This Overgrazing Essay example is published for educational and informational purposes only. If you need a custom essay or research paper on this topic, please use our writing services. EssayEmpire.com offers reliable custom essay writing services that can help you to receive high grades and impress your professors with the quality of each essay or research paper you hand in.
Overgrazing is a term without a precise scientific meaning. Yet, it is widely used and its use has enormous implications for the management of livestock and wildlife and for the livelihoods of individuals and societies throughout the world. It is called one of the most destructive human practices on earth. It is said to be harmful to vegetation and wildlife and to cause soil erosion and desertification. But without a precise definition, these claims have no real meaning, nor can they be proved or disproved.
Range management is a profession that uses range science and practical experience to maintain and improve grazing system components (plants, animals, soil, water) and the production of goods and services from rangelands in combinations needed by society. Range management defines grazing as the consumption of standing forage (edible grasses and forbs) by livestock or wildlife, and browsing as the consumption of edible leaves and twigs from woody plants (trees and shrubs) by large-hoofed animals. Forage plants coevolved with grazers and have developed the capacity to recover from grazing. But this capacity depends on how much tissue is lost, when it is lost in the life cycle, and how frequently it is lost. From the individual plant’s point of view, overgrazing could be defined as exceeding its capacity in any of these ways. However, this is not a definition that can be easily generalized.
Range management does not offer a scientifically validated and agreed upon definition of overgrazing. This is because there are many different grazing systems, different ways to measure the effects of grazing that are difficult to measure and calculate in practice (examples are carrying capacity, utilization, and range condition and trend), and different temporal and spatial scales over which the effects could be measured. In addition, since the 1980s, nonequilibrium models of ecology have been replacing the equilibrium models on which the range succession model, which has guided range science since the 1950s, is based. The range succession model posited a predictable, linear relationship between grazing and vegetation change and the existence of an optimal level of grazing that could balance desired outcomes. Nonequilibrium models, on the other hand, emphasize variability and unpredictability, making it even more difficult to define overgrazing.
As it is commonly used, the term overgrazing indicates damage or harm to vegetation caused by grazing or browsing. For example, wildlife biologists debate whether the decline of willow and aspen in Yellowstone National Park is due to overgrazing by elk. Most often the term refers to harm to vegetation caused by domestic livestock grazing. It is also frequently used to explain environmental change in regions where ranching or “pastoralism” is practiced. Because the term overgrazing does not have a precise definition, its common usage is problematic for several reasons. First, harm is often in the eye of the beholder. For example, rangelands in arid regions can appear to be overgrazed from the perspective of an observer from a wetter climate. Thus, eastern visitors to the western United States might see western rangelands as overgrazed. Or European visitors to Africa might enthuse over herds of nondomestic ungulates grazing the African savannah, but deplore the depredations of native livestock. Second, perceived harm is often attributed to livestock grazing without actual evidence of a causal relationship.
False Cause
This is a mistake in reasoning called false cause: It assumes that two events juxtaposed in time or space have a cause and effect relationship. The tendency to make this mistake can be aggravated when there is an awareness of events in the nottoo-distant past where overgrazing could be said to have occurred on a vast scale, as in the late 19th century in the American West. Grazing is not harmful, by definition, so overgrazing should require evidence of harm. The third reason that common usage of the term overgrazing is problematic is that, when livestock are seen as the cause of overgrazing, the livestock owners are usually blamed. This attribution of blame does not take into consideration the wider social, political, and economic conditions in which livestock owners operate in the present. It may also be informed by colonial and racist pasts. When these types of assumptions underlie the use of the term overgrazing, it becomes an example of “received wisdom”: A powerful orthodoxy that is taken for granted and rarely questioned. Usage of the term may convey more information about its user’s social, geographical, and ideological position than about actual conditions on the ground. To understand why the term overgrazing carries this ideological baggage, it is helpful to examine the early development of range management.
Although “pastoralism,” a human adaptation to marginal environments that emphasizes the herding of livestock, originated approximately 7,000 years ago, the scientific discipline of range management only began to develop toward the end of the 19th century. Both European colonialism, particularly in Africa, and Euro-American western expansion in North America were central to this development. As a result, the term overgrazing carries along with it traces of Eurocentric histories and environments. In Africa, European colonial administrators were charged with managing and making productive vast territories whose climate, landscape, and societies were very different from their countries of origin. They were accompanied by an array of scientists whose job it was to inventory and develop scientific management regimes for their colony’s natural resources. Europeans either did not recognize indigenous resource management systems, although these systems may have developed and been sustainable over many centuries, or they considered them unproductive because they were not designed to produce the surplus colonists needed for export.
In southern Africa, a science-based approach to range management began to develop toward the end of the 19th century when colonial scientists tailored climatic theories prevalent at the time, which linked deforestation to climate change, to the arid environment of southern Africa. Their “dessication theory” predicted that grazing could reduce vegetation cover and lead to decreased rainfall, increased frequency of drought, soil erosion, and eventually desertification. Scientific range management was intended to prevent desertification and, at the same time, increase livestock production. When scientific range management failed to live up these expectations, instead of questioning science, colonial administrators blamed African graziers who failed to adopt the new methods. Although it has been brought into question, the belief that there is a cause-and-effect relationship between grazing and desertification is still strong today.
In North America at about the same time, a rapid expansion of livestock herding west of the 100th meridian-into a region where average annual precipitation is significantly less than to the east and farming is not possible without irrigation-was taking place. Fueled by a rapid rise in beef prices, the building of railroads, and an influx of foreign capital after the end of the Civil War in 1865, the western rangelands soon became a “cattle kingdom” where cattle and sheep “barons” built up huge herds and competed for forage on the unregulated public domain lands. Overgrazing serves as the classic example of the Tragedy of the Commons and this tragedy played out in the late 18th century on the American rangelands as a series of droughts denuded the range and were followed by severe winters that killed off a larger part of the weakened livestock population.
The disaster shocked ranchers, the American public, and government officials and contributed to a change in attitudes toward ranchers and toward open range grazing. The damage done to the western range during this period is probably irreversible. Range management became an imperative in the United States in the wake of this disaster. Because of its implication with colonial histories, the term overgrazing may carry unavoidable ideological implications.
Modern range management has moved away from the use of the term overgrazing, and the retroactive consideration of damage done that it implies, to a more proactive consideration of the ecological processes that sustain range productivity.
Bibliography:
- Richard Grove, Green Imperialism: Colonial Expansion, Tropical Island Edens and the Origins of Environmentalism, 1600-1860 (Cambridge University Press, 1995);
- Jerry Holechek, Rex D. Pieper, and Carlton H. Herbel, Range Management: Principles and Practices (Prentice Hall, 2004);
- Terry G. Jordan, North American Cattle-Ranching Frontiers: Origins, Diffusion, and Differentiation (University of New Mexico Press, 1993);
- Melissa Leach and Robin Mearns, , Lie of the Land: Challenging Received Wisdom on the African Environment (James Currey, 1996);
- Nathan Sayre, The New Ranch Handbook: A Guide for Restoring Western Rangelands (The Quivira Coalition, 2001);
- Martin Vavra, William A. Laycock, and Rex Pieper, eds., Ecological Implications of Livestock Herbivory in the West (Society for Range Management, 1994).