[Spruce provenance in the canton of Vaud [Switzerland]: balance of 30 years of comparative trials]
1997
Fouvy, P. | Jeantet, G. (Service cantonal des forets, de la faune et de la nature, Lausanne (Switzerland))
Thirty years after planting the results of the oldest spruce provenance trial in Switzerland, conducted in the canton of Vaud, is presented. Depending on their origin from one of 74 sites in Vaud, spruce trees were planted at two experimental sites: those from lower altitudes at 480 m, those from higher altitudes in the Jura region, at 980 m above sea level. The results are the fruits of 30 years of tending the trees as well as measuring and evaluating them, all works being carried out by the forest service of the canton of Vaud. The results show that there are substantial genetic differences between spruce tree populations in the canton of Vaud. By selecting sites of origin where spruce trees grow fast, it is possible to increase the volume by up to 150 % without harming the qualtiy of the trunks and wood. The growth capacity of four to five-year old trees is ideal for predicting the capacity of older trees. Up to 64 % of the variation in volume after 30 years of growth is correlated to the height of the young trees. In addition, characteristics which are identifiable at early stages of growth, such as seed weight, age of the forest stands from which the seeds are harvested, time of sprouting, and the percentage of spprouts in August, allow the most suitable, best adapted tree origins for a given location to be chosen. Based on these observations, current practices are analysed and some of the principles presented that should be taken into account when selecting origins
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