You could say it started with the Spaniards.
Back in 1540, the Spanish explorer Francisco Vasquez de Coronado introduced domestic livestock on the U.S. range500 head of cattle, 5,000 sheep, and 1,000 horses. The pace picked up when Spanish missionaries spreading across the Southwest brought an estimated 50,000 sheep and 20,000 cattle north from Mexico.
Obviously, the concept of livestock grazing the range is not a new oneand neither is the concept of concern about the environmental impact of livestock on the range. More than 60 years ago, Congress passed the Taylor Grazing Act of 1934, aimed at stopping "injury to public grazing lands by preventing overgrazing and soil deterioration, to provide for their orderly use, improvement and development, to stabilize the livestock industry dependent upon the public range, and for other purposes."
The United States today has about 770 million acres of rangeland, of which more than half are privately owned, with 43 percent federally owned. To put that total in perspective, today's rangeland acreage is about 272 million acres less than available rangeland at the time Europeans began settling what is now the United States.
In other words, we still have about 74 percent of the rangelands of those early days. The "missing" 272 million acres have been converted into our farms, forests, urban areas, industrial sites, highways, and reservoirs.
How should we take care of these remaining 770 million acres? By using a variety of management tools to work within the rangeland ecosystem. One of these toolsa very valuable oneis grazing.
Livestock grazing can help promote vegetation that's good for watersheds and wildlife. That's because different classes of animals graze different types of plants. Cattle and elk eat mostly grass, deer primarily browse woody plants and eat forbsbroadleaf herbswhile sheep and goats have a mixture of plants in their diet.
Producers can put different types of animals on range at different times of the year to alter the array of vegetation present by virtue of what those animals will eat and what they'll leave behind. Producers can also use some livestock to control noxious weeds or to thin or clear brush.
A good place to see this highly diversified vegetation use in nature is Africa's Serengeti Plain. A wide variety of wild and domestic ruminants live in that area, each group following another over the plain, each with a certain niche diet of specific vegetation. The various parts of the ecosystemincluding the animals and plantshave worked together over centuries to achieve a relative balance.
During the past decade, research has enhanced our knowledge of how these natural systems work and how to manage within them to reach specific goalswhether those goals are greater meat production, more wildlife, or even wildfire control by grazing blaze-prone areas such as California's chaparral slopes.
We know much more today than we did 60 years ago, when the Taylor Grazing Act was passed. But there's still a lot to learn. By focusing more on the interrelationship between soil, plants, and animals, we can gain a better understanding of how productivity and diversity of our rangelands can be enhanced through careful management.
On some rangeland, climatic changes, soil erosion, natural disasters, and other factors have altered the diverse mixture of plant and animal life, and renewal of those communities is not possible for the foreseeable future. But we attempt to find ways to manage and protect the remaining rangeland to prevent further degradation.
We must be flexible enough to think in terms of using new, as well as different, management tools on rangelandto see that there's a place for sheep and cattle and goats and deer, as well as humans.
We must also learn to let go of certain myths: that grazing is automatically bad for rangeland, for example, or that livestock will always destroy streambanks and riparian areas when those areas are grazed.
In this issue of Agricultural Research magazine, you'll read how ARS scientists at Dubois, Idaho, are simulating commercial sheep operations in order to study the actual impact of grazing on summer range in the Centennial Mountains of Montana and Idaho.
They've found that when sheep arc managed wisely at a moderate stocking rate, there's plenty of vegetation left after the sheep move on, and they do not cause massive soil erosion in riparian areasone myth dismissed.
Large ruminants have always been part of our rangeland, though in pre-settler days they may have been bison, elk, or moose. Our research is aimed at finding ways to continue using the rangeland for many purposes, including harvesting vegetation and turning it into food and fiber, while ensuring that the actions we take today don't imperil natural rangeland resources for tomorrow's generations.
R. Dennis Child
ARS National Program Leader Range and Global Climate