Five major classes of residue biomass harvesting can adopted, each with its own silvicultural implications.
- Harvesting residues can occur either simultaneous to a roundwood harvest (one-pass method) or following logging operations (two-pass method) (Richardson et al., 2002). This type of residue removal can reduce fire risks and certain forest health issues within the stand. The timing of the residue harvest can impact silvicultural practices and costs associated with stand regeneration and subsequent stand development.
- A second class is the harvest of small-diameter trees that would not otherwise be usable to the traditional forest industry and which may be used to modify and improve the management of existing stands.
- The utilization of low-value trees is most applicable to large areas of degraded forest to improve species composition and stand quality.
- A fourth class is the harvest of competing woody shrubs as part of site preparation treatments designed to prepare a stand for regeneration.
- The final class is the harvest of short-rotation woody crops grown for the specific purpose of producing large volumes of biomass within a short period of time. While fiber from these forests is currently only a very minor source of biomass compared to that coming from forest residues, strategies have been developed for managing short-rotation woody crops.
In all of these situations, bioenergy operations can be integrated into a silvicultural system to optimize outcomes.