environmental Policy Act

of 1969. This act required preparation of Environmental Impact Statements or

Environmental Assessments for every BLM activity on the land. Resource Management

Plans are now used to guide activities on the public lands.

These and many other acts present regulations for ranchers and agencies to

follow. Many rancher groups argue that land should be controlled locally and not from

the nation's capital or by those not directly connected to the land. Disputes have been

common between ranchers and land management agencies, between ranchers and

environmental groups, and between environmental groups and land management

agencies

Current Debate

The current debate about livestock grazing in the Chihuahuan centers around

grazing impacts. The basic argument is that livestock remove plant material during the

grazing process and the grazed plants have a reduced competitive ability (Caldwell 1984

and Pieper 1994). Thus palatable plants gradually decline in abundance and less

palatable plants tend to increase. Often less palatable plants are shrubs or other

undesirable forage plants. Eventually, under continued heavy stocking, even some of the

14

unpalatable plants are grazed and erosion accelerates. Fleischner (1994) reviewed

grazing studies in the western U. S. (including three in Chihuahuan Desert locations in

Arizona and New Mexico) and concluded that "The ecological costs of this nearly

ubiquitous form of land use can be dramatic. Examples of such costs include loss of

biodiversity; lowering of population densities for a wide variety of taxa; disruption of

ecosystem functions, including nutrient cycling and succession; change in community

organization; and change in the physical characteristics of both terrestrial and aquatic

habitats." Later Brown and McDonald (1995) disputed many of the conclusions made by

Fleischner, stating "We detect a dangerously one-sided presentation of data and opinions

on livestock grazing....” In the southwestern U.S., results of exclosure studies have

presented somewhat variable results (Table 3). In some cases, density of grasses was

higher under protection and in other cases under livestock grazing. The problem with

such studies is that we seldom know the grazing pressure just outside the exclosure where

vegetational measurements are made. At least these studies suggest that livestock

grazing may not be detrimental in the Chihuahuan desert. Three long-term grazing

studies in the Chihuahuan Desert in southern New Mexico (one nearly 50 years and the

other one nearly 40 years) suggest that conservative livestock grazing is sustainable

(Pieper et al. 1992).

Much of the current debate in the southwestern U. S. centers on riparian systems.

These systems tend to attract both livestock and people. Livestock concentrations have

been blamed on deterioration of riparian. Federal judges have upheld requests from

environmental groups to fence riparian areas from livestock grazing. Although detailed

studies comparing vegetation on grazed and ungrazed riparian areas are lacking for the

15

Southwest (Bock et al. 1993) studies in other regions have linked heavy livestock

concentrations with degraded riparian habitats (Chaney and Elmore 1993 and Fleischner

1994). Limited studies in southwestern New Mexico indicate that cattle do not prefer

riparian areas during all seasons. Near Fort Bayard, NM, on the northern edge of the

Chihuahuan Desert, cattle spent 95% of their time in upland areas and only 5% of their

time in riparian areas during the dormant season (Goodman 1987). These data suggest

that control of grazing on riparian areas could minimize detrimental impact of grazing on

these important areas.

Grazing Fees

Another controversial subject on public lands in the U.S. has been grazing fees

charged to livestock operators for grazing privileges. Grazing fees have been set by a

formula based partly on livestock prices, grazing leases on private land and costs of beef

production (Torell et al. 1995). Opponents of livestock grazing on public lands argue

that these fees are much lower than comparable fees on private lands and therefore public

land ranchers are being subsidized. Ranchers counter that public land grazing permits do

not include many amenities routinely included in private leases. Detailed analyses by

several economists in the western states indicated that perhaps current fees are slightly

undervalued, but the problem is complex and determining fair fees is not an easy task

(Torell et al. 1992, Torell et al. 1995).

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Endangered Species Management

Management of endangered species is another problem on U.S. rangelands.

According to the Endangered Species Act, endangered species and habitats must be

protected. In many cases livestock grazing is identified as the main threat for endangered

species. An example in Arizona and New Mexico is the southwestern Willow Flycatcher

that inhabits riparian areas. Environmental groups have listed current and historic

livestock grazing as one factor responsible for low population densities. On the other

hand rancher David Ogilvie reported that nest densities, number of young and adult birds

were higher on grazed riparian areas on the U Bar Ranch in southwestern New Mexico

than on comparable protected areas (Ogilvie 1998). Apparently, necessary habitat

components for the flycatcher (e.g. willows and cottonwoods) could be maintained under

the grazing regime practiced on the ranch.

Some areas of public ranges have been grazed by the same family for several

decades. These ranchers view livestock grazing as a "right" and not a privilege. Such

contentions fly in face of the idea that public lands belong to all the people and all have a

"right" to enjoy and use these lands.

Conclusion – A Plea For Planning at Coarse Scales

Vegetational patterns in the Chihuahuan Desert are complex with a variety of

plant communities occurring on different soils and topographic positions. Plant species

diversity is different for each of these communities. Animals also correspond to

vegetational patterns. In the Chihuahuan Desert planning at the landscape level would

entail determining goals for size and arrangement of grassland, mixed grass-shrub, and

17

shrubby communities. Each of these communities support a unique assemblage of

animals although there may be overlap and use of more than one community by some

species. Biodiversity might best be served by creating mosaics of vegetational patches of

different shapes and sizes. Livestock at low densities could play a role in maintaining

some of these patches, could be neutral or contribute to large degraded states. Such

planning might involve passive restoration of some plant species in the mix to favor

certain animal species and to increase vegetational diversity or reduction in density and

size of others (Fulbright 1996). The key is to manage habitats and species will follow.

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