ALBERT

Note: Table of Contents: SECTION A: MODERN OCEAN AND SEA-ICE PROCESSES. - Features of Seasonal and Interannual Variability of the Sea Level and Water Circulation in the Laptev Sea / V. K. Pavlov and P. V. Pavlov. - Numerical Modelling of Storm Surges in the Laptev Sea Based on the Finite Element Method / I. Ashik and A. Novakov. - Large-Scale Variations of Sea Level in the Laptev Sea / G. N. Voinov and E. A. Zakharchuk. - Extreme Oscillations of the Sea Level in the Laptev Sea / I. Ashik, Y. Dvorkin and Y. Vanda. - Internal Waves in the Laptev Sea / E. A. Zakharchuk. - The Composition of the Coarse Fraction of Aerosols in the Marine Boundary Layer over the Laptev, Kara and Barents Seas / V. P. Shevchenko, A. P. Lisitzin, R. Stein, V. V. Serova, A. B. Isaeva and N. V. Politova. - New Data on Sea-Ice Albedo in the Laptev and Barents Seas / B. V. Ivanov. - Possible Causes of Radioactive Contamination in the Laptev Sea / V. K. Pavlov, V. V. Stanovoy and A. I. Nikitin. - Oceanographic Causes for Transarctic Ice Transport of River Discharge / I. Dmitrenko, P. Golovin, V. Gribanov and H. Kassens. - Step-Like Vertical Structure Formation Due to Turbulent Mixing of Initially Continuous Density Gradients / A. Zatsepin, S. Dikarev, S. Poyarkov, N. Sheremet, I. Dmitrenko, P. Golovin and H. Kassens. - Dissolved and Paniculate Major and Trace Elements in Newly Formed Ice from the Laptev Sea (Transdrift III, October 1995) / J. A. Hölemann, M. Schirmacher and A. Prange. - Particle Entrainment into Newly Forming Sea Ice - Freeze-Up Studies in October 1995 / F. Lindemann, J. A. Holemann, A. Korablev and A. Zachek. - Frazil Ice Formation during the Spring Flood and its Role in Transport of Sediments to the Ice Cover / P. Golovin, I. Dmitrenko, H. Kassens and J. A. Hölemann. - SECTION B: THE MARINE ECOSYSTEM. - Pelagic-Benthic Coupling in the Laptev Sea Affected by Ice Cover / C. Grahl, A. Boetius and E.-M. Nöthig. - Chlorophyll a Distribution in Water Column and Sea Ice during the Laptev Sea Freeze-Up Study in Autumn 1995 / K. v. Juterzenka and K. Knickmeier. - Composition, Abundance and Population Structure of Spring-Time Zooplankton in the Shelf-Zone of Laptev Sea / E. N. Abramova. - Macrobenthos Distribution in the Laptev Sea in Relation to Hydrology / V. V. Petryashov, B. I. Sirenko, A. A. Golikov, A. V. Novozhilov, E. Rachor, D. Piepenburg and M. K. Schmid. - Carepoctus solidus sp.n., a New Species of Liparid Fish (Scorpaeniformes, Liparidae) from the Lower Bathyal of the Polar Basin / N. V. Chernova. - Spring Stopover of Birds on the Laptev Sea Polynya / D. V. Solovieva. - SECTION C: LAND-OCEAN INTERACTIONS AND PATHWAYS. - Major, Trace and Rare Earth Element Geochemistry of Suspended Particulate Material of East Siberian Rivers Draining to the Arctic Ocean / V. Rachold. - Carbon Isotope Composition of Particulate Organic Material in East Siberian Rivers / V. Rachold and H.-W. Hubberten. - Distribution of River Water and Suspended Sediment Loads in the Deltas of Rivers in the Basins of The Laptev and East-Siberian Seas / V. V. Ivanov and A. A. Piskun. - Dissolved Oxygen, Silicon, Phosphorous and Suspended Matter Concentrations During the Spring Breakup of The Lena River / S. V. Pivovarov, J. A. Hölemann, H. Kassens, M. Antonow and I. Dmitrenko. - Distribution Patterns of Heavy Minerals in Siberian Rivers, the Laptev Sea and the eastern Arctic Ocean: An Approach to Identify Sources, Transport and Pathways of Terrigenous Matter / M. Behrends, E. Hoops and B. Peregovich. - The Role of Coastal Retreat for Sedimentation in the Laptev Sea / F. E. Are. - SECTION D: TERRESTRIAL ENVIRONMENT - PAST AND PRESENT. - Seasonal Changes in Hydrology, Energy Balance and Chemistry in the Active Layers of Arctic Tundra Soils in Taymyr Peninsula, Russia / J. Boike and P. P. Overduin. - The Landscape and Geobotanical Characteristics of the Levinson-Lessing Lake Basin, Byrranga Mountains, Central Taimyr / M. A. Anisimov and I. N. Pospelov. - Studies of Methane Production and Emission in Relation to the Microrelief of a Polygonal Tundra in Northern Siberia / V. A. Samarkin, A. Gundelwein and E.-M. Pfeiffer. - Carbon Dioxide and Methane Emmissions at Arctic Tundra Sites in North Siberia / M. Sommerkom, A. Gundelwein, E.-M. Pfeiffer and M. Bolter. - The Features of the Hydrological Regime of the Lake-River Systems of the Byrranga Mountains (by the Example of the Levinson-Lessing Lake) / V. P. Zimichev, D. Yu. Bolschyanov, V. G. Mesheryakov and D. Gintz. - Lead-210 Dating and Heavy Metal Concentration in Recent Sediments of Lama Lake (Norilsk Area, Siberia) / B. Hagedorn, S. Harwart, M. M. R. van der Loeff and M. Melles. - Late Weichselian to Holocene Diatom Succession in a Sediment Core from Lama Lake, Siberia and Presumed Ecological Implications / U. Kienel. - Climate and Vegetation History of the Taymyr Peninsula since Middle Weichselian Time - Palynological Evidence from Lake Sediments / J. Hahne and M. Melles. - Laminated Sediments from Levinson-Lessing Lake, Northern Central Siberia - A 30,000 Year Record of Environmental History? / T. Ebel, M. Melles and F. Niessen. - High-Resolution Seismic Stratigraphy of Lake Sediments on the Taymyr Peninsula, Central Siberia / F. Niessen, T. Ebel, C. Kopsch and G. B. Fedorov. - Archaeological Survey in Central Taymyr / V. V. Pitul'ko. - Marine Pleistocene Deposits of the Taymyr Peninsula and their Age from ESR Dating / D. Bolshiyanov and A. Molodkov. - Paleoclimatic Indicators from Permafrost Sequences in the Eastern Taymyr Lowland / C. Siegert, A. Yu. Derevyagin, G.N. Shilova, W.-D. Hermichen and A. Hiller. - SECTION E: MARINE DEPOSITIONAL ENVIRONMENT - PAST AND PRESENT. - Stable Oxygen Isotope Ratios in Benthic Carbonate Shells of Ostracoda, Foraminifera, and Bivalvia from Surface Sediments of the Laptev Sea, Summer 1993 and 1994 / H. Erlenkeuser and U. von Grafenstein. - Determination of Depositional Beryllium-10 Fluxes in the Area of the Laptev Sea and Beryllium-10 Concentrations in Water Samples of High Northern Latitudes / C. Strobl, V. Schulz, S. Vogler, S. Baumann, H. Kassens, P. W. Kubik, M. Suter and A. Mangini. - Spatial Distribution of Diatom Surface Sediment Assemblages on the Laptev Sea Shelf (Russian Arctic) / H. Cremer. - Diatoms from Surface Sediments of the Saint Anna Trough (Kara Sea) / R. N. Djinoridze, G. I. Ivanov, E. N. Djinoridze, and R. F. Spielhagen. - Distribution of Aquatic Palynomorphs in Surface Sediments from the Laptev Sea, Eastern Arctic Ocean / M. Kunz-Pirrung. - Distribution of Pollen and Spores in Surface Sediments of the Laptev Sea / O. D. Naidina and H. A. Bauch. - Clay Mineral Distribution in Surface Sediments of the Laptev Sea: Indicator for Sediment Provinces, Dynamics and Sources / B. T. Rossak, H. Kassens, H. Lange and J. Thiede. - Planktic Foraminifera in Holocene Sediments from the Laptev Sea and the Central Arctic Ocean: Species Distribution and Paleobiogeographical Implication / H. A. Bauch. - Holocene Diatom Stratigraphy and Paleoceanography of the Eurasian Arctic Seas / Y. Polyakova. - Late Quaternary Organic Carbon and Biomarker Records from the Laptev Sea Continental Margin (Arctic Ocean): Implications for Organic Carbon Flux and Composition / R. Stein, K. Fahl, F. Niessen and M. Siebold. - Late Pleistocene Paleoriver Channels on the Laptev Sea Shelf - Implications from Sub-Bottom Profiling / H. P. Kleiber and F. Niessen. - Main Structural Elements of Eastern Russian Arctic Continental Margin Derived from Satellite Gravity and Multichannel Seismic Reflection Data / S. S. Drachev, G. L. Johnson, S. W. Laxon, D. C. McAdoo and H. Kassens. - High Resolution Seismic Studies in the Laptev Sea Shelf: First Results and Future Needs / B. Kim, G. Grikurov and V. Soloviev. - SECTION F: SUMMARY. - Dynamics and History of the Laptev Sea and its Continental Hinterland: A Summary / J. Thiede, L. Timokhov, H. A. Bauch, D. Bolshiyanov, I. Dmitrenko

