*3.1. Potential of Biomass*

The estimates for the current and potential use of forest biomass (timber, residues, and total in dry tonnes) for biofuel are illustrated in Figure 4. It is clear that timber is the major source of forest biomass and the availability of it increases steady in the foreseeable future. Harvest residues account for only a small proportion of the forest biomass and increase slowly over time. The results indicate that the study region has the potential to supply 0.75–1.4 Megatonnes (Mt) dry timber annually, and less than 0.05 Mt of dry residue produced from these harvests. These results are significantly smaller than that of [3], which did not consider the impacts of different harvest types on collecting residues.

**Figure 4.** Long term forest biomass probabilities in Michigan.
