Rodrigues, José Carlos de CarvalhoPereira, Helena Margarida NunesAlves, Ana Maria Martins2011-06-082011-06-082010http://hdl.handle.net/10400.5/3364Doutoramento em Engenharia Florestal - Instituto Superior de AgronomiaIn this work analytical pyrolysis and near infrared spectroscopy (NIR) were used to assess lignin amount and composition, namely the H/G (phydroxyphenyl/ guaiacyl) ratio, in the wood of three softwood species Pinus pinaster, Picea abies and Larix sp.. A method was developed for the quantification of lignin directly from analytical pyrolysis results (Py-lignin). A good correlation was found between Py-lignin and Klason lignin content (R2=0,93). A commom model (Py-lignin=0,7188×Klason lignin+4,3045) was obtained for the three species studied, allowing the estimation of lignin in samples of 75 μg. Analytical pyrolysis in combination with principal component analysis also allowed the identification of species and provenances within species. Rapid, non-destructive methods were developed for the quantification of lignin (R2=0,97) and determination of lignin composition (R2=0,89) by near infrared spectroscopy, using Klason and analytical pyrolysis as reference methods. These NIR models were used for the characterization of samples from an improvement program for wood quality of Pinus pinaster, and revealed that lignin quantity is under stronger genetic control (0,75), whilst lignin composition is under moderate genetic control (0,24)porsoftwoodsPinus pinasterPicea abiesLarix sp.ligninH/G ratioanalytical pyrolysisnear infrared spectroscopyKlason methoddoctoral thesis