Effect of Natural Drying Methods on Moisture Content and Mass Change of Scots Pine Roundwood

Abstract

This study evaluated changes in mass and the moisture content of stored summer-harvested Scots pine small diameter roundwood subject to different types of preparation and storage (drying methods). Small diameter roundwood was naturally dried for three months, from 15 June to 15 September 2018. We analyzed three methods of preparation and storage. First, logs 1.2 m in length were stored and air-dried in piles (C). In the second case, a transpirational drying method was used (W). Thirdly and finally, we used air-drying for logs with lengths between 9.6 and 14.4 m (L) stored in the harvesting area. Within three months, the moisture content of the logs stored in piles decreased by 22.9 percentage points. With the transpirational drying method (W) the decrease in moisture content was 10.0 percentage points. In scenario L, at the end of the storage period the moisture content was lower by 15 percentage points. Within three months, the density of the roundwood stored in piles decreased to 700 kg/m3, which is about 140 kg/m3 more than in scenarios W and L. Cutting stemwood into short segments and storing it in a pile appears to have positive effects on drying performance. Overall, this study shows that, for Scots pine wood, air-drying is a better method than transpirational drying.