Author’s note. I wrote this piece several decades ago, but never published. Although some of the references may be outdated, the general theme of the article is still valid today. The main conclusion is that Agriculture is the biggest source of biological impoverishment and your food choices can do more for the environment than just about any other actions.
Irrigated alfalfa is grown for livestock forage in Arizona. Photo George Wuerthner
One of the least examined human activities contributing to biological impoverishment and ecosystem degradation is agriculture. In 1933 Aldo Leopold, author of the now classic Sand County Almanac, wrote in his book Game Management: “what remains of our native fauna and flora, remains only because agriculture has not got around to destroying it.”
Since then, there has been a small but continuing critique of agriculture, particularly livestock production (Ferguson and Ferguson 1984, Fleischner 1994, Wuerthner 1990 and 1994, Horning 1994, Jacobs 1992, Rifkin 1992, Donahue 1999) as well as farming (Licht 1997).
Much of the agricultural land in the US goes towards production of livestock and livestock feed. Photo George Wuerthner
Yet despite the volumes of scientific data that demonstrates the role that agriculture plays in ecosystem alteration and biological impoverishment, those in agriculture proclaim themselves as the “original environmentalist” and many in the media help to promote this view (Dagget 1995, Knize 1999).
Given this continual uncritical reporting by the media, as well as a lack of scrutiny from even the scientific community, it’s not surprising that few recognize agriculture as a largely destructive land use and the single greatest factor in biological impoverishment in the nation.
Media attention is continuously focused on the conversion of ranch or farmland to development as a loss of “wildlife habitat”, never questioning that the existence of agriculture itself is a major factor responsible for significant wildlife habitat degradation or loss.
The idea of the independent yeoman farmer and the bucolic farm landscape is a huge part of our collective mythology. Photo George Wuerther
There are a host of reasons why agriculture has thus far avoided close scrutiny for its role in ecosystem destruction. Agriculture plays a huge role in the collective American cultural mythology of the yeoman farmer, and the Jeffersonian vision of America as a loose confederation of small land owning farmers.
The cowboy is even more enshrined in our collective mythology of the West. Photo George Wuerthner
The American cowboy holds an even higher position in American mythology. Since the days of the Virginian to modern-day rodeo star, the cowboy symbolizes independence, and self-sufficiency—never mind that most modern agriculturists are among the nation’s biggest welfare recipients (Ferguson and Ferguson 1984, Power 1996, Myers and Kent 1998).
There are better and worse ways to farm. Small-scale organic farming is preferable to large-scale chemical farming, but agriculture by its very nature is almost always inherently destructive of biodiversity. It funnels the majority of water, space and nutrients in a select few species at the expense of the broader collection of plants and animals. Typically, it involves the husbandry of exotic species over native species. It is about manipulation, control, and management of nature—and these attributes are the exact opposite of the goals of those who advocate rewilding North America.
Yet the myth of the “independent” cowboy and farmer are so strong that even many board members of western environmental organizations are “ranchers” and no one sees anything wrong with this.
Although many factors have contributed to the decline in native species, including urbanization, competition with exotic species, overexploitation, and disease, habitat loss remains the major factor in species decline in the conterminous United States (Wilcove et al. 1998).
For example, Flather et al. (1994) found that habitat loss or alteration was responsible for the listing of 95% of all species under the US Endangered Species Act. Wilcove et al. (1998) came to similar conclusions noting that “habitat loss is the top-ranked threat (in terms of the number of species it affects) for all species groups.” Given the huge amount of land affected by agriculture, it’s not surprising that it is responsible for the majority of endangered species.
This is an ariel photo taken of the Gallatin Valley in Montana. Subdivisions and new housing tracts make up a very small portion of the valley-which is largely dominated by agricultural fields. Photo George Wuerthner
Taken together, livestock production and farming, are easily the single most destructive human activity in North America. This is confirmed by recent studies that suggest that farming and livestock grazing are responsible respectively for 42% and 28% of all endangered species (USDA 1999), a phenomenal 70% of all species listed under the ESA.
But this figure still doesn’t capture the full impact of agriculture’s role in species endangerment since water development is considered a separate category in most studies on species losses. Yet the vast majority of water development, particularly in the West is for irrigated agriculture.
