2 A SUMMARY OF EXPERIENCE WITH DIFFERENT FOREST MANAGEMENT SYSTEMS
Sustainable forest management
in moist tropical forests
Moist tropical forests generate a significant number of global externalities. However, of all the forest types in the world, moist tropical forests probably also present the greatest technical challenges to implementing sustainable forest management. Many experiments conducted to examine sustainable forest management have taken place in this region. Most, however, have been marred by non-technical obstacles and events that materialised before conclusive empirical evidence of the technical feasibility of sustainable forest management could emerge. Most of the obstacles that have appeared have mainly been related to a number of economic, institutional and social factors. These have appeared not only due to the technical complexity of tropical forest ecosystems, but also due to a range of other factors, including:
· the length of time required for tropical trees to achieve commercial size;
· the use of inappropriate harvesting systems;
· economic pressures to repeatedly log areas in which regenerated trees have not yet matured;
· encroachment pressures from migratory communities that survive by practising slash and burn agriculture; and
· conflicting land use claims, including settlement schemes and infrastructure developments.
The background papers produced as part of this review have examined a number of different forest management systems that can, if implemented properly, be termed sustainable yield systems. The systems examined include complex shelterwood systems such as the Plenterwald in Central Europe and the Malaysian Uniform System in the tropics, to clearfell and replanting systems employed throughout much of Western Europe and North America.
The systems examined all aimed at the sustainable production of wood, with little or no consideration of the many other objectives often associated with the broader interpretation of sustainable forest management. If only this limited objective is considered, most specialists agree that, in many cases, the forest management systems that have been developed were technically sound, despite the fact that the empirical evidence of sustainable wood production remains incomplete and is mostly limited to evidence of successful regeneration.3
The Asian experience shows that forest management of moist tropical forests for sustainable wood production is technically feasible but that most experiments have not lasted for long enough to eliminate all doubts. In Latin America, various researchers believe that sustainable wood production is technically feasible, at least in some ecosystems. For example, Barros and Uhl (1995) contend that sustainable wood production is feasible in the Brazilian Amazon, especially in the floodplains where the diversity of timber species is lower, the volume per hectare of commercial species is relatively high, growth rates are also high and logging does relatively less damage to the remaining vegetation and to the soil. Southgate (1998) reports that the forest management system used in the Palcazú project in Peru is probably biologically sound on the basis of the evidence of abundant regeneration after harvesting. However, the project itself could not be sustained because of security concerns and the poor economic results, which were due to a relative abundance of alternative wood supplies in the area. In Africa, plans to practice sustainable forest management have similarly shown promise but have been plagued by political, social and economic turmoil. It is interesting to note that, in the latter two regions, success has not been determined by the forestry sector but by events outside the sector. This is a common occurrence in forestry.
The little evidence that there is generally points to the fact that the forests under examination are either evolving as the researchers expected them to, or that any technical failures could easily be corrected with existing knowledge. In fact, the balance of the technical evidence is quite positive and the numerous studies and projects already completed provide a solid base for technically sound forest management for sustainable wood production in most of the world's moist tropical forests.
In dry tropical forests, the context for sustainable forest management is completely different to that in moist tropical forests. Forests are more highly valued for their non-timber services. There are a few examples of the successful implementation of sustainable forest management (e.g. Nepal and India) and it is generally believed that sustainable forest management is technically possible. However, for sustainable forest management to work in this type of forest it is essential that forest managers secure the participation of rural people, by integrating their activities with the rural economy and with other activities that sustain the livelihoods of local people. In addition, as in the case of other experiences in the tropical region, it is generally too early to judge whether or not the few approaches, which currently appear to be successful, will be sustainable in the long run.
Experience in the boreal forest region is limited by the fact that there have been few attempts to advance from purely timber oriented forest management systems to more ecosystem-orientated sustainable forest management systems. The few attempts that have been made are all fairly recent and are surrounded by long-term uncertainties. However, despite these caveats, it is believed that enough technical knowledge is currently available to practice sustainable wood production in the boreal forest, or at the very least, to identify and avoid the most unsustainable practices.
Similar conclusions can be drawn from experience in the temperate forest zone. It is somewhat difficult to generalise from the experience that has been gained in the temperate forest zone because of the many different types of forest ecosystem within this zone. However, it is believed that, in most cases, there is generally enough technical knowledge and experience to manage most of these forests for sustainable wood production and to avoid the most excessive examples of unsustainable practices.
Finally, there is adequate technical knowledge to establish forest plantations that produce a sustainable flow of wood, but there is less certainty about the sustainability of current forest plantation practices in the broader sense (e.g. in terms of water quality and local land rights). There is also insufficient evidence to report on how successful reforestation projects in degraded tropical forests have been or will be in the future.
3 Dupuy et al (1998), Hagner (1998) and Contreras (1999), supporting documents to this study, provide a comprehensive review of the experiences with forest management systems for most common forest ecosystems.
