There is a rapidly increasing need to demonstrate that rates of exploitation of tropical moist forest (TMF) are sustainable over time, and do not lead to degradation of the forest, either rapid or gradual. Current conventional methods of yield regulation and determination of an allowable cut, tend to rely on extensive data on rates of growth, mortality, and recruitment at one end of the spectrum; or they may be by almost rule of thumb methods at the other. Cut may also be determined by the requirements of the logging company to make a profit - a dangerous method on its own. This type of extensive data is obtained over time by recurrent measurement, and is often not available, even in situations with a relatively long history of forest management. In many cases where there may be data available the expertise to make use of the information is not present, and it may not be used in an efficient way.

There is very little written work on the regulation of yield in TMF, either in textbooks or in research publications; what there is usually presumes a knowledge of growth.

With the rapid extension of participatory management to communities, the presence of dynamic information becomes even less likely. What always tends to be available, however, is static information, i.e.: data from forest inventory (increasingly participatory by forest communities) and volume studies. The problem is thus to try and develop methods which can use this type of information, supplemented perhaps by other variables, that can be measured at the same time. It should be an approach that can be easily refined as more data becomes available, enabling more confident predictions to be made.

To develop appropriate tools and methodology for yield and sustainable allowable cut determination when only minimal data exists for the forest in question, such as that from a static inventory, and to represent this methodology in a user-friendly and relatively simple manual.

• Yield regulation and relevant aspects of tropical forest dynamics reviewed.
• A single pan-tropical yield regulation system developed.
• A technical guide and handbook to the yield regulation system prepared and distributed.