Defining the transition from earlywood to latewood in black spruce based on intra-ring wood density profiles from X-ray densitometry
Defining the transition from earlywood to latewood in black spruce based on intra-ring wood density profiles from X-ray densitometry
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DOI：
10.1051/forest:2002035
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发表时间：
2002-07-01
影响因子：
3
通讯作者：
Makni, S
中科院分区：
文献类型：
--
作者：
Koubaa, A;Zhang, SYT;Makni, S
定义年轮从早材到晚材的转变是一项重要的任务，因为测量木材密度和年轮宽度成分的准确性取决于定义。长期以来，莫克的指数一直被用作从早材到晚材的解剖学定义。这一定义是任意的，极难应用于X射线密度测量。对于X射线密度法，根据树种的不同，阈值密度选择在0.40到0.55g cm(-3)之间，以区分早材和晚材密度，但这种方法存在不足。因此，需要开发新的方法，并将其整合到用于生成X射线密度测量数据的计算程序中。在本研究中，我们提出了一种数学方法。对100株人工种植的黑云杉(Picea Mariana(Mill.)B.S.P.)使用高阶多项式的树。密度的预测值和实测值之间的相关性非常高且非常显著。在此模型的基础上，我们将早材向晚材的转变定义为拐点。结果表明，从幼龄材到成熟材，早材-晚材交界处的木材密度不同。这种方法可以很容易地集成到任何X射线密度测量程序中，并允许以一致的方式比较各个环。
Defining the transition from earlywood to latewood in annual rings is an important task since the accuracy of measuring wood density and ring width components depends on the definition. Mork's index has long been used as an anatomical definition of the transition from earlywood to latewood. This definition is arbitrary and extremely difficult to apply to X-ray densitometry. For X-ray densitometry, a threshold density of between 0.40 to 0.55 g cm(-3), depending on species, has been chosen to differentiate between earlywood and latewood density, but this method has shortfall. Therefore, new methods need to be developed and integrated into the computational programs used to generate X-ray densitometry data. In this study, we presented a mathematical method. We modelled the intra-ring wood density profiles in 100 plantation-grown black spruce (Picea mariana (Mill.) B. S. P.) trees using high order polynomials. The correlation between the predicted and the measured densities is very high and highly significant. Based on this model, we define the transition from earlywood to latewood as the inflexion point. Results indicate that wood density at the earlywood-latewood transition point varies from juvenile to mature wood. This method could be easily integrated into any X-ray densitometry program and allows to compare individual rings in a consistent manner.