ALBERT

Note: Table of Contents: 1 The Solid Phase of Marine Sediments / DIETER K. FÜTTERER 1.1 Introduction 1.2 Sources and Components of Marine Sediments 1.2.1 Lithogenous Sediments 1.2.2 Biogenous Sediments 1.2.3 Hydrogenous Sediments 1.3 Classification of Marine Sediments 1.3.1 Terrigenous Sediments 1.3.2 Deep-Sea Sediments 1.4 Global Patterns of Sediment Distribution 1.4.1 Distribution Patterns of Shelf Sediments 1.4.2 Distribution Patterns of Deep-Sea Sediments 1.4.3 Distribution Patterns of Glay Minerals 1.4.4 Sedimentation Rates 2 Geophysical Perspectives in Marine Sediments 2.1 Physical Properties of Marine Sediments / MONIKA BREITZKE 2.1.1 Introduction 2.1.2 Porosity and Wet Bulk Density 2.1.2.1 Analysis by Weight and Volume 2.1.2.2 Gamma Ray Attenuation 2.1.2.3 Electrical Resistivity (Galvanic Method) 2.1.2.4 Electrical Resistivity (Inductive Method) 2.1.3 Permeability 2.1.4 Acoustic and Elastic Properties 2.1.4.1 Biot-Stoll Model 2.1.4.2 Full Waveform Ultrasonic Gore Logging 2.1.5 Sediment Classification 2.1.5.1 Full Waveform Gore Logs as Acoustic Images 2.1.5.2 P-and S-Wave Velocity, Attenuation, Elastic Moduli and Permeability 2.1.6 Sediment Echosounding 2.1.6.1 Synthetic Seismograms 2.1.6.2 Narrow-Beam Parasound Echosounder Recordings 2.2 Sedimentary Magnetism / ULRICH BLEIL 2.2.1 Introduction 2.2.2 Biogenie Magnetic Minerals in Marine Sediments 2.2.3 Reduction Diagenesis of Magnetic Minerals in Marine Environments 3 Quantification of Early Diagenesis: Dissolved Constituents in Marine Pore Water / HORST D. SCHULZ 3.1 Introduction: How to Read Pore Water Concentration Profiles 3.2 Calculation of Diffusive Fluxes and Diagenetic Reaction Rates 3.2.1 Steady State and Non-Steady State Situations 3.2.2 The Steady State Situation and Fick's First Law of Diffusion 3.2.3 Quantitative Evaluation of Steady State Concentration Profiles 3.2.4 The Non-Steady State Situation and Fick's Second Law of Diffusion 3.2.5 The Primary Redox-Reactions: Degradation of Organic Matter 3.3 Sampling of Pore Water for Ex-Situ Measurements 3.3.1 Obtaining Sampies of Sediment for the Analysis of Pore Water 3.3.2 Pore Water Extraction from the Sediment 3.3.3 Storage, Transport and Preservation of Pore Water 3.4 Analyzing Constituents in Pore Water, Typical Profiles 3.5 In-Situ Measurements 3.6 Influence of Bioturbation, Bioirrigation, and Advection 4 Organic Matter: The Driving Force for Early Diagenesis / JÜRGEN RULLKÖTTER 4.1 The Organic Carbon Cycle 4.2 Organic Matter Accumulation in Sediments 4.2.1 Productivity Versus Preservation 4.2.2 Primary Production of Organic Matter and Export to the Ocean Bottom 4.2.3 Transport of Organic Matter through the Water Column 4.2.4 The Influence of Sedimentation Rate on Organic Matter Burial 4.2.5 Allochthonous Organic Matter in Marine Sediments 4.3 Early Diagenesis 4.3.1 The Organic Carbon Content of Marine Sediments 4.3.2 Chemical Composition of Biomass 4.3.3 The Principle of Selective Preservation 4.3.4 The Formation of Fossil Organic Matter and its Bulk Composition 4.3.5 Early Diagenesis at the Molecular Level 4.3.6 Biological Markers (Molecular Fossils) 4.4 Organic Geochemical Proxies 4.4.1 