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A control system framework for simulating forest landscape management

University of British Columbia

Traditional forest planning models, based on mathematical programming techniques for constrained optimization, have failed to adequately address the new realities of managing forest landscapes so as to sustain in perpetuity a full range of intrinsic values and human benefits. This thesis proposes a general simulation modelling framework for the analysis and management of forest landscapes. The framework, based on state space techniques for modelling of complex dynamic systems, addresses many of the requirements of modern forest planning analysis. Application of the general framework is demonstrated in the development of a specific simulation model for designing spatially explicit harvest schedules that balance biodiversity and timber production objectives. A state space model is developed to predict the dynamics stand level structure over a landscape represented in raster format. This portion of the model is shown to provide realistic predictions of the temporal development of stand structure, and demonstrates the potential of the state space format for representing the physical attributes and complex dynamics of forest landscapes. An heuristic control procedure based on simple multi-criteria decision making techniques is developed to determine the spatial and temporal sequence of management actions according to their combined effect on the objectives for the landscape. To demonstrate and evaluate the feasibility of the proposed approach, the completed model is used to simulate the management of a 3850 hectare landscape over 150 years using a 5 year time step. Scenarios are presented to show achieved levels of serai stage, patch size, and timber outputs under different weightings of the corresponding management objectives. The model was able to maintain the system output within the desired limits when harvest volume was the only specified management objective. The desired harvest levels were achieved primarily through clearcut and heavy thinning activities. In the case of managing for serai stage, patch size, and timber objectives the model was an effective tool for exploring the trade-offs required to find a balance between all seven objectives. Serai stage objectives were fully met, although at the expense of violating the upper bound on harvest levels in several simulation periods. Patch size objectives were met in some periods, and were significantly improved in all other periods compared to the scenario involving only the volume objective. This broad mix of landscape outputs was achieved using a much wider range of harvest treatment intensities than in the single objective case. The case study demonstrates that it is feasible to represent a detailed description of stand level dynamics in a spatially explicit forest level model using readily available desktop computing systems. Such a simulation model is intended to have application as a tool for designing alternative management strategies to provide input to an iterative multi-objective planning process.

Thesis/Dissertation

application/pdf

2009-03-21

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http://hdl.handle.net/2429/6319

Resource Management and Environmental Studies

University of British Columbia

UBCV

DSpace