Uncertainty in forest simulators and forest planning systems
Mäkinen A. (2010). Uncertainty in forest simulators and forest planning systems. https://doi.org/10.14214/df.97
Abstract
The forest simulator is a computerized model for predicting forest growth and future development as well as effects of forest harvests and treatments. The forest planning system is a decision support tool, usually including a forest simulator and an optimisation model, for finding the optimal forest management actions. The information produced by forest simulators and forest planning systems is used for various analytical purposes and in support of decision making. However, the quality and reliability of this information can often be questioned. Natural variation in forest growth and estimation errors in forest inventory, among other things, cause uncertainty in predictions of forest growth and development. This uncertainty stemming from different sources has various undesirable effects. In many cases outcomes of decisions based on uncertain information are something else than desired. The objective of this thesis was to study various sources of uncertainty and their effects in forest simulators and forest planning systems. The study focused on three notable sources of uncertainty: errors in forest growth predictions, errors in forest inventory data, and stochastic fluctuation of timber assortment prices. Effects of uncertainty were studied using two types of forest growth models, individual tree-level models and stand-level models, and with various error simulation methods. New method for simulating more realistic forest inventory errors was introduced and tested. Also, three notable sources of uncertainty were combined and their joint effects on stand-level net present value estimates were simulated. According to the results, the various sources of uncertainty can have distinct effects in different forest growth simulators. The new forest inventory error simulation method proved to produce more realistic errors. The analysis on the joint effects of various sources of uncertainty provided interesting knowledge about uncertainty in forest simulators.
Keywords
forest planning;
uncertainty;
growth model;
inventory error
Published 5 February 2010
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Available at https://doi.org/10.14214/df.97 | Download PDF
Original articles
Mäkinen, A., Kangas, A., Kalliovirta, J., Rasinmäki, J. & Välimäki, E. 2008. Comparison of treewise and standwise forest simulators by means of quantile regression. Forest Ecology and Management 255: 2709-2717.
Mäkinen, A., Kangas, A., Holopainen, M. & Rasinmäki, J. 2009. Propagating the errors of initial forest variables through stand- and tree-level growth simulators. European Journal of Forest Research. Published Online.
https://doi.org/10.1007/s10342-009-0288-0
Mäkinen, A., Kangas, A. & Mehtätalo, L. Correlations, distributions and trends of forest inventory errors and their effects on forest planning. Manuscript.
Holopainen, M., Mäkinen, A., Rasinmäki, J., Hyytiäinen, K., Bayazidi, S. & Pietilä, I. 2009. Comparison of various sources of uncertainty in stand-level net present value estimates. Manuscript.