How valuable is Wood?
We all know that certain woods, like Brazilian rosewood (Dalbergia nigra) for example, because they have beautiful grain pattern and come from trees that are in very short supply, often growing in locations that are difficult to access, have very high market value. Yet very common woods harvested from the right trees and handled in special ways can sometimes yield even higher prices. Some of the most valuable wood in the world today is found in the violins built by Stradivari and his contemporaries in Cremona, Italy from about 1664 to 1737. Today these violins sell for more than a million US dollars each. Until recently all the credit for the unique tone of those violins had been lavished on the violin builders. Certainly they were very skilled luthiers and knew how to carve the spruce tops to maximize sound transmission, but we now know that some of the credit for the special tonal properties of these musical instruments is attributable to how the spruce trees grew and how the logs were subsequently handled.
Recent research by Burkle and Grissimo-Mayer (2003) has revealed that spruce trees growing in the Italian Alps that provided the wood for the Cremona luthiers, grew during a particularly cold period in Europe known as the Maunder Minimum. Because the growing season was shorter and cooler the trees grew more slowly than normal, producing narrower rings and thereby increasing the volume of latewood, where sound is transmitted the fastest. High speed of sound transmission or ‘response’ allows a violin to capture and radiate all of the notes produced by the strings.
Of equal importance was how the spruce logs were handled before milling. During this period the spruce forests were under the absolute control of the Republic of Venetia. Spruce logs cut in the Italian Alps were transported by streams and rivers to Venice where they could be inventoried. Often these logs remained ponded in the Venetian lagoon for up to five years, during which time these green logs absorbed sea salts by diffusion. Based on laboratory tests (Erickson and Rees, 1940), we know that conifer wood impregnated with chloride salts, such as NaCl or MgCl, have compression strength improved by 25% or more. This added compression strength prevented the arched violin top from undergoing creep under the constant pressure of the strings, and, in addition, allowed the luthiers to experiment with thinner tops to improve sound transmission.
As managers, we cannot control future weather patterns or even wait for five years while logs steep in a brine solution, but we can manage planted forests to match the quality of the wood with anticipated market demands.