Stem biomass model for jack pine (Pinus banksiana Lamb.) in Ontario

Quantifying carbon sources and sinks and their spatial distribution and dynamics through time is a current global research focus. Extraction of forest carbon (wood biomass) via harvesting is part of those dynamics. Inventorying forest carbon at different scales (forest regions, stands, timber products) requires practical models based on rigorous studies. Therefore, a mathematically tractable taper equation-based model (Zakrzewski, 1999) was developed to estimate the amount of biomass or carbon in stems of jack pine (Pinus banksiana Lamb.) in Ontario. A density-integral approach was used to provide a DBH/tree height (H) input-based modeling solution. The model accounts for the declining trend in wood specific gravity (SG) along stem length. Trend in the SG was modeled simultaneously with stem morphology (taper). Results are based on a sample of 41 trees from a 90-year-old naturally regenerated jack pine stand from Ontario’s boreal Northeast Region. The application of the model was exemplified using data from Ontario’s boreal Northwest Region. Biomass and carbon in wood harvested in Northwest over a 10-year period was evaluated using sample of 13,976 harvested jack pine stems and regional harvest records. Zakrzewski (2011) implicit height method was applied in support of obtaining estimates of the amount of carbon harvested from the region of interest. The presented modeling solutions may have applications to other regions and tree species.

► Jack pine stem wood volume and biomass are described using a taper model.
► The taper model was generated using a density-integral approach.
► We demonstrate use of the model to produce regional scale estimates of wood biomass.