Agroforestry can help prevent land degradation while allowing continuing use of land to produce crops and livestock. A problem with the evaluation of agroforestry using long-run static models and traditional discounting techniques is that the present value of the forestry enterprise is generally much lower than that of other production activities. This problem is common with Australian native species which tend to have a high environmental value but a low market value.

Continuing land degradation and increasing numbers of people living in poverty are among the symptoms of the current pressure on land resources. To date, the world’s response to the two challenges of satisfying human needs and maintaining the integrity of global ecosystems has been less than successful.

The countries of circum-Sahara Africa adversely affected by desertification, their sub-regional organisations, their Northern partners and the concerned international organisations of the United Nations System have created the Sahara and Sahel Observatory (OSS) in May 1992. OSS's mission is conducted within the international framework of the Convention to Combat Desertification (CCD) and Agenda 21 and aims to favour the development and the optimisation of its African partners' information wealth, for an optimal use of the means for combating desertification.

This paper focuses on the environment and water resources in Africa. Africa is at a threshold of changes and faces challenges that will have a fundamental impact on the survival and prosperity of its people. These challenges are already manifesting themselves in many ways; the most significant of winch is the ability of

African states to ensure food security for a growing population on a sustained basis.

This paper outlines a framework for understanding the complexity of land degradation processes, their impacts, and offers insights into their remediation.

This paper outlines a framework for understanding the complexity of land degradation processes, their impacts, and offers insights into their remediation.

The aim of this paper is to illustrate how projects could be designed to address land degradation through the four focal areas; with special reference to incremental costs assessment. Approaches the question from a generic form through to specific examples.