Selon les objectifs que l'on se fixe en matire d'amnagement des terres, selon aussi toute une foule de variables lies l'environnement, le feu peut tre un ennemi ou un ami; mais presque toujours, il continuera d'exercer une puissante influence sur les cosystmes naturels et leurs ressources. C'est pourquoi il faut, dans tous les plans d'utilisation des terres et programmes de mise en valeur des forts, tenir dment compte des effets potentiels (tant positifs que ngatifs) de l'lment feu.

Le prsent numro d'Unasylva examine en dtail le rapport entre la foresterie et la scurit alimentaire et se pose la question suivante: Que peut-on faire pour que les programmes et activits de dveloppement forestier contribuent dans la mesure du possible assurer l'accs conomique et physique aux produits alimentaires pour tous et en tout temps? Dans l'article de fond, M.

The current issue of Unasylva takes a long look at the relationship of forestry with food security, and asks the question, ''How can forestry development programmes and activities become as relevant as possible in ensuring economic and physical access to food by all people at all times?" In the lead article, M. Hoskins sets out the actual and potential contributions of forestry to food security, and suggests practical strategies for the incorporation of food security components in forestry development activities.

The oft-cited UN Habitat report on the 1989-1990 urban resettlement programme in Burma which the report estimates affected 1.5 million people (16 percent of the urban population). "...During the early months of 1990 international attention was focused on the Yangon squatter clearance and resettlement programme launched by the Government in 1989. The Mission found that the programme is not limited to Yangon, but has broad national coverage.

The conservation of scarce land resources is essential to the long-term viability of agriculture in Rwanda. High population density, steep slopes, and abundant rainfall prevail in the highland portions of this African country, making the task of erosion control uncommonly difficult for the peasant farmer. The specific use to which land is put, e.g., cultivation, fallow, pasture, woodlots, and, if it is cultivated, the particular combination of crops grown, can be seen as contributing to both the cause and the solution of the land degradation problem.

This article suggests that communual rangeland management policies in Botswana and Zimbabwe are based on incorrect technical assumptions about the stability of semiarid rangelands, the nature of rangeland degradation, and the benefits of destocking. Consequently, inappropriate policies, stressing the need to destock and stabilise the rangelands, are pursued.Acknowledgement of the great instability but intrinsic resilience of rangeland would encourage the Governments to more favourable regard the opportunistic stocking strategies of the agro-pastoralists of the Communual Areas.

This document contains a collection of critical comments by experts working in the field of pastoralism with regard to several PDN papers.

The ionic composition of water in the vadose zone of the Salt River Valley in south central Arizona was studied for three different water regimes: desert, irrigated, and flooded by urban runoff. The desert area exhibited high salinity in the top 10 m, probably due to concentration of salts over several years. Below 15 m, the salinity decreased with depth and approached the salinity of the native ground water. For the irrigated area, the chemical composition of the soil water was similar to that of the applied water but concentrations were higher.

Throughout Africa the importance of land use issues in relation to tsetse control planning has been emphasized consistently in the tsetse literature. Because of inappropriate land use, concerns for the environment in tsetse-freed areas have been expressed frequently. This debate is very relevant to Zimbabwe, where extensive tsetse control operations in recent years have confined the remaining area of tsetse infestation to parts of the Zambezi valley, a semi-arid region of the country with a fragile eco-system and limited agricultural potential.