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. 6
... indicated relationships between elk, their habitat, and associated wildlife were different from what existed in primeval times; that ecological changes since the early 1900s were “unnatural.” . . . I think we are being less than ...
... indicated relationships between elk, their habitat, and associated wildlife were different from what existed in primeval times; that ecological changes since the early 1900s were “unnatural.” . . . I think we are being less than ...
Стр. 9
... indicating that the northern range has not been overgrazed (Finley 1997). Yet alternative conclusions have been published in the professional literature. These differential interpretations of factors affecting herd and ecological ...
... indicating that the northern range has not been overgrazed (Finley 1997). Yet alternative conclusions have been published in the professional literature. These differential interpretations of factors affecting herd and ecological ...
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... removal effects on population trend indicate that they were partially if not largely additive. The population evidently declined with removals >20–25%. That lesser removals did not cause decline does not The Census Period: 1923–2003 25.
... removal effects on population trend indicate that they were partially if not largely additive. The population evidently declined with removals >20–25%. That lesser removals did not cause decline does not The Census Period: 1923–2003 25.
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... indicate lack of additivity, which I define here as absence of effect on r-values. Figure 2.1 shows that at 10,000 animals, the population could withstand an additional 15% reduction in r without being forced to decline, but with ...
... indicate lack of additivity, which I define here as absence of effect on r-values. Figure 2.1 shows that at 10,000 animals, the population could withstand an additional 15% reduction in r without being forced to decline, but with ...
Стр. 31
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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