Tending of seedling stands involves early clearing and thinning of seedlings.
In early clearing, the growth conditions of productive stands are maintained by removing stands and deciduous trees that compete with the tree species being grown. The need for early clearing occurs in eutrophic areas. Early clearing is done in spruce planting areas when the seedlings are 1–2 meters long. In pine seeding areas and areas of natural regeneration, the time of early clearing is when the seedlings are 0.5–1 meters long. Early clearing is necessary in pine regeneration areas only if deciduous trees are abundant.
Seedling thinning is an investment in the future. The aim of this measure is to secure the growth conditions of the remaining stands by regulating the density of seedlings and tree species composition. In the selection of trees to be grown, attention is paid to the tree species suitable for the site and the trees of the best quality. Broadleaved tree stands and dense tree stands increase biodiversity. Preservation of mixed-species stands is emphasized in tending of seedling stands in nutrient-poor habitats where less broadleaved trees are produced than in eutrophic habitats.
In pine forests, seedling thinning is most cost-effective when stands are 3 to 7 meters long. In pine forests regenerated by seeding, it is worth thinning the seedling groups when they are 2–3 meters long. In spruce forests, thinning is done when the seedlings are 2–4 meters long and in birch-dominated forests when the seedlings are 4–7 meters long. After the thinning, the target density varies by tree species and habitat from 1,600 to 2,500 trunks per hectare. Seedling stands can be thinned independently with a brush saw or thinning can also be outsourced.
Improvement of young forests
If tending of seedling stands is delayed or not done at all, the stand will grow poorly and tree crowns will shrink. In a degraded forest, improvement of a young forest is done instead of first thinning. Its aim of the improvement measures is to thicken and strengthen the remaining trees so that they can be sold after the first thinning. Improvement of young forests can be done mechanically, and removable trunks can be used as energy wood. Timely tending of seedling stands is cheaper and, from the viewpoint of stand development, a better option than improvement of young forests.