TROPFOMS, a decision support model for sustainabele management of south Cameroon's rainforests

Natural forests play an important role in the economy of Cameroon, at both the national and local levels. Unfortunately, there is still a general sense that in Cameroon, like in most tropical countries, forests are not managed in a sustainable way. The poor forest management practices, which still prevail in Cameroon, result from both an inadequate institutional context and insufficient scientific and technical knowledge. For the last few decades important research efforts have been made in tropical forestry. However, these efforts concentrate mostly on developing silvicultural systems and more and more on predicting growth and yield of forest stands. Research on supporting decision-making for forest has been negligible in tropical forestry. The research presented here confronts the problem of how to assist decision-making in tropical forest management using the best available scientific information gathered in different disciplines. The specific objectives of the research were:To design a system for supporting decision-making with respect to the management of tropical forests.To assess the effects of different management options on the economic returns of the logging enterprise as well as on the structure of the forest at steady state.To provide insights into the trade off between income generation through sustainable timber harvesting and the use of the forest by the local population on the one hand, and between income generation through sustainable timber production and nature conservation on the other hand.To derive recommendations for conversion of the current forest at the Tropenbos Cameroon Programme (TCP) research site into a steady state forest.To suggest and evaluate adaptations of existing strategies aimed at sustainable management of the tropical moist forest in south Cameroon.A methodological tool was developed to support decision making with respect to tropical forest management. The system was given the acronym of TROPFOMS (TROPical Forest Management support System). The management items to which TROPFOMS provides support for decision making include:The target steady state growing stock characteristics, mainly the structure in terms of number of trees per size class to be found both before and after harvest and the species composition of the standThe appropriate cutting cycle for timber harvest,The amount of wood to be harvested at the end of each cutting cycle,The expected length of the conversion period and the expected levels of harvest during that periodThe multiple use of the forest through an analysis of the trade off between alternative land use typesConsequences of changes in management parameters.TROPFOMS consists of four modules including a mathematical programming module, a growth and yield module, and economic module and a constraint definition module. TROPFOMS was developed using mostly quantitative techniques and methods such as transition matrices, cluster analysis, logistic regression analysis, mathematical programming and stumpage prices derivation. The outcomes show that the optimal cutting cycle is about 30 years, for a harvest of 13.4 m 3/ha for the species currently commercialized in south Cameroon. In addition it would require about 120 year to convert the current forest of the Tropenbos Cameroon research site to a regulated forest. TROPFOMS has shown a great deal of sensitivity to hypotheses concerning growth and yield and timber value. Research needs for the improvement of the outcomes of TROPFOMS include: Costs and returns of silvicultural operations, relationships between growth and yield and density of forest stands, reproductive maturity of different tree species, logging efficiency, costs and damage, the utilization of the forest by local population, royalties.