Total Organic Carbon and Sulfur 4.4.2 Marine Versus Terrigenous Organic Matter 4.4.3 Molecular Paleo-Seawater Temperature and Climate Indicators 4.5 Analytical Techniques 4.5.1 Sam pie Requirements 4.5.2 Elemental and Bulk Isotope Analysis 4.5.3 Rock-Eval Pyrolysis and Pyrolysis Gas Chromatography 4.5.4 Organic Petrography 4.5.5 Bitumen Analysis 4.6 The Future of Marine Geochemistry of Organic Matter 5 Bacteria and Marine Biogeochemistry / Bo BARKER JORGENSEN 5.1 Role of Microorganisms 5.1.1 From Geochemistry to Microbiology - and back 5.1.2 Approaches in Marine Biogeochemistry 5.2 Life and Environments at Small Scale 5.2.1 Hydrodynamics of Low Reynolds Numbers 5.2.2 Diffusion at Small Scale 5.2.3 Diffusive Boundary Layers 5.3 Regulation and Limits of Microbial Processes 5.3.1 Substrate Uptake by Microorganisms 5.3.2 Temperature as a Regulating Factor 5.3.3 Other Regulating Factors 5.4 Energy Metabolism of Prokaryotes 5.4.1 Free Energy 5.4.2 Reduction-Oxidation Processes 5.4.3 Relations to Oxygen 5.4.4 Definitions of Energy Metabolism 5.4.5 Energy Metabolism of Microorganisms 5.4.6 Chemolithotrophs 5.4.7 Respiration and Fermentation 5.5 Pathways of Organic Matter Degradation 5.5.1 Depolymerization of Macromolecules 5.5.2 Aerobic and Anaerobic Mineralization 5.5.3 Depth Zonation of Oxidants 5.6 Methods in Biogeochemistry 5.6.1 Incubation Experiments 5.6.2 Radioactive Tracers 5.6.3 Example: Sulfate Reduction 5.6.4 Specific Inhibitors 5.6.5 Other Methods 6 Early Diagenesis at the Benthic Boundary Layer: Oxygen and Nitrate in Marine Sediments / CHRISTIAN HENSEN AND MATTHIAS ZABEL 6.1 Introduction 6.2 Oxygen and Nitrate Distribution in Seawater 6.3 The Role of Oxygen and Nitrate in Marine Sediments 6.3.1 Respiration and Redox Processes 6.3.1.1 Nitrification and Denitrification 6.3.1.2 Coupling of Oxygen and Nitrate to other Redox Pathways 6.3.2 Determination of Consumption Rates and Senthic Fluxes 6.3.2.1 Fluxes and Concentration Profiles Determined by In-Situ Devices 6.3.2.2 Ex-Situ Pore Water Data from Deep-Sea Sediments 6.3.2.3 Determination of Denitrification Rates 6.3.3 Oxic Respiration, Nitrification and Denitrification in Different Marine Environments 6.3.3.1 Quantification of Rates and Fluxes 6.3.3.2 Variation in Different Marine Environments: Case Studies 6.4 Summary 7 The Reactivity of Iron / RALF R. HAESE 7.1 Introduction 7.2 Pathways of Iron Input to Marine Sediments 7.2.1 Fluvial Input 7.2.2 Aeolian Input 7.3 Iron as a Limiting Nutrient for Primary Productivity 7.4 The Early Diagenesis of Iron in Sediments 7.4.1 Dissimilatary Iran Reductian 7.4.2 Solid Phase Ferric Iron and its Bioavailability 7.4.2.1 Properties of Iron Oxides 7.4.2.2 Bioavailability of Iron Oxides 7.4.2.3 Bioavailability of Sheet Silicate Sound Ferric lron 7.4.3 Iron and Manganese Redax Cycles 7.4.4 Iron Reactivity towards S, O2, Mn, NO3, P, HCO3, and Si-AI 7.4.4.1 lron Reduction by HS and Ligands 7.4.4.2 Iron Oxidation by O2, NO3, and Mn4+ 7.4.4.3 Iron-Sound Phosphorus 7.4.4.4 The Formation of Siderite 7.4.4.5 The Formation of lron Searing Aluminosilicates 7.4.5 Discussion: The Importance of Fe-and Mn-Reactivity in Various Enyironments 7.5 