Seasonal changes of pinosylvin distribution in the sapwood/heartwood boundary of Pinus sylvestris

Changes in pinosylvin concentration and distribution across the sapwood/hea rtwood boundary were studied on Scots pine (Pinus sylvestris L.) tree stems to detect seasonal activity in heartwood formation. Pinosylvin concentrati ons were measured with FT-(NIR) Raman spectroscopy for a total of 96 trees equally distributed on 16 different sampling occasions. In another experime nt, cores were sampled every month from six individual Scots pine trees fro m June to October and analysed for pinosylvin. There was a great between-tr ee variation in concentration and spatial distribution of pinosylvin. No se asonal trend in the distribution pattern or concentration of pinosylvin was found. Therefore, the results indicate that there is no specific period du ring the year when heartwood is formed.