Irrigated fields growing livestock forage near Bend, Oregon. Photo George Wuerthner
Indeed, in the 17 western states, irrigation accounted for 82% of all water withdrawals from a high of 96% in Montana to 21% in North Dakota (Committee on Interior and Insular Affairs 1987). Storage reservoirs for irrigation fragments watersheds, and withdrawals from streams reduces flows and changes water quality—all of which are known to contribute to the decline in aquatic species from snails to trout. Therefore at least some percentage of water development species endangerment should be considered part of agriculture’s contribution to species losses.
Landstat photo of Montana Alberta border east of Sweet Grass Hills showing fragmentation of land by agricultural fields. Photo George Wuerthner.
The geographic foot-print of agriculture is enormous. Anyone flying over the middle of the United States and looking down on the miles upon miles of corn and wheat fields would not doubt this. Yet it’s surprising how few people really grasp the magnitude of agriculture’s effect upon biodiversity.
Consider these statistics. The entire United States land area takes in 2.3 billion acres (NRI 1997). However, a significant chunk of that, nearly 375 million acres are found in Alaska. If you substrate Alaska out of this total, there are approximately 1.9 billion acres of land in the conterminous United States. Non-federal lands make up 1.49 billion acres (NRI 1997). Of this acreage, 400 million acres are private farmlands (USDA 1999) with most devoted to cultivated crops, with more than half growing crops exclusively for livestock feed (Rifken 1992). Some 529 million acres or one-quarter of the nation’s private lands are used for grazing. This includes 126 million acres of pasture, and 403.1 million acres are considered to be private rangelands (USDA 1999).
Of the 405 million acres of public lands (this figure excludes Alaska) in the lower 48 states, some 300 million or so are grazed by domestic livestock (Jacobs 1992). This consists primarily of BLM and Forest Service lands, however, very few public acres are actually protected from livestock grazing. Indeed, even most western wildlife refuges and even some national park units (Grand Teton, Black Canyon of the Gunnison, Point Reyes to name a few) are grazed by domestic livestock. Most of the ungrazed public land acreage is simply too steep, too far from water, too heavily forested, or otherwise unsuitable for livestock production.
There are also 399 million acres of private forest lands.
Cattle grazing in Florida. Photo George Wuerthner
Not included in the above figure is the acreage of private forest lands also grazed by domestic livestock. In many parts of the country, including much of the West, as well as the South, a substantial percentage of these tree-covered lands are grazed by domestic livestock and should be considered part of agriculture’s total impact. However, I have no figures on the exact percentage of forested habitat grazed so will leave this out of my calculations, but keep in mind that any total figure on the impact of agriculture UNDERESTIMATES the full geographical effect.
The bottom line—when you add together all the lands used for agricultural purposes in the United States, it exceeds 1.225 billion acres. At a minimum agriculture affects 65%-75% of the US land area excluding Alaska!
This domestication and alteration of the natural landscape is not evenly distributed, however, and agriculture has not only contributed to significant species loss but has almost completely shattered some ecosystems. For example, 77 percent of Iowa is now cropland, as are 62 percent of North Dakota, and 59 percent of Kansas (Licht 1997) essentially eradicating the entire tallgrass prairie and most of the mid-grass prairie.
Ag field near Dickerson North Dakota stretch to the horizon. Photo George Wuerthner
The significance of the above figure in terms of its effects upon biodiversity is even greater since the presence of farming and ranching amid otherwise undeveloped land can fragment the remaining habitat to the point where its suitability for wildlife is greatly reduced.
Particularly in the heart of agricultural lands, the small habitat patches that remain are useless for many wildlife species except for those that thrive on edge and disturbed landscapes. Indeed, the presence of undeveloped land in the midst of farmland can contribute to mortality sinks and is one of the problems of the Conservation Reserve Program that pays farmers to idle croplands. These small patches of grasslands become attractive to ground-nesting birds, and other wildlife, but also become easy focal points for predators leading to the loss of most nesting birds (Basore et al 1986).
Dairy farm, Snake River Plain, Idaho. Photo George Wuerthner
As Licht (1997) has noted with regard to agriculture on the Great Plains; “It’s not so much that agriculture has converted 43 percent of the prairie biome to cropland, but that it has fragmented virtually 100 percent of the entire prairie ecosystem.”
Similarly, an isolated ranch or grazing allotment in the midst of otherwise good grizzly and wolf country can preclude the use of the tens of thousands of the surrounding acreage if predators are automatically killed whenever there is a livestock loss.
Agicultural activities like livestock production on public lands poses a major threat to predators like grizzly bears and wolves. Photo George Wuerthner
For instance, the Upper Green River area is home to grizzlies and wolves but is part of the largest Forest Service grazing allotment in the West. Continual conflicts over livestock depredation have resulted in the death and/or removal of dozens of grizzlies. In effect, this allotment is a huge mortality sink for predators in the midst of otherwise superlative wildlife habitat.
