Arnič Domen, Krajnc Luka, Gričar Jožica, Prislan Peter
Department for Forest Technique and Economics, Slovenian Forestry Institute, Ljubljana, Slovenia.
Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia.
Front Plant Sci. 2022 Apr 8;13:872950. doi: 10.3389/fpls.2022.872950. eCollection 2022.
Environmental conditions affect tree-ring width (TRW), wood structure, and, consequently, wood density, which is one of the main wood quality indicators. Although studies on inter- and intra-annual variability in tree-ring features or density exist, studies demonstrating a clear link between wood structure on a cellular level and its effect on wood density on a macroscopic level are rare. Norway spruce with its simple coniferous structure and European beech, a diffuse-porous angiosperm species were selected to analyze these relationships. Increment cores were collected from both species at four sites in Slovenia. In total, 24 European beech and 17 Norway spruce trees were sampled. In addition, resistance drilling measurements were performed just a few centimeters above the increment core sampling. TRW and quantitative wood anatomy measurements were performed on the collected cores. Resistance drilling density values, tree-ring (TRW, earlywood width-EWW, transition-TWW, and latewood width-LWW) and wood-anatomical features (vessel/tracheid area and diameter, cell density, relative conductive area, and cell wall thickness) were then averaged for the first 7 cm of measurements. We observed significant relationships between tree-ring and wood-anatomical features in both spruce and beech. In spruce, the highest correlation values were found between TRW and LWW. In beech, the highest correlations were observed between TRW and cell density. There were no significant relationships between wood-anatomical features and resistance drilling density in beech. However, in spruce, a significant negative correlation was found between resistance drilling density and tangential tracheid diameter, and a positive correlation between resistance drilling density and both TWW + LWW and LWW. Our findings suggest that resistance drilling measurements can be used to evaluate differences in density within and between species, but they should be improved in resolution to be able to detect changes in wood anatomy.
环境条件会影响树木年轮宽度（TRW）、木材结构，进而影响木材密度，而木材密度是主要的木材质量指标之一。尽管存在关于树木年轮特征或密度的年际和年内变异性的研究，但在细胞水平上的木材结构与其对宏观水平上木材密度的影响之间建立明确联系的研究却很少。选择具有简单针叶结构的挪威云杉和一种散孔被子植物欧洲山毛榉来分析这些关系。在斯洛文尼亚的四个地点从这两个物种中采集了增材芯样。总共对24棵欧洲山毛榉和17棵挪威云杉进行了采样。此外，在增材芯样采样点上方几厘米处进行了阻力钻孔测量。对采集的芯样进行了TRW和定量木材解剖测量。然后对测量的前7厘米的阻力钻孔密度值、树木年轮（TRW、早材宽度 - EWW、过渡 - TWW和晚材宽度 - LWW）以及木材解剖特征（导管/管胞面积和直径、细胞密度、相对传导面积和细胞壁厚度）进行平均。我们观察到云杉和山毛榉的树木年轮与木材解剖特征之间存在显著关系。在云杉中，TRW与LWW之间的相关性值最高。在山毛榉中，TRW与细胞密度之间的相关性最高。山毛榉的木材解剖特征与阻力钻孔密度之间没有显著关系。然而，在云杉中，阻力钻孔密度与切向管胞直径之间存在显著负相关，与TWW + LWW和LWW之间存在正相关。我们的研究结果表明，阻力钻孔测量可用于评估物种内部和物种之间的密度差异，但应提高其分辨率以能够检测木材解剖结构的变化。
