Applications of NIR spectroscopy to forest research

Research conducted at CSIRO Forestry ana Forest Products and the Cooperative Research Centre for Hardwood Fibre and Paper Science (CRC-HFPS) has investigated the feasibility of using near-infrared (NIR) spectroscopy as a rapid, inexpensive method for assessing the pulpwood quality of plantation eucalypts. Michell and Schimleck (1) have published a review of this research. Since that review the methodology has been utilised in a number of research applications, which are summarised in this paper. Reliable pulp yield calibrations have been developed using NIR spectroscopy. A pulp yield calibration with a yield range of only 3 percentage points has been developed. It is also demonstrated that NIR spectroscopy can be successfully applied to the selection of 'high yield' trees. Collaborative research with the CRC for Sustainable Production Forestry has investigated the influence of fertiliser application on pulp yield in Eucalyptus globulus. An investigation of genotype by environment interactions in E. globulus has also been conducted. Further collaborative research has investigated the ability of NIR spectroscopy to estimate the cellulose content of increment core samples, with the view of using cellulose content as a secondary standard for pulp yield. Several excellent calibrations for cellulose content have been developed. The influence Of growth rate on pulp yield has also been investigated in trees of E. globulus and E. nitens grown on irrigated and rainfed sites. It was found that growth rate did not have a significant influence on pulp yield. This study provided a textbook example of how NIR spectroscopy can be used to provide information at relatively low cost.