Though species loss is an indication of the impact of agriculture on biodiversity, it is as Noss and Cooperrider (1994) conclude only the “last and most obvious state of biotic impoverishment.” A decline in biodiversity also results in a loss of ecological processes like predation, wildfire, and other evolutionary influences which are degraded or extirpated over most of the US land area primarily due to non-urban land uses such as logging, farming, and livestock grazing.
Wolf. Photo George Wuerthner
The effort to recover wolves in the northern Rockies illustrates this point. While we have been successful in recovering some token populations of large predators such as the wolf in places like Yellowstone and Central Idaho, we have not yet restored the biological function of wolf predation as an evolutionary process across the landscape. Due the nearly ubiquitous presence of domestic livestock outside of these reserves, and the conflicts that sooner or later arise over livestock depredation by wolves, it is questionable that we ever will as long as livestock dominates the western landscape.
Although the amount of land converted to urbanization is accelerating, amounting to more than 16 million acres nationwide between 1992 and 1997 (NRI 1997), the total amount of land devoted to urbanized uses is still surprisingly small—less than 3% of the total US land area (USDA 1999). According to the NRI (1997) an estimated 80.7 million acres of the United States are considered “urban and built-up.” To put this into perspective, this is slightly more than the acreage we recently planted to one crop—feeder corn (80.2 million acres).
The acreage figures for different land uses by various states are startling. For example, Wisconsin, a relatively well-settled mid-western state has 37% of its land in forest, 30% in cropland, 8% in pastureland, 16% in “other”, 4% in water while only 4% urbanized (NRI 1997).
Despite California’s large urban population, only 4.5% of the state’s land area is urbanized. Photo George Wuerthner
In California, the most densely populated western state, some 4.5% of the land area is urbanized, while an estimated 75-80% is affected by farming and livestock grazing (California GAP Analysis 1998).
Yet, ask the average Californian what the biggest threat to the state’s wildlife and urbanization and sprawl would be the answer. Certainly, in southern California’s booming megalopolis, such a conclusion is accurate, but almost half of California is federal land that can never be built upon, plus much of the state outside of the San Francisco Bay, Sacramento, and LA-San Diego basin is virtually uninhabited.
The impact of agriculture is even more skewed in lightly populated western states. Wyoming, the Cowboy State, is perhaps one of the best examples of this schism between reality and common perception. According to the Wyoming GAP analysis, less than 0.29% of the state is urbanized or settled by humans. Some 7% of Wyoming are croplands—primarily irrigated hay fields, while domestic livestock graze most of the rest of the state. Yet the state’s newspapers and conservation groups focus primarily on the growing threat of “condos” with condos being a metaphor for all development and sprawl.
Only 0.17% of Montana was urbanized or developed. Most of the state’s counties still qualify as “frontier” by the definiation of the 1890s census. Photo George Wuerthner
A similar discord between reality and perception exists in neighboring Montana. According to the Montana GAP analysis (Montana GAP 1998), only 0.17% of the state’s 94 million acres are urbanized. This is not difficult to believe once you realize that 12% of the state is completely uninhabited, and 95% of the state has 4 people or less per square mile according to a recent Montana Dept. Fish, Wildlife and Parks report. Despite recent immigration of new residents, most of Montana would still qualify as a “frontier” under the 1890’s census definition.
Even with this low population density, dozens of species are either already extirpated from the state or so restricted in numbers that they are candidates or already listed under the Endangered Species Act including the swift fox, blackfooted ferret, grizzly bear, wolf, Colombian sharptail grouse, and Arctic grayling. What is particularly unique about all these species is that they were formerly widespread, and numerous, not animals with narrow distribution and habitat needs. So how do we explain such a decline in the face of an almost uninhabited landscape? The answer is habitat loss or degradation—primarily as a consequence of agriculture.
Cattle grazing the Gallatin Valley. Livestock production is the dominant land use in Montana. Photo George Wuerthner
While less than 0.17% of Montana is urbanized, some 15 million acres are cultivated, 3.5 million acres are pastureland, another 2.7 million are former croplands that are currently in CPR but could be farmed again. In total more than 21% of the state’s land area is affected directly by farming. In addition, another 37 million acres are grazed by private rangelands. These figures do not include the 34 million acres of state and federal lands, most of which are also used by livestock. As a rough estimate, approximately 87% of Montana is affected by agriculture.
