International Symposium On Biosphere Atmosphere Exchange 1

An essential reference work on climate change and the effect of greenhouse gases.

The biosphere is the ultimate sink for air pollutants and is also the source of many precursors for the formation of photo-oxidants. In any analysis of air pollution and for determining source-receptor relationships, reliable emission and pollutant concentrations or depositions must be taken into account, together with their interactions between the atmosphere and the biosphere. This book presents a number of authoritative review articles covering topics which include biosphere-atmosphere exchange of ammonia, nitrogen oxides, ozone and sulfur-containing gases, the biological mechanisms involved in the exchange of trace gases, as well as generalizations of deposition over Europe.

Trace gases are those that are present in the atmosphere at relatively low concentrations. Small changes in their concentrations can have profound implications for major atmospheric fluxes, and thereore, can be used as indicators in studies of global change, global biogeochemical cycling and global warming. This new how-to guide will detail the concepts and techniques involved in the detection and measurement of trace gases, and the impact they have on ecological studies. Introductory chapters look at the role of trace gases in global cycles, while later chapters go on to consider techniques for the measurement of gases in various environments and at a range of scales. A how-to guide for measuring atmospheric trace gases. Techniques described are of value in addressing current concerns over global climate change.

Sulphur (S) plays a pivotal role in various plant growth and development processes being a constituent of sulphur-containing amino acids, cysteine and methionine, and other metabolites viz., glutathione and phytochelatins, co-factor of enzymes which contribute to stress repair and amelioration of heavy metal toxicity. Besides, a number of S-containing components are biologically active and, thus, a source for use as medicinal value. The basic global issue before the agricultural scientist and world community is to evolve cultivars and develop methodologies for efficient use of inputs to enhance agricultural productivity. This is particularly true of the developing countries which are going to see maximum rise in population with changing food demands and declining availability of land. Amongst the inputs, nutrients play a crucial role. The major requirement is for N, P and K followed by several micro-nutrients. In this context reports of world-wide S deficiency in the agricultural systems are relevant. The reasons are many. Broadly speaking reduction inS emission, use of S-free N, P and K fertilizers and higher biomass production contributed the maximum. Despite the need for sulphur as an essential plant nutrient and the substantial returns expected from its use, very little attention has been given to fill the gap between supply and demand of S.

Certain trace gases in the atmosphere are able to absorb electromagnetic energy from the reflection of solar radiation from the Earth's surface. These gases have been increasing steadily and there is concern that they will change global climatic conditions by warming the atmosphere--the so-called ``greenhouse effect.'' Many of these gases originate from biological systems. The Biogeochemistry of Global Change discusses the role of radiative trace gases in this process. The disciplines covered in the book include microbiology, geochemistry, atmospheric chemistry, plant physiology, oceanography and limnology, and soil science. This diversity allows for cross-fertilization, achieving a better understanding of the complex mechanisms for biological and chemical formation, the destruction of trace gases, and the manipulation of ecosystems. Some of the topics covered include: biological mechanisms of formation and destruction of various ``greenhouse'' gases (such as methane, nitrous oxide, carbon dioxide, dimethylsulfide, and chlorofluorocarbons); the outward and consumptive flux of trace gases from marine and terrestrial systems (including anthropogenic sources); global trace gas modeling studies; the atmospheric physical and chemical reactions of trace gases; and the environmental significance of various trace gases in ancient and current atmospheres. The Biogeochemistry of Global Change provides both reviews and primary source material for active researchers in this field and for microbiologists and atmospheric chemists.