The Assay for Ferric and Ferrous Iron 8 Sulfate Reduction in Marine Sediments / SABINE KASTEN AND BO BARKER JØRGENSEN 8.1 Introduction 8.2 Sulfate Reduction and the Degradation of Organic Matter 8.3 Biotic and Abiotic Processes Coupled to Sulfate Reduction 8.3.1 Pyrite Formation 8.3.2 Effects of Sulfate Reduction on Sedimentary Solid Phases 8.4 Determination of Sulfate Reduction Rates 9 Marine Carbonates: Their Formation and Destruction / RALPH R. SCHNEIDER, HORST D. SCHULZ AND CHRISTIAN HENSEN 9.1 Introduction 9.2 Marine Environments of Carbonate Production and Accumulation 9.2.1 Shallow-Water Carbonates 9.2.2 Pelagic Calcareous Sediments 9.3 The Calcite-Carbonate-Equilibrium in Marine Aquatic Systems 9.3.1 Primary Reactions of the Calcite-Carbonate-Equilibrium with Atmospheric Contact in Infinitely Diluted Solutions 9.3.2 Primary Reactions of the Calcite-Carbonate-Equilibrium without Atmospheric Contact 9.3.3 Secondary Reactions of the Calcite-Carbonate-Equilibrium in Seawater 9.3.4 Examples for Calculation of the Calcite-Carbonate-Equilibrium in Ocean Waters 9.4 Carbonate Reservoir Sizes and Fluxes between Particulate and Dissolved Reservoirs 9.4.1 Production Versus Dissolution of Pelagic Carbonates 9.4.2 Inorganic and Organic Carbon Release trom Deep-Sea Sediments 10 Influences of Geochemical Processes on Stable Isotope Distribution in Marine Sediments / TORSTEN SICKERT 10.1 Introduction 10.2 Fundamentals 10.2.1 Principles of Isotopic Fractionation 10.2.2 Analytical Procedures 10.3 Geochemicallnfluences on 18O/16O Ratios 10.3.1 δ18O of Seawater 10.3.2 δ18O in Marine Carbonates 10.4 Geochemical Influences on 13C/12C Ratios 10.4.1

Note: Contents: 1 Global Distribution of Lakes / M. MEYBECK. - 1 Introduction. - 2 Background Material and Approaches to Global Lake Census. - 2.1 Data Used. - 2.2 Approaches to Global Lake Census. - 3 General Laws of Lake Distribution. - 3.1 Lake Density . - 3.2 Limnic Ratio. - 4 Distribution of Lakes of Tectonic Origin. - 5 Lakes of Glacial Origin. - 5.1 Lake Densities. - 5.2 Global Deglaciated Area. - 5.3 Total Number of Glacial Lakes. - 6 Fluvial Lakes. - 7 Global Distribution of Crater Lakes. - 8 Global Distribution of Saline Lakes. - 8.1 Coastal Lagoons. - 8.2 Salinized Lakes due to Evaporation. - 9 Global Lake Distribution. - 9.1 Extrapolation Approach. - 9.2 Lake Type Approach. - 9.3 Climatic Typology Approach. - 9.4 Lake Distribution in Endorheic Areas. - 9.5 Global Dissolved Salt Distribution in Lakes. - 10 Major Changes in Global Lake Distribution in the Geological Past. - 10.1 Lake Ages. - 10.2 Historical Changes. - 10.3 Postglacial Changes. - 11 Discussion and Conclusions. - References. - 2 Hydrological Processes and the Water Budget of Lakes / T. C. WINTER. - 1 Introduction. - 2 Hydrological System with Regard to Lakes. - 2.1 Interaction of Lakes with Atmospheric Water. - 2.2 Interaction of Lakes with Surface Water. - 2.3 Interaction of Lakes with Subsurface Water. - 2.4 Change in Lake Volume. - 3 Summary. - References. - 3 Hydrological and Thermal Response of Lakes to Climate: Description and Modeling / S. W. HOSTETLER. - 1 Introduction. - 2 Hydrological Response. - 3 The