Forest Decline and Air Pollution

1 Introduction: The Problem of Forest Decline and the Bavarian Forest Toxicology Research Group..- 2 The Vegetation of the Fichtelgebirge: Origin, Site Conditions, and Present Status..- 1 Introduction.- 2 Vegetation History.- 3 Natural Forest Vegetations.- 4 Present Forest Vegetation.- 5 Vegetation of Raised Bogs.- 6 Vegetation of Boulder Streams and Summit Rocks.- 7 Water Plants and Acidic Swamp Vegetation.- 8 Vegetation of Farmland.- 9 Conclusion.- References.- 3 Potentials and Limitations of Field Studies on Forest Decline Associated with Anthropogenic Pollution..- 1 Introduction.- 2 Defining Forest Decline.- 3 Inference of Causality.- 3.1 The Inductive Approach.- 3.2 The Deductive Approach.- 3.3 The Integrated Approach.- 4 The Study of a Decline in the Fichtelgebirge — a First Step in an Integrated Approach.- 5 Conclusion.- References.- 1: Air Pollution: Transport and Deposition: Preface.- 1-A Long-Range Transport and Deposition of Pollutants in the Fichtelgebirge..- 1 Introduction.- 2 Basic Equations for the Time-Dependent Prediction of Pollutant Transport in the Atmosphere.- 2.1 The Meteorological Model.- 2.1.1 Equations of Motion.- 2.1.2 The Parameterization of Turbulence.- 2.2 The Transport Equation.- 3 Two-Dimensional Prediction of Pollutant Transport.- 3.1 General Outline of the Experiments.- 3.2 Discussion of Results.- 3.2.1 Idealized Topography.- 3.2.2 Structured Topography.- 4 Three-Dimensional Predictions of Pollutant Transport.- 5 Conclusions.- Appendix I.- Appendix II.- References.- 1-B Air Pollution and Deposition..- 1 Introduction.- 2 General Geographical and Climatological Description of the Observation Areas.- 3 Gaseous and Particulate Atmospheric Pollutants and Atmospheric Conditions.- 3.1 Basic Immission Data.- 3.2 Some Selected Gaseous and Particulate Pollutants.- 4 Chemical Composition of Precipitation and Fogwater.- 4.1 Properties of Selected Precipitation Samples.- 4.2 Results of Time-Resolved, On-Line Monitoring of the pH Value and the Electrical Conductivity of Precipitation.- 4.3 Collection and Properties of Fog.- 4.4 Deposition of Fogwater upon a Spruce.- 5 Concentration of Hydrogen Peroxide in Precipitation and Fogwater.- 6 Comparison of Bulk Precipitation Water and Fogwater Data from Surrounding and Remote Areas.- 6.1 Bulk Deposition Studies in the Catchment “Große Ohe”.- 6.2 Comparison of Representative Data of Different Regions.- 7 Comments and Conclusions.- References.- 2: The Role of Fungi, Microorganisms and Soil Animals: Preface.- 2-A Soil Fungi and Other Microorganisms..- 1 Introduction: Aluminum and the Possible Effects of Microorganisms.- 2 The Effect of Aluminum and Heavy Metals on the Mycorrhizal Fungus Suillus variegates.- 2.1 Influence of Aluminum and Heavy Metals on Growth.- 2.2 Element Contents in the Presence of Lead and Aluminum.- 3 Mycorrhizal Flora of Two Forest Locations.- 4 Conclusion.- References.- 2-B Endophytic Needle Fungi: Culture, Ultrastructural and Immunocytochemical Studies..- 1 Introduction.- 2 Electron Microscopy of Needle Fungi.- 2.1 Isolation of Internal Fungi.- 2.2 Lophodermium piceae-Antiserum and Antibody Conjugates.- 2.3 Electron Microscopy.- 2.3.1 Scanning Electron Microscopy (SEM).- 2.3.2 Transmission Electron Microscopy (TEM).- 3 Needle Colonization by Fungi.- 3.1 The Isolation of Fungi from Green, Symptomless Needles.- 3.2 The Isolation of Fungi from Needles Showing Disease Symptoms.- 3.3 Observation of Needle Fungi at the Cellular Level.- 4 Needle Fungi and Forest Decline.- 5 Conclusions.- References.- 2-C Soil Fauna Comparisons in Healthy and Declining Norway Spruce Stands..- 1 Introduction.- 2 Sampling Procedure and Site Description.- 3 Species Composition and Density of Healthy and Declining Norway Spruce Stands.- 3.1 Macrosaprophagous Invertebrates.