Some Aspects of Carbohydrate Metabolism in Lichens.- Photosynthetic Parameters in Ramalina duriaei, in vivo, Studied by Photoacoustics.- Method for Field Measurements of CO2-Exchange. The Diurnal Changes in Net Photosynthesis and Photosynthetic Capacity of Lichens under Mediterranean Climatic Conditions.- Water Relations and Net Photosynthesis of Usnea. A Comparison between Usnea fasciata (Maritime Antarctic) and Usnea sulphurea (Continental Antarctic).- Photosynthesis, Water Relations and Thallus Structure of Stictaceae Lichens.- CO2 Exchange in Lichens: Towards a Mechanistic Model.- Photosynthetic Capacity Changes in Lichens and their Potential Ecological Significance.- Electrophoretic and Gas Exchange Patterns of Two Populations of Peltigera rufescens.- Multiple Enzyme Forms in Lichens.- Studies on the Nitrogen Metabolism of the Lichens Peltigera aphthosa and Peltigera canina.- Nitrogen Losses from Diazotrophic Lichens.- Influence of Automobile Exhaust and Lead on the Oxygen Exchange of Two Lichens Measured by a New Oxygen Electrode Method.- Mineral Element Accumulation in Bog Lichens.- The Distribution of Uranium and Companion Elements in Lichen Heath Associated with Undisturbed Uranium Deposits in the Canadian Arctic.- Temporal Variation in Lichen Element Levels.- Lead and Uranium Uptake by Lichens.- The Role of the Cell Wall in the Intracellular Uptake of Cations by Lichens.- Ultrastructural Studies of Desiccated Lichens.- The Architecture of the Concentric Bodies in the Mycobiont of Peltigera praetextata.- Fine Structure of Different Types of Symbiotic Relationships in Lichens.- Changes in Photobiont Dimensions and Numbers During Co-development of Lichen Symbionts.- Selectivity in the Lichen Symbiosis.- Lectins and Morphogenesis: Facts and Outlooks.
It is currently impossible to grow lichens under controlled conditions in the laboratory in sufficient quantity for physiological experiments. Lichen growth is slow and conditions which might accelerate the process tend to favour either the algal or fungal partner, resulting in the breakdown of balance symbiosis. Lichen physiologists are therefore forced to use field-grown material with all the problems associated with the unknown influences of unpredictable and unreproducible climatic conditions. Study of major biochemical topics, such as the nature of the carbohydrate and nitrogenous compounds passing between the symbionts, is less influenced by climatic conditions than the intrinsic nature of the symbionts and many advances have been made in these areas. Recently, the challenge of using field-grown plant material, the physiological status of which is intimately linked to environmental conditions, has proved to be a stimulus rather than a hindrance to a number of research groups. The occurrence of lichens in extreme habitats has prompted a number of field and laboratory studies with material from such diverse localities as the cold deserts of Antarctica and the temperate rain forests of the New Zealand bush. A comparative approach, using contrasted species or habitats from a particular geographical region has yielded much information and an appreciation of the variety of physiological adaptations which may exist. The close linkage between morphology and physiology is now being directly demonstrated, as is the relevance of ultrastructural information.
Springer Book Archives