“Cattle had indeed wrecked havoc. They destroyed watersheds, trampled riparian vegetation, and turned grasslands to hardpan, triggering severe erosion. To top it off, the livestock industry spent the twentieth century securing cheap access to public lands through thousands of grazing permits now granted by the Bureau of Land Management and the U.S. Forest Service. Today, ranchers enjoy tax-supported access to 270 million acres of public land. Seventy-three percent of publicly-owned land in the west is currently grazed by privately owned livestock. Some of that grazing might be done responsibly. Most of it, according to the BLM itself, is definitely not.”
— From a Forbes article titled “Ranchers Insistence On Cheap Grazing Keeps Wolf Population In The Crosshairs”
The story of the American Bison’s connection with Nature is also the story of America’s Midwestern Great Plains tall-grass prairies. These huge grassland environments were complex tall-grass ecosystems where the American Bison was a keystone species that was inextricably interconnected with its environment.
Before the 1800′s, it is estimated that over 30 million bison inhabited North America from Alaska to Mexico. The slaughter of these creatures by humanity in the 50 year period starting around 1830 reduced the population to a few thousand. In the Great Plains, the human migration to the prairies and subsequent futile attempts at farming reduced the grazing area of the bison to less than 5% of its original range. Because of more recent conservation efforts, the bison population has rebounded to a revitalized North American population of about 500,000. Most of these animals are constrained by fences in mixed-grass prairie preserves and private ranches. Only 20,000 bison that are part of conservation herds are considered to be truly wild number.
Nonetheless, recent research has shown the American Bison to play a keystone role in the health of the remaining prairies. The primary beneficial behavior is the bison’s tendency, unlike cattle, to selectively graze in patches leaving broad-leaved herbs (called forbs) and woody plants untouched. The bison then revisit areas throughout the season. The resulting patchiness promotes plant species diversity by allowing the forbs to grow unharmed.
Dynamic spatial and seasonal bison grazing with the ongoing presence of forbs enhances density and plant cover above ground as well as gas exchange below ground. With parts of the prairie grazed, photosynthesis rates are enhanced because more light is made available.
In addition, bison grazing increases animal diversity. Herds of grazing bison shape grasslands and create habitat. Prairie Dog foraging capabilities are enhanced. In turn, these Prairie Dogs are prey for ferrets, foxes, hawks, and eagles. Prairie Dog tunnels are homes for the Burrowing Owl, small mammals, and reptiles.
Fire is a natural and healthy phenomenon in prairie ecosystems. Bison grazing limits the loss of nitrogen through fire by reducing the amount of plant litter. Through grazing in patches, the bison helps produce patchiness in fire.
The bison’s profound and complex connections to prairie ecosystems produce a unique ecology that has deep effects on mixed-prairie ecosystems. This interdependency is summarized in a recent research document entitled “Managing Bison To Restore Biodiversity” by Joe C. Truett, et.al. He says:
“Prior to their demise in the late 1800s, bison coexisted with and helped sustain a diverse and spectacular assemblage of animals and plant communities on the Great Plains. Bison, in concert with fire, exerted strong control on the structure of the vegetation by grazing, trampling, and wallowing. The changes in the vegetation induced changes in many animal populations. These impacts, coupled with the bison’s role as the major converter of grass to meat, so greatly affected other species that some have called bison a “keystone” species in the Great Plains ecosystem. The black-tailed prairie dog, dependent on bison grazing over a large part of the Great Plains, amplified the keystone influence of bison by its own grazing and burrowing activities and its utility as prey.“
- To control cows and sheep, fences are used. Fences prohibit or inhibit the free passage of wild animals, reducing their access to food and water as well as isolating subpopulations.
- Cattle grazing has completely changed the soil structure and primary plant species in most Southwest riparian zones. In turn, this has adversely affected populations of local and migrating birds, animals that live near a river, and fish who live in the rivers.
- Cattle grazing has resulted in some 464 million acres of land becoming arid desert.
- Cattle grazing has reduced the density and biomass of many plant and animal species.
- Cattle grazing has reduced biodiversity.
- Cattle grazing has aided in the spread of exotic invasive species.
- Cattle grazing impedes the cycling of soil nitrogen.
- Cattle grazing changes habitat structure and disturbs community organization.
- Cattle and sheep ranching has resulted in a huge draw on water reserves. Urban use, flood control, and recreation are commonly cited as major uses of a region’s water supply, But, these uses are negligible (only 10%) compared to the 90% of water used by agricultural interests associated with the livestock industry.
- One can also argue that eating meat is unhealthy and that cattle grazing ultimately puts humans at a greater health risk. To this, we must include the social health cost of eating meat.
- A recent University of Minnesota study states that “reallocating croplands away from fuels and animal feed could boost food available for people by 70 percent without clearing more land.”
- The whole process of issuing grazing rights to ranchers is questionable because it requires the U S Forest Service and other government organizations who oversee our public lands for us to “scientifically” assess the capacity of grazing areas owned by the government. It has been repeatedly shown that, much like the weather, it is impossible for mankind to predict and control Nature. Yet, government employees truly believe that they have some innate ability to do so.
The good news is that the studies cited above have shown that the reduction or elimination of grazing can result in ecological restoration in riparian areas where there is water even though the 464 million acres of land that has become desert because of grazing is not restorative. And of course, with the elimination of grazing, most of the fear and conflict over our wolf populations would disappear while we get healthier.
What do you think?
Worth Your Extra Attention :
I am grateful to those of you who responded to my request to read and review my eBook entitled “Connections: Life Sustaining Relationships In Nature” .
Here are some well written articles on the adverse ecological effects of cattle grazing that might interest you.
- Ranchers Insistence On Cheap Grazing Keeps Wolf Population In The Crosshairs
- What’s Wrong With Livestock Grazing on Public Lands?
- Ecological Costs Of Livestock Grazing In Western North America
- Cattle And Sheep Grazing
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My name is Bill Graham. As a Marine Biologist who has worked in the US and Mexico for 30 years, I am a student of Nature, a teacher, a researcher, and a nature photographer. Through my work, I have acquired an ever growing passion for how everything in Nature is connected. Today, I travel extensively contemplating about, writing about, and photographing Nature’s connections. I also work with conservation projects in the USA and Mexico and mentor talented youth.