Determination of the natural durability of larch wood (Larix decidua Mill.) from the Western Italian Alps

Abstract

family, is an importantresource in Piedmont, northwestern Italy, both becauseit provides timber with high technological value andbecause, in that region, pure larch stands, mostly naturalin alpine valleys, cover about 50 000 hectares of forest(Ministero dell’Agricoltura e delle Foreste 1988).The natural durability of European larch wood has beena subject of discussion for many years. The controversyis mainly constituted by technical issues, resulting fromthe lack of experimental protocols which allow a com-parative analysis of the results obtained through varioustesting methods. Even using a single methodology (EN350-1), however, the considerable variability of the dataobtained leads to the hypothesis that the natural dura-bility of the species might depend not only on the gen-otype but also on the provenance of the timber tested,which can introduce several factors known to influencedurability.Such considerations have motivated us to study thenatural durability of local larch populations and to testwood from three sites in order to check any variability inresistance to fungal degradation. They also led us to acomparison of our results with those available in the lit-erature from studies performed abroad on larch woodderiving from other European populations (mainly artifi-cial), which grow in very different conditions from thoseof the alpine areas.