- 3.2 Microphytophagous — Saprophagous Invertebrates.- 3.2.1 Enchytraeidae.- 3.2.2 Acari-Cryptostigmata.- 3.2.3 Collembola.- 3.2.4 Symphyla — Protura.- 3.2.5 Diptera.- 3.3 Omnivorous Invertebrates.- 3.4 Predators.- 3.5 Comparison of Soil Fauna Biomass.- 3.6 Comparison of Decomposition Rates.- 4 Acid Rain and Soil Fauna.- 5 Conclusions.- References.- 3: Direct Effects of Pollutants on Above-Ground Plant Parts: Preface.- 3-A The Cuticles of Conifers: Structure, Composition and Transport Properties..- 1 Introduction.- 2 Fine Structure and Chemical Constitution of Cuticles.- 2.1 Fine Structure.- 2.2 The Composition of Cutin.- 2.3 Soluble Culticular Lipids.- 2.3.1 Chemical Composition.- 2.3.2 Fine Structure of Epicuticular Waxes.- 3 Transport Properties of Plant Cuticles.- 3.1 The Description of Cuticular Penetration.- 3.1.1 Nonelectrolytes.- 3.1.2 Electrolytes.- 3.2 Transport Parameters.- 3.3 Factors Affecting Cuticular Transport and Accumulation.- 3.4 The Role of Cuticles in Transport.- 3.5 Gas Diffusion in the Stomatal Antechamber of Pinaceae.- 4 Conclusions.- References.- 3-B Organic Micropollutants and Plants.- 1 Introduction.- 2 Occurrence and Distribution of Some Chlorinated Micropollutants in Norway Spruce Needles.- 3 Distribution Between the Cuticular Wax and the Needle.- 4 Phytotoxicity of Organic Atmospheric Micropollutants: A Summary.- 5 Conclusions.- 1 References.- 3-C Leaching and Uptake of Ions Through Above-Ground Norway Spruce Tree Parts..- 1 Introduction.- 2 Can Needle Surfaces Buffer Acid Rain?.- 2.1 Direct Measurement of pH Buffering on Spruce Needles.- 2.2 pH and Magnesium Concentrations on Wetted Spruce Needles.- 3 Short-Term Studies of Sulfate Uptake by Needles.- 3.1 Experimental.- 3.2 Time Kinetics of 35SO42- Uptake.- 3.3 Influence of pH on the Uptake of Sulfate by Norway Spruce Needles.- 3.4 Incorporation of 35S upon Drying of the Superficially Applied Solution.- 4 Uptake of Water and Solutes Through Bark and Needle Surfaces.- 5 Leaching of Cations by Acid Rain from Twigs and Single Needles.- 5.1 Materials and Methods.- 5.2 Leaching of Cations from Foliated Twigs.- 5.3 Leaching of Cations from Detached Needles.- 6 Leaching of Minerals from Seedlings under Laboratory Conditions.- 7 Leaching of Minerals with a Canopy Balance Model.- 8 Conclusions.- References.- 3-D Atmospheric Pollutants and Plant Metabolism.- 1 Introduction.- 2 Fluxes of Gaseous Air Pollutants into Leaves.- 2.1 Uptake of SO2.- 2.2 Fate of SO2 Inside the Leaf.- 2.3 Uptake of Nitrogen Oxide.- 2.4 Fate of NO2 Inside the Leaf.- 2.5 Uptake of Ozone.- 2.6 Fate of Ozone Inside the Leaf.- 2.7 Pollution Stress in the Fichtelgebirge.- 3 Direct Effects of Atmospheric Pollutants on Metabolic Features of Norway Spruce in the Fichtelgebirge?.- 3.1 Photosynthesis.- 3.2 Stomatal Responses.- 3.3 Chloroplast Pigments.- 3.4 Needle Sulfur Content.- 4 Discussion and Conclusions.- References.- 4: Soil Responses to Acid Rain and Associated Effects on Plants: Preface.- 4-A Mineral Nutrition of Forest Trees: A Regional Survey.- 1 Introduction.- 2 Sampling Procedure.- 3 Nutrient Status of Trees on Forest Sites in Bavaria.- 3.1 Nitrogen.- 3.2 Phosphorus.- 3.3 Sulfur.- 3.4 Potassium, Calcium and Magnesium.- 3.5 Trace Element Nutrition.- 4 Discussion.- 5 Conclusions.- References.- 4-B Effects of Acid Rain on Soil Chemistry and Nutrient Availability in the Soil..- 1 Introduction.- 2 Chemical and Physical Properties of the Study Soils.- 3 Mechanisms and Kinetics of Buffering in Acid Soils.- 3.1 Organic Horizons.- 3.1.1 Chemical Properties and Actual Acidification Status of the Organic Layers.- 3.1.2 Proton Consumption During pH 3 Stat Titration.- 3.1.3 Cation Exchange as a Buffering Reaction.- 3.1.4 Reduction of Fe and Mn as Buffering Reactions.- 3.1.5 Mineralization of Organic Matter as a Buffering Reaction.- 3.1.6 pH Changes and Cation Release in the Percolation Experiment.