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Olafur Arnalds
The ever-increasing demand for food and natural resources by a rapidly growing human population has exerted environmental stress resulting in widespread ecosystem degradation. An extreme form of such degradation, termed ‘desertification’, is estimated to affect the living conditions of about one billion people. As a result, this topic spawned the United Nations Convention to Combat Desertification (UN-CCD) in 1994. The term ‘desertification’ encompasses a variety of processes and is driven both by natural and anthropogenic forces. Desertification has occurred in most regions of the world, cutting across a broad spectrum of contrasts in climate, ecosystem types, land uses and socio/economic settings. The complexity of this phenomenon has challenged our ability to categorize, inventory, monitor and repair the condition of the land. Short-comings in communication and understanding are magnified by the improper, incomplete or ‘out of context’ transfer of knowledge from one region or land use category to another. One of the most important distinctions to be made in relation to land degradation is between cultivated land used for annual crop production and ‘rangelands’. Rangelands represent a variety of ecosystems and landforms not suited for intensive agriculture or forestry, because of limitations imposed by climate, soils or topography (Stoddardt et al., 1975; Holecheck et al., 1989). Grazing by free-ranging livestock is the traditional primary use of the world’s rangelands. However, there is growing recognition of the importance of these vast acreages for wildlife habitat, hydrology and ground water recharge, recreation and aesthetics. Historic approaches to halting, mitigating or reversing rangeland degradation were agronomically-based rather than ecologically-based. Agronomic approaches were typically intensive, costly and non-sustainable. As such, they were ill-suited to extensively managed rangelands characterized by variable or extreme climatic conditions, poor soils, and/or rugged topography. Agronomic efforts at rangeland improvement often consisted of practices such as broadcast seeding and fertilization with little regard for spatial and temporal heterogeneity or the status of underlying ecosystem processes that promote or retard degradation and restoration. In recognition of these short-comings, a group of about 80 experts from over 40 countries were assembled in Iceland in September 1997 for a workshop on rangeland desertification. The goal of the workshop was to bring together a broad spectrum of scientific expertise representing bioclimatically and culturally diverse regions to compare and contrast ecological perspectives on rangeland desertification. Why convene a desertification workshop in Iceland? As noted elsewhere in this volume, severe land degradation has radically impacted most of Iceland’s rangeland ecosystems. Iceland thus exemplifies the fact that the problem of desertification extends beyond Africa and the dryland regions of the world. Ongoing degradation continues in much of Iceland, yet there have been significant scientific and social advances in combating desertification. Thus, there is both cause for concern and reason for optimism. In this context, Iceland provided an appropriate, and somewhat extraordinary setting for this workshop. The experts that attended the workshop represented many disciplines and geographical regions and shared a common interest in severe land degradation. During the workshop, principles of land degradation were discussed and illustrated by a diverse array of case studies from all regions of the world (Figure 1).
Figure 1 . Geographical distribution of degradation research reviewed at the 1997 Rangeland Desertification Workshop in Iceland. The wealth of information introduced at the workshop could not be presented in a single publication. We, as editors assisted by inputs from an organizational committee, were therefore faced with the task of dividing the papers into two volumes. The volume presented here focuses on concepts and principles. The second volume, published as RALA Report No. 200, summarizes workshop discussions and recommendations and contains a compilation of case studies. As such, it represents a unique documentation of rangeland desertification in many countries and regions of the world. This volume is divided into two sections. The chapters in the first section explore the spatial and temporal aspects of disturbance interactions, thresholds and non-linear change with respect to vegetation, hydrology, nutrient cycling and erosion. Chapters in the second section of the book are dedicated to socio-economic constraints, remedies and approaches for preventing and reversing degradation. It begins with an overview of United Nations databases on desertification, followed by chapters discussing approaches for implementing conservation practices. A concluding example shows how environmental accountability can be woven into the policy and law of a society. Reversal of the effects of desertification is most difficult in countries with limited resources. One chapter articulates the problems facing developing countries; another describes the constraints to implementing the articles of the UN-CCD in Africa. Acknowledgements We thank Ms. Vigdís Finnbogadóttir, former President of Iceland for her support of this project from beginning to end. We also thank David Sanders, Denis Peter, Bjorn Sigurbjornsson, Magnus Johannesson, Sveinn Runolfs-son, Thorsteinn Tomasson, Halldor Thorgeirsson, Andres Arnalds, Asa L. Aradottir, Ulfur Bjornsson, Einar Gretarsson, Steinunn Geirsdottir, and the numerous Icelanders involved ‘behind the scenes’ in organizing the logistics of the workshop, field trips and this publication. Both books from the workshop were typeset by Tryggvi Gunnarsson at RALA with the help of Dagny E. Arnalds. We are very thankful for their good work. The chapters in this book were subject to anonymous peer-reviews. We are grateful to those who generously donated their time for this thankless task. The workshop was funded by the Icelandic Ministry of Agriculture and the Ministry for the Environment, the Agricultural Research Institute and the Soil Conservation Service. Additional funds were provided by the European Commission. We thank all these organizations for their important contributions.
REFERENCES Arnalds, O. and Archer, S. (Eds.) 1999. Proceedings of the Rangeland Desertification, International Workshop, September 1997, Iceland. RALA Report No. 200. (In press). Holechek, J.L., Pieper, R.D. and Herbel, C.H. 1989. Range Management: Principles and Practices. Prentice Hall, Endlewood Cliffs, New Jersey. Stoddardt, L.A., Box, T.W. and Smith, A.D. 1975. Range Management. McGraw-Hill Book Company, New York, NY
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