This report covers the work of forest resources mapping undertaken by the Remote Sensing Unit of the Forestry Development Authority of Liberia between March 1982 and June 1984. Its principle aim is to reassess the actual forest cover area of Liberia by interpretation of recent aerial photography and the subsequent transfer of this photo detail to 1 in 125,000 map series. The procedures adopted for this mapping study are detailed.

El principal articulo de este nmero de Unasylva, que es del Profesor Gene Namkoong, se basa en la ponencia que present a los debates sobre recursos genticos en el Noveno Congreso Forestal Mundial, celebrado en Mxico, D.F., en julio de 1985. Considerando problemas de naturaleza tanto tcnica como tica, el Dr. Namkoong esboza varias estrategias alternativas para la ordenacin de los recursos genticos de las plantas leosas y examina su aplicacin a una serie de condiciones socioeconmicas, niveles de tecnologa y objetivos biolgicos.

Le rle de la fort dans la recherche de la scurit alimentaire fait l'objet de l'article principal. Ce rle est vident et multiple: maintien, amlioration ou restauration de la capacit productive des systmes agricoles, apport direct de produits alimentaires vgtaux et animaux, production d'nergie domestique indispensable la cuisine. L'article suivant traite du danger que prsentent les pluies acides. Enfin, il faut considrer que les meilleurs gardiens des ressources forestires devraient tre les populations qui en sont les premires bnficiaires.

The lead article on forestry and food security describes the importance of forestry In the maintenance, improvement or rehabilitation of the productive capacity of agriculture. Following is an article dealing with the threat of acid rain. Finally, it must be kept in mind that the best guardians of forest resources are the people who are the first to benefit from them. Therefore, the efforts of non-governmental organizations should be directed toward helping to increase people's participation in all aspects of forest management. The third article deals with this topic.

Le prsent numro d'Unasylva est principalement consacr l'Afrique. Une bonne partie du continent a t ravage par plusieurs annes successives de scheresse, et des millions d'tres humains souffrent de faim et de malnutrition. Dans de nombreux pays d'Afrique, les cultures empitent rapidement sur les forts et les zones arides cause de la famine.

Durante todo el desarrollo de la presente consultoría, el consultor recibió el apoyo de las autoridades del Ministerio de Aguas, Bosques y Repoblación Forestal, asi como de la Oficina de la FAO en Malabo, sin cuya colaboración no hubiera sido posible finalizar el trabajo. Se recibió también el apoyo por parte de la Representación de las Naciones Unidas. Se agradece especialmente al Viceministro de Aguas, Bosques y Repoblación Forestal, Sr. Angel Alogo Nchama, al igual que al Director General de Pesca, Sr. Pedro Bayeme Ayingono.

This issue of Unasylva focuses on Africa. A large part of the continent has been overrun by drought in successive years, and millions of people are exposed to hunger and malnutrition. In many African countries, cultivation is because of hunger - rapidly expanding into forest land and areas of low rainfall. This process, coupled with necessarily unmanaged exploitation for fuelwood, fodder and other basic goods and services that forests and trees provide, has led to a progressively increasing rate of deforestation.