Tuyển tập các báo cáo nghiên cứu về lâm nghiệp được đăng trên tạp chí lâm nghiệp quốc tế, đề tài: "Variation in the composition and content of ellagitannins in the heartwood of European oaks (Quercus robur and Q petraea). A comparison of two French forests and variation with heartwood age. | Ann Sci For 1996 53 1005-1018 Elsevier INRA 1005 Original article Variation in the composition and content of ellagitannins in the heartwood of European oaks Quercus robur and Q petraea . A comparison of two French forests and variation with heartwood age JR Mosedale1 B Charrier2 N Crouch3 G Janin4 PS Savill1 1 Department of Plant Sciences Oxford Forestry Institute University of Oxford South Parks Road Oxford OX1 3RB UK 2 École supérieure du bois CP 3029 rue Christian-Pauc 44087 Nantes cedex 03 France 3 Dyson Perrins Laboratory University of Oxford South Parks Road Oxford OX1 3QY UK 4 Station de recherches sur la qualité des bois Inra 54280 Champenoux France Received 3 March 1995 accepted 28 July 1995 Summary - The ellagitannin concentration was measured in water extracts of different heartwood sections of Pressler cores from three Russian and one English Quercus roburtree. As the heartwood age increased the concentration of total soluble ellagitannins showed a logarithmic decline while individual ellagitannins varied in their response. A simple model relating the total soluble ellagitannins and heartwood age was calculated. In a second study two heartwood samples were taken from each of 20 oak trees O roburand Q petraea from each of two contrasting Limousin and Tronẹais French forests. Over 70 of the total variation in the concentration of water soluble ellagitannins and total phenolics extracted from the samples was attributed to differences between forests while relatively little variation occurred between the two within-tree samples. Lower concentrations were found in more slowly grown timber from the Tronẹais forest than in wood from the Limousin region. The different tannin concentrations could not be explained solely by the greater heartwood age of Tronẹais samples if one assumed that the rate of ellagitannin decline with heartwood age was similar in all trees. A correlation between wood colour as defined by CIELab colour parameter hue colour saturation and
