The Lichens

The Lichens covers the structure and development, physiology of the intact thallus, environmental response and effects, secondary metabolic products, and symbiont interactions of lichens. This book is divided into five parts encompassing 19 chapters. It also includes appendices consist of a taxonomic scheme, methods for isolating and culturing lichen symbionts and thalli, and methods for isolating and identifying lichen substances.
The first part of this book describes the original fungal cell and its development into specialized cells of which the various tissues and thalli are composed. This is followed by discussions on sexual reproduction of ascolichens and basidiolichens and on systematic criteria for the definition of taxa in different hierarchical steps. This book also explains the types of propagules produced by lichens and the submicroscopical investigations of lichens, including phycobiont and mycobionts' substructure and symbiotic relationship.
The second part of this book examines the physiological aspects of lichens. It includes discussions on metal cation uptake and translocation in vascular plants and on lichens' role in rock weathering and soil formation. This part also studies photosynthetic rates and nitrogen absorption and metabolism by the intact thallus of lichens. Succeeding chapters discuss physiological and morphological responses of lichens to the most important environmental factors and the relationship of these factors to lichen distribution. Substrate preferences of lichens and their causes and implications with regard to the ecology, distribution, and taxonomy of lichens are also examined. This text also discusses lichen thalli growth, methods of measurement, and factors influencing growth. Finally, the concluding parts deal with the biosynthesis of lichen substances, secondary metabolic products, and symbiotic relations of lichens to fungi and algae.
This multi-authored book is an ideal source of information for researchers, teachers, and students who wish to broaden their knowledge in the diversity of lichenology.

Contenu

List of Contributors
Preface
Part I Structure and Development
Chapter 1. Anatomy, Morphology, and Development
I. Introduction
II. Anatomy of the Thallus
III. Morphology of the Thallus
IV. Vegetative Structures and Their Development
V. Influence of Fungus and Alga on the Habit of the Lichen
VI. Influence of Fruiting Bodies on the Development of Thallus Tissues
References
Chapter 2. Sexual Reproduction
I. Ascolichens
II. Basidiolichens
References
Chapter 3. Systematic Evaluation of Morphological Characters
I. Introduction
II. Systematic Criteria
III. Modifiability and Its Taxonomic Significance
References
Chapter 4. Lichen Propagules
I. Introduction
II. Vegetative Propagules
III. Sexual Propagules
References
Chapter 5. Fine Structure
I. Introduction
II. Cellular Structure of the Lichenized Symbionts
III. Symbiotic Relationship between Fungus and Alga
IV. Thallus Layers and Surface Structures as Viewed with SEM
V. Some Aspects of Changes in Ultrastructure Due to Ecological Conditions
VI. Conclusions
References
Part II Physiology of the Intact Thallus
Chapter 6. Absorption and Accumulation of Mineral Elements and Radioactive Nuclides
I. Introduction
II. Metal Content of Lichens
III. Concentration and Retention of Radionuclides
IV. Uptake and Translocation of Cations
References
Chapter 7. Pedogenetic Significance of Lichens
I. Introduction
II. Biogeophysical Weathering
III. Biogeochemical Weathering
IV. Plant Succession and Soil Development
V. Conclusions
References
Chapter 8. Photosynthesis and Carbohydrate Movement
I. Introduction
II. Photosynthesis by the Intact Lichen
III. Interactions between Lichen Symbionts
IV. The Mobile Carbohydrate and Its Release
V. Fate of the Transferred Carbohydrate
VI. Carbohydrate Movement between the Symbionts
VII. Conclusions
References
Chapter 9. Nitrogen Metabolism
I. Introduction
II. Chemical and Biochemical Analyses of Whole Thalli
III. Assimilation of Combined Nitrogen
IV. Fixation of Elementary Nitrogen
V. Translocation of Nitrogen Compounds between the Symbionts
VI. The Relationship of Lichens to Other Nitrogen-Fixing Symbiotic Systems
References
Part III Environmental Response and Effects
Chapter 10. Response to Extreme Environments
I. Introduction
II. Determination of Viability and Resistance
III. Responses to Environmental Stresses
IV. Extreme Habitats of Lichens
V. Conclusions
References
Chapter 11. Water Relations
I. Introduction
II. Water Absorption
III. Mechanism of Water Absorption and Water Conduction to the Thallus
IV. Water Contents of Thalli
V. Water Loss
VI. Conclusions
References
Chapter 12. Substrate Ecology
I. Introduction
II. Practical Aspects
III. Substrate Factors
IV. The Lichen-Substrate Interface
V. The Effect of Lichens on Their Substrate
VI. Substrate Specificity
VII. Substrates and Speciation
VIII. Summary and Conclusions
References
Chapter 13. Lichens and Air Pollution
I. Historical
II. Lichen Deserts
III. Causes of Lichen Deserts
IV. Effect of Environment
V. Biological Estimation of Air Pollution
References
Chapter 14. Growth
I. Introduction
II. Techniques of Measuring Growth
III. Growth Rates and Life History
IV. Conclusions
References
Part IV Secondary Metabolic Products
Chapter 15. Nature of Lichen Substances
I. Introduction
II. Structure of Lichen Substances
References
Chapter 16. Biosynthesis of Lichen Substances
I. Introduction
II. Biosynthesis
III. Conclusion: The State of the Problem
References
Chapter 17. Antibiotics in Lichens
I. Folklore
II. Pharmacopoeias
III. Lichen Substances
IV. Pharmacological Studies
V. Antibiotics in Lichens
References
Part V Symbiont Interactions
Chapter 18. Resynthesis of Lichens
V. Ahmadjian
I. Introduction
II. Developmental Stages of Synthesis
III. Physiological Relationships between the Symbionts
IV. Lichens Synthesized in Laboratory Cultures
V. Factors that Influence Synthesis
VI. Conclusions
References
Chapter 19. Evolutionary Aspects of Symbiosis
I. Introduction
II. Symbiosis in Retrospect
III. Symbiosis Achieved
IV. Symbiosis in Prospect
References
Appendix A. Classification
I. Early Lichen System
II. Parasitic Lichens, Parasymbionts, and Lichen Parasites
III. Lichenized and Nonlichenized Fungi
IV. Taxomomic Categories in Lichenology
V. Proposed Classification: Ascolichens
VI. Proposed Classification: Basidiolichens
VII. Lichenes Imperfecti
References
Appendix B. Identification and Isolation of Lichen Substances
I. Identification without Previous Isolation
II. Isolation
III. Identification after Previous Isolation
References
Appendix C. Methods of Isolating and Culturing Lichen Symbionts and Thalli
I. Fungal Symbiont
II. Algal Symbiont
III. Lichen Thallus
References
Author Index
Taxonomic Index
Subject Index