Half of the countries of the world lie partly or wholly in arid and semi-arid zones. These zones, together with their sub-humid margins, or the so-called dry lands, cover a total area of about 45 million km² or one-third of the total land area of the world. Ecological degradation develops at an alarming rate in the areas and threatens the livelihood of some 850 million inhabitants.
Human intervention, through control operations or application of viable land use systems, can halt and eventually reverse the process of degradation. The conception, formulation and application of such interventions have to be based on sound knowledge and an appreciation of the human, ecological and economic factors involved in any given situation. They also require that field personnel be kept abreast with technological progress. However, one dominant constraint in this respect so far has been the dearth of manuals for forestry field technicians.
This manual aims, therefore, at upgrading the skills of forestry field personnel in the operation of tree nurseries, the planting of trees and shrubs, the prevention and control of wind erosion, and the execution of other types of activities related to tree planting in agricultural lands. Basic understanding of constraints and conditions for people's participation is also provided.
FAO is grateful to the many authors who have contributed to the preparation of this publication. Mr H. Sjöholm, during his assignment in the Forest Resources Division, prepared the first draft of this document. Mr M. I. Reynders, former FAO staff member and currently Professor at the Forestry Faculty of the University of Gent (Belgium), expanded and edited the draft. Professor P. Ffolliott, School of Renewable Natural Resources, University of Arizona (United States of America), finalized the present text.
Mr B. Ben Salem of this Division coordinated the planning and the preparation of the publication.
It is hoped that this manual will be useful to forestry instructors in the arid regions for training field technicians, and that it will thus contribute to the success of arid land forest restoration programmes.