Monitoring of wood decay by near infrared spectroscopy

Wood as a natural resource is subject to continuous degradation by means of different environmental agents, where fungal decay is one of the main factors affecting timber structure elements. The goal of this work was to monitor and model effects of fungal growth on the chemical-physical properties of Norway spruce (Picea abies L. Karst.). The spectra of wood samples were obtained with near infrared spectrometer and subjected to chemometric analysis. It was found that the white root fungi (Trametes versicolor) affected spectral bands related to lignin and also hemicelluloses. Brown root fungi (Postia placenta, Coniphora puteana, Gleophyllum trabeum) exhibit spectra deviations mostly in the regions related to carbohydrates. However, it was evident that the degradation efficiency of Coniphora puteana was the highest among all the investigated fungi. It was possible to classify the wood samples to clusters separating the investigated fungi. Accordingly, different effects on the strength loss of the wooden members can be identified. It was shown that near infrared spectroscopy has a great potential for in-field assessment of the fungal degradation of wood.