Use of the Pilodyn for Estimating Basic Density and Its Applicability to Density-based Classifying of Cryptomeria japonica Green Logs

Abstract

We used a Pilodyn for estimating basic density in the green condition for the purpose of classifying logs of Cryptomeria japonica D. Don based on their density. The relationships between Pilodyn penetration depth in the radial direction Pr and basic density of blocks with pin penetration were examined in a wide basic density range of hardwoods and softwoods 199 779 kg/m 3 , and C. japonica 221 474 kg/m 3 . There were signifi cant negative correlations in hardwoods r 0.92, P 0.001 , softwoods r 0.86, P 0.001 and C. japonica r 0.82, P 0.001 . Thus, the basic density of the block could be estimated based on the penetration depth. Curvilinear regressions gave the best fi ts in hardwoods, softwoods and C. japonica and the estimated basic densities from the curvilinear regressions for the same Pr were close to each other. In C. japonica, Pr varied between sample groups with similar basic densities, and Pr was smaller in the group with greater earlywood width in spite of similar densities. We examined the applicability of the Pilodyn to estimating average density of C. japonica green logs. There was a signifi cant correlation between Pr and the disk-averaged basic density r 0.84, P 0.001 . The 95% confi dence limits of the disk-averaged basic density estimated from Pr were 47 kg/m 3 when Pr was measured once, in each of two directions. The variations of the disk-averaged basic density within logs were smaller than the confi dence limits except for those at the ground level. It was concluded that the Pilodyn could be used for classifying logs of C. japonica based on their density, although it is necessary to consider that the density variation from pith to bark could be varied by tree age, inherited characters and growth conditions.

Microbiological community structure on logs used for groynes in a riverbank system

“…The average moisture content in the aqueous and underground sections was 171% and 180%, respectively [16]. A comparison between the penetration depth of this study and the values reported in previous studies suggested that the cedar logs collected in this study were almost sound [28,29]. The split surfaces of the log were observed by SEM to investigate the microbial presence and microstructure inside the log (Fig.…”

Genetic relationship between wood properties and growth traits in Larix kaempferi obtained from a diallel mating test

“…Pilodyn penetration is used as an indirect measurement of wood density in many species [19,20,22,23,25,43]. In our research, Pilodyn had a strong genetic correlation with wood density, which resulted in a high efficiency of indirect selection using Pilodyn targeting wood density.…”

“…The direct measurement of wood density is costly, so several indirect estimation methods are utilized, such as the Pilodyn penetration depth, which has a negative correlation with wood density [19][20][21][22]. A genetic correlation of wood density and Pilodyn penetration depth has also been reported for several species [23][24][25], but not yet for L. kaempferi.…”

Efficiency of the indirect selection and the evaluation of the genotype by environment interaction using Pilodyn for the genetic improvement of wood density inCryptomeria japonica

“…The correlation between PP and either heartwood density or disc density was, nevertheless, moderately high. Several studies reported a high correlation between PP and wood density (Cown 1978;Taylor 1981;Hall 1988;Yamashita et al 2007;Fig. 3 Genetic gain in wood density by the direct selection and by the indirect selection using the Pilodyn.…”

“…Hall (1988) reported correlation coefficients between the Pilodyn results and wood density of -0.48 in Picea mariana, -0.62 in Picea glauca and -0.48 in Larix laricina. In Japanese species, Yamashita et al (2007) reported a correlation coefficient of -0.82 between penetration depth and the wood density of wood blocks from Cryptomeria japonica. Based on family means, the correlation coefficients are -0.79 in Cryptomeria japonica and -0.78 in Larix kaempferi (Fukatsu et al 2007).…”