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The emergence of Norway spruce seedlings on different types of germination sites in uneven-aged Norway spruce dominated stands four years after selection harvesting was studied. The data were collected from 20 stands in southern Finland. In each stand, ground cover was measured from a set of 64 one square metre subplots on a permanent experimental plot of 1600 m2. Correlation analysis, direct comparison of subplots with and without seedlings and mixed-effects models were used to estimate the influence of ground and tree cover on seedling occurrence. Grass cover, dwarf shrub cover, cover of certain moss species and close vicinity of trees decreased the occurrence probability and number of seedlings, while greater stand and local basal area around the subplots increased the seedling number. The cover of vegetation free surfaces, usually considered as good germination sites, was rather low. Variation in seedling emergence between plots was high. We concluded that spruce regeneration was slightly more abundant in stands with greater overall stand density and local density within a stand in postharvest conditions. [ABSTRACT FROM AUTHOR]

The study focused on the success of regeneration on patch cuts in spruce-dominated stands in terms of stocking and tree height. It was based on an experiment in the Kainuu region in northern Finland. The experimental design included 8 stands with 58 clearcut patches of variable size (0.09–0.37 ha), on which either natural regeneration without site preparation or site preparation and planting of Scots pine was applied. A regeneration survey was conducted 13–15 growing seasons after treatments. Patches without site preparation had been restocked quite well from natural seed sources. The average number of trees was about 11,000 ha−1, of which 1700 ha−1 crop trees. With site preparation and planting, the stocking levels were also very high, 25,000 and 2100 ha−1, respectively. One hundred percent of the planted patches and 75% of the naturally regenerated patches had an acceptable density. Restocking was equally good across the range of patch sizes. Tree growth had been somewhat slower in the smallest patches than in the largest ones in the range. Natural regeneration was capable of yielding good regeneration results in most patches, especially when site preparation was applied. Stocking levels and height development were higher yet in the planted patches. [ABSTRACT FROM AUTHOR]

The success of natural regeneration on patch clear-cuts in Norway spruce stands in Southern Finland was examined in terms of stocking and tree height. The experiment was established in mature spruce stands in the submesic Myrtillus (MT) site type. In each of the eight study sites, three plots were treated with clear-cutting and planting, clear-cutting with partial tree retention and planting, and patch clear-cutting without site preparation, respectively. In three of the study sites, one plot with patch clear-cutting and site preparation was established. Each plot was 1 ha, out of which three patches of 40×40 m were clear-cut in the patch treatments. 10–11 years after cutting, the patches had on average 1316 crop trees ha–1, of which 91% were spruces. Some 27% of the stands were up to the target stocking level (≥1600 ha−1), and 36% were at least satisfactory (≥1300 ha−1). Site preparation did not yield greater stocking levels on patches, but that result is ambiguous due to a difference in initial stocking. The average spruce tree height in the patches (0.76 m) was much smaller than in the case of clear-cutting and planting (2.42 m). In conclusion, the patches had been restocked tolerably well with spruce and birch for practical purposes during the 10- to 11-year period, but the regeneration process had been very slow compared to clear-cutting and planting. [ABSTRACT FROM AUTHOR]

This study addresses the dynamics of young stands established in areas of southern Finland which have been site prepared with spot mounding and planted with Norway spruce. The principal attributes investigated were the density of natural birch on the major soil surface types associated with the method (mounds, patches and undisturbed soil) and the growth rate of the planted spruces compared with natural birches. The study material included 18 regeneration areas treated with spot mounding and planted with Norway spruce container seedlings, around three, six or nine growing seasons before measurement. Rather than permanent plots that would have constituted a genuine time series, the data collected for the study originated from a sample of stands of different ages. The results indicated that there were comparatively few birches on the mounds after 3 years, but greater average densities were evident at 6 and 9 years than on the patches and undisturbed soil. Compared with methods such as patch scarification and disc trenching, the observed delay in the emergence of birch probably gives spruce a competitive advantage during the most susceptible, earliest stages of development in spot mounding. [ABSTRACT FROM AUTHOR]