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close this bookForests, Climate, and Hydrology: Regional Impacts (UNU, 1988, 217 pages)
View the documentAcknowledgements
View the documentForeword
View the documentPreface
Open this folder and view contents1. Introduction
Open this folder and view contents2. The living past: Time state of the tropical rain forest
Open this folder and view contents3. Effects of tropical forest on water yield
Open this folder and view contents4. Effects of forests on precipitation in India
Open this folder and view contents5. The Influence of forests and forest reclamation practice on streamflow and water balance
Open this folder and view contents6. Hydrologic process models
Open this folder and view contents7. Modelling the behaviour of water
Open this folder and view contents8. Review of general circulation models as a basis for predicting the effects of vegetation change on climate
Open this folder and view contents9. Résumé and conclusions
View the documentGlossary
View the documentWorkshop participants


The United Nations University has contributed notably to the subject area of the possible repercussions of land use change on climate in sponsoring the workshop (at St. John's College, Oxford, 25-30 March 1984) that has resulted in this publication. The initiative was largely that of Professor Walther Manshard (Freiburg and United Nations universities). The workshop was part of the Resource Policy and Management Programme of the UNU. It is anticipated that it will catalyse the efforts of the University to establish field research projects under the Programme as well as under the existing series of biennial Global View and other workshops. The Oxford meeting impinges on tasks of the Associated Institutions of the UNU and the Research and Training Institutes that are being initiated. The outcome of the Forests, Climate, and Hydrology Workshop should also promote the Fellowship Programme of the UNU as well as their publications programme.

Through their enthusiastic and critical contributions the participants are largely responsible for the success of the workshop. We wish to acknowledge the assistance of the Meteorological Office (Bracknell, UK) and the Institute of Hydrology (Crowmarsh, UK) in planning the workshop and especially Dr. Howard Oliver (Institute of Hydrology) for his help during the meeting.

The bulk of this book comprises the reviews prepared in advance of the workshop for selected areas of the subject. The reviewers kindly accepted many of our suggestions and the changes necessary to achieve a degree of conformity among the various chapters. The authors brought to the notice of the workshop participants the most recent investigations: the bibliographies following each contribution should prove particularly valuable. Interpretations of data were usually critical and carry suggestions of the physical processes involved. Special mention should be made of Dr. David Mabberley's lecture (chap. 2) presented to the members of the workshop and their guests at a reception given at the Commonwealth Forestry Institute, University of Oxford.

This showed the biological significance, complexity, and dynamism of the tropical rain forest as a background to the deliberations of the workshop on the regional and global climatic impact of its exploitation. Only the scale of the hydrological and climatological phenomena treated is implied by our use of "regional": we do not wish to confine our considerations to named geographical regions. However, among the local case studies that were communicated to the workshop, we have taken the opportunity of publishing that by Dr. Meher-Homji. This respresents perhaps the most refined of the challenging genre of somewhat anecdotal evidence for associating changing forest extent with changing rain climate. As with the Russian research (chap. 5), intriguing correlations in hydrology ought to generate quantitative hypotheses as to the underlying physical mechanisms, and these should be critically tested.

A number of experts from various disciplines were invited to the workshop with the reviewers to comment on the evidence and to suggest an appropriate course for future investigations. These assessments, much abbreviated and more the consensus of the workshop rather than merely the contributions of individual participants, are appended to each paper. At two points during the workshop, a resume of the preceding papers was presented. These and the resulting discussions are reported in the first part of chapter 10. Since a major objective of the workshop was to produce from the reviews and subsequent discussions conclusions as far as agreement by the participants could be achieved, the last day of the workshop was devoted to this end. The second part of chapter 10 sets out these conclusions. It was not appropriate to direct these at specific agencies, so they can hardly be termed recommendations or guidelines. However, it is to be hoped that scientists involved in the climatic and hydrologic effects of land use changes will be stimulated by the conclusions of the workshop, that agencies supporting research will refer to this consensus, and that those who determine policies of land use will find them informative.

Oxford University
August 1984

Evan R. C. Reynolds
Frank B. Thompson