%0 Research article
%T Combining GIS and forest modelling in estimating regional supply of harvest residues in Norway
%A Rørstad, Per Kristian
%A Trømborg, Erik
%A Bergseng, Even
%A Solberg, Birger
%D 2010
%J Silva Fennica
%V 44
%N 3
%R doi:10.14214/sf.141
%U https://silvafennica.fi/article/141
%X New and ambitious targets for renewable energy production put attention  to increased supply of biomass. Harvest residues are only to a limited  extent demanded by the traditional forest industries and represent an  unutilized resource for increased production of renewable energy in  Norway. The overall objective of this paper is to study how GIS and  forest modelling can be combined to improve estimates of the supply of  harvest residues, taking different environmental and economic  constraints into consideration. The analyses are based on a case study  of a forest area of more than 40 000 ha in Southern Norway divided into  about 500 private forest properties. The study was carried out by  computations of timber harvest using the forestry scenario model SGIS  based on extensive forest inventory data at stand level. In the studied  area energy utilization of harvest residues is not profitable below an  energy price of about EUR 3.2/GJ (NOK 0.10 /kWh) when the distance from  roadside to industry is 20 km. Above this level supply increases rapidly  over a rather narrow price range and is nearly inelastic above EUR  4.1/GJ (NOK 0.12/kWh). We did not find significant negative shifts in  the residues supply caused by changes in location of roundwood harvest  over time. Exclusion of collection from stands with a site index (H<sub>40</sub>)  below 14 reduced the potential supply of residues by 16–27%. The  optimisation method combined selection of exogenous variables in order  to map observed harvesting level and is probably the best approach to  map future harvest.