Modeling Forest Stand Dynamics

Forecasts of even-aged stand development obtained from two contemporary growth and yield models. Stands were planted at 400 trees/acre and thinned from above and below at age 40 (refer to the poster for further details).

There is considerable value in the ability to make reliable predictions about how forests will change over time. While existing models work reasonably well for certain forest types and management regimes (e.g. plantation culture of loblolly pine), the same can not be said for natural multiaged stands, and in particular those maintained at low density with frequent fire. We have identified at least two factors contributing to poor model performance; the treatment of density independent mortality and growth potential of large/old trees. Based on these findings we are attempting to calibrate an existing model, and also exploring the possibility of adapting or developing a new framework that will better accommodate unique features of open-canopied upland pine systems.

References

Ray, D. 2008. Stand dynamics of even-aged longleaf pine according to two contemporary growth and yield models: FVS-SN and ForSim LPGS. Joint meeting of the Longleaf Alliance and Forest Guild. Sandestin, FL. October 2008.

Ray, D., M.R. Saunders, R.S. Seymour. 2009. Recent changes to the Northeastern Variant of the Forest Vegetation Simulator (FVS-NE) and some basic strategies for improving model outputs. Northern Journal of Applied Forestry. 26(1): 31-34.

Ray, D., C. Keyser, R. Seymour, J. Brissette. 2008. Predicting the recruitment of established regeneration into the sapling size class following partial cutting in the Acadian Forest Region: Using long-term observations to assess the performance of FVS-NE. In: Havis, Robert N.; Crookston, Nicholas L., comps. 2008. Third Forest Vegetation Simulator Conference; 2007 February 13–15; Fort Collins, CO. Proceedings RMRS-P-54. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station. p. 186-200.