Etat et évolution de la ressource forestière feuillue en Suisse. Résultats du deuxième inventaire forestier national (IFN 2) | State and Development of Hardwood Resources in Swiss Forests – Results of the Second National Forest Inventory (NFI 2)

The results of the second national forest inventory (NFI 2) allow a reliable and comprehensive assessment of the Swiss forests'development for the first time. One of the most obvious changes is the important increase in hardwoos. The most significant facts of NFI for hardwood-resources are presented as the basis for discussions and measures for an increased hardwood utilisation. The whole stock in Swiss forests amounts to 418 Mio m3. About 60% of the hardwood stock of 118 Mio m3 is beech. The share of hardwood has increased by 2% both in surface and growing stock. These developments will remain constant in the future. The increase in stock amounts to 5% in softwood,whereas the one of hardwood amounts to 12%, maple and ash are dominating. The most important increase in standing volume is evident in trees of 36 to 52 cm DBH. With an unchanged utilisation, the share in large timber will further increase. The increase was harvested to 80% in softwood, to 59% in hardwood, less so, however, in the French part than in the rest of Switzerland. But in the distinct cantons, not more than 40 to 80% of the increment of hardwood has been harvested. In hardwood, the non-exploited increment amounts to 1.4 Mio m3per year, of which 58% is beech, almost as the growing stock. For silvicultural reasons, it would be possible to double the volume of exploited hardwood – which would make sense, too,for ecological and socio-economic reasons. However, the calculated harvest expenditure for such an increased utilisation is in most of the cases high above the present average proceeds for hardwood.