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| Contributors | |
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| Introduction | |
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| General Introduction | |
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| The Kluane Region | |
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| Geography and Geology | |
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| Weather and Climate | |
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| Temperature | |
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| Precipitation | |
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| Study Area and Vegetation | |
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| Vertebrate Food Web | |
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| History of Hare Cycles | |
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| Large Mammals | |
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| Human Impacts | |
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| Trophic Interactions, Community Organization, and the Kluane Ecosystem | |
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| Trophic-level Theory | |
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| Community Structure | |
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| Control of Trophic-level Biomass | |
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| Case Studies in Mammalian Communities | |
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| Interactions of Trophic Levels | |
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| Bottom-up Models | |
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| Top-down Models | |
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| Herbivore-dominated Models | |
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| Vegetation-dominated Models | |
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| Dilution Models | |
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| Reciprocal Models | |
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| Experimental Perturbations in the Boreal Forest | |
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| Experiment 1: Application of Fertilizer | |
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| Experiment 2: Addition of Rabbit Chow | |
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| Experiment 3: Exclusion of Carnivores | |
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| Experiment 4: Exclusion of Carnivores and the Addition of Rabbit Chow | |
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| Experiment 5: Exclusion of Hares | |
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| Experiment 6: Exclusion of Hares and the Addition of Fertilizer | |
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| Experiment 7: Removal of Vegetation | |
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| Discussion | |
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| Limitations of the Models | |
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| Models of Trophic-level Interactions in Different Ecosystems | |
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| Summary | |
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| Experimental Design and Practical Problems of Implementation | |
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| Experimental Design | |
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| Choice of Treatments | |
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| Size and Spatial Location of Treatments | |
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| To Replicate or Not to Replicate | |
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| Practical Problems of Implementation | |
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| The Evolution of a Predator-proof Fence | |
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| Food Supplementation | |
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| Fertilizer | |
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| Hare Exclosures | |
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| Organization, Personnel, and Equipment | |
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| Organizational Structure | |
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| The Problem of Training and Protocols | |
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| Seen Sheets | |
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| Winter Work at Kluane | |
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| Equipment | |
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| Summary | |
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| Plant Dynamics | |
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| Herbs and Grasses | |
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| Hypotheses Regarding Vegetation | |
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| Study Area | |
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| Tests of Predictions from Three Models | |
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| Donor Control Model | |
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| Herbivore Control Model | |
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| Combined Top-down Bottom-up Model | |
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| Which Model Best Describes Boreal Forest Herbs and Grasses? | |
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| Transient Dynamics and Stability | |
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| Impacts of Climatic Warming | |
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| Summary | |
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| Shrubs | |
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| The Shrub Community at Kluane | |
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| Species Composition | |
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| Pattern Changes and Succession | |
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| Secondary Chemicals in Kluane Shrubs | |
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| Biomass Dynamics | |
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| Methods of Estimation | |
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| Impacts of Treatments | |
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| Growth Rates of Shrubs | |
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| Methods of Estimation | |
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| Impacts of Treatments | |
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| Losses of Twigs to Browsing and Natural Mortality | |
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| Methods of Estimation | |
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| Impacts of Treatments | |
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| What Limits Primary Production of Shrubs? | |
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| Succession in Boreal Forest Shrubs | |
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| Impact of Hare and Moose Browsing | |
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| Role of Secondary Chemicals | |
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| Summary | |
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| Trees | |
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| Tree Community at Kluane | |
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| Tree Abundance on the Study Area | |
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| Tree Growth | |
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| White Spruce Cone and Seed Production | |
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| Vegetation Mapping | |
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| Fire History of the Study Area | |
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| Other Forms of Disturbance | |
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| Succession in the Boreal Forest | |
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| Fertilizer Effects on Trees | |
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| Summary | |
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| Herbivores | |
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| Snowshoe Hare Demography | |
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| The Snowshoe Hare Cycle | |
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| Methods | |
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| Demographic Parameters | |
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| Density and Rates of Change | |
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| Sex and Age Structure | |
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| Reproduction | |
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| Survival Rates | |
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| Causes of Death | |
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| Immigration and Emigration | |
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| Impacts of Experimental Treatments | |
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| Impacts on Hare Demography | |
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| Causation of the Hare Cycle | |
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| Efficacy of the Experimental Treatments | |
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| Experimental Scale and Methodological Concerns | |
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| Interactions with Other Species | |
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| Conclusions | |
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| The Role of Red Squirrels and Arctic Ground Squirrels | |
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| Natural History | |
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| Red Squirrels | |
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| Arctic Ground Squirrels | |
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| Community Interactions and Factors Affecting Population Dynamics | |
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| Methods | |
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| Red Squirrels | |
