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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... authors. In all cases I have followed the previously described criteria by considering those authors' views, weighed their evidence, and explained why I consider my evidence to be more valid or my conclusions to be more probable. This ...
... authors. In all cases I have followed the previously described criteria by considering those authors' views, weighed their evidence, and explained why I consider my evidence to be more valid or my conclusions to be more probable. This ...
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... authors, although not as detailed as some. I use slightly different numbers for reasons that I describe shortly and update the time series from those used in the excellent Lemke et al. (1998) and Taper and Gogan (2002) studies, which ...
... authors, although not as detailed as some. I use slightly different numbers for reasons that I describe shortly and update the time series from those used in the excellent Lemke et al. (1998) and Taper and Gogan (2002) studies, which ...
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... authors constructed a multivariate analysis–based sightability model. In separate studies, Mack and Singer (1992) calculated annual population sizes with models using demographic parameters of the herd. During 10 years of comparison ...
... authors constructed a multivariate analysis–based sightability model. In separate studies, Mack and Singer (1992) calculated annual population sizes with models using demographic parameters of the herd. During 10 years of comparison ...
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... authors discussed next. Visually, the numbers in table 2.1 point to a continuous increase in the minimum fall population from 1968–69 to 1974–75. There is a suggestion of slowing growth or leveling off between 1975–76 and 1978–79 ...
... authors discussed next. Visually, the numbers in table 2.1 point to a continuous increase in the minimum fall population from 1968–69 to 1974–75. There is a suggestion of slowing growth or leveling off between 1975–76 and 1978–79 ...
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... authors have conducted similar tests for different sets of years. Merrill and Boyce (1991) found a similar inverse relationship for the period 1971–88. They provided no R2 value, but it was presumably smaller than mine because 77% of ...
... authors have conducted similar tests for different sets of years. Merrill and Boyce (1991) found a similar inverse relationship for the period 1971–88. They provided no R2 value, but it was presumably smaller than mine because 77% of ...
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 |
Другие издания - Просмотреть все
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