TBLU - Rangeland (Lesson)

Rangeland

The large expanses of undeveloped land contain primarily low vegetation such as grasses and shrubs and are suitable for grazing livestock. Throughout the world cattle, goats, and sheep are necessary for the survival of many people and cultures, both for food and for the economic value of the animals.

Raising livestock is widely considered to be another essential part of feeding the human population. Livestock include cows, chicks, pigs, goats, sheep, and other domesticated animals raised for profit. Commonly animals such as cows are kept on large expanses of land to graze for a period of time until they are sold to feedlots. Feedlots also called factory farms or concentrated animal feeding operations, are areas where livestock are fed foods high in energy to fatten them up before market. Feedlots require less land per cow and are a more efficient way of meeting the meat consumption needs of a large population. Also, the manure produced by feedlot animals is frequently used as fertilizer for farms.

Negative aspects of feedlots include potential contamination of water sources from runoff-containing waste products and the increased potential for the spread of disease among animals in close contact, which necessitates the use of antibiotics. This industry is monitored by states and federally by the Environmental Protection Agency, to help minimize the environmental impact.

Overgrazing

When vegetation on rangelands is over-consumed, it hinders plant re-growth. If the plants that are being eaten are not being replaced over time, the land becomes degraded and unusable. Consequences of overgrazing include the following:

• Soil erosion
• Soil compaction
• Desertification
• Proliferation of invasive species
• Reduction in biodiversity and native vegetation
• Economic loss to those who depend on the land, such as ranchers

The land is exposed to wind and water when excessive vegetation is removed from the soil. Once the soil starts to erode, it is more difficult for plant cover to re-grow. The vegetation that does get a toehold in degraded rangeland consists mainly of invasive, wee-type plants, which livestock do not eat. The livestock also compact the soils with their weight and hooves; over time the soil can become compacted enough that it is more difficult for water to seep through, blocking air from filling pore spaces, which roots need to grow. Once the consequences of over-grazing become visible, the cycle is hard to break, and each step creates more degradation of the land.

The cycle of degradation creating more degradation is called a positive feedback loop, in which, once the system starts moving in a direction, it accelerates in that direction unless an intervention stops the progression. This ultimately drives a system to an extreme. In this case, the extreme is degraded, unusable land.

Conservation-Related Law

Because the United States has faced serious soil depletion and erosion issues, laws have been enacted to protect this precious resource. In 1935, in response to the Dust Bowl, Congress enacted the Soil Conservation Act, which established the Soil Conservation Service to monitor soil erosion. Now called the Natural Resources Conservation Service, the agency has expanded to include water quality and pollution control.

 

RESOURCES IN THIS MODULE ARE OPEN EDUCATIONAL RESOURCES (OER) OR CREATED BY GAVS UNLESS OTHERWISE NOTED. SOME IMAGES USED UNDER SUBSCRIPTION.