No abstract

Demand of teak wood increases every year along the increase of human population and prosperity. On the other hand, teak is one of the long rotation tree species. Furthermore, the avaibility of teak from the Perum

No abstract

The selection of species for enrichment planting that involves native species in a secondary lowland dipterocarps forest as one of the tropical rainforest types should be conducted to maintain the sustainable management of tropical rainforests. The research of species trial of dipterocarp species was planted under a randomized complete block design with four replications. The following parameters were examined: survival rate, diameter breast height (DBH), pilodyn penetration (PP), and stress wave velocity (SWV). The survival rate (F ¼ 1.72; p ¼ 0.047), DBH (F ¼ 6.67, p < 0.0001), and pilodyn penetration (F ¼ 14.19; p < 0.001) significantly differed at 12.5 years after planting. The survival rate of Shorea leprosula was the highest (85%) of all the species, and the survival rate of other species, namely, S. macrophylla, S. ovalis, S. johorensis, S. scaberima, and S. parvifolia, was more than 70%. The best growth of DBH parameter was observed in S. platyclados. The DBH growth of S. platyclados 12.5 years after planting were 27.62 cm (mean annual diameter increment [MADI] ¼ 2.2 cm/year). The species whose growth in DBH was similar to those of S. platyclados were S. leprosula, S. parvivolia, and S. ovalis. However, stress wave velocity (SWV) was not significantly different among dipterocarp species (F ¼ 1.26; p ¼ 0.234). Pilodyn penetration (PP) was significantly correlated with DBH (Pearson's correlations ¼ 0.306; p < 0.001), whereas stress wave velocity was not significantly correlated with DBH and PP (p > 0.05), and their Pearson's correlations were 0.043 and À0.012, respectively. These results suggested that each dipterocarp species varied in terms of their growth and wood properties. Thus, choosing the species for enrichment planting in secondary tropical rainforests depends on the characteristics of each species and the desired final product of forest management.

No abstract

Zelkova serrata is an important hardwood species for the timber industry in Japan. Tree breeding programs for this species have mainly focused on growth characteristics such as stem diameter (D), tree height (TH), stem form, and branching. In order to fulfill timber industry needs, wood quality improvement should be included in the tree breeding program of this species. In the present study, growth characteristics, such as D and TH, and the stress-wave velocity (SWV), which is highly correlated with Young's modulus of wood, were measured for 20-year-old Z. serrata from eight half-sib families planted in a progeny test site with three different initial spacings. Significant differences in all the measured characteristics were found among the eight half-sib families. The variance components of the half-sib families for D, TH, and SWV were 27.2%, 47.3%, and 33.5%, respectively. These results indicate that all the measured characteristics of this species could be improved by tree breeding programs. In addition, only low correlation coefficients were obtained between the growth characteristics and SWV, indicating that extensive selection on SWV in tree breeding programs may not always lead to a reduction in yield volume.

No abstract

Zelkova serrata (Thunb.) Makino (''keyaki'' in Japanese) is an important broad-leaved species for the wood industry in Japan. To analyze the among-family variation of anatomical characteristics in Z. serrata, wood fiber length (WFL), vessel element length in earlywood (VEL), fiber wall thickness (FWT), and vessel diameter in earlywood (VD) were investigated for 20-year-old trees from eight half-sib families. Mean values of WFL, VEL, FWT, and VD ranged from 1.31 to 1.51 mm, 0.19 to 0.22 mm, 1.2 to 2.1 lm, and 131 to 188 lm, respectively. Relatively higher F values were obtained by analysis of variance for WFL and VEL, suggesting that these characteristics might be improved though the selection of mother trees under tree breeding programs. In addition, growth characteristics were not significantly correlated with anatomical characteristics, except for FWT.