With one new volume each year, this series keeps scientists and advanced students informed of the latest developments and results in all areas of botany. The present volume includes reviews on plant physiology, genetics, taxonomy and geobotany.

Review.- Botanical Aspects of Landscape Ecology with Outlooks on Forest Dieback.- 1. Introduction.- 2. Important Concepts.- a) Landscape and Landscape Ecology.- b) Geoecology.- c) Ecotopes and Other Units in the Landscape.- d) Site and Environment.- 3. Research Methods and Some Results.- a) Exploring and Mapping the Ecological Pattern.- b) Functions and Turnovers in Landscapes.- c) Potentials, Suitabilities, Values, and Risks.- 4. Regional Examples of Landscape Ecological Studies.- a) Central Europe.- b) Other Parts of the World.- 5. Practical Tasks and Responsibilities.- a) Land Use Planning and Nature Conservation.- b) Public Importance of Landscape Ecology.- 6. Problems of Forest Dieback.- a) Known Forms and Causes of Forest Decline.- b) The General Forest Dieback as a Construct.- References.- A. Physiology.- I. Plant Water Relations: Metabolic Responses to Water Deficit and Surplus.- 1. Introduction.- 2. Effects of Water Deficit on Cellular Processes.- a) Influence of Water Stress on Protein Biosynthesis.- b) Metabolism of Drought Stress-Protective Compatible Nitrogen Compounds.- c) Oxidative Damage and Compensatory Metabolic Responses Under Cellular Water Stress.- 3. Effects of Water Surplus on Plant Performance.- a) Transcription and Protein Synthesis Under Hypoxic Conditions.- b) Disturbance Effects of Hypoxia on Intermediary Metabolism.- 4. Conclusions.- References.- II. The Leaf Epidermis: its Ecophysiologieal Significance.- 1. Introduction.- 2. The Morphology of Epidermal Cells and Their Subcellular Organization.- 3. New Methods in the Investigation of Epidermal Functions.- 4. Interactions Between Environmental Factors Acting on Plants and the Leaf Epidermis.- a) Visible and UV Light.- b) Water Vapor Saturation Deficit.- c) Gases.- d) Xenobiotics.- e) Pathogens.- 5. The Biochemistry of the Epidermis.- a) Basic Epidermal Metabolism.- b) Synthesis of Cuticular Compounds.- c) Secondary Plant Products.- 6. Function of the Epidermis in Mineral Nutrition.- a) Compartmentation of Nutrient Elements.- b) Salt and Water Stress.- c) Heavy Metal Stress.- 7. The Role of the Epidermis in Homeostasis of the Plant Stress Hormone Abscisic Acid (ABA).- a) ABA Uptake.- b) Basic Permeability of the Epidermis Plasma Membrane.- c) ABA Transport Across the Epidermis Plasma Membrane.- d) ABA Transport Across the Epidermis Tonoplast.- e) ABA Metabolism in the Epidermis.- f) Consequences of Epidermal ABA Uptake and Metabolism for ABA Redistribution in Stressed Leaves.- 8. First Approaches Towards a Genetic Understanding of Epidermal Cell Specificity.- References.- III. Developmental Physiology: Regulation of Polar Cell Growth and Morphogenesis.- 1. Introduction.- 2. Cellular Morphogenesis.- a) Induction and Rise of Polarity in the Fucacean Zygote.- b) Cell Shape Formation in Desmid Cells.- 3. Polar Tip Growth of Pollen Tubes, Rhizoid and Root Hair Cells.- a) Morphology, Cytoskeleton, and Cytoplasmic Streaming.- b) Turgor Pressure and Cell Growth.- c) Ion Pumps, Channels, Currents, and Growth Localization.- d) Exocytosis and Vesicle Fusion.- e) Molecular Biology of Polar Growth.- 4. Concluding Remarks.- References.- IV. Intracellular Movement.- 1. Introduction.- 2. Actin- and Microtubule-Dependent Organelle Motors.- 3. Cytoplasmic Streaming.- a) Vaucheria andAcetabularia.- b) Characean Internodal Cells.- ?) Actin and Myosin.- ?) Tubulin.- ?) Mechanism of Streaming.- ?) Calcium Effects on Reconstituted Motility.- 4. Oriented Positioning of Organelles.- a) Nuclear Positioning.- b) Chloroplast Orientation in Mougeotia, Mesotaenium, and Adiantum.- ?) Photoreceptors.- ?) Mechanics of the Movement.- ?) Calcium Effects.- ?) Microtubules.- References.