Mathey A-H FEMC2007

Decentralized Planning for the Evaluation of Spatial and Inter-temporal Tradeoffs in Forest Management

Anne-Helene Mathey, Forest Resources Management, Faculty of Forestry, 2424 Main Mall, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada, mathey@interchange.ubc.ca

The scope of forest management has broadened to encompass ever more values and services. Designing decision support tools to provide for them involves incorporating a number of spatial and dynamic processes. This paper presents a case for a decentralized planning tool designed to address forest planning objectives that are both spatial and temporal and subject to global constraints. A novel algorithm based on cellular automata (CA) is used to generate solutions. In this decentralized framework, the landscape management goals are achieved through a co-evolutionary decision process between interdependent stands. One rationale for using a decentralized approach is that the fulfillment of spatial objectives is not only related to individual stands’ characteristics, it is also a function of their spatial relationship to other stands. Similarly, the scheduling of interventions in a particular time period impacts how well objectives are met in other time periods. The solution algorithm is supported by an object-oriented framework that efficiently integrates spatial and temporal data. The object orientation permits a fast computation of both local and global limitations on local decision making and speedy modification of the problem definition (local and global requirements or spatial resolution). The CA-based planning approach is used on a large scale planning unit to investigate different policy scenarios. The problems considered involve the maximization of cumulative harvest volume, net present value and amount of clustered old growth subject to stable flow and minimum old growth retention. Tradeoffs between generating financial revenues, generating timber volume and conserving old growth are examined. Finally the impact of different management strategies (e.g. clustering harvest activities or using intensive silvicultural regimes) on these tradeoffs is presented.