A.- Introduction: Perspectives in Ecological Plant Physiology.- 1 Fundamentals of Radiation and Temperature Relations.- 2 Photosynthetically Active Radiation.- 3 Responses to Different Quantum Flux Densities.- 4 Non-photosynthetic Responses to Light Quality.- 5 Responses to Photoperiod.- 6 Plant Response to Solar Ultraviolet Radiation.- 7 Responses to Ionizing Radiation.- 8 The Aquatic Environment.- 9 Responses to Light in Aquatic Plants.- 10 Responses of Macrophytes to Temperature.- 11 Responses of Microorganisms to Temperature.- 12 Responses to Extreme Temperatures. Cellular and Sub-Cellular Bases.- 13 Ecological Significance of Resistance to Low Temperature.- 14 Ecological Significance of Resistance to High Temperature.- 15 Wind as an Ecological Factor.- 16 Fire as an Ecological Factor.- 17 The Soil Environment.- Author Index.- Taxonomic Index.