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biotaCattle and Sheep Grazing

old sheep grazing (21a).jpg (28133 bytes)
Sheep grazing in ponderosa pine forests and grasslands near Flagstaff, AZ, ca. 1899. Image 21a by F.H. Maude courtesy of Cline Library Special Collections, Northern Arizona University.

History

One of the most significant human-induced changes affecting the biota of the Colorado Plateau has been the widespread introduction of domestic livestock.  Brought to the Southwest by the Spanish in the late 1500s, cattle and sheep only began to have a significant impact on the region's biota with their large scale transportation into the region with the arrival of the railroads in the late 1800s. By 1890, hundreds of thousands of cattle and large numbers of sheep were grazing on the Plateau—in pine forests, on grasslands, and along riparian corridors.

Cattle Drive

Cattle Drive in Grand Staircase Escalante National Monument. Photo 1998 Ray Wheeler.

By the time federal forest reserves were proclaimed in the 1890s, ranchers on the Colorado Plateau had become accustomed to unregulated use of public lands as range for livestock. As a result of these excessive stocking numbers, once rich grasslands were seriously degraded even before the turn of the century, after less than a human generation of use. By the early 1900s, overstocking of sheep on many middle-elevation mesas and in the area's highlands had brought forest regeneration to a halt. The forest floor in some places was "as bare and compact as a roadbed." The fire ecology of the region's forests, particularly the once grass-rich ponderosa pine forests, was drastically altered, causing significant long-term changes to their structure and composition.

By 1912, livestock pressures had penetrated the most remote, timbered and mountainous areas. Theodore Rixon, one of the first foresters in the Southwest, described the situation:

"At the beginning the mountains and heavily timbered areas were used but little, but as the situation grew more acute in the more accessible regions the use of these areas became more general and in course of time conditions within them were more grave than elsewhere... The mountains were denuded of their vegetative cover, forest reproduction was damaged or destroyed, the slopes were seamed with deep erosion gullies, and the water-conserving power of the drainage basins became seriously impaired. Flocks passed each other on the trails, one rushing in to secure what the other had just abandoned as worthless, feed was deliberately wasted to prevent its utilization by others, the ranges were occupied before the snow had left them. Transient sheepmen roamed the country robbing the resident stockmen of forage that was justly theirs." (Source: Roberts, P.H. 1963. Hoof prints on forest ranges. San Antonio, TX: Naylor. 151 p.)

Over one hundred years later, the effects of intense grazing in the latter part of the 19th century can still be readily seen in many parts of the Colorado Plateau.

Impact on Riparian Areas

Ungrazed riparian area
Grazed riparian area

Photographs of ungrazed (top) and grazed (bottom) sections of the Rio de Las Vacas, New Mexico. Photographs courtesy of Forest Guardians.

Although riparian habitats represent less than 1 percent of the total acreage of public lands in the 11 western states, they are among the most biologically diverse and important fish and wildlife habitats. In Arizona and New Mexico, approximately 80 percent of all vertebrate wildlife use riparian habitat during part of their lives.

The abundance of food, water, and shade which attracts wildlife to these areas also attracts livestock. Despite widespread recognition of the problem and attempts to remove or restrict livestock from riparian areas, riparian degradation due to overgrazing is a serious problem on the Colorado Plateau. Destruction of streamside vegetation, shallowing of channels or its opposite, arroyo formation, are some of the effects of poor grazing practices.

Livestock and Water Use

One common misconception of water use in the Colorado River basin and in the West in general is that rapidly growing urban areas are the main users of the region's limited water. In the upper Colorado River basin states, Wyoming, Colorado, Utah, and New Mexico, 90% of the water used is spread on land irrigated for crops, leaving 10% for urban and other uses. Of the 1.6 million acres irrigated in the upper basin, feed for livestock is raised on 88% of the irrigated land. In the lower basin states, California, Arizona, and Nevada, 85% of water goes to agricultural purposes, with a significant but slightly less percentage going to grow feed for livestock. Of the 99 million acres in the lower basin, 82 million acres are rangeland or pasture, while only 500,000 acres are classified as urban.

Studies have shown that nearly all Colorado River water is used for the irrigation agriculture, and most of the crops produced, including heavily water-consumptive crops such as alfalfa, are grown to provide feed for cattle. Despite the enormous public cost of the region's elaborate water damming and diversion projects, the seven Colorado River basin states, including those portions of the states lying outside the basin and not receiving any Colorado River water, produced only 13% of the total value of the nation's livestock. Though urban use, flood control, and recreation are commonly cited as major uses of the region's water supply, these uses are negligible when compared to that of agricultural interests associated with the livestock industry.

Grazing on the Navajo Reservation

Livestock raising on the Colorado Plateau has always been a marginal business subject to the climate irregularities typical of semi-arid areas. The primary climate component is precipitation, usually only sufficient to support a scant forage but capable, during the summer rainy period, of dropping over two inches of moisture in a few hours. Many of the ranchers who have struggled with the semi-arid conditions of the area consider much of the Plateau to be '60-40 range.' This is a range where a cow must have a mouth sixty feet wide and move at forty miles-per-hour to be able to find enough to eat. The Navajo Reservation is no exception to this rule and, if anything, conditions there are worse than in other locations on the Plateau.

Just prior to the Navajo War their sheep numbered between 250,000 and 500,000. Upon their return to the Reservation in 1868 following the Navajo War and the Long Walk, their livestock assets were 940 sheep, 1,025 goats, 1,550 horses and 20 mules. Rapid growth of the herds was the trend for the 1870s followed by a leveling off during the 1880s. By 1892 sheep and goats totaled almost 1.72 million with horses at 250,000 and cattle just under 10,000 head and overgrazing was becoming a recognized problem on the Reservation range lands. Between 1893 and 1900 there was a precipitous decline in stock numbers followed by an equally rapid recovery between 1900 and 1915 that brought total stock numbers to their highest level since the Navajo were placed on the reservation. From 1915 to 1922 there was another rapid descent when Navajo horse herds were greatly reduced along with more modest declines in sheep, goats and cattle. During the period 1923 through 1931, herds and flocks again increased but at a much slower pace although overstocking was still very much of a problem. In 1933, the Bureau of Indian Affairs, judging two-thirds of the Navajo range to have been destroyed by overgrazing, unilaterally instituted a stock reduction program on the Reservation which was greeted with little enthusiasm on the part of the Navajo. As a result of this program, stock numbers declined until well into the 1940s. From 1950 through 1975, there was a steady, gradual increase in animals which led again to calls for a new reduction program, a pattern which has been repeated regularly to the present day.


Research:

The Social and Ecological Consequences of Early Cattle Ranching in the Little Colorado River Basin. Examines the early development of cattle ranching in the Little Colorado River Basin, the various factors which contributed to overgrazing in the region, and the pervasive effects that early commercial cattle ranching had on the local environment. Adapted from a published journal article by William S. Abruzzi.

Where have all the grasslands gone? Numerous ecological studies across the Southwest have documented the decline in herbaceous vegetation (grasses and non-woody flowering plants) while forests thicken and brush invades. Documenting the changes in the Jemez Mountains of northern New Mexico, ecologist Craig Allen considers the evidence that these patterns are tied to changes in land use history, primarily livestock grazing and fire suppression.

Native Americans and the Environment. A comprehensive survey of twentieth century environmental issues facing Native Americans on the Colorado Plateau and throughout the Southwest, including discussions of agriculture, logging, mining, grazing, water rights, and tourism. Adapted from a published journal article by David Rich Lewis.


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