This book provides a critical and selective review of lichen physiological ecology.

O.L. LANGE, P.S. NOBEL, C.B. OSMOND, and H. ZIEGLER Growth, development and reproductive success of individual plants depend on the interaction, within tolerance limits, of the factors in the physical, chemical and biological environment. The first two volumes of this series addressed fea tures of the physical environment (Vol. 12A) and the special responses of land plants as they relate to water use and carbon dioxide assimilation (Vol. 12B). In this volume we consider specific aspects of the chemical and biological envi ronment, and whereas the previous volumes were primarily concerned with the atmospheric interactions, our emphasis here shifts very much to the soil. This complex medium for plant growth was briefly reviewed in Chapter 17, Volume 12A. Since it is difficult to determine the precise physical and chemical interactions in the soil, it is even more difficult to determine the important biological interactions among organisms. Nevertheless there is growing aware ness of the significance of these interactions and their effects on physiological processes in the individual plant.

Not only an invaluable reference to what is known about lichen bionts and their interactions but also a guide to future studies. Compares various aspects of lichen-forming bionts with those of other fungi, algae and cyanobacteria. Features in-depth descriptions of culture methods. Includes over 1000 references representing a selective sampling in such subjects as air pollution, photosynthesis and respiration.

Although, as W.D. Billings notes in his chapter in this book. the development of physiological ecology can be traced back to the very beginnings of the study of ecology it is clear that the modern development of this field in North America is due in the large part to the efforts of Billings alone. The foundation that Billings laid in the late 1950s came from his own studies on deserts and subsequently arctic and alpine plants, and also from his enormous success in instilling enthusiasm for the field in the numerous students attracted to the plant ecology program at Duke University. Billings' own studies provided the model for subsequent work in this field. Physiological techniques. normally confined to the laboratory. were brought into the field to examine processes under natural environmental conditions. These field studies were accompanied by experiments under controlled conditions where the relative impact of various factors could be assessed and further where genetic as opposed to environmental influences could be separated. This blending of field and laboratory approaches promoted the design of experiments which were of direct relevance to understanding the distribution and abundance of plants in nature. Physiological mechanisms were studied and assessed in the context of the functioning of plants under natural conditions rather than as an end in itself.