ALBERT

Note: Contents: I INTRODUCTION. - 1 Ecosystem Response, Resistance, Resilience, and Recovery in Arctic Landscapes: Introduction / J. F. Reynolds and J. D. Tenhunen. - 1.1 Introduction. - 1.2 NRC Committee Report. - 1.3 The R4D Program. - 1.3.1 Objectives and Conceptual Framework. - 1.3.2 Program Implementation. - 1.3.3 Landscape Function. - 1.4 Summary. - References. - 2 Integrated Ecosystem Research in Northern Alaska, 1947-1994 / G. R. Shaver. - 2.1 Introduction. - 2.2 Early Days at NARL. - 2.3 The U.S. Tundra Biome Program. - 2.4 The Meade River RATE Program. - 2.5 Eagle Creek and Eagle Summit. - 2.6 The Arctic LTER Program at Toolik Lake. - 2.7 Other Studies In Alaska and Elsewhere. - 2.8 Summary and Prospects. - References. - 3 Disturbance and Recovery of Arctic Alaskan Vegetation / D. A. Walker. - 3.1 Introduction. - 3.2 Disturbance and Recovery. - 3.3Typical Disturbance and Recovery Patterns. - 3.3.1 Small Disturbed Patches. - 3.3.2 Contaminants. - 3.3.2.1 Hydrocarbon Spills. - 3.3.2.2 Seawater and Reserve-Pit Spills. - 3.3.3 Fire. - 3.3.4 Transportation Corridors. - 3.3.4.1 Bulldozed Tundra and Related Disturbances. - 3.3.4.2 Off-Road Vehicle Trails. - 3.3.4.2.1 Summer Travel. - 3.3.4.2.2 Winter Travel. - 3.3.4.3 Permanent Roads and Pads. - 3.3.4.4 Gravel Mines. - 3.3.4.5 Native Species in Revegetation of Gravel Pads and Mines. - 3.3.4.6 Road Dust. - 3.3.4.7 Roadside Impoundments. - 3.3.5 Cumulative Impacts. - 3.4 Conclusions. - References. - 4 Terrain and Vegetation of the Imnavait Creek Watershed / D. A. Walker and M. D. Walker. - 4.1 Introduction. - 4.2 Terrain. - 4.2.1 Glacial Deposits. - 4.2.2 Retransported Hillslope Deposits. - 4.2.3 Colluvial Basin Deposits. - 4.2.4 Floodplain Deposits. - 4.3 Vegetation. - 4.3.1 Flora. - 4.3.2 Vegetation Types. - 4.3.2.1 Lichen-Covered Rocks. - 4.3.2.2 Dry Heath. - 4.3.2.2.1 Exposed Sites. - 4.3.2.2.2 Snowbeds. - 4.3.2.3 Tussock Tundra. - 4.3.2.4 Riparian Areas. - 4.3.2.5 Mires. - 4.3.2.6 Beaded Ponds. - 4.4 West-Facing Toposequence. - 4.5 Terrain Sensitivity to Disturbance. - 4.6 Conclusions. - Appendix A. List of Plants for Imnavait Creek, Alaska. - References. - 5 Vegetation Structure and Aboveground Carbon and Nutrient Pools in the Imnavait Creek Watershed / S. C. Hahn, S. F. Oberbauer, R. Gebauer, N. E. Grulke, O. L. Lange, and J. D. Tenhunen. - 5.1 ntroduction. - 5.2 Description of Vegetation. - 5.3 Sampling Methods. - 5.3.1 Cover. - 5.3.2 Biomass and Nutrient Pools. - 5.4 Cover. - 5.5 Aboveground Biomass. - 5.5.1 Live Biomass. - 5.5.2 Photosynthetic Biomass. - 5.5.3 Lichen Biomass. - 5.5.4 Organic Litter. - 5.5.5 Watershed Patterns. - 5.6 Nutrient Pools. - 5.6.1 N and P in Heath Cryptogams. - 5.6.2 N and P in Communities. - 5.7 Discussion and Conclusions. - References. - II PHYSICAL ENVIRONMENT, HYDROLOGY, and TRANSPORT. - 6 Energy Balance and Hydrological Processes in an Arctic Watershed / L. Hinzmann, D. L. Kane, C. S. Benson, and K. R. Everett. - 6.1 Introduction. - 6.2 Radiation and Thermal Regimes. - 6.2.1 Surface Energy Balance. - 6.2.2 Snow Cover and Soil Thermal Regime. - 6.3 Hydrological Processes. - 6.3.1 Snowmelt. - 6.3.2 Plot and Basin Water Balance. - 6.3.3 