- V. Thermotropic Responses of Biomembranes Exemplified by the Tonoplast of Crassulacean Acid Metabolism Plants.- 1. Introduction.- 2. The Role of the Vacuole in Crassulacean Acid Metabolism (CAM) and the Transport of Malic Acid Across the Tonoplast.- 3. The Tonoplast as a Likely Target of Temperature Effects on CAM: Physiological Evidence.- 4. Modalities of Order and Dynamics in Biomembranes.- a) Modalities of Order.- ?) Domains.- ß) Asymmetry.- b) Modalities of Dynamics.- 5. The Thermotropic Responses of Tonoplast Fluidity in CAM Plants.- 6. Outlook.- References.- VI. Nitrate or Ammonium Uptake and Transport, and Rapid Regulation of Nitrate Reduction in Higher Plants.- 1. General Introduction.- 2. Uptake of Nitrogen.- a) Nitrate Uptake Mechanisms.- b) Ammonium Uptake Mechanisms.- c) Energy Dependency.- d) Nitrate Versus Ammonium Uptake.- e) Summary.- 3. Long-Distance Transport of Nitrogen.- a) Site of Nitrogen Assimilation.- b) Transported N Compounds.- c) Partitioning.- 4. Rapid Regulation of Nitrate Reduction.- a) In Vivo Conditions Modulating NRA.- ?) Light.- ß) Response to CO2.- ?) Oxygen Availability.- b) Reversible Protein Phosphorylation as the Regulatory Mechanism.- c) Involvement of an Inhibitor Protein.- d) Signals Triggering PK and PP.- References.- VII. Secondary Plant Substances: Benzylisoquinoline Alkaloids.- 1. Introduction.- 2. Reticuline.- 3. Morphinan-Type Alkaloids.- 4. Bisbenzylisoquinoline Alkaloids.- 5. Cularine-Type Alkaloids.- 6. Aporphine Alkaloids.- 7. Protoberberine Alkaloids.- 8. Benzophenanthridine Alkaloids.- 9. Phytoalexins.- References.- VIII. Carbohydrate Processing in the Mesophyll Trajectory in Symplasmic and Apoplasmic Phloem Loading.- 1. Introduction.- 2. Outlines and Definitions of Phloem Loading.- 3. The Principal Modes of Phloem Loading.- a) Evolution of the Phloem-Loading Machinery.- b) Apoplasmic Phloem Loading.- c) Symplasmic Phloem Loading.- d) Physiological Evidence for Two Modes of Phloem Loading.- 4. Carbohydrate Metabolism and Intracellular Compartmentation.- a) Sucrose Metabolism and Intracellular Compartmentation of C-Metabolites.- b) Interplay Between Chloroplastic, Cytosolic and Vacuolar Compartmentation of Sucrose.- c) Uptake of Sucrose and Hexoses by Vacuoles.- d) Metabolism and Compartmentation of Other Soluble Carbohydrates.- 5. Intercellular Compartmentation, Metabolic Processing, and Division of Labor in the Production Compartment of "Apoplasmic Loaders".- a) Driving Forces of Intercellular Photosynthate Movement.- b) Path of Intercellular Movement.- c) Retrieval Along the Production Compartment.- d) Scattered or Focused Release from the Production Compartment?.- e) Mechanism of Release from the Production Compartment.- 6. Intercellular Compartmentation, Metabolic Processing, and Divison of Labor in the Mesophyll Domain of "Symplasmic Loaders".- a) Driving Forces of Intercellular Photosynthate Movement.- b) Intercellular Photosynthate Movement.- c) Retrieval Along the Mesophyll Trajectory.- d) Localization of the Galactosyl Oligosaccharide Synthesis in the Mesophyll Trajectory.- 7. The Consequences of the Spatial Cell Arrangement for Photoassimilate Trafficking in the Production Compartment.- a) Preferential Pathways Through the Production Compartment Towards the Collection Compartment?.- b) Differences in C-Processing Between Palisade and Spongy Parenchyma?.- 8. Concluding Remarks.- References.- B. Genetics.- I. DNA Replication and DNA Repair.- 1. Introduction and Some Impressive Numbers.- 2. General Reviews and Hot Topics.- 3. DNA Repair Mechanisms.- a) Photoreactivation.- b) Excision Repair.- c) Transcription-Coupled Repair.- d) Mismatch Repair (Postreplication Repair).- e) Telomeres.- 4. DNA Repair in Plants.- 5. News on DNA Amplification.- 6. Conclusions.- References.- II. Recombination: Novel Gene and Genome Combinations for Resistance Breeding by Hybridization and Genetic Transformation.- 1. Introduction.- 2. Introgression of Foreign Genes for Disease and Pest Resistance by Interspe…