Agroforestry is analysed by means of economic concepts. The paper is mainly theoretical, since there are little adequate data to test the conceptual framework.
Agroforestry needs not be limited to integration of agriculture and forestry on a plot, but may also include integration on a holding. Design and evaluation of agroforestry systems require thorough knowledge of relationships between agriculture and forestry. Complementary and supplementary relationships, mainly resulting from biological factors, were identified, which make agroforestry an efficient system of land use.
Agroforestry can be an appropriate technology in areas with fragile ecosystems and subsistence farming. The objectives of participants in an agroforestry programme may not coincide with social objectives, and so do not lead to the socially optimum combination of agriculture and forestry. For that social optimum institutional arrangements will often be required.
1. Def'mitions of agroforestry
With increasing interest in combinations of forestry and agriculture, the term 'agroforestry' has been coined. The paper suggests extension of this term based on an economic argument. Economics is concerned with the analysis of choice and decisions: which goods are produced with which resources, and how much of these resources may be used in order to achieve certain objectives. It is also concerned with the distribution of revenues of production. This paper on economic aspects of agroforestry examines factors influencing the choice of combination of agriculture and forestry, allocation of resources to agroforestry and to some degree distribution of revenues from agroforestry.
Definitions of agroforestry (e.g. [3,14,5,28]) often mention both structures and objectives of agroforestry. Among objectives mentioned are: maximum or sustained production and optimum conservation or production. These objectives are not necessarily identical nor compatible. A certain objective may also have a different content for the various categories of people involved in agroforestry. For a farmer, optimum production may mean a different form of land use than for a forest service; the social opti-*This paper is a shortened updated version of part of a lecture series on agroforestry, organized by the Departments of Forestry, Agricultural University, Wageningen [29]. * *The author thanks his colleagues C.P. Veer and K.F. Wiersum for helpful comments.