Impact Of Uv B Radiation On Pelagic Freshwater Ecosystems

This book offers extensive coverage of the most important aspects of UVR effects on all aquatic (not just freshwater and marine) ecosystems, encompassing UV physics, chemistry, biology and ecology. Comprehensive and up-to-date, UV Effects in Aquatic Organisms and Ecosystems aims to bridge the gap between environmental studies of UVR effects and the broader, traditional fields of ecology, oceanography and limnology. Adopting a synthetic approach, the different sections cover: the physical factors controlling UVR intensity in the atmosphere; the penetration and distribution of solar radiation in natural waters; the main photochemical process affecting natural and anthropogenic substances; and direct and indirect effects on organisms (from viruses, bacteria and algae to invertebrate and vertebrate consumers). Researchers and professionals in environmental chemistry, photochemistry, photobiology and cell and molecular biology will value this book, as will those looking at ozone depletion and global change.

Human health as well as aquatic and terrestrial ecosystems are threatened from increa sing levels of environmental radiation of various sources, many of them of anthropoge nic causality: large areas of the former Soviet Union suffer from radioactive pollution, in particular after the Chemobyl accident; the increase in the incidence of UVB radiati on at the Earth's surface as a result of a progressive depletion of stratospheric ozone is a global problem that requires international concerted actions; in areas of former uranium mining the natural radiation level is substantially increased due to elevated radon levels; a growing portion of the population involved in air traffic is exposed to increased levels of natural radiation; and with the International Space Station an increasing number of astronauts will be exposed to the complex field of cosmic radiation. To estimate the corresponding risks, a better knowledge of the underlying radiobiological mechanisms at the molecular, cellular and system level is required. This book is the result of a multidisciplinary effort to discuss the current state of knowledge of the fundamental processes that result from interactions of environmental radiation -ionizing as well as UV radiation -with living matter and the existing radiati on protection concepts, and then to define future research work needed as fundamental information for the assessment of risks from increased levels of environmental radiation to human health and ecosystem balance. It comprises the key lectures and statements presented at the NATO Advanced Research Workshop.

This book, first published in 2000, provides a comprehensive, multidisciplinary review of UV radiation effects in the marine environment. It is aimed at researchers and graduate students in photobiology, photochemistry and environmental science. It will also be useful as a supplementary text for courses in oceanography, climatology and ecology.

Organisms and environment have evolved through modifying each other over millions of years. Humans appeared very late in this evolutionary time scale. With their superior brain attributes, humans emerged as the most dominating influence on the earth. Over the millennia, from simple hunter-food gatherers, humans developed the art of agriculture, domestication of animals, identification of medicinal plants, devising hunting and fishing techniques, house building, and making clothes. All these have been for better adjustment, growth, and survival in otherwise harsh and hostile surroundings and climate cycles of winter and summer, and dry and wet seasons. So humankind started experimenting and acting on ecological lines much before the art of reading, writing, or arithmetic had developed. Application of ecological knowledge led to development of agriculture, animal husbandry, medicines, fisheries, and so on. Modem ecology is a relatively young science and, unfortunately, there are so few books on applied ecology. The purpose of ecology is to discover the principles that govern relationships among plants, animals, microbes, and their total living and nonliving environmental components. Ecology, however, had remained mainly rooted in botany and zoology. It did not permeate hard sciences, engineering, or industrial technologies leading to widespread environmental degradation, pollution, and frequent episodes leading to mass deaths and diseases.

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.

Although there are some biological processes that are supported by UV radiation, most organisms are stressed by it in various ways, e.g. through DNA damage. Top international experts present an integrated overview of UV radiation and its effects on terrestrial, freshwater and marine Arctic biota. Increased stratospheric ozone depletion and the corresponding increase in ground levels of UV radiation as well as ambient, "natural" UV radiation as a key ecological factor in the Arctic spring and summer are discussed in detail. Additionally, basic information on Arctic ecosystems is given. The volume provides not only an excellent account of present-day knowledge of the subject, but also describes the state of the art on which future research can be built.

From microbial to plant ecosystems, this book examines how changes in UV radiation, caused by anthropogenic ozone depletion, as well as changes in radiation levels throughout the evolution of life on Earth, can alter species composition and interspecies competitiveness. It focuses on the evolutionary aspects of the effects of UV as well as the various synergistic interactions of UV radiation with other environmental factors. Because our knowledge of UV effects on whole ecosystems is still at a relatively early stage, an important part of each chapter is an overview of future research directions and indications of where new date and knowledge is needed.