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| Arctic Ground Squirrels | |
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| Results | |
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| Red Squirrels | |
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| Arctic Ground Squirrels | |
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| Discussion | |
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| Role of Stochastic Events | |
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| Treatment Effects | |
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| Role of Squirrels in the Boreal Forest Community | |
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| Conclusions | |
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| Voles and Mice | |
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| Natural History and Food Web Links | |
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| Community Interactions and Factors Affecting Population Dynamics | |
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| Methods | |
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| Small Mammal Trapping | |
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| Data Analysis | |
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| Robustness of Data | |
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| Impacts of the Manipulations | |
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| Northern Red-Backed Vole | |
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| Microtus Voles | |
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| What Limits Mice and Vole Populations at Kluane? | |
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| Northern Red-Backed Vole | |
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| Microtus Species | |
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| Summary | |
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| Forest Grouse and Ptarmigan | |
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| The Ecological Role of Forest and Alpine Grouse | |
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| Trophic Position | |
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| Life History | |
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| Habitats | |
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| Current Understanding of Population Dynamics | |
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| Predicted Responses to Experimental Treatments | |
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| Methods | |
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| Duration of Grouse Studies | |
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| Shakwak Valley Population Trends | |
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| Numerical and Reproductive Parameters on Treatment Grids | |
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| Data Robustness and Limitations | |
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| Demography of Grouse | |
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| Population Trends in the Shakwak Valley | |
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| Reproductive Parameters | |
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| Population Trends on Control Plots | |
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| Relationship of Changes to the Snowshoe Hare Cycle | |
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| Response of Forest Grouse to Experimental Treatments | |
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| Fertilizer Addition | |
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| Food Addition | |
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| Predator Exclosure | |
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| Predator Exclosure + Food | |
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| Discussion | |
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| Hypotheses Related to Grouse Population Trends | |
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| Did the Experiments Change the Dynamics for Grouse? | |
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| Linkages on the Same Trophic Level | |
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| Linkages to Other Trophic Levels | |
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| Conclusions | |
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| Comparison with Other Studies | |
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| Unexpected Results | |
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| Unanswered Questions | |
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| Other Herbivores and Small Predators: Arthropods, Birds, and Mammals | |
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| Methods | |
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| Arthropods | |
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| Songbirds and Woodpeckers | |
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| Other Herbivores | |
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| Predicted Responses to Experimental Treatments | |
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| Responses by Species Groups | |
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| Arthropods | |
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| Birds | |
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| Other Herbivores | |
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| Discussion | |
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| Links to the 10-Year Cycle | |
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| Effects of Fertilization | |
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| Other Patterns in the Food Web | |
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| Summary | |
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| Mammalian Predators | |
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| Coyotes and Lynx | |
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| Methods | |
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| Population Monitoring | |
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| Foraging Behavior | |
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| Functional Responses | |
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| Numerical Responses | |
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| Density | |
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| Adult Survival | |
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| Emigration | |
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| Recruitment | |
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| Social Organization | |
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| Home Ranges | |
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| Social Groups | |
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| Foraging Behavior | |
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| Diets | |
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| Scavenging Behavior | |
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| Hunting Tactics | |
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| Group Hunting | |
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| Use of Trails | |
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| Habitat Use | |
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| Functional Responses | |
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| Components of Functional Responses | |
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| Prey Switching | |
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| Synthesis and Conclusions | |
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| Numerical Responses | |
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| Functional Responses | |
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| Total Impact of Predation by Coyotes and Lynx on Hares | |
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| Impact of Predation by Coyotes and Lynx on Alternative Prey | |
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| Coexistence of Coyotes and Lynx | |
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| The Specialist-Generalist Contrast | |
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| Other Mammalian Predators | |
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| Methods | |
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| Red Fox | |
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| Wolf | |
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| Weasel | |
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| Wolverine | |
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| Marten | |
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| Mink and Otter | |
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| Synthesis and Conclusions | |
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| Avian Predators | |
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| Great Horned Owls | |
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| Methods | |
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| Population Census | |
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| Monitoring Diets | |
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| Radio Telemetry | |
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| Analysis of Telemetry Data | |
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| Statistical Analyses | |
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| Demography | |
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| Reproduction and Population Productivity | |
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| Survival and Emigration | |
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| Estimating Numerical Responses | |
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| Foraging Behavior | |
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| Diet | |
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| Prey Preferences | |
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| Estimating Functional Responses and Predation Impact | |
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| Social Organization | |
