Bøger af Jelte Rozema

September 1987, the Faculty Biology of the Vrije Universiteit, Amsterdam commemorated the fact that Prof. Dr. Wilfried Hans Otto Ernst had been active as a scientist for 25 years. This period of 25 years of scientific research started at the Institut flir Angewandte Botanik (Institute of Applied Botany) of the University of Munster, FRG. In 1965 he completed his Ph. D. thesis, entitled "Untersuchungen der Schwermetallpflanzengesellschaften Mitteleuropas unter Einschluss der Alpen. " He was appointed full Professor at the Department of Ecology of the Vrije Universiteit, Amsterdam in 1973. On the occasion of his 25th anniversary as a scientist, a promise was made, though in covert terms, which we could not redeem at that time. The promise held to offer Prof. Ernst a book, in which his former and present staffmembers, Ph. D. students and colle ages should write a review about their specialism concerning a central theme. Now, at the beginning of 1990 we consider the chapters of "Ecological Responses to Environmental Stresses" to be completed. The book reflects the wide range of research approaches that has been initiated and organized by Wilfried Ernst. The editors hope to have attained the primary aim of the production of the book of friends, that is to gather relevant papers of staff-members and colleagues of Wilfried Ernst. The title of the book "Ecological Responses to Environmental Stresses" covers the majority of the chapters included.

An international workshop on `CO2 and Biosphere' was held in Wageningen, the Netherlands on 15-19 November 1991 as part of the activities of the CO2 Commission of the Netherlands Organization for Scientific Research: this volume includes 32 papers presented at the workshop. The CO2 Commission stimulates and coordinates a broad range of research projects related to the greenhouse effect. This is reflected in the scope of papers presented, ranging from detailed analyses of ecological and physiological effects of atmospheric CO2 enrichment to biosphere-atmosphere aspects, such as regional evaporation, energy balance and ecosystem responses. Relevant directions for future research are indicated by presentations on carbon fluxes in the soil, secondary plant metabolism and plant-insect interactions.

The research in this book covers papers on a great number of research projects on the responses of plants and crops of natural terrestrial ecosystems, of agro-ecosystems, and of aquatic ecosystems, to enhanced solar UV-B as a result of stratospheric ozone depletion. Some introductory chapters deal with general aspects of how plants respond to UV-B radiation. Photosynthetically Active Radiation (PAR) is a primary energy resource for terrestrial plants, necessary for plant growth. Inevitably terrestrial plants absorb UV-B when exposed to solar radiation. The spectral balance between PAR and UV-B is discussed in several chapters. The responses of plants and ecosystems from the Antarctic and Arctic to enhanced solar UV-B radiation as a consequence of the hole in the ozone layer are considered in some detail. In addition the papers in the book discuss the problem of how responses of plants to UV-B radiation interact with other environmental factors. The book is of great importance for those who are involved in global change topics: biologists, ecologists, earth scientists, agronomists, environmental scientists, and those who develop environmental policy.