Impact of Storage Method on the Chemical and Physical Properties of Poplar Wood from Short-Rotation Coppice Stored for a Period of 9 Months

Abstract

AbstractIn addition to the use as biofuel, the utilization of poplar wood as a raw material from short-rotation coppice (SRC) became increasingly important in recent years. Because poplar SRCs are harvested during dormant season, wood storage is of particular importance to guarantee wood processing industries a continuous wood supply. The study focuses on the change of physical and chemical properties of poplar wood by the application of different storage strategies over a 9-month period. Therefore, a total amount of 60 m3 test log piles were set up in 2018 for six different storage variants: compact piles, compact piles with water sprinkling and oxygen exclusion, each with logs in bark and debarked. The effects on wood moisture content, equilibrium moisture content and wood density (ρ0) and the changes in the chemical components lignin, cellulose, hemicellulose and extracts were determined and evaluated. As expected, the wood moisture content changed in a wide range over the storage period, depending on the variant. The levels of equilibrium moisture (changes from − 4% to − 13.1%) as well as wood density (changes from − 2.61% to − 9.01%) decreased for all variants between start and end of storage. Changes in chemical composition were observed for all storage variants, which indicates microbial activity supporting the assumption that the observed mass loss is driven by wood decay. Overall, changes were more homogeneous for logs in compact piles compared to the other storage methods. Considering the weather conditions during the investigated period, the results indicate that storage in compact piles with debarked logs is the best method for the conservation of poplar wood from SRC.