Hydrological Budget. - 4 Hydrological Models. - 5 Thermal Response. - 5.1 Energy Budget and Energy Budget Models. - 5.2 Models and Modeling. - 6 Use of Models to Link Lakes with Climate Change. - 7 Input Data Sets. - 8 Sample Applications. - 9 Summary. - References. - 4 Mixing Mechanisms in Lakes / D. M. IMBODEN and A. WÜEST. - 1 Transport and Mixing. - 2 Lakes as Physical Systems. - 3 Fluid Dynamics: Mathematical Description of Advection and Diffusion. - 3.1 Equations of Fluid Motion. - 3.2 Turbulence, Reynolds' Stress, and Eddy Diffusion. - 3.3 Vertical Momentum Equation. - 3.4 Nonlocal Diffusion and Transilient Mixing. - 4 Density and Stability of Water Column. - 4.1 Equation of State of Water. - 4.2 Potential Temperature and Local Vertical Stability. - 5 Energy Fluxes: Driving Forces Behind Transport and Mixing. - 5.1 Thermal Energy. - 5.2 Potential Energy. - 5.3 Kinetic Energy. - 5.4 Turbulent Kinetic Energy Balance in Stratified Water. - 5.5 Internal Turbulent Energy Fluxes: Turbulence Cascade. - 6 Mixing Processes in Lakes. - 6.1 Waves and Mixing. - 6.2 Mixing in the Surface Layer. - 6.3 Diapycnal Mixing. - 6.4 Boundary Mixing. - 6.5 Double Diffusion. - 6.6 Isopycnal Mixing. - 7 Mixing and Its Ecological Relevance. - 7.1 Time Scales of Mixing. - 7.2 Reactive Species and Patchiness. - 7.3 Mixing and Growth: The Search for an Ecological Steering Factor. - References. - 5 Stable Isotopes of Fresh and Saline Lakes / J. R. GAT. - 1 Introduction. - 1.1 Isotope Separatio During Evaporation. - 2 Small-Area Lakes. - 2.1 Seasonal and Annual Changes. - 2.2 Deep Freshwater Lakes. - 2.3 Transient Surface-Water Bodies. - 3 Interactive and Feedback Systems. - 3.1 Network of Surface-Water Bodies. - 3.2 Recycling of Reevaporated Moisture into the Atmosphere. - 3.3 Large Lakes. - 3.4 Large-Area Lakes with Restricted Circulation. - 4 Saline Lakes. - 4.1 Isotope Hydrology of Large Salt Lakes. - 4.2 Ephemeral Salt Lakes and Sabkhas. - 5 Isotopie Paleolimnology. - 6 Conclusions: From Lakes to Oceans. - References. - 6 Exchange of Chemicals Between the Atmosphere and Lakes / P. VLAHOS, D. MACKAY, S. J. EISENREICH, and KC. HORNBUCKLE. - 1 Introduction. - 2 Air-Water Partitioning Equilibria. - 3 Diffusion Between Water and Air. - 4 Volatilization and Absorption: Double-Resistance Approach. - 5 Factors Affecting Mass-Transfer Coefficients. - 6 Partitioning of Chemical to Paniculate Matter in Air and Water. - 6.1 Air. - 6.2 Water. - 7 Atmospheric Deposition Processes. - 7.1 Dry Deposition. - 7.2 Wet Deposition. - 8 Specimen Calculation. - 8.1 Step 1: Physicochemical Properties. - 8.2 Step 2: Mass-Transfer Coefficients. - 8.3 Step 3: Sorption in Air and Water. - 8.4 Step 4: Equilibrium Status. - 8.5 Step 5: Volatilization and Deposition Rates. - 9 Role of Air-Water Exchange in Lake Mass Balances. - 10 Case Studies. - 10.1 Mass Balance on Siskiwit Lake, Isle Royale. - 10.2 Mass Balance on Lake Superior. - 10.3 Air-Water Exchange in Green Bay, Lake Michigan. - 10.4 Air-Water Exchange in Lake Superior. - 11 Conclusions. - References. - 7 Atmospheric Depositions: Impact of Acids on Lakes / W. STUMM and J. SCHNOOR. - Abstract. - 1 Introduction: