Modelling in Forest Management

Forest management has traditionally been considered management of trees for timber. It really includes vegetation management and land management and people management as multiple objectives. As such, forest management is intimately linked with other topics in this volume, most especially those chapters on ecological modelling and human dimensions. The key to responsible forest management is to understand both how forest ecosystems work and how to use this understanding to satisfy society’s expectations and values. The key to forest modelling is to accurately portray the dynamics of forests. Successful forest-management modelling finds a means to improve management through accurate representation of all parts of the systems. In this chapter I will review both modelling approaches and the types of applications that various modelling techniques have been used to address. The complexity of forest management does not stop with the intricate details of the biological system found in a forest. Because all forest management is by people to meet goals or objectives desired by people, forestry is at its core a social activity. Thus, it demands that we understand the relationships among land owners, professional forest managers, forest-dependent communities, and other stakeholders if we are to model the results of decisions regarding forest management. Individuals and communities have broad interests in the physical, biological, and social goods and services that forest ecosystems provide. To meet the challenges of today we need to know as much about the people as about the physical and biological conditions, and to deepen our understanding of the social goods and services that we expect our forest ecosystems to supply. Models used to assist in forest management consist of several types. First and most prevalent are growth and yield models, which predict the development of stands of trees through time. Initially, these models focused on single species, single age stands, such as one would find in plantations. Little wonder, because in plantations were the highest investments of forest managers who primarily sought timber value from the forest. As modelling sophistication increased, so did the models. Multiple species and multiple age and size classes in an individual stand have been included in growth models with varying success. Further developments along a different track have seen modelling techniques used to help schedule activities, such as harvesting or thinning in forests. Linear programming and other techniques that allow a modeller to specify constraints on resources have allowed models to find solutions to allocation problems, again primarily for those interested in extracting timber value from forests. As various public and private groups have come to recognize the importance of forests for values beyond timber and focused research into those topics, further modelling efforts have begun to characterize these resources. Wildlife habitat, recreation opportunities, and watershed protection are just a few of the benefits that now must be modelled and presented to decision-makers for their evaluation of alternative forest management strategies. These efforts face many challenges due to the inherent complexities of the systems they attempt to model and the lack of good quantitative date for many of the factors involved. In addition, the most complex and fuzziest of the factors is that of the role of humans in the forest. Models capable of predicting human needs and desires, and their implications for the state of forested ecosystems, are a great need that is still largely unmet.