The goal is to gather most of the logging residue generated.
In 2011, some 8.5 million cubic metres of logging residue was produced in regeneration fellings in Finland. Of it, some 1.5 million was collected for use.
Some 7.7 million cubic metres stumps were produced in regeneration fellings in 2011. Of them, 0.95 million cubic metres were harvested for energy use.
Forest chips are produces of stumps, crowns, branches and stems. In the present situation, the theoretical maximum of forest chip production is considered to be about 25 million cubic meters annually in Finland.
The target for 2020 is 12.5 million million cubic meters annually, but there are great doubts whether this is technically and economically possible. On the other hand, the amounts available will increase in the future as both the volume of timber in forests forests’s growth increase.
Spruce fellings produce logging residues
Most of the logging residue is produced in regeneration fellings of spruce; the volume of logging residue produced is 20–30 percent of the volume of roundwood harvested. In Southern Finland this means 50–80 solid cubic metres of logging residue per hectare. This would generate 125–200 cubic metres of forest chips. Amount of stumps after this kind of felling is about 60 cubic metres per hectare.
The greater part, or about 60 percent, of forest chips are made from logging residue: from the branches and crowns of trees felled. The rest is made from stems, stumps and stubs, stout stems and debranched stems. Estimates are that over 60 percent of the forest chips used originate from regeneration fellings, ten percent from energy wood thinnings and the rest from thinnings.
Energy wood thinnings are carried out in young forests which are too dense and require thinning due to forestry reasons. In forests of this kind, the stem diameter is too small for use as pulp wood, and the thinnings are used for energy.
Gathering forest residue from final fellings of spruce forest is the most profitable. In all other sites it requires state subsidies to be economical.
Updated on the 4th of January, 2016.