Yellowstone's Destabilized Ecosystem: Elk Effects, Science, and Policy ConflictOxford University Press, 25 мая 2006 г. - Всего страниц: 392 Wagner, one of our most distinguished wildlife biologists, is a strong critic of ecological practices in the national parks. This book provides an assessment of the ecological history of Yellowstone's northern range, since before the park existed, showing the impact of US Park Service policies on the health of the areas they oversee. He demonstrates that elk had been historically rare throughout the region and that overgrazing by elk has seriously degraded the landscape and altered the structure of the area. This is a major contribution to reconstructing the ecology of this region over the course of the past 500 years. It is also a critique of US Park Service management policies and their stewardship of the nation's most cherished natural areas. Wagner's book will generate substantial attention and debate both in the scientific and policy/management communities. |
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Стр. 5
... reduce the herd. “Direct reduction” (shooting by park rangers) began in the 1930s and continued annually until the herd had been reduced to 3,172 animals counted in the 1968 winter census (Houston 1982). The fourth management phase was ...
... reduce the herd. “Direct reduction” (shooting by park rangers) began in the 1930s and continued annually until the herd had been reduced to 3,172 animals counted in the 1968 winter census (Houston 1982). The fourth management phase was ...
Стр. 6
... reduction remained a viable management option. This policy was based on recommendations of an outside National Parks Advisory Board chaired by University of California, Berkeley, wildlife professor A. Starker Leopold (Leopold et al ...
... reduction remained a viable management option. This policy was based on recommendations of an outside National Parks Advisory Board chaired by University of California, Berkeley, wildlife professor A. Starker Leopold (Leopold et al ...
Стр. 8
... reduced the term's utility as a falsification criterion. Even more uncertainty surrounds the term overgrazing. Not only was it not defined ecologically in terms of the northern range at the beginning of the congressionally funded ...
... reduced the term's utility as a falsification criterion. Even more uncertainty surrounds the term overgrazing. Not only was it not defined ecologically in terms of the northern range at the beginning of the congressionally funded ...
Стр. 11
... reduce the size of the northern elk herd. But the wolves have established territories precisely in the Park portions of the northern range. The northern herd winter censuses have declined since the mid-1990s (see chapter 2), and the ...
... reduce the size of the northern elk herd. But the wolves have established territories precisely in the Park portions of the northern range. The northern herd winter censuses have declined since the mid-1990s (see chapter 2), and the ...
Стр. 16
... reduced the population before the winter counts. An annual winter hunt begun in the 1970s has taken varying numbers of animals, in many cases some before the censuses. The third source of variation is the weather-induced fluctuations in ...
... reduced the population before the winter counts. An annual winter hunt begun in the 1970s has taken varying numbers of animals, in many cases some before the censuses. The third source of variation is the weather-induced fluctuations in ...
Содержание
1 | |
13 | |
Part III Elk Effects on Ecosystem Structure and Function | 57 |
Part IV The Role of Science in Policy Process | 305 |
References | 335 |
Index | 359 |
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Yellowstone's Destabilized Ecosystem: Elk Effects, Science, and Policy Conflict Frederic H. Wagner Ограниченный просмотр - 2006 |
Yellowstone's Destabilized Ecosystem: Elk Effects, Science, and Policy Conflict Frederic H. Wagner Ограниченный просмотр - 2006 |
Yellowstone's Destabilized Ecosystem: Elk Effects, Science, and Policy Conflict Frederic H. Wagner Ограниченный просмотр - 2006 |
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abundance animals aspen authors Barmore beaver bighorn bighorn sheep biomass Bishop bison Butte Creek censuses century clones commented competition components conifers Coughenour Coughenour and Singer decades density Despain early ecological effects elk herd elk numbers elk population Engstrom ern range erosion estimates evidence exclosures factors figure forage grasses grazing habitat herbaceous herbaceous vegetation herbivory higher elevations highlining Houston hunting impacts increase indicates inferences inside the exclosures interspecific competition Kay’s Keigley Kittams lakes Lamar River levels lower measurements ment mule deer National Park northern herd northern range ecosystem observed occurred park establishment park history park’s period photographs plants processes production pronghorn r-values reduced reported result riparian riparian zones sagebrush Schullery sediment shrub significant soil species studies suggest tannin tion trees trends ungrazed ungulate Wagner Wambolt willow decline winter range Yellowstone Yellowstone National Park