- 3.1.7 BNC and ANC of Humics.- 3.2 Mineral Horizons.- 3.2.1 pH 3 Stat Titrations: ANC, Kinetics and Cation Balance.- 3.2.2 Long-Term Batch Titration of pH 3.- 3.2.3 Sulfuric Acid Percolation.- 3.2.4 Nature of the Reactive Al Compound.- 3.2.5 Soil Acidification and Nutrient Availability.- 4 Effects of Soil Structure on Water Transport, Proton Buffering, and Nutrient Release.- 4.1 Soil Aggregate Formation and Its Possible Role in Water and Nutrient Transport.- 4.1.1 The Process of Soil Aggregate Formation.- 4.1.2 Soil Water Fluxes.- 4.1.3 Soil Aggregation, Ion Mass Flow and Diffusion.- 4.1.4 Soil Aggregation and Root Growth.- 4.2 Water Flux, Proton Buffering and Nutrient Release in Structured Forest Soils.- 4.2.1 Water Transport.- 4.2.2 Proton Buffering.- 4.2.3 Nutrient Release.- 5 Conclusions.- References.- 4-C Water Relations of Two Norway Spruce Stands at Different Stages of Decline..- 1 Introduction.- 2 Assessment of the Forest Water Balance.- 3 The Water Budget of the Healthy and the Declining Forest Sites.- 4 Water Uptake and Soil Water Status.- 5 Conclusions.- References.- 4-D CO2- Assimilation and the Carbon Balance of Healthy and Declining Norway Spruce Stands.- 1 Introduction.- 2 Photosynthesis and Stomatal Response.- 2.1 Gas Exchange Rates in Relation to Site and Needle Age.- 2.2 Stomatal Conductance in Relation to Changes in Climatic Factors.- 2.3 Diurnal Course of Assimilation.- 3 Seasonal Carbon Balance.- 4 Assimilation Rates in Relation to Needle Color.- 5 Annual CO2 Uptake in Relation to Canopy Leaf-Area.- 6 Conclusions.- References.- 4-E Root and Mycorrhizal Development in Healthy and Declining Norway Spruce Stands..- 1 Introduction.- 2 Distribution and Seasonal Development of Fine-Root Biomass, Number of Root Tips, and Ectomycorrhizas.- 2.1 Comparison Between Young Healthy and Declining Spruce Stands.- 2.2 Comparison of Young and Old Trees at the Declining Site.- 2.3 Root Tips and Ectomycorrhizas.- 3 Carbohydrate Concentration of Roots.- 4 Root Growth in Relation to Soil Chemical Properties.- 4.1 Comparison Between Young Healthy and Declining Spruce Stands.- 4.2 Comparison Between Old and Young Spruce Stands at the Declining Site.- 5 Influence of Acidifying Processes on the Soil-Root Interface.- 6 Conclusions.- References.- 4-F Nutrient Relations of Trees in Healthy and Declining Norway Spruce Stands..- 1 Introduction.- 2 Nutrient Status of Healthy and Declining Norway Spruce Trees and Stands.- 3 Interactions Between Root and Shoot.- 4 Nutrient Relations and Growth.- 4.1 Nutrient Pools and Nutrient Use for Growth.- 4.2 Relations Between Element Concentrations and Growth.- 4.3 Growth as Related to an Imbalance of Magnesium and Nitrogen.- 5 Conclusions.- References.- 4-G Effects of Fertilization..- 1 Introduction.- 2 Sprinkling Norway Spruce Trees with Nutrient Solutions.- 3 Soil Fertilization Experiments.- 4 Fertilization of Canopies.- 5 Conclusions.- References.- 4-H Nutritional Disharmony and Forest Decline: A Conceptual Model.- 1 Introduction.- 2 Canopy Growth Phase.- 3 Stem Growth Phase.- 4 Recharge Phase.- 5 Conclusion: Nutritional Disharmony and Decline.- References.- 4-I Nutrient Balance and Element Cycling in Healthy and Declining Norway Spruce Stands..- 1 Introduction.- 2 Assessment of the Ecosystem Balance.- 2.1 Quasi-Stationary Pools.- 2.2 Element Input to the Soil.- 2.2.1 Precipitation and Canopy Processes.- 2.2.2 Soil Processes.- 2.3 Output of Elements.- 3 Seasonal Variations of Precipitation, Throughfall, and Seepage of Elements.- 4 The Ecosystem Balance.- 5 Conclusions.- References.- 5.- Processes Leading to Forest Decline: A Synthesis.- 1 Introduction.- 2 Direct Effects of Pollutants on the Canopy.- 3 Effects of Pollutants Via the Soil.- 4 Conclusion.- 5 Historic Considerations.- 6 Future Perspectives.- References.