Runoff and Basin Discharge. - 6.3.4 Precipitation, Evaporation, and Evapotranspiration. - 6.4 Energy Balance and Hydrology Models. - 6.4.1 Simulation of the Thermal Regime. - 6.4.2 Simulation of Snowmelt. - 6.4.3 Simulation of Catchment Runoff. - 6.5 Conclusions. - References. - 7 Shortwave Reflectance Properties of Arctic Tundra Landscapes / A. S. Hope and D. A. Stow. - 7.1 Introduction. - 7.2 Shortwave Reflectance Studies in Arctic Environments. - 7.2.1 Environmental Considerations. - 7.2.2 Radiometric Data. - 7.2.3 Image Data. - 7.3 Spectral Reflectance. - 7.3.1 Aboveground Biomass. - 7.3.2 Vegetation Composition. - 7.3.3 Landscape Patterns. - 7.3.4 Effects of Dust Deposition. - 7.4 Albedo. - 7.4.1 Undisturbed Tussock Tundra. - 7.4.2 Effects of Dust Deposition. - 7.5 Conclusions. - References. - 8 Isotopic Tracers for Investigating Hydrological Processes / L. W. Cooper, I. L. Larsen, C. Solis, J. M. Grebmeier, C. R. Olsen, D. K. Solomon, and R. B. Cook. - 8.1 Introduction. - 8.1.1 Units. - 8.1.2 Conservative vs Nonconservative Isotopes. - 8.2 Nonconservative Tracers. - 8.3 Sulfur-35. - 8.4 Oxygen-18. - 8.4.1 Oxygen-18 Content of Snowpack. - 8.4.2 Oxygen-18 Content of Imnavait Creek. - 8.4.3 Oxygen-18 Content of Soil Moisture. - 8.4.4 Covariance of Oxygen-18 and Deuterium in Watershed Compartments. - 8.4.5 Covariance of Oxygen-18 and Deuterium in Plant Water. - 8.5 Long-Lived Radioisotopes: Lead-210 and Cesium-137. - 8.5.1 Distribution of 137Cs on Tundra and in Lake Sediments. - 8.5.2 Cycling of 137Cs in Annual Berries. - 8.5.3 Distribution of 210Pb in Tundra. - 8.6 Conclusions. - References. - III NUTRIENT AND CARBON FLUXES. - 9 Surface Water Chemistry and Hydrology of a Small Arctic Drainage Basin / K. R. Everett, D. L. Kane, and L. D. Hinzman. - 9.1 Introduction. - 9.2 Watershed Instrumentation. - 9.3 Snowmelt Period. - 9.3.1 Snowmelt Hydrology. - 9.3.2 Snowmelt Chemistry . - 9.3.2.1 Overland Flow. - 9.3.2.2 Water Track Flow. - 9.3.2.3 Imnavait Creek Flow. - 9.4 Post Snowmelt Period. - 9.4.1 Atmospheric Inputs. - 9.4.1.1 Rainfall. - 9.4.1.2 Dry Deposition. - 9.4.1.3 Rime. - 9.4.2 Water Chemistry. - 9.4.2.1 Overland Flow. - 9.4.2.2 Active Layer Flow. - 9.4.2.3 Imnavait Creek Flow. - 9.5 Conclusions. - References. - 10 Nutrient Availability and Uptake by Tundra Plants / J. P. Schimel, K. Kielland, and F. S. Chapin III. - 10.1 Introduction. - 10.2 Controls on Mineralization and Nutrient Supply. - 10.2.1 Patterns of Nutrient Supply in the Soil. - 10.2.2 Patterns of Mineralization. - 10.2.3 Controls on N and P Mineralization. - 10.2.4 Controls on Decomposition and Mineralization. - 10.2.4.1 Temperature. - 10.2.4.1.1 Enzyme Activities. - 10.2.4.1.2 Microbial Activity at Low Temperatures. - 10.2.4.1.3 Freeze-Thaw Events. - 10.2.4.2 Effects of Low Oxygen on Microbial Activity and Mineralization. - 10.2.4.3 Substrate Quality. - 10.3 Fate of Available Nutrients. - 10.3.1 Microbial Nutrient Uptake and Competition with Plants. - 10.3.2 Plant Uptake. - 10.3.2.1 Soil Factors Controlling Nutrient Absorption. - 10.3.2.2 Rooting Strategies. - 10.3.2.3 Uptake Characteristics of Tundra Plants. - 10.3.2.4 Retranslocation vs Current Uptake. - 10.4 