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| Social Status and Vocal Activity | |
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| Stability and Size of Home Ranges | |
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| Effect of Territoriality on Spacing of Owls | |
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| Territorial Behavior and Limitation of Population Increase | |
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| Social Behavior and the Time Lag in the Numerical Response | |
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| Responses to Large-Scale Experiments | |
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| Space Use in Territories with Experimental Hot Spots of Prey | |
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| Predator Movements from Poor Patches to Rich Patches | |
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| Discussion | |
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| Large Floating Population When Resources Are Abundant | |
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| Factors Affecting Functional Responses and Predation Impact | |
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| Limitation of Population Growth at Peaks of Cyclic Prey | |
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| Time Lag in the Numerical Response of a Predator of Cyclic Prey | |
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| Factors Limiting Spatial Aggregation of Predators | |
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| Raptors and Scavengers | |
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| Methods | |
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| General Approach | |
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| Population Surveys: The Intensive Search Area | |
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| Reproductive Success | |
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| Diets | |
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| Data Analysis | |
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| Predicted Responses of Raptors and Corvids | |
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| Responses by Groups and Individual Species | |
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| Large Resident Raptors | |
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| Large Migratory Raptors | |
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| Small Migratory Raptors | |
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| Small Owls | |
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| Corvids | |
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| Other Raptors | |
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| Intraguild Predation | |
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| Discussion | |
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| Functional, Numerical, and Reproductive Responses to Hare Densities | |
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| Resource Partitioning and Diet Width | |
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| Intraguild Predation | |
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| Methodology and Limitations | |
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| Summary | |
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| Community and Ecosystem Organization | |
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| Testing Hypotheses of Community Organization for the Kluane Ecosystem | |
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| Experimental Perturbations of the Boreal Forest | |
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| Direct and Indirect Effects | |
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| The Experiments | |
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| Methods | |
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| Soil Nitrogen | |
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| Vegetation | |
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| Plant Secondary Chemicals | |
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| Herbivore Biomass | |
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| Predator Activity | |
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| Direct Effects of Trophic-level Perturbations | |
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| Fertilizer Addition | |
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| Addition of Hare Food | |
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| Predator Exclosure | |
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| Predator Exclosure and Food Addition | |
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| Hare Exclosure | |
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| Hare Exclosure Plus Fertilizer | |
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| Vegetation Removal | |
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| Indirect Effects of Trophic-level Perturbations | |
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| Fertilizer Addition | |
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| Food Addition | |
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| Predator Exclosure | |
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| Food Addition and Predator Exclosure | |
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| Hare Exclosure | |
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| Discussion | |
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| Direct Effects | |
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| Indirect Effects | |
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| Top-down versus Bottom-up | |
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| Productivity and Biomass Responses | |
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| Other Indirect Effects | |
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| The Role of Secondary Chemicals | |
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| The Dominant Pathways in the Vertebrate Community | |
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| Conclusion | |
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| Summary | |
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| Vertebrate Community Structure in the Boreal Forest: Modeling the Effects of Trophic Interaction | |
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| Trophic Interaction and Species Coexistence | |
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| Interaction between Vegetation and Herbivores | |
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| Interaction between Herbivores and Predators | |
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| Modeling | |
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| Interaction between Vegetation and Herbivores | |
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| Equilibrium Conditions for Snowshoe Hares and Ground Squirrels | |
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| Adding Predation to Models of Interaction between Herbivores and Vegetation | |
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| The Effect of Herbivore Cycles on Predators | |
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| Discussion | |
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| Unresolved Modeling Issues | |
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| Mechanisms of Coexistence | |
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| Top-down and Bottom-up Influences on Community Structure | |
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| Trophic Mass Flow Models of the Kluane Boreal Forest Ecosystem | |
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| Questions about the Ecosystem Dynamics of the Boreal Forest | |
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| Modeling the Kluane System | |
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| Methods for Constructing Mass Balance Models | |
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| Parameterization of Mass Balance Models | |
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| Results from Mass Balance Models | |
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| Consumption of Plant Biomass by Herbivores | |
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| Phase of Cycle Models | |
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| Seasonal Models | |
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| Food Addition and Predator Reduction Models | |
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| Partial Food Web Models | |
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| Discussion | |
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| Do Predator-Prey Dynamics Structure the Boreal Forest Ecosystem? | |
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| Potential for Other Ecopath Models | |
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| Synthesis and Implications | |
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| Summary | |
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| Conclusions and Future Directions | |
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| Primary Findings | |
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| Predator Trophic Level | |
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| Herbivore Trophic Level | |
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| Plant Trophic Level | |
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| Secondary Findings | |
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| Predator Trophic Level | |
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| Herbivore Trophic Level | |
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| Plant Trophic Level | |
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| Opportunities for Further Work | |
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| Unsolved Problems | |
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| Future Boreal Forest Research | |
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| How to Use the Enclosed Kluane CD-ROM | |
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| Table of Contents for the Kluane CD-ROM | |
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| Index | |