 หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Seasonal Changes of Wood Formation and some Characteristics of Heartwood Formation in Teak (Tectona grandis L.) Plantation) ผู้เขียน: Tadashi Nobuchi, Sirirat Janmahasatien, Masaharu Sakai สื่อสิ่งพิมพ์:pdf AbstractSome fundamental investigations of wood and heartwood in plantation grown teak (Tectona grandis L.) were carried out. In order to verify the relationship between wood formation and growing conditions, moisture content of soil and the development of leaves were also studied. It was found that moisture content of soil was higher in the rainy season. Since trees started budding in May which was the beginning of the rainy season, those trees grown at the foot of the hill showed earlier development of leaves. As for the time sequence of wood formation using the pining method, it was revealed that wood formation started after the budding and continued to do so until the end of rainy season. Parenchyma cells of the outer sapwood had great amount of starch grains as reserve substances and this amount abruptly decreased in the middle and inner part of sapwood. Parallel with the decrease of starch grain, lipid droplets increased. However, in the heartwood, both parenchyma cell and wood fibers contained lipid droplets. Elemental analysis of the black substance in the outer heartwood was tried by SEM-EDXA method and it was revealed that no special element was contributed to the black streak of heartwood. |
หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Ralating Environmental Factors to Growth of Some Australian Tree Species at Different Sites in Thailand) ผู้เขียน:Sirirat Janmahasatien, Chingchai Viriyabuncha, Peter Snowdon, Trevor H. Booth สื่อสิ่งพิมพ์:pdf AbstractHeight (Ht), diameter at breast height (DBH) and basal area (BA) growth of Eucalyptus camaldulensis, Acacia mangium and Acacia auriculiformis at three years of age were measured as well as climatic and soil conditions at over 180 plots at seven trial sites in Thailand. The results for Ht, DBH and BA showed highly significant differences among sites, but there were no significant differences among seedlots for all species. E. camaldulensis and A. auriculiformis showed generally high overall growth. E. camaldulensis grew particularly well at Si Sa Ket, whilst Sai Thong was the best site for A. auriculiformis. A. mangium grew poorly at all sites. Analysis of variance (ANOVA) was carried out for each year of planting with the growth of E. camaldulensis showing significant differences between years. Trees planted in 1987 grew more slowly than those planted in 1986 at both Sakaerat and Chanthaburi. Tree growth measurements were related to environmental factors using stepwise linear regression. The results of the statistical analyses showed that much of the variation in growth data could be explained by regression models including soil and climatic factors. The combined influence of all environmental factors in the models were shown by r2 values. E. camaldulensis relationships produced high r2 values of 0.70 or greater and similar r2 values were obtained for most soil depths. A. mangium data produced highly variable r2 values ranging between 0.26 and 0.85. A. auriculiformis data produced generally high r2 values with values ranging between 0.65 and 0.91, with especially good relationships for Ht and DBH. |