Yet even here the common message portrayed in the media is that sprawl is the major threat to Montana’s wildlife.
Agricultural supporters have capitalized upon the condos vs. cows frenzy arguing that ranching and farming are the last bastion in the effort to preserve the West’s wildlife habitat. For example, New Mexico’s former Senator Pete Domenici (R), an ardent supporter of livestock interests proclaimed when he introduced grazing bill S.1459 into Congress that ranching was essential to “maintaining the open space and habitat for big game, wildlife and fish.”
Nevertheless, if you want to address the land uses that are compromising biodiversity, environmental organizations should be focusing far more attention upon agriculture than any other land use.
A wheat field is the antithesis of biodiversity. It is one species of grass planted to the exclusion of all other species across millions of acres. Photo George Wuerthner
As important as fighting the next subdivision might be, we would gain far more land for restoration, and do far more for native biodiversity by reducing the amount of land used for Ag than any other single factor.
Agriculture’s impacts are multiple and significant. Agriculture is responsible for the greatest amount of soil erosion in the country. It is the single greatest factor responsible for the spread of exotic weeds. It is the single greatest source of non-point water pollution in rivers and lakes. It is the main factor polluting ground water across the country. And in the West it is the largest consumer of water. It is as noted earlier, responsible for more endangered species than any other human activities, and what more, has even destroyed entire biomes like the tallgrass prairie.
Furthermore, we expend a huge amount on agricultural subsidies to maintain overproduction and the continuing degradation of our landscape. In 1999, the federal government paid out more than $26 billion in direct agricultural payments, plus another $8.7 billion in emergency relief. Some estimates place this subsidy even higher.
Urban growth boundary is readily seen here in this view of the Willamette Valley. While the urbanization is contained, the majority of the valley is still degraded by agriculture. Photo George Wuerthner
Myers and Kent (1998) estimated that total US agricultural subsidies were more than $69 BILLION in 1996! To put this in some kind of perspective, the entire 1999 budget to operate all 520 national wildlife refuges in the nation was just $280 million and we spent less than $30 million on our entire endangered species program in that year.
If we could shift a fraction of these agricultural subsidies to land acquisition, we could go a long way towards protecting open space and wildlife habitat—even in the face of growing sprawl.
Furthermore, we could also afford to fund substantial landscape-scale ecological restoration. For instance, I have calculated that roughly ten years of current agricultural subsidies including CPR payments received by Montana farmers would be sufficient to purchase outright more than 30 million acres of eastern Montana’s farm and ranchlands at current land prices. Thirty million acres is easily enough land for a major grassland reserve large enough to preserve most biological processes and all native species including wide-roaming native herbivores like bison and predators like grizzlies and wolves.
Indeed, Licht (1997) concludes that “the amount that has been spent on direct farm payments in the grassland biome since 1933 is enough (in 1992 dollars) to have bought every single acre of cropland and rangeland in the region and the buildings on it, with $42 billion left over.”
In fact, most of these lands are simply not suitable for sustained agricultural activity. They are too arid, and too erosion-prone to be grazed or farmed. Without government subsidies, most of this land would have been abandoned and returned to the public domain decades ago.
In many years, farm subsidies are a major portion of the farm “income”. Redirecting those subsidies towards outright acquisition would do far more for the public and wildlife than maintaining welfare Agiculture. Photo George Wuerthner
Consider that Guither, Baumes and Meyers (1994) observed, “In 1990, direct government payments provided 54.9 percent of the net cash farm income in Montana, 55.1 percent in North Dakota, and 48.6 percent in Kansas.”
As Cochrane and Runge (1992) noted, “Urbanites and their representatives in Congress have the votes to write the farm legislation, if they knew what they wanted. But they don’t. They are so deeply mired in a set of false and misleading images about farmers, farming and rural America, that they can not take effective legislative action.
Urbanites witness the conversion of hundreds of acres of farmland to suburban residential sites, and they perceive food shortages. What they do not see are the tens of millions of acres of Great Plains farmland being retired because of surplus capacity, and that they are paying for it.” The specter of food shortages and famine is exploited by the agricultural industry to maintain government subsidies.
The fact remains that any amount of land lost to urbanization is relatively insignificant for the nation’s food supplies. Notwithstanding that some of this sprawl covers prime farmland, the fact remains that sprawl affects a relatively small amount of the total agricultural land base.
