SCOPE 21 - The Major Biogeochemical Cycles and Their Interactions 

Preface

The biogeochemical cycles of the major compounds carbon, nitrogen, phosphorus, and sulphur are still only known in their broad outline. It may then seem premature to attempt to consider their interaction, since we by necessity need to understand the processes in which the element interaction takes place. The interactions occur at the micro-scale and involve chemical and biological processes, the consequences of which on the global scale cannot easily be deduced. On the other hand this very problem is of such a fundamental nature that further advancement in global ecology can hardly be achieved without its thorough analysis. An attempt in this direction might at least define the key problems better than has been the case so far. Also as systematic a presentation as possible of the outcome of a workshop with this aim might stimulate further research in the field, which is very much needed. An integrated and global view of this kind is necessary to deal with a great number of the major environmental problems with a long term perspective in mind.

When the SCOPE Executive Committee decided to support a workshop with this aim, a steering committee was formed consisting of B. Bolin, P. Crutzen, J. Freney, E. Goldberg, T. Rosswall, P. Vitousek and R. Woodmansee. The committee met in June 1980 and agreed on key topics to be covered at the workshop and authors were selected to provide papers. Further, an opponent was chosen for each contribution. The basic papers were available in advance of the workshop and appear, in revised form, as chapters 319 in the present volume. Most of the time during the workshop, held 2531 May 1981, was devoted to discussions around themes that appeared particularly important in the light of the material that was available. These were:

• the effect upon carbon storage in sediments, soils, and vegetation (primary production) of additional N, P, and S from fossil fuel burning and deforestation;
• soil management practices the potential deterioration of soils through alteration of the N, P, and S via cultivation;
• the biosphere as a source of trace gases which influence the chemistry of the atmosphere; the processes within the biosphere that produce these gases;
• the eutrophication of coastal marine waters through the entry of N, P, and S by man's activities;
• water quality changes from the mountains to the sea as a consequence of N, P, and S entry from man's activities;
• The long term effects of population increases and material utilization via N, P, and S dispersion upon the carrying capacity of the earth for humanity.

At the end of the workshop five members of the steering committee were given the task to write an introductory chapter to the report presenting a synthesis of the contributed papers and the group discussions held during the workshop. Also, brief overviews of the cycles of the four elements were to be provided as a background and they appear in chapter 2.

The synthesis chapter was submitted to UNEP as a SCOPE contribution to the preparations for the UNEP conference `Ten years after Stockholm' in Nairobi May 1982. A summary of the results was also published in Nature in October 1981 (Vol. 293, p. 434).

As responsible to SCOPE for the present project, we wish to express our sincere thanks to all those that have contributed to the successful completion of a difficult undertaking. Particularly the work by the steering committee has been of great value. The Mellon Fellowship that was made available to one of us (R.C.) to work on this project is gratefully acknowledged.

Dr. Phil Goldsmith (British Meteorological Office), on behalf of SCOPE, has carried the responsibility for an external review of the revised manuscripts submitted for publication.

Finally, Siv Feusi, Solveig Larsson, Mona Öhnfeldt, Benita Wahlström, Anders Johnson, Sven-Åke Odh, and Mats Arbman of the International Meteorological Institute in Stockholm have solved all practical problems that needed to be taken care of in a project of the present kind. Their engaged work is much appreciated.