Biogeochemistry Of Major World Rivers

This extract of the SCOPE/UNEP project ``Transport of Carbon and Minerals in Major World Rivers, Lakes, and Estuaries'' provides a comprehensive overview of the biogeochemistry of major rivers and their role in the biogeochemical cycles of its life-supporting animals for the first time. Rivers are viewed by continent or under certain scientific aspects. Concrete data on the chemistry and fluxes of major world rivers are given in addition to a more theoretical approach to the riverine system.

There is an intuitive belief among scientists that each estuary or lagoon is unique and different. Similarities do exist, however, and this book attempts to highlight some common properties and perhaps some innovative views on biogeochemical processes, and biological fluxes which are of central concern in the understanding of the land-sea boundary. The contents are based upon lectures given at a Seminar organised as the scientific component of the 17th General Meeting of SCOR, held at the Station Biologique de Roscoff, France, on 22-24 October 1984. The original lectures have been substantially extended and revised in order to give a fuller treatment of the subject. The contributions identify important processes influencing (I) Behaviour of chemical species, (II) Nutrient cycling and mechanisms of organic transformations and (III) Uptake of trace elements by living systems. The connection between terrestrial and oceanic systems is a functional one and the consequences of this linkage on the very large variety of coastal systems are profound. It is widely recognized that many of the major processes which influence the biological properties and chemical forms of elements, and their biogeochemical cycles in the ocean occur at the land-sea boundary, especially in estuaries, coastal lagoons, the coastline and the shelf. Over 80% of living systems and their fisheries take place in near shore waters and the consequential production of organic matter produced triggers off the high level of activity. Over the last fifteen years, there has been considerable stimulus to provide framework to evaluate the interactions and effects of human activities. The rich assemblage of tables and figures and of literature citations contained in the chapters provides an excellent basis for in-depth investigations. Oceanographers, limnologists, aquatic chemists, marine biologists, and environmental specialists will find this book highly valuable reading for advanced research and training purposes.

A comprehensive, state-of-the-art synthesis of biogeochemical dynamics and the impact of human alterations at major river-coastal interfaces for advanced students and researchers.

This ia a synopsis and review of the major rivers of the world.

Oceanographic discontinuities (e. g. frontal systems, upwelling areas, ice edges) are often areas of enhanced biological productivity. Considerable research on the physics and biology of the physical boundaries defining these discontinues has been accomplished (see [I D. The interface between water and sediment is the largest physical boundary in the ocean, but has not received a proportionate degree of attention. The purpose of the Nato Advanced Research Workshop (ARW) was to focus on soft-sediment systems by identifying deficiencies in our knowledge of these systems and defining key issues in the management of coastal sedimentary habitats. Marine sediments play important roles in the marine ecosystem and the biosphere. They provide food and habitat for many marine organisms, some of which are commercially important. More importantly from a global perspective, marine sediments also provide "ecosystem goods and services" [2J. Organic matter from primary production in the water column and contaminants scavenged by particles accumulate in sediments where their fate is determined by sediment processes such as bioturbation and biogeochemical cycling. Nutrients are regenerated and contaminants degraded in sediments. Under some conditions, carbon accumulates in coastal and shelf sediments and may by removed from the carbon cycle for millions of years, having a potentially significant impact on global climate change. Sediments also protect coasts. The economic value of services provided by coastal areas has recently been estimated to be on the order of $12,568 9 10 y" [3J, far in excess of the global GNP.

This book is a natural extension of the SCOPE (Scientific Committee of Problems on the Environment) volumes on the carbon (C), nitrogen (N), phosphorus (P) and sulfur (S) biogeochemical cycles and their interactions (Likens, 1981; Bolin and Cook, 1983). Substantial progress in the knowledge of these cycles has been made since publication of those volumes. In particular, the nature and extent of biological and inorganic interactions between these cycles have been identified, positive and negative feedbacks recognized and the relationship between the cycles and global environmental change preliminarily elucidated. In March 1991, a NATO Advanced Research Workshop was held for one week in Melreux, Belgium to reexamine the biogeochemical cycles of C, N, P and S on a variety of time and space scales from a holistic point of view. This book is the result of that workshop. The biogeochemical cycles of C, N, P and S are intimately tied to each other through biological productivity and subsequently to problems of global environmental change. These problems may be the most challenging facing humanity in the 21 st century. In the broadest sense, "global change" encompasses both changes to the status of the large, globally connected atmospheric, oceanic and terrestrial environments (e. g. tropospheric temperature increase) and change occurring as the result of nearly simultaneous local changes in many regions of the world (e. g. eutrophication).

Interest in marine dissolved organic matter (DOM) is very high because it plays an important role in oceanic and global carbon cycling, which in turn impacts weather. Understanding the processes involved in the transformations of carbon, phosphorus, nitrogen, and other major elements in the oceans has been a primary goal of marine biogeochemists and oceanographers over the past decade.This book, in 16 chapters with over 170 figures and tables, reports on the major advances in this area by a distinguished group of international chemical and biological oceanographers. Additionally, it focuses on the role of DOM in elemental cycling - where the greatest informational need currently exists. Biological cycling of the major elements through DOM is assessed throughout, with particular emphasis on the role of marine microbes as active agents in the processing of this materialThe ocean science community's advances for inclusion of DOM in both ecosystem and global circulation models are evaluated

For the past 4 billion years, the chemistry of the Earth's surface, where all life exists, has changed remarkably. Historically, these changes have occurred slowly enough to allow life to adapt and evolve. In more recent times, the chemistry of the Earth is being altered at a staggering rate, fueled by industrialization and an ever-growing human population. Human activities, from the rapid consumption of resources to the destruction of the rainforests and the expansion of smog-covered cities, are all leading to rapid changes in the basic chemistry of the Earth. The Third Edition of Biogeochemistry considers the effects of life on the Earth's chemistry on a global level. This expansive text employs current technology to help students extrapolate small-scale examples to the global level, and also discusses the instrumentation being used by NASA and its role in studies of global change. With the Earth's changing chemistry as the focus, this text pulls together the many disparate fields that are encompassed by the broad reach of biogeochemistry. With extensive cross-referencing of chapters, figures, and tables, and an interdisciplinary coverage of the topic at hand, this text will provide an excellent framework for courses examining global change and environmental chemistry, and will also be a useful self-study guide. Emphasizes the effects of life on the basic chemistry of the atmosphere, the soils, and seawaters of the EarthCalculates and compares the effects of industrial emissions, land clearing, agriculture, and rising population on Earth's chemistrySynthesizes the global cycles of carbon, nitrogen, phosphorous, and sulfur, and suggests the best current budgets for atmospheric gases such as ammonia, nitrous oxide, dimethyl sulfide, and carbonyl sulfideIncludes an extensive review and up-to-date synthesis of the current literature on the Earth's biogeochemistry.