We actually idle millions of more acres of farmland annually with various government set-aside programs than are lost to urbanization and sprawl. For example, the CRP program alone accounts for 32.7 million acres of idled farmland (NRI 1977). Shifting production back to the idled acres could easily make up any losses to urbanization.
The majority of both public and private land is used for livestock production. Here cattle graze along the North Fork of the Big Lost River, Idaho. Photo George Wuerthner
But more importantly, we could easily make up any losses by shifting Ag production from production of livestock feed to crops consumed directly by humans. Since more than a billion acres of the US land area is currently utilized for livestock production, rather than the production of crops for direct human consumption, a slight shift in diet from meat to greater consumption of vegetables and grains could easily make up for any reduction in agricultural production due to sprawl.
But my real point isn’t to argue that we should accept sprawl as inevitable or inconsequential in terms of its impacts upon the landscape and wildlife. Indeed, I fully support all efforts to reduce sprawl for many reasons besides the loss of agricultural production opportunities, including impacts on watersheds, wildlife, soils, air quality, scenery, and other reasons. Nevertheless, the above statistics demonstrate the tremendous prospects we have for reducing the impacts of agriculture on native biodiversity and the enormous opportunity for the restoration of a significant amount of land for natural ecological processes.
Just for argument’s sake, let’s presume it was possible to convince all Americans to adopt a completely vegetarian diet, eliminating the need for any animal Agriculture. According to Francis Lappe quoted in Robbins (1987) to supply one person with a meat habitat food supply for a year requires three and a quarter acres.To supply one pure vegetarian requires one sixth of an acre.” Even a small shift in our dietary preferences could potentially free up as much as a billion acres of land for landscape and wildlife restoration, including much of our western public lands as well as a majority of the Great Plains and mid-west plains and prairie regions.
The acreage used to grow crops consumed directly by humans is surprisingly small. Strawberries near Salinas, California. Photo George Wuerthner
The actual amount of land we would need to feed ourselves is surprisingly small. All the vegetables grown in this country are produced on slightly more than 3 million acres of land (NRI 1997). Fruit and nuts production occupies another 5 million acres. Potatoes and grains are grown on nearly 100 million acres of land—but a percentage of the grains (just how much I don’t know) including some oats, wheat, barley, and other crops are fed to livestock. Obviously, if meat were eliminated from our diets, there would be a shift towards greater grain and vegetable production. Nevertheless, given the inefficiencies of grain conversion to meat by large animals, particularly cows, any increase in acres devoted to grains and vegetables would easily be counterbalanced by the more substantial decline in acres used for livestock production.
Some agricultural supporters assert that livestock serves a useful function by grazing grasses, hay and other forage that humans can’t digest, turning this roughage into food (meat and milk) that humans can use. But these claims ignore the inefficiencies of using a single or a couple of species to process grass and other herbage.
Snow geese near Honey Lake, California. Native herbivores from geese to elk would more efficiently utilize rangelands and pasture than single species like cattle. Photo George Wuerthner
The dominance of rangelands by livestock precludes the full utilization of these lands by native wildlife. A suite of native species that could include waterfowl like geese, game birds like grouse, as well as larger ungulates like bison, antelope and elk exploit rangelands far more efficiently by splitting up the available plant matter between multiple species.
As a consequence, any assemblage of native species can produce far more pounds of meat per acre than reliance upon exotic single species of livestock like cattle. If some people feel compelled to eat meat, let them hunt.
A shift to more vegetables and less meat is not only healthier for humans, but also to the land. Photo George Wuerthner
The benefits of a major shift in diet would have many other unappreciated benefits. The reduction in the amount of land used for crop production would significantly reduce soil erosion, pesticide use, fertilizer use, water pollution, air pollution (in some agricultural areas farm equipment and agricultural sprays are a major source of air pollution), and the spread of exotic weeds.
Reducing meat production would also reduce the heavy use of antibiotics and other drugs in livestock that are producing drug-tolerant viruses and bacteria.
Finally, the reduction in meat consumption would significantly reduce meat-induced health problems including colon cancer, heart disease, and other health problems that cost all of us billions of dollars each year, plus a loss in our mobility, health, and happiness (Robbins 1987).
A reduction in meat production would also significantly reduce the influence of corporate and factory farming in the United States since it is the large-scale efficiencies of producing a few crops like corn and soybeans as well as factory animal farms that attract the bulk of corporate interests.
In addition, since a significant proportion of this production is exported overseas which leads to lower prices for locally produced food in third world countries, a reduction in factory and corporate farming could foster more local small-scale agriculture and increase diversity of global food supplies.
