by Si Balch

     In the Jura Mountains of Switzerland is a farm woodlot managed for individual spruce trees of the highest quality. It is a fascinating example of very intensive irregular aged management following a silviculture system called the “check method” developed by Swiss and French foresters in the early 1900s; especially Gurnaud & Biolley.

     Managing quality spruce has applicability for Maine woodlot owners given the reduction in spruce pulpwood markets. Most Maine trees will continue to go to normal lumber markets, but there is a small and hopefully growing market for high-quality clear spruce. Boat builders, paddle and oar makers use clear spruce.

     There are also American musical instrument makers buying some fine spruce logs from the Northeast for resonance wood. Michael Cyr of Noteworthy Wood in Liberty, and John Griffen of Fulton, Missouri are two such craftsmen. How much intensive management will be done by Maine woodlot owners remains to be seen.

    The Swiss woodlot we visited comprises 100 acres of rolling plateau at 3,800 feet elevation. The region has thin soils, averaging one foot, and is said to be the coldest place in Switzerland.

     It is a mixed age Norway spruce (Picea abies) and silver fir (Abies alba) forest. The trees grow steadily with 3/16th inch ring widths. This slow, steady growth of knot-free wood is the key to meeting high quality market specifications.

     The landowner, Monsieur Bernard Lavarini, only discovered that his trees had resonance-grade wood when a visiting researcher examined old beams in his barn. Resonance wood is made into sounding boards for stringed instruments, harps and pianos.

     The wood has fairly low density and high elasticity, resulting in desirable sound transmission speeds. It cannot be identified until after harvest and occurs in a very small percentage of trees. One customer is a local harp maker who sells one or two harps a year for about $30,000.

     Forest management, since 1963, has focused on growing “A” quality trees. The target market is high-quality spruce lumber that has recognized value in the European market. Resonance wood is a happy bonus occurring in less than 10% of the volume. “A” quality trees produce evenly grown clear wood. Pruning is required. The goal over time is 60% Class A timber.

      Management since 1900 has been by partial cutting, and since 1963 has focused on increasing the large tree component (21 to 40 inches) to 45% of the volume, reducing the volume in medium trees (13 to 21 inches) to 41%, and maintaining small trees (7 to 13 inch) at 14% of volume. Total standing volume is approximately 38 cords per acre.

     Biolley’s classification system for stands helps determine whether they are regular (even-aged)or irregular (uneven-aged), and which tree size group they fall into. The goal of Monsieur Lavarini is to be in the IS (irregular softwood) section with as many big trees as possible.

     About 20 trees per acre are pruned. Before pruning, each tree is evaluated for a strong root system, straightness and being the tallest in the immediate area.  First pruning is done when the tree is between seven and 13 inches diameter at breast height. They are then grown to three times the pruned size before harvesting. Trees are pruned to 60 feet in stages, to maintain 33 to 50% live crown; as an aid to pruning, some trees are marked with white paint every 20 feet.

     The pruning is done with an ingenious system  of a movable climbing chair combined with battery powered clippers to remove the branches, with a small saw for finer trimming. Pruning takes 15 minutes per tree for an experienced woods worker. The estimated cost of the chair is $1,800 and the clippers are $2,000.

     The system uses small (five to 10 acre) stands treated on a five-year cycle. Stands are 100% inventoried – they measure every tree – and harvests occur based on the volume that has grown in the last five years. That is why it is called the “check method.” You check the growth, and then do a harvest.

     This forest management method may seem overly structured, expensive, rigid and “organized” to us in Maine, but it has been used by M. Lavorini and his managing forester, Willem Pleines, to grow amazing and valuable trees. These methods show us some practices we could make use of in our own forests.

Posted in: Forest Management
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