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

Note: Pages 1-10, Introduction and basic principles of isotope geochemistry --- Pages 11-31, Weathering --- Pages 33-45, Isotope geochemistry of river water --- Pages 47-88, Isotope geochemistry in the environment --- Pages 89-153, Isotopic composition of seawater past and present (Sr, Nd, Pb, Os, Ce) --- Pages 155-184, Isotope geochemistry of detrital and authigenic clay minerals in marine sediments (Rb−Sr, K−Ar, O) --- Pages 185-211, The Sm−Nd isotope system in detrital and authigenic argillaceous sediments

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: Univ. of Western Australia, Diss. von D. Müller--Nedlands , Pages 1-2, Introduction --- Pages 3-10, Definitions and Nomenclature --- Pages 11-39, Tectonic settings of potassic igneous rocks --- Pages 41-64, Selected type-localities of potassic igneous rocks from the five tectonic settings --- Pages 65-84, Primary enrichment of precious metals in potassic igneous rocks --- Pages 85-134, Direct associations between potassic igneous rocks and gold-copper deposits --- Pages 135-158, Indirect associations between lamprophyres and gold-copper deposits --- Pages 159-171, Halogen contents of mineralized versus unmineralized potassic igneous rocks --- Pages 173-176, Implications for mineral exploration --- Pages 177-200, Characteristics of some gold-copper deposits associated with potassic igneous rocks

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