The use of forest resources and the assessment of their extent and state are inextricably linked. From the time humans began to break branches off trees to create shelters and feed the fires that afforded warmth, energy for cooking and protection from animal predators, the adequancy of the forest resource has been crucial; indeed, a question of life or death.
As humankind evolved from a forest dweller into an industrialized and later an urban-based animal, the assessment of forest resources tended to concentrate on their economic value, primarily as a source of industrial wood. More recently, with recognition of the interrelationship between forests and environmental stability, the demand for information derived from forest resource assessment has broadened at all levels.
This issue of Unasylva focuses on the recently completed FAO assessment of forest resources at a global level, with 1990 taken as the reference year (a similar assessment was undertaken a decade ago). The articles presented in this issue consider the data generated in the assessment as well as some of the difficult underlying questions inherent in forest resource assessment.
In the opening article, K. Janz, FAO Senior Forestry Officer for forest resources appraisal and monitoring, provides an overview of the 1990 assessment. On a global basis, forest resources declined significantly in the 1980s. In the industrialized countries, forest resources have increased over the past decade, slightly in terms of overall area but substantially in terms of standing volume. In the tropical countries, on the other hand, deforestation has continued and even accelerated - reaching an average of 15.4 million ha per year between 1981 and 1990. These data serve not to assign responsibility or "blame" for deforestation; rather they must be used to gain a better understanding of the dynamics of deforestation and the driving forces behind it as well as of the need and scope for action directed towards sustainable forestry. Janz' article also notes the weakness of most developing countries' capability in national forest resource assessment and describes FAO's commitment to country capacity-building assistance as an essential part of its assessment efforts.
K.D. Singh, Coordinator of the FAO Forest Resources Assessment Project, provides an analysis of the methodology and results of the 1990 Tropical Forest Resources Assessment. Building on the 1980 assessment, the 1990 project approaches assessment on a continuing rather than a periodic basis, using a combination of ground-level and remote sensing data. Of particular significance is the project's deforestation model which expresses a statistical relationship between deforestation, ecological zone and population density. The assessment also provides crucial insights into changes in use of forest land over time; a key point that emerges is that thinking only in terms of deforestation, i.e. forest versus non-forest uses, is vastly oversimplistic. A.V. Korotkov and T.J. Peck of the UN's Joint ECE/FAO Agriculture and Timber Division examine the results and implications of the forest resources assessment for industrialized countries. The challenge of responding to demands for an increasingly wide range of information is a thread that runs through the text. Moreover, the article stresses that, in spite of the long experience with forest resource assessment and extensive resources dedicated to this activity in industrialized countries, information is not comprehensive and difficulties in comparability of country data exist.
Perhaps the most rapidly developing component of forest resource assessment is satellite-based remote sensing. J.-R Malingreau of the Institute for Remote Sensing Applications of the European Communities assesses the potential of remote sensing approaches to answer emerging needs in the field of forest assessment, and considers the possibility of a global forest information system based on remote sensing. As attention to the ecological role of forests has increased, concern about the potential relationship between air pollution and forest decline has risen sharply. Numerous articles have been written, suggesting that widespread forest decline provoked by atmospheric pollution is imminent or even actually occurring and arguing for major changes in forestry policy. In a provocative article based on a decade of research in Germany, O. Kandler argues that the pollution/forest decline connection cannot be scientifically corroborated.
Finally, J.R Lanly, Director of the FAO Forest Resources Division, offers a concluding perspective on the importance of forest resource assessment and of the role played by FAO. This issue of Unasylva is unusual in that the majority of the articles are authored by FAO staff members, a situation dictated by the direct involvement of the Organization in the global forest resources assessment. However, these articles are envisaged as a point of departure for the participation of a much wider community in analysing and disseminating the policy implications of the assessment's basic results. The analysis will be particularly important at the national level, where sovereign decisions about the conservation and use of forest resources are taken. Unasylva strongly solicits readers to provide feedback and proposals for special follow-up articles. This issue of Unasylva is complemented by a statistical supplement which provides a review of current trends in forestry production and trade. In an article linking the supplement to the main text, FAO's Senior Forestry Economist, P. Wardle, discusses the collection and use of international forestry statistics.
