Schwarze Francis W M R, Spycher Melanie, Fink Siegfried
Section of Wood Protection and Biotechnology, Wood Laboratory, Swiss Federal Laboratories for Materials Testing and Research (EMPA), Lerchenfeldstrasse 5, 9014 St Gallen, Switzerland.
Albert-Ludwigs-Universität Freiburg, Professur für Forstbotanik, Bertoldstrasse 17, 79085 Freiburg i. Br., Germany.
New Phytol. 2008;179(4):1095-1104. doi: 10.1111/j.1469-8137.2008.02524.x. Epub 2008 Jul 9.
Violins produced by Antonio Stradivari during the late 17th and early 18th centuries are reputed to have superior tonal qualities. Dendrochronological studies show that Stradivari used Norway spruce that had grown mostly during the Maunder Minimum, a period of reduced solar activity when relatively low temperatures caused trees to lay down wood with narrow annual rings, resulting in a high modulus of elasticity and low density. The main objective was to determine whether wood can be processed using selected decay fungi so that it becomes acoustically similar to the wood of trees that have grown in a cold climate (i.e. reduced density and unchanged modulus of elasticity). This was investigated by incubating resonance wood specimens of Norway spruce (Picea abies) and sycamore (Acer pseudoplatanus) with fungal species that can reduce wood density, but lack the ability to degrade the compound middle lamellae, at least in the earlier stages of decay. Microscopic assessment of the incubated specimens and measurement of five physical properties (density, modulus of elasticity, speed of sound, radiation ratio, and the damping factor) using resonance frequency revealed that in the wood of both species there was a reduction in density, accompanied by relatively little change in the speed of sound. Thus, radiation ratio was increased from 'poor' to 'good', on a par with 'superior' resonance wood grown in a cold climate.
安东尼奥·斯特拉迪瓦里在17世纪末和18世纪初制作的小提琴被誉为具有卓越的音质。树木年代学研究表明，斯特拉迪瓦里使用的挪威云杉大多生长在蒙德极小期，这是一个太阳活动减少的时期，相对较低的温度导致树木形成的木材年轮狭窄，从而具有高弹性模量和低密度。主要目的是确定木材是否可以通过特定的腐朽真菌进行处理，使其在声学上与生长在寒冷气候中的树木的木材相似（即密度降低且弹性模量不变）。通过将挪威云杉（欧洲云杉）和悬铃木（假挪威槭）的共振木材标本与能够降低木材密度但至少在腐朽早期阶段缺乏降解复合中层能力的真菌物种一起培养来进行研究。对培养后的标本进行显微镜评估，并使用共振频率测量五个物理特性（密度、弹性模量、声速、辐射率和阻尼因子），结果表明，两种木材的密度都有所降低，而声速变化相对较小。因此，辐射率从“差”提高到“好”，与生长在寒冷气候中的“优质”共振木材相当。
