The IUFRO 1964/68 Provenance Experiment with Norway Spruce (Picea abies) in Norway. Variation in Mortality and Height Growth

1989

7 Abb., 4 Tab., 23 Lit. Ang.

Unselbständiges Werk

2693

200037838

The IUFRO 1964/68 provenance experiment with Norway spruce comprises 1 100 seed sources from most of the present range of Norway spruce. This experiment was planted in 1968 at three different sites in western (Ilsvag/Vats) and south-eastern Norway (Bjerkoy and Overud). The Ilsvag/Vats experiment comprises the complete set of seed sources, while another set is divided between the two experiments at Bjerkoy and Overud. This report presents the mortality and height growth development during the first 13 years after planting. The seed sources (provenances) are pooled into 20 geographical zones based on geographical and historical patterns. These zones are used to describe the large scale patterns of variation in mortality and height growth. The mortality was lower at Ilsvag/Vats than at the two other sites. However, the amount of dead and undeveloped trees, defined as having not reached 1.3 m in 13 years, was remarkably stable and close to 10% at all three sites. Provenances of southern and northern origin had an above average mortality at all three sites. This mortality could be an effect of small seedling size of the northern provenances and great size of the southern provenances at planting. At all three sites a large variation in mortality was observed between provenances within zones. Pooling the number of dead and undeveloped trees, i.e. trees not having reached a height of 1.3 m in 1980, shows that the success of the planting activity is very equal at the three sites. The best success is found at Overud excluding the climatically most extreme block. The mean height growth of provenances varied considerably within zones as did the zonal means. A geographically ordering of the zones from Western Europe through Central Europe into Fennoscandia (Fig. 6) clearly show general trends in height growth performance for each site and some differences between them. The zones of Eastern Central Europe had the highest means at all three sites. At Ilsvag/Vats the Alpine sources performed better than they did in Eastern Norway. The provenances originating in western USSR had a considerably higher growth at Overud compared to Bjerkoy and Ilsvag/Vats. The mean relative growth of the southern Scandinavian provenances was further considerably better in eastern than in western Norway, but the Nordic sources had an inferior growth at all three sites. Comparisons were made of the height increment in two successive periods, before and after 1974. At Ilsvag/Vats, the relative zone means were much the same in the two periods, except that the provenances from Northern Poland, wester USSR and the Nordic countries had a reduced relative growth in the second period (Fig. 7). The opposite was the case at Bjerkoy and Overud. Here the Nordic provenances clearly improved their growth from the first to the second period.