Wood chemical composition of forest management residues for bioenergy

We studied the suitability of forest management residues as feedstock for bioenergy production. We focused on the variability of their chemical and physical properties that are most likely to influence the efficiency of thermochemical conversion and the factors underlying this variability, namely wood species, stage of wood decomposition, and the site characteristics of the source location. We used wood from leftover logs and large branches of birch (Betula papyrifera and Betula alleghaniensis) and balsam fir (Abies balsamea), which are abundant in the boreal and mixedwood forests of Quebec (Eastern Canada) and likely to be found as residues on cutblocks. We used factor analysis of mixed data and linear mixed models to explore the relationships among wood species, decomposition class, chemical concentrations and density, and site characteristics such as bioclimatic conditions and soil cation exchange capacity. Model results showed significant impacts of species interacting with bioclimatic domains, notably on net calorific value, wood base cations (calcium, magnesium and potassium) and carbon concentrations. Balsam fir had the highest net calorific value (ranging from 17.0 to 17.4 MJ kg^-1) compared with birch (16.3 to 17.0 MJ kg^-1) in two of the three studied bioclimatic domains. However, balsam fir potassium concentration was doubled compared to birch (593 vs 245 ppm respectively) in one bioclimatic domain, which can be undesirable for thermochemical conversion. The wood decomposition class was effective at predicting significant decreases in wood chemical components (potassium, cellulose and hemicellulose concentrations). Our results suggest that forest management residues from balsam fir and birch could be suitable for biomass procurement, providing insights into their potential for bioenergy production in eastern Canada.

The online version contains supplementary material available at 10.1007/s00226-026-01760-z.