The Color of Wood Related to Its Structure in Silver Fir Trees from Old-Growth Carpathian Forests

In healthy wood, color variations can betray structural changes that substantially affect the quality of the raw material. In the case of silver fir (Abies alba), compression wood is a very common structural anomaly. The material used for this study originates from centenary trees and serves to verify how the color of the wood responds to structural changes caused by the formation of compression wood. The color changes were tracked in the CIELab color space for different types of wood structures, such as normal wood, mild, moderate and severe compression wood. They occur in all directions of the wood, under the influence of compression stress and the cambium age, and they are discussed in relation to fluctuations in chemical composition at the tree level. Results of this study revealed that the color redness and yellowness react promptly to structural changes, and reveal the intensity levels of compression wood (mild, moderate, and severe). It was noticed that lightness is slightly sensitive to the onset of compression wood. Clear trends in wood color change along the trees were observed. The chromatic specificity of compression wood and its relationship with the environment could allow historical reconstruction and monitoring of tree life conditions through wood color.