Uv B And Biosphere

Current phase-out schedules of the production and emission of CFC's indicate that chlorine loading in the stratosphere is not yet at its maximum. The recovery of stratospheric ozone is estimated to take time and ele vated levels of UV-B radiation are expected to occur throughout most of the next century. Despite numerous physiological studies of UV-B effects on plants, often grown in climate chambers, knowledge of UV-B effects on organisms and processes in natural aquatic or terrestrial ecosystems is poor. Currently it appears that UV-B radiation is not just an environmental stress' factor to plants. In various ways, which are incompletely understood, UV-B affects a wide range of physiological and ecological processes. Remarkably, recent field studies indicate that enhanced UV-B does not markedly affect photosynthesis, growth and primary production, but rather interferes with plant morphogenesis and plant and ecosystem functions relating to the secondary metabolism. This special issue and book UV-B and Biosphere is an attempt to cover this range and to report the progress made in the research of ecological effects of enhanced solar UV-B radiation. The papers in this book formed the basis of an international workshop entitled' UV-B and Biosphere' , December 15-18, 1995, in Wageningen, The Netherlands. A first reaction of Hans de Boois on the number of papers and sessions scheduled from Friday to Sunday morning was: far too many.

Do changes in stratospheric ozone relate to changes in UV-B irradiance and do both relate to life on Earth? This volume presents the latest data available in the basic scientific disciplines associated with these questions. The key topics are the interactive factors between the various research elements and the measurements needed to both validate ozone depletion and monitor UV flux changes in the biosphere.

Do changes in stratospheric ozone relate to changes in UV-B irradiance and do both relate to life on Earth? This volume presents the latest data available in the basic scientific disciplines associated with these questions. The key topics are the interactive factors between the various research elements and the measurements needed to both validate ozone depletion and monitor UV flux changes in the biosphere.

There are by now well-established connections between the introduction of chlorine-containing molecules into the stratosphere, a consequent decrease in the concentration of stratospheric ozone, and an increase in UV-B radiation at the surface of the Earth. An increase in UV-B on average would increase the incidence rate of non-melanoma skin cancer worldwide, with an unproved but likely increase in melanoma skin cancer. Other effects on humans could include cataracts and immune system inhibition, but these are less well established. The response of domestic and wild animal populations to UV-B is not thought to be a serious problem at this time, in part because they are protected by fur. The response of plants is complex because plants exist in a highly competitive situation with other plants for water and light, and must survive in an environment of pests and diseases, which may also be affected by UV-B. The oceanic phytoplankton are the basis of the ocean food chain and are responsible for half of the natural carbon dioxide fixation. Studies have indicated that the phytoplankton are adversely affected by UV-B, and thus there is a potential for excess UV-B to affect fishing yields and the amount of carbon dioxide in the atmosphere.

Ultraviolet-B (UV-B) is electromagnetic radiation coming from the sun, with a medium wavelength which is mostly absorbed by the ozone layer. The biological effects of UV-B are greater than simple heating effects, and many practical applications of UV-B radiation derive from its interactions with organic molecules. It is considered particularly harmful to the environment and living things, but what have scientific studies actually shown? UV-B Radiation: From Environmental Stressor to Regulator of Plant Growth presents a comprehensive overview of the origins, current state, and future horizons of scientific research on ultraviolet-B radiation and its perception in plants. Chapters explore all facets of UV-B research, including the basics of how UV-B's shorter wavelength radiation from the sun reaches the Earth's surface, along with its impact on the environment's biotic components and on human biological systems. Chapters also address the dramatic shift in UV-B research in recent years, reflecting emerging technologies, showing how historic research which focused exclusively on the harmful environmental effects of UV-B radiation has now given way to studies on potential benefits to humans. Topics include: UV-B and its climatology UV-B and terrestrial ecosystems Plant responses to UV-B stress UB- B avoidance mechanisms UV-B and production of secondary metabolites Discovery of UVR8 Timely and important, UV-B Radiation: From Environmental Stressor to Regulator of Plant Growth is an invaluable resource for environmentalists, researchers and students who are into the state-of-the-art research being done on exposure to UV-B radiation.

In response to the overwhelming concern for possible acute and long-term effects of ozone depletion on terrestrial and aquatic life, this volume presents a comprehensive collection of review articles from an internationally acknowledged group of experts.

A review of the literature an the potential effects of an increase in UV-B reaching the Earth's surface shows that there might have been very serious consequences if we had not restricted the production and use of chlorfluorocarbons. Even a modest increase of UV-B, on average, would in all likelihood have increased the amount of skin cancer worldwide, leading to an estimated 2,000 additional deaths per year per percentage point decrease in ozone. Small changes in agriculture and in the forests could cost a great deal of money, although these costs would likely be hidden by weather fluctuations. Small changes in the productivity of ocean phytoplankton could accelerate the greenhouse effect. The effect of space launch operations is a small perturbation on all this, with an average effect on the ozone of perhaps 0.02%, or about 40 additional skin cancer deaths out of 50,000 per year, at steady state. This estimate is based on a launch rate equivalent to about 600 tons of chlorine per year delivered to the stratosphere (7 shuttle or 12 Titan launches per year), and assumes that the solid rocket boosters would continue to be based on chlorine containing oxidizers. Without chlorine, there would be a negligible effect.

Every four years the photobio1ogists of the world get together in an International Congress. They discuss and learn not only re search details and findings in their own, often narrow, fields but educate one another broadly in the many biological systems that interact with light. It is this latter purpose that is exemplified by these proceedings - the Symposium papers and Workshop summaries of the VIIth International Congress on Photobiology held in Rome, August 29 - September 3, 1976. Photobiology is one of the few true interdisciplinary fields. It has an air of excitement about it. A glance at the table of contents indicates clearly that photobiology and its practitioners (individuals whose primary interests are in medicine, plant sci ences, animal sciences, molecular properties, and energy conversion) interact with the entire and diverse world of living creatures. We supply not only the basic research background to help evaluate many present-day environmental problems but are also evaluating and pointing the way toward solutions to a number of these problems.

An excellent summary of solar UV measurement for anyone involved in, or contemplating, measuring the UV part of the solar spectrum. The book is addressed predominantly to the newcomer to this expanding area of environmental measurement, but contains sufficient detail and practical information to be a valuable reference for the more experienced worker. The practical considerations of solar UV measurement are clearly described and the book explores the current state of the art of UV monitoring, explained by the historical demand for data. The many applications of solar UV data are discussed and the importance of making appropriate measurements and collecting sufficient supporting data for the analysis required of these applications is highlighted.

Since the realisation that the ozone layer protecting the earth is suffering massive depletion, atmospheric science has been increasingly in the spotlight. It is recognised that we need to increase our knowledge and understanding of the likely impact that increases in UV-B radiation will have on life on earth. Charting research that encompasses the changing distribution of atmospheric ozone, changes in UV-B radiation and the consequent effects on photochemistry and biological systems in the aquatic and terrestrial environments, Causes and Environmental Implications of Increased UV-B Radiation draws together experts from the international community. Also included is a discussion of the emotive and highly topical subject of skin cancer as related to increased UV-B radiation. As an up-to-date and authoritative summary of the state of this highly complex science, this book will be welcomed by all practitioners and researchers in the field.