The Truth about Our Wildlife Managers’ Plan to Restore “Native” Ecosystems

George Dovel. 2008. The Truth about Our Wildlife Managers’ Plan to Restore “Native” Ecosystems. The Outdoorsman,  Number 30, Aug-Sept 2008.

Full text [here]

Selected excerpts:

In 1935 when Cambridge University botanist Arthur Tansley invented the term “ecosystem” in a paper he authored, he was attempting to define the system that is formed from the relationship between each unique environment and all the living organisms it contains.

Ecologists concluded that these individual systems evolved naturally to produce an optimum balance of plants, herbivores that ate the plants, and carnivores that ate the herbivores.  Many accepted this “food chain” theory as a permanent state of natural regulation and a theory was advanced that certain “key” species of plants and animals were largely responsible for maintaining these “healthy” ecosystems.

But subsequent archeological excavations or core samples of the buried layers of periods in time revealed that these “perfected” ecosystems were actually in a continuing state of change which could be caused by changes in weather, climate or various organisms.  They concluded that parasites or other organisms that were not included in their food chain charts often caused radical population changes in one or more of the keystone species.

The “Balance-of-Nature” Myth Keeps Surfacing

In 1930 noted Wild Animal Ecologist Charles Elton wrote, “The ‘balance of nature’ does not exist and perhaps never has existed. The numbers of wild animals are constantly varying to a greater or less extent, and the variations are usually irregular in period and always irregular in amplitude (being ample).”  Yet 33 years later, in a highly publicized Feb. 1963 National Geographic article, titled, “Wolves vs. Moose on Isle Royale,” fledgling Wolf Biologist David Mech and his mentor, Durward Allen, claimed just the opposite. …

Debunking the “Balance-of-Nature” Myth

The extreme “spikes” (highs and lows) in numbers of keystone species resulting from reliance on the theory that “natural regulation” will produce a “balance” are evidence that the so-called “Balance of Nature” is a pipe dream. One fairly long-term example of this is seen in the following graph recording 50 years of wolf and moose populations on Isle Royale National Park in Michigan.

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21 Oct 2008, 3:39pm
Population Dynamics Wildlife Habitat Wildlife Management Wildlife Policy
by admin
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Yellowstone’s Destabilized Effects, Science, and Policy Conflict

Frederick H. Wagner. 2006. Yellowstone’s Destabilized Effects, Science, and Policy Conflict. Oxford, United Kingdom: Oxford University Press.

Review by Cliff White, Parks Canada, Banff, Alberta, Ca. [first published in Mountain Research and Development Vol 28 No 2 May 2023]

In an influential book of the 1960s, Fire and Water: Scientific Heresy in the Forest Service, Ashley Schiff (1962) documented how, for over 3 decades, the United States Forest Service subverted ecological science to justify an agency policy of total fire suppression. This policy was especially flawed in southeastern pine forests that evolved under a regime of periodic burning. Schiff’s exposé showed how, in a technologically-based society, science could be systematically manipulated to become clever advocacy for a political end. The book became a must read for a generation of ecological researchers and natural resource policy specialists.

Fred Wagner, formerly associate dean of the Natural Resources department at Utah State University, continues this tradition of exceptional scholarship to describe policy-driven research in Yellowstone, the United States’ flagship national park. Ironically, the general political and ecological scenario is in many respects similar to the southeastern pine forest debacle—management actions driven by a strong political constituency were imposed on an ecosystem ill-adapted to them, and scientists were unwilling or unable to evaluate and document obviously negative outcomes. In Schiff’s example, the fire suppression program was rooted in a strong American land management and resource husbandry movement of the early 1900s. In Wagner’s work, Yellowstone’s management and scientific research is motivated by equally powerful, but opposite societal forces supporting wilderness or “natural regulation.”