Disturbances. - 10.4.1 Vehicle Tracks. - 10.4.2 Road Dust. - 10.4.3 Gray Water. - 10.4.4 Climate Change. - References. - 11 Landscape Patterns of Carbon Dioxide Exchange in Tundra Ecosytems / S. F. Oberbauer, W. Cheng, C. T. Gillespie, B. Ostendorf, A. Sala, R. Gebauer, R. A. Virginia, and J. D. Tenhunen. - 11.1 Introduction. - 11.2 Methods. - 11.2.1 Community Types. - 11.2.2 Leaf Photosynthesis. - 11.2.3 Ecosystem Efflux. - 11.2.4 Ecosystem Net CO2 Exchange. - 11.3 CO2 Uptake. - 11.3.1 Factors Affecting CO2 Uptake. - 11.3.1.1 Light. - 11.3.1.2 Temperature. - 11.3.1.3 Phenology. - 11.3.1.4 Water Availability. - 11.3.1.5 Nutrition. - 11.3.2 Landscape Patterns in Leaf Photosynthesis. - 11.4 CO2 Efflux. - 11.4.1 Factors Affecting CO2 Efflux. - 11.4.1.1 Live Plant Biomass. - 11.4.1.2 Soil Quality. - 11.4.1.3 Thaw Depth and Depth to Water Table. - 11.4.1.4 Soil Moisture. - 11.4.1.5 Soil Temperature. - 11.4.2 Landscape Patterns of CO2 Efflux. - 11.4.3 Daily and Seasonal Patterns of CO2 Efflux. - 11.4.4 Dust Deposition Effects on CO2 Efflux. - 11.5 Landscape Patterns in Net CO2 Exchange. - 11.6 Conclusions. - References. - 12 Control of Tundra Methane Emission by Microbial Oxidation / S. C. Whalen, W. S. Reeburgh, and C. E. Reimers. - 12.1 Introduction. - 12.2 Sampling Procedure. - 12.3 Results and Discussion. - 12.3.1 Methane Flux and Environmental Variables in Tundra and Taiga. - 12.3.2 Physiology, Controls, and Potential for Microbial CH4 Oxidation. - 12.3.3 Methane Oxidation by Tundra Soils in a Warmer Climate. - 12.4 Conclusions. - References. - 13 Dynamics of Dissolved and Particulate Car

Note: Contents Observed Climatic Variability: Time Dependence / J. M. WALLACE Observed Climatic Variability: Spatial Structure / J. M. WALLACE Predictability of the Atmosphere and Oceans: From Days to Decades / T. N. PALMER Mechanisms for Decadal-to-Centennial Climate Variability / E. S. SARACHIK, M. WINTON and F. L. YIN Long-Term Coordinated Changesin the Convective Activity of the North Atlantic / R. DICKSON, J. LAZIER, J. MEINCKE and P. RHINES Mechanism for Decadal Climate Variability / M. LATIF, A. GROTZNER, M. MUNNICH, E. MAIER-REIMER, S. VENZKE and T. P. BARNETTA The Climate Response to the Changing Greenhouse Gas Concentration in the Atmosphere / L. BENGTSSON Analysis of Thermohaline Feedbacks / J. MAROTZKE An Overview of Century Time-Scale Variability in the Climate System: Observations and Models / T. F. STOCKER Steady States and Variability in Oceanic Zonal Flows / D. OLBERS and C. VOLKER Spectral Methods: What They Can and Cannot Do for Climatic Time Series / M. GHIL and P. Yiou Subject Index List of Participants

Note: Contents: 1 The Biological Paradigm ; 2 Threshold Logic ; 3 Weighted Networks - The Perceptron ; 4 Perceptron Learning ; 5 Unsupervised Learning and Clustering Algorithms ; 6 One and Two Layered Networks ; 7 The Backpropagation Algorithm ; 8 Fast Learning Algorithms ; 9 Statistics and Neural Networks ; 10 The Complexity of Learning ; 11 Fuzzy Logic ; 12 Associative Networks ; 13 The Hopfield Model ; 14 Stochastic Networks ; 15 Kohonen Networks ; 16 Modular Neural Networks ; 17 Genetic Algorithms ; 18 Hardware for Neural Networks