Physiological Plant Ecology

Ecology is the science of the relationships between living organisms and their envi ronment . . It is concerned with the web of interactions involved in the circulation of matter and the flow of energy that makes possible life on earth, and with the adapta tions of organisms to the conditions under which they survive. Given the multitude of diverse organisms, the plant ecologist focuses upon the plants, investigating the influence of environmental factors on the character of the vegetation and the be havior of the individual plant species. Plant ecophysiology, a discipline within plant ecology, is concerned fundamentally with the physiology of plants as it is modified by fluctuating external influences. The aim of this book is to convey the conceptual framework upon which this discipline is based, to offer insights into the basic mechanisms and interactions within the system "plant and environment", and to present examples of current problems in this rap idly developing area. Among the topics discussed are the vital processes of plants, their metabolism and energy transformations as they are affected by environmental factors, and the ability of these organisms to adapt to such factors. It is assumed that the reader has a background in the fundamentals of plant physiology; the physiological bases of the phenomena of interest will be mentioned only to the extent necessary for an understanding of the ecological relationships.

The Environment of Plants.- The Hydrosphere.- The Atmosphere.- The Lithosphere and the Soil.- The Biosphere.- The Ecosystem: Interplay of Biological and Environmental Factors.- The Sun's Radiation as a Source of Energy.- Radiation within the Atmosphere.- Uptake of Radiation by Plants.- Distribution and Effects of Radiation in Bodies of Water.- Carbon Utilization and Dry Matter Production.- Carbon Metabolism in the Cell.- CO2 Exchange in Plants.- Carbon Budget and Dry-Matter Production in Plants.- Productivity and Carbon Turnover in Plant Communities.- The Utilization and Cycling of Nitrogen.- The Nitrogen Metabolism of Higher Plants.- The Nitrogen Metabolism of Microorganisms.- Nitrogen Turnover in the Ecosystem.- The Role of Plants and Microorganisms in the Global Cycling of Nitrogen.- The Utilization and Cycling of Mineral Elements.- The Soil as a Nutrient Source for Plants.- The Role of Mineral Nutrients in Plant Metabolism.- Mineral Balance in the Vegetation and the Cycling of Minerals in the Ecosystem.- The Toxic Effect of Atmospheric Pollutants.- Water Relations.- Water Relations of the Plant Cell.- Absorption, Transpiration and Water Balance in the Plant.- Water Economy in Plant Communities.- The Earth's Water Balance and Its Significance for Vegetation.- Effects of Temperature.- Plant Temperatures and Energy Balance.- The Effects of Temperature upon the Vital Processes of Plants.- Periodicity in Climate and Vegetation.- Climatic Rhythms.- Activity Rhythms.- Synopsis.- References.