Forest Investment Account (FIA) - Forest Science Program
FIA Project Y081264

    Modelling the development of Coastal BC stands: an individual tree model linked to a variable retention microclimate model
Project lead: Smith, Nick (Island Timberlands Limited Partnership)
Author: Smith, Nick J.
Subject: Forest Investment Account (FIA), British Columbia
Series: Forest Investment Account (FIA) - Forest Science Program
The proposed model is designed to meet the following requirements for Coastal BC: •take an existing inventory and grow each tree forward.•take a given stand condition (for instance 900 fir, site index 30, age 30 years) and grow it forward.•take a regeneration description (i.e. plant 1000 fir, natural regeneration of 300 hemlock, 10% group retention) and grow it forward.•incorporate a mechanism for modelling the impacts of variable retention on the above•output should be for any specified year (i.e. not just 5 year periods).The proposed data set includes: •PSP database (~2500 PSPs): includes mainly trees greater than breast height, 1.3m.•Regeneration data: collected from seedlings at planting to breast height in clearcut retention stands (~100 stands). •A variable retention growth database of 10 experimental sites and 19 gradient analysis sites (Beese et al. 2005) that contributes regeneration data up to 8 years after planting, as well as the MASS site (Mitchell and Beese 2005) where data will be 15 years post harvest in 2007. Data collection is funded separately.
See also: •Taper data: over 200 destructively sectioned trees, continued collection as an in-kind contribution. •Leaf area index and branch data base and estimating equations for Douglas-fir previously developed. While most of these data themselves are proprietary we will make the information available for the purposes of this project. Everything resulting from the Forest Science Program project will be in the public domain. Existing models: no ITDI yield validated model exists for the BC Coast, existing models have weak regeneration components with rudimentary linkage to variable retention (i.e. they are largely data free). The following model components will be developed:1.Height growth;2.diameter growth;3.mortality;4.modifier effects of fertilizer and thinning, on 1,2 and 3;5.regeneration model: clearcut data and variable retention data;6.taper equation;7.modifier effects of variable retention on 1,2,3 and 5. Novel component of the model: We do not expect to merely copy existing model structures but want to develop new solutions that make original contributions to Forest Science in BC. For instance we propose to use difference equations as in FVS (Stage 1973) and ORGANON (Hann et al 2003) but the model form will allow for annual growth steps (FVS/ORGANON are limited to 5 year steps). We currently have a leaf area index estimating model for Douglas-fir. We would like to extend this to western hemlock as a mostly in-kind contribution. We propose to use a mortality model that is based on stand and trees variables rather than just tree variables. Finally we will incorporate the ITDI model into an existing variable retention model called FORGE (Forest Growth Engine). See the following link for a description of FORGE: (contains: Smith, N.J. Variable retention, microclimate, experimental and modelling projects in TFL 39: Improvements to the Forge model). See Smith et. al 1991 for some of the internal details of the model. FORGE uses a user defined grid that gets populated with trees growing in a similar ‘environment’. Adjacent cells interact and affect the light and moisture environment of surrounding cells (Smith and Raynor, 2005). Forest management issues addressed: a calibrated and validated ITDI model that can be used on the BC Coast; an inventory projection system; a regeneration component that enables the model to begin at bare ground; and incorporation into a spatially explicit model framework (FORGE) that allows explicit treatment of variable retention (complex stands). Finally the model provides an important synthesis for numerous separate but linked data collection endeavors that will provide important information on various growth issues such as regeneration (planed and natural) and growth impacts of variable retention. The model will assist in management issues concerning levels of silvicultural investment, harvesting plans and short term tree and log profiles. The project will enhance the cooperation of industrial operational need and academic expertise.
Literature cited: Beese, W.J., B.G. Dunsworth, and N.J. Smith. 2005. Variable retention adaptive management experiments: testing new approaches for managing British Columbia’s coastal forests. In: IUFRO: Balancing Ecosystem Values: innovative experiments for sustainable forestry, Portland, Oregon, August 2004. Hann, D.W., D.D. Marshall and M.L. Hanus. 2003. Equations for predicting height-to-crown-base, 5-year diameter growth rate, 5-year height growth rate, 5-year mortality rate and maximum size density trajectory for Douglas-fir and western hemlock in the Coastal region of the Pacific Northwest. Research Contribution 40. Forest Research Lab, Oregon State Univ., Corvallis. Mitchell, A.K. and W.J. Beese. 2005. Montane Alternative Silvicultural Systems (MASS) designing experiments for the future. Abstract In: IUFRO: Balancing Ecosystem Values Conference, Portland, Oregon, USA. Aug 16-20 2004. pg. 98. Smith, N.J. and K. Raynor. 2005. FORGE users manual. Available on request. Smith, N.J., L. Kremsater, J.M. Chen, F. Bunnell, T. A. Black, X. Lee and B. Sagar. 1991. Managed stands for deer winter range. Model Documentation. Weyerhaeuser BC Coastal Group. Stage, A.R. 1973. Prognosis model for stand development. USDA Forest Service. Res. Paper INT-137.
Related projects:  FSP_Y092264FSP_Y103264
Contact: Smith, Nick, (250) 758-9931,


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Updated August 16, 2010 

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