Urban garden in Eugene, Oregon. Photo George Wuerthner
A change in focus to the production of organic crops, more local food production, and even small-scale vegetable production from suburban and urban garden plots offer a way out of our current reliance upon large-scale agriculture and livestock production.
Vegetables at farmstand near Moss Landing, California. Photo George Wuerthner
It also provides a way to reverse the current acceleration in species endangerment and a tremendous opportunity to rewild much of the North American continent. Depending upon other variables such as the import and export of agricultural goods and foods, the amount of land we may ultimately need to utilize could vary by quite a bit from the above estimates. But I am certain that a change in diet is nevertheless the most direct way that any American can contribute to slowing the biological impoverishment and the subsequent rewilding of North America. The best way to restore wildlands across the continent begins with a forkful of food at a time.
REFERENCES:
Basore, N.S., L.B. Best, and J.B. Wooley 1986. Bird nesting in Iowa no-tillage and tilled cropland. J. Wildl. Manage. 50:19-28.
California GAP Analysis. 1998. California Fish and Game Dept. Sacramento, CA.
Committee on Interior and Insular Affairs. 1988. Hearing record on a bill to Amend the Reclamation Projects Act of 1939. US Government Printing Office, Washington DC
Cochrane W.W. and C.F. Runge 1992. Reforming farm policy. Ames:Iowa State University Press.
Dagget, D. 1995. Beyond the Rangeland Conflict:Towards a West that Works. Gibbs Smith Books, Layton, Utah.
Donahue, D. L. 1999. The Western Range Revisited—Removing Livestock from Public Lands to Conserve Native Biodiversity. U of Oklahoma Press, Norman.
Ferguson, D. and N. Ferguson. 1984. Sacred Cows at the Public Trough. Marverick Books, Bend, Oregon.
Flather, C.H., L.A. Joyce, and C.A. Bloomgarden. 1994. Species Endangerment Patterns in the United States. USFA Gen. Tech. Rep. RM-241. Fort Collins, CO.
Fleischner, T. H. 1994. Ecological Costs of Livestock Grazing in Western North America. Conservation Biology 8:629-644.
Guither, H.D., H.S. Baumes and W.H. Meyers. 1994. Farm Prices, Income, Stability, and Distribution. In Food, Agriculture, and Rural Policy into the Twenty First Century. Ed. M.C. Hallberg, R.G. Spitze, and D.E. Ray. Westview Press. Boulder, Colorado.
Horning, J. 1994. Grazing to Extinction: Endangered, Threatened, and Candidate Species Imperiled by livestock grazing on western public lands. National Wildlife Federation. Washington DC.
Jacobs, L. 1992. Waste of the West: Public Lands Ranching. Tucson, Arizona Lynn Jacobs Publishing.
Knize, P. 1999. Winning the War for the West. Atlantic Monthly, Vol. 284.
Leopold, Aldo. 1933. Game Management. Charles Scribner’s Sons. New York.
Licht, D. S.1997. Ecology and Economics of the Great Plains. University of Nebraska Press, Lincoln.
Myers, N. and J. Kent. 1998. Perverse Subsidies: Tax Dollars Undercutting Our Economies and Environments Alike. International Institute for Sustainable Development. Manitoba, Canada.
Montana GAP Analysis. 1998. Montana Land Cover Atlas, Wildlife Spatial Analysis Lab, University of Montana, Missoula.
Noss, R.F. and A. Y. Cooperrider. 1994. Saving Nature’s Legacy. Island Press, Washington DC.
NRI. 1997. National Resources Inventory. USDA. www.nrcs.usda.gove/CCS/pentnon.htmul
Power, T.M. 1996. Lost Landscapes and Failed Economies. Island Press. Washington DC.
Rifken, J. 1992. Beyond Beef—The Rise and Fall of the Cattle Culture. Penguin Books, NY , NY
Robbins, J. 1987. Diet for a New America. Stillpoint Publishing Walpole, NH.
USDA 1999a. America’s Private Land, A Geography of Hope. UDSA Government Printing Office. Washington DC
Wilcove, D.S., D.Rothstein, J. Dubow, A. Phillips, and E. Losos. 1998. Quantifying Threats to Imperiled Species in the United States. Bioscience August 607-615.
Wuerthner, G. 1990. Grazing the Western Range. What costs. What Benefits. Western Wildlands, Summer 27-29.
Wuerthner, G. K. 1994. Subdivisions vs. Agriculture. Conservation Biology 8:905-908.