For those unfamiliar with the Yellowstone situation, removal of native peoples from the park in the 1800s and reduction in large carnivores in the early 1900s provided favorable conditions for the population of elk (Cervus elaphus), a generalist herbivore, to increase dramatically. After government biologists observed the effects of high densities of elk on soil and vegetation in the 1920s, park rangers routinely culled the herd for over 4 decades. In the 1960s, recreational game hunters lobbied to take over the cull. Given the potential political incompatibility of sport hunting with conservation in one of the world’s premier national parks, the federal government made the decision to cease elk culling. Park managers and senior scientists then carefully selected a generation of researchers to evaluate the revised policy. The result was a new paradigm of “natural regulation” that was underlain by 4 key hypotheses:

1) long-term human hunting, gathering and burning had not substantially influenced the ecosystems of North America’s Rocky Mountains;

2) ungulate populations in Yellowstone were, over the long term, generally high;

3) carnivore predation was a “non-essential adjunct” having minimal influence on elk numbers; and

4) high elk numbers would not cause major changes in plant communities, ungulate guilds, and other long-term ecosystem states and processes.

Although the natural regulation paradigm seems rather farfetched today, remember that it was born in the 1960s, a time of antiestablishment flower children, when wilderness was untrammeled by Native Americans, when biologist and author Farley Mowat’s wolves subsisted on mice (Mowat 1963), and the only “good fires” were caused by lightning. Moreover, an excellent argument can be made that ecological science needs large “control ecosystems” with minimal
human influences.

In the 40 or so years since the implementation of the national regulation policy, both the National Park Service and outside institutions conducted many ecological studies. These culminated in 1997 with a congressionally mandated review by the National Research Council. It is this wealth of research and documentation that Fred Wagner uses to evaluate changes over time in the Yellowstone ecosystem. He provides meticulous summaries of research in chapters on each of several different vegetation communities, the ungulate guild, riparian systems, soil erosion dynamics, bioenergetics, biogeochemistry and syntheses for the “weight of evidence” on the primary drivers of ecological change. This background allows readers to develop their own understanding on the results of this textbook case of applied ecological science.

Wagner clearly shows that most studies did not support the hypotheses of natural regulation. In cases where studies did seem to support a hypothesis, methods and results were suspect. The elk population clearly grew beyond predictions, some plants and animals began to disappear, and the importance of Yellowstone’s lost predators and Native Americans should have become undeniable. However, faced with these incongruities, park managers still supported the natural regulation policy. Some researchers closely affiliated with management then began to invoke climate change as a potential factor for observed ecosystem degradation, but the evidence for this was similarly tenuous. On the basis of the almost overwhelming evidence, Wagner concludes that much of the park-sponsored science on the natural regulation paradigm “missed the mark” and that “Yellowstone has been badly served by science.”

For scientists or managers working in similar arenas of high ecosystem values and intense politics, the book’s concluding chapters will be of most interest. Here, Wagner explores the interface between science and policy. As an alternate model to Yellowstone’s research and management system, he promotes an adaptive management process (Walters 1986) where an open political environment exists between scientists, stakeholders, and managers. Here, a controversial management option such as natural regulation could have been evaluated, as Wagner advises, “in the bright light of objective scientific understanding.” Stakeholders and managers could then use this knowledge as a basis to adjust policies quickly before grave ecological consequences occur.

However, the limited and, in terms of literature review, dated discussion of the public policy process is a weakness of the book. A more complete discussion of ecosystem management in a highly polarized political environment could have described a range of current approaches for collaborative problem solving. In fact, another recent review of wildlife management in Yellowstone concluded that the major problem facing the park was not the quantity or quality of the science, but the lack of mechanism to resolve conflicts between and within groups of scientists, stakeholders and agency managers. Gates et al (2005) remark that “collaboration is necessary to define what is acceptable; science is necessary to define what is possible; organizing people to use knowledge to design and implement management in the face of uncertainty is fundamental.” Applied ecological researchers, progressive managers, and stakeholders with a strong civic responsibility should strive for this ideal. Our parks, and indeed most places on our planet, need high-profile models such as Yellowstone, where science should help people to understand, value, and maintain the biodiversity of ecosystems.


Gates CC, Stelfox B, Muhley T, Chowns T, Hudson RJ. 2005. The Ecology of Bison Movements and Distribution in and beyond Yellowstone National Park. Calgary, Canada: Faculty of Environmental Design, University of Calgary.

Mowat F. 1963. Never Cry Wolf. Toronto, Canada: McClelland and Stewart.

Schiff AL. 1962. Fire and Water: Scientific Heresy in the Forest Service. Cambridge, MA: Harvard University Press.

Walters C. 1986. Adaptive Management of Renewable Resources. New York: Macmillan.

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