Fulvio Di Fulvio Assistant Researcher Assistant Researcher Department of Forest Biomaterials and Technology Swedish University of Agricultural Sciences Swedish University of Agricultural Sciences Sustainable forest management and biomass supply in Sweden

Million. m 3 standing volume incl. bark Trend for total standing volume since 1920

Annual gross fellings and increment

Stumps Logging residues Forest Fuel supply in Sweden represents 18 TWh/year (logging residues ca. 50%) Today = 11 TWh Potential = ca. 20 TWh Today = 0.5 TWh Potential = ca. 10 TWh (some concerns) Small trees from energy thinning Today = 1.5 TWh Potential = ca. 10 TWh

Branches Stemwood Stump Spruce: 20-35% Pine: 10-25% Spruce: 45-60% Pine: 55-70% Spruce and Pine 20%

Overview of supply chains in final felling

Logging residues 18 EUR/ton DS (forwarding 180m) 18 EUR/ton DS 16 EUR/ton DS (hauling 50 km) Spruce stand Finall felling 80 year old Stemwood =180 ton DS /ha Logging residues (branches and tops) = 50 ton DS /ha

Harvesting “long tops” Increase of forwarded capacity compared to logging residues Forwarder productivity than logging residues Increase of energy volume/ha Partially delimbed tops with the harvester  branchy tops, small trees,  small surfaces for energy-wood removal (<100 m 3 ) Danielsson & J-E Liss

12-15 EUR/ton DS (forwarding 180m) 24 EUR/ton DS (hauling 50 km) 10 EUR/ton DS

Is the soil fertile enough or is there a risk of growth losses (dry soils/peat soils)? ca. 30% of branches should be left on site in Sweden (Swedish Forest Agency). There are more passages of forest machine on site than in roundwood harvesting. On moist soil > it is better to avoid logging residues removal/leave on site a certain amount Harvesting should be on dry or frozen ground on moist soils. It is better for the soil to extract the residues on a frozen ground, but it is more difficult to remove the slashes in the snow. Environmental restrictions

Forest biomass is a bulky material %35-40 %40 %60-70%

Expansion of machines load spaces and load compression stakes and bunks

Slash grapples  avoid contaminations  Increase grapple grip  15–25 % more productive Grapple saw in case of long tops

The storage is matched with the peak demand for fuel that is greater in winter. The logging residues can be stored at the cutting area in heaps or extracted fresh to the landing area. For each percent reduction in moisture content > the energy value increase by two percent. Moisture content can be reduced 20-25% in a good summer. Storage Roadside stacks consider:  Good sun and wind exposure  Not store on a wet ground  Covered stacks >10% lower moisture content than uncovered

Road transportation Truck with side blades for logging residues <50 km distance Truck and trailer for chips Container truck for chips

Chipping at the terminal or industries with large chippers or grinders Comminution Small disc chipper at roadside Chipping at roadside with a forwarder mounted chipper

Market factors and choice of the method/ assortment Modified from Kärhä & Mutikainen 2009

Thanks! Fulvio Di Fulvio Department of Forest Biomaterials and Technology Swedish University of Agricultural Sciences