Tree and stand recovery after heavy diameter-limit cutting in Norway spruce stands

Stand development after heavy diameter-limit cutting in spruce forests in southern Finland was addressed in this study. Tree diameter growth, regeneration and undergrowth, stand structure, and volume yield level were addressed with data from an experimental set of six stands. They were harvested once with a breast-height diameter limit of 21-23 cm and left to recover for 26-29 years until remeasured and studied. Spruce regeneration was abundantly present with an average of 5000 seedlings (height 3-129 cm) ha−1. Additionally, there were some 500 saplings (diameter at breast height 0.1-4.0 cm) ha−1, which included both the regeneration established and developed after the harvest and included seedlings and saplings that were already present before the harvest. Trees in all size classes reacted to partial release with accelerating diameter increment without substantial lag. Trees with a high initial diameter had a consistently higher average growth rate than smaller trees. The stands had recovered quite well and evolved into fully stocked stands with a high number of trees in the lower canopy layers, implicating good prospects for the application of sustainable single tree selection. The average stand volume growth was 4.9 m3 ha−1 year−1, which was close to the level achieved in single tree selection with spruce in the area. Heavy diameter-limit cutting had not resulted in the depletion or destruction of stands.