Woody biomass may be harvested by any of the harvesting systems currently in use. Whole trees may be chipped on site and the chips delivered to a biomass facility. Chips may be produced on-site, at the same time as harvest for roundwood, following it, or occasionally preceding it. Producers may also gather harvest residue such as limbs, tops, small trees, and otherwise nonmerchantable material, chipped it on site or compress it for delivery to the biomass facility. Biomass may also be produced during thinning operations where merchantable stems to be thinned are harvested for conventional markets and tops and limbs are chipped.
In the case of a dedicated bio-energy plantation, harvest is typically accomplished through a system similar to traditional row-crop harvesting, and systems now under development to intercrop a bio-energy crop with conventional timber may be able to achieve similar efficiencies.
New harvest and handling technologies are be explored. They include using a bundler mounted on a forwarder or trailer to gather logging residue and then process that material into composite residue logs (CRLs) that can be transported on conventional logging truck and tracker rigs. Other methods are to bale logging residue into rolled or square bales. The latest innovation is looking at in-woods chipping followed by in-woods conversion of the biomass to a bio-oil to simply transport to a center for refining the bio-oil.
Some material contributed by NCSU Extension Forestry and used with permission by authors.