Changes in the stand structure on permanent Picea abies plots managed with single-tree selection
1993
Lundqvist, L. (Sveriges Lantbruksuniv., Umeaa (Sweden). Inst. foer Skogsskoetsel)
Eleven permanent plots, established in central and northern Sweden during the years 1913-59, were repeatedly treated with single-tree selection for between 30 and 67 years. The plots were all dominated by Norway spruce (Picea abies (L.) Karst.), soil moisture was mesic, and the ground vegetation was dominated by Vaccinium myrtillus L. All trees higher than 1.3 m were numbered and cross-calipered at the time of plot establishement, and at following treatments. In the study trees with DBH less than 8.5 cm were excluded from the calculations. Stand densities generally decreased as a result of harvests and mortality together exceeding increment and ingrowth. The number of trees was generally declining over DBH at the time of plot establishment. Six plots maintained such distributions during the whole observation period. Changes in stand structure were mainly caused by the harvests being concentrated to trees with DBH less than 30 cm, and low levels of ingrowth. The low ingrowth was probably an effect of overcutting of saplings and small trees.
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