Modelling the sustainability of forest production and yield for a changing and uncertain future

Abstract

The expected growth of human population to about 11 billion sometime within the next rotation of most northern temperate forest crops will put greatly increased and varied demands on today's forested lands. Development of the resources on those lands that remain dedicated to timber production must be demonstrably sustainable if forest management is to help arrest rather that aggravate the continuing deterioration of the global environment, and if managed forests are to be a carbon sink rather than a carbon source with respect to the global "greenhouse effect'. It is time for foresters around the world to confront this issue and to develop and use more ecologically-sensitive, ecosystem-level stand growth and yield models. Knowledge-based, process-simulation stand growth models have many theoretical advantages, and are the only way of predicting future forest growth and carbon budgets on a particular site in the absence of accurate data on the past growth of forests on that site. However, such models have generally had significant practical limitations as an alternative to traditional forest yield models. An alternative approach which combines both the experience-based and the knowledge-based approaches offers a more practical alternative. The combination of "historical bioassay' and process-based modelling approaches into "hybrid simulation' stand models can provide a means by which to rank the most probable outcomes and the sustainability of alternative stand-level management strategies under a variety of possible future growing conditions. -from Author