Current issue: 53(4)
Under compilation: 54(1)
Systematic resin collection has not been practiced in Finland or other Nordic areas. One reason is the short growing season. Also, the local pine species, Scots pine (Pinus sylvestris L.) gives smaller resin yield than the southern species, such as Pinus maritima. In Nordic boreal forests resin has been collected only in the Soviet Union, where it has been practised also in Eastern Karelia, near the Finnish border. Resin collection experiments were arranged in former resin collection stands in Karelia in 1943. A so-called German method for running resin had been used in the stands. 30-40 sample trees were chosen in five sample sites.
Forest type did not have big influence in the resin yield. The yield seemed to be slightly higher in Scots pine stands growing in fertile sites compared to poorer sites. The diameter of the tree had largest effect on the yield. It is recommended to focus on stands with large trees, and trees with a large, vital crown. In this kind of stands it is possible to get best yield in relation to the work required. The height of the patch that was cut in the stem had no influence on the yield. The size of the patch should, however, not exceed 35-50% of the diameter of the tree.
The PDF includes a summary in German.
The material consists of four Scots pine (Pinus sylvestris L.) stems from which 757 samples were taken from various heights and distances from the pith. According to the results, the number of rays and their sizes are greater at the stump level than higher up in the stem. The size increases, and the number decreases on moving from the pith outwards. However, there are differences between stems as regards the variation model. The ratio between the number of fusiform rays and that of uniseriate rays seems to be lower than anticipated earlier, about 1:40–1:50. The average proportion of ray volume varied from 5.6% to 7.3%.
The PDF includes a summary in English.