Where residues for woodfuel are to be harvested alongside sawlogs, there are a number of harvesting options.  Optimum choice will depend on terrain, equipment available, tree size and species.

In addition, there are a number of pre-preparation alternatives to help minimise the moisture content  of the wood.  These include:

• Ring barking
• Chemical thinning
• Sour felling
• Use of dead and dying trees.

Once the produce has been felled and extracted from the forest there is the option of whether to process on site to the desired type of woodfuel, or to transport it in its harvested form.

Further information:

Straight small round wood (SRW) can be relatively efficiently stacked for storage and transport.  It is also the best form to allow drying.

SRW should be stacked on bearers (such as two lengths of roundwood) in a sunny place, with the cut ends exposed to the prevailing wind, and away from any drip line.  Some kind of roof or waterproof or semi-permeable cover should be used to prevent re-wetting, but one that leaves the ends exposed.  Scoring or partial removal of the bark will also help drying.

SRW is conveniently transported in that form, preferably after drying and chipped at the usage site.

Further information:

Wood chips can be conveniently transported, but the bulk density is lower than for SRW, and because airflow through a heap of chips is not good drying can be less efficient.  In addition there are potential problems with composting in heaps of chips that can lead to loss of biomass and raised temperatures that can cause spontaneous ignition.

It is therefore advised that heaps of chips not be constructed greater than 10 m high to prevent excessive heat build up.  If managed carefully, however, the heat from composting can help to drive moisture out from a pile of chips. 

Storage of wood chips with a high moisture content can also lead to formation of moulds which can lead to health problems as a result of spores, and it is recommended that a P3 filter dust mask be used when working with stores or deliveries of chips.

Further information:

Branches and brash are the lowest density form, however they will give good drying rates.

Once dried to a suitable level they can be chipped. However there will be a high proportion of bark and leaves which are high in mineral (ash) content.

Equipment to bundle up brash into 'residue logs' has been developed in Sweden to assist the harvesting and handling of this low density material. However it is specialized equipment and is not widely available in the UK.

Further information: