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
... significant impact on the vegetation. He cited 11 sources, including 6 intra-agency reports, 3 conference presentations, 1 Ph.D. dissertation, and 1 peer-reviewed publication, but he neither 6 A YELLOWSTONE SYNTHESIS.
... significant impact on the vegetation. He cited 11 sources, including 6 intra-agency reports, 3 conference presentations, 1 Ph.D. dissertation, and 1 peer-reviewed publication, but he neither 6 A YELLOWSTONE SYNTHESIS.
Стр. 11
... significant fraction of the northern herd out of the park each winter, and whatever the extent to which the wolves may reduce the number of animals wintering in the park, the effect should be to ease foraging pressure on the park winter ...
... significant fraction of the northern herd out of the park each winter, and whatever the extent to which the wolves may reduce the number of animals wintering in the park, the effect should be to ease foraging pressure on the park winter ...
Стр. 20
... significant at p = 0.05 with an R2 = 0.398. The r = 0 intercept of the regression line is 16,800 elk. Taper and Gogan (2002) performed similar calculations, subdividing the time series into a 1964–65 to 1978–79 “early” period and 1985 ...
... significant at p = 0.05 with an R2 = 0.398. The r = 0 intercept of the regression line is 16,800 elk. Taper and Gogan (2002) performed similar calculations, subdividing the time series into a 1964–65 to 1978–79 “early” period and 1985 ...
Стр. 21
... significant at p = 0.05 with an R2 = 0.40. Test for the late period, based on only five points, also showed a negative slope but was short of significance. Hence it is not possible to ascertain with my analysis whether the early and ...
... significant at p = 0.05 with an R2 = 0.40. Test for the late period, based on only five points, also showed a negative slope but was short of significance. Hence it is not possible to ascertain with my analysis whether the early and ...
Стр. 34
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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