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Summary and conclusions

The objective of this study was to consider two countries, one with some experience and the other with pressing problems of arid zone development, and to compare and contrast them in terms of environmental, technical, social, and economic factors in order to identify constraints to tree planting in arid and semi-arid lands (ASAL). It proved easier to make a fuller assessment of the environmental and technical aspects than of the socio-economic aspects.

Expanding world populations and increasing cultural requirements are placing heavy demands on arid and semi arid lands, often causing loss of productivity and desertification. The value of trees is recognized inter nationally in prevention of desertification, restoration of degraded areas, provision of goods and services, amelioration of climate and soils, and general improvement of the quality of life. However, rural communities experience a competition for land between agriculture and forestry at both macro. and micro-levels in which the pressing demands for immediate food outweigh the long-term advantages of trees. Nevertheless, the increasing demand for lands for food production continually degrades both soil and forest so that legitimate demands for forest products cannot be met in the future. These demands are principally for fuel, fencing, and fodder and may be met by agro-forestry systems involving multiple crops and products.

There are some technical problems of afforestation in the arid zone; these include the very short planting season, the competition for labour during this season, and the often difficult and expensive techniques of raising nursery stock, field planting, and tending. Forestry administrations need to solve the logistical problems of planting in arid areas. However, environmental factors and practical afforestation technique are not the major constraints to tree planting in ASAL. More important are social features (including land use and tenure and community organization) and economic constraints (such as the lack of a monetarized economy, poor transport and marketing systems, poor understanding of long-term cost-benefit appraisal, and lack of precise information on establishment costs). Little is known about the perception of problems, solutions, and con" straints and the costs and benefits to the individual, house" hold, or community of subsistence activities, particularly those involving tree planting and especially in the ASAL.

There is great difficulty also in evaluating the costs and benefits to society or the economy of the environmental damage associated with excessive deforestation (or the costs and benefits of avoiding or reducing such damage). Throughout the world there are issues of intertemporal economics and intergenerational justice relating to resource use that are equally difficult to evaluate. Within the ASAL particularly there is a large lacuna in our knowledge of the economic parameters of tree growing. Further work is needed to understand the causes of the deterioration of arid areas, their impact on the people, and the recognition by the people of the importance of resulting problems and the need to act.

There is a great need for information distribution, professional and non-professional training in extension techniques for ASAL, and in research and development methods, but above all there is a need to include rural people individually and communally in the planning, control, and management of treeplanting schemes. Greater difficulties exist in those parts of the ASAL subject to nomadic pastoralism, yet these are the areas that could benefit most from tree planting; they require an integrated approach to development.

These factors exist in the ASAL of both India and Kenya, but successful examples of overcoming constraints have been developed in India that could act as a model for Kenya. Kenya, in contrast, has a well-defined policy for arid land development that will partition efforts among various national and international agencies. In some countries, increased urban drift reduces rural human and livestock population pressures on the land, At present this is not a significant feature in either India or Kenya, but, in applying the lessons of this study to other countries, it is a factor to be taken into account. What must be considered in all ASAL countries is an integrated approach to rural development in which research into tree and crop species and their efficient use is paralleled by research into the carrying capacity of land, development of improved breeds of domestic animals, stall feeding, and, in some cases, acceptance of public education in the limitation of populations of both domestic animals and people, which may have serious cultural, religious, and political overtones.

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