Anthropogenic Generation of Acidity. - 1.1 Genesis of Acid Precipitation. - 2 Acidity and Alkalinity: Neutralizing Capacities. - 2.1 Transfer of Acidity (or Alkalinity) from Pollution Through the Atmosphere to Ecosystems. - 3 Acidification of Aquatic and Terrestrial Ecosystems. - 3.1 Disturbance of H+ Balance from Temporal or Spatial Decoupling of the Production and Mineralization of the Biomass. - 3.2 In Situ H+ Ion Neutralization in Lakes. - 3.3 Krug and Frink Revisited. - 4 Brønsted Acids and Lewis Acids: Pollution by Heavy Metals, as Influenced by Acidity. - 4.1 Cycling of Metals. - 4.2 Pb in Soils. - 5 Impact of Acidity on Ecology in Watersheds. - 5.1 Soils. - 5.2 Lakes. - 5.3 Nitrogen Saturation of Forests. - 6 Critical Loads. - 6.1 Critical Load Maps. - 6.2 Models for Critical Load Evaluation. - 7 Case Studies. - 7.1 Chemical Weathering of Crystalline Rocks in the Catchment Area of Acidic Ticino Lakes, Switzerland. - 7.2 Watershed Manipulation Project at Bear Brooks, Maine. - 8 Summary. - References. - 8 Redox-Driven Cycling of Trace Elements in Lakes / J. HAMILTON-TAYLOR and W. DAVISON. - 1 Introduction. - 2 Major Biogeochemical Cycles and Pathways. - 3 Iron and Manganese. - 3.1 Transformations and Cycling. - 3.2 Iron and Manganese Compounds as Carrier Phases. - 4 Sediment-Water Interface. - 4.1 Diffusive Flux from Sediments. - 4.2 Evidence of Little or No Diffusive Efflux from Sediments. - 4.3 Transient Remobilization. - 4.4 Diffusive Flux into Sediments. - 5 Pathways Involving Redox Reactions Directly: Case Studies. - 5.1 Arsenic. - 5.2 Chromium. - 5.3 239,240Pu. - 5.4 Selenium 6 Pathways Involving Redox Reactions Indirectly: Case Studies. - 6.1 137Cs. - 6.2 Stable Pb, 210Pb, and 210Po. - 6.3 Zinc. - 7 Summary and Conclusions. - References. - 9 Comparative Geochemistry of Marine Saline Lakes / F. T. MACKENZIE, S. VINK, R. WOLLAST, and L. CHOU. - 1 Introduction. - 2 General Characteristics of Marine Saline Lakes. - 3 Comparative Sediment-Pore-Water Reactions. - 3.1 Mangrove Lake, Bermuda. - 3.2 Solar Lake, Sinai. - 4 Conclusions. - References. - 10 Organic Matter Accumulation Records in Lake Sediments / P. A. MEYERS and R. ISHIWATARI. - 1 Introduction. - 1.1 Significance of Organic Matter in Lake Sediments. - 1.2 Origins of Organic Matter to Lake Sediments. - 1.3 Alterations of Organic Matter During Deposition. - 1.4 Similarities and Differences Between Organic Matter in Sediments of Lakes and Oceans. - 1.5 Dating of Lake-Sediment Records. - 2 Indicators of Sources and Alterations of Total Organic Matter in Lake Sediments. - 2.1 Source Information Preserved in C/N Ratios of Sedimentary Organic Matter. - 2.2 Source Information from Carbon-Stable Isotopic Compositions. - 2.3 Source Information from Nitrogen-Stable Isotopic Compositions. - 3 Origin and Alterations of Humic Substances. - 4 Sources and Alterations of Lipid Biomarkers. - 4.1 Alteration of Lipids During Deposition. - 4.2 Changes in Sources vs Selective Diagenesis. - 4.3 Effects of Sediment Grain Size on Geolipid Compositions. - 4.4 Source Records of Alkanes in Lake Sediments. - 4.5 Preserv

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