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.

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.

This volume originates from the NATO Advanced Study Institute Environmental UV Radiation: Impact on Ecosystems and Human Health and Predictive Models, held in Pisa, Italy in June 2001. The Institute was sponsored and mainly funded by the NATO Scientific Affairs Division, whose constant contribution in favour of the cooperation among scientists from different countries must be acknowledged. Other Institutions substantially contributed to the success of the ASI and our thanks and appreciation go to the Italian National Research Council (Consiglio Nazionale delle Ricerche), the Italian Space Agency (Agenzia Spaziale Italiana), the European Society for Photobiology and the bank Banca Toscana. In the last two decades of the past century, concern has been growing for the possible effects on the biosphere of the stratospheric ozone depletion, due to anthropogenic emissions of ozone-destroying chemicals. The ozone loss causes an increase in the biologically important part of the solar ultraviolet radiation (UV) reaching the Earth’s surface, which constitutes a threat to the biosphere, because of UV damaging effects on humans, animals and plants. The international agreements have reduced the production of ozo- destroying compounds, which, however, are still present in high concentrations in the stratosphere, mainly because of their longevity, and thus ozone depletion will likely continue for several decades.

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.

A comprehensive review of this important aspect of environmental change.

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.