Tree regeneration before and after restoration treatments in managed boreal Picea abies stands

Questions: What are the short-term effects of restoration treatments, including fire and/or partial cutting with dead wood creation, on seedling density and distribution among microsites, and do they differ between upland and paludified biotopes? Location: Mature managed Picea abies-dominated stands in southern Finland. Methods: The restoration treatments consisted of four levels of cutting, with and without fire: uncut, low-CWD ( partial cutting leaving 50 m(3) ha(-1) of standing retention trees and 5 m(3) ha(-1) of down retention trees, DRT), intermediate-CWD (as previous but with 30 m(3) ha(-1) of DRT), and high-CWD (as previous but with 60 m(3) ha(-1) of DRT). Results: The cutting treatment alone did not affect seedling density. Fire had an immediate effect, both by itself in upland biotopes (decreasing effect on P. abies density) and in combination with cutting in paludified biotopes (increasing effect on Betula spp. density). The density of other deciduous species (Sorbus aucuparia, Populus tremula, and Salix spp.) was not affected. Before treatments, seedlings grew predominantly on level ground and mounds. After treatments, more Betula, but fewer P. abies and other deciduous species, grew on these microsites. More Betula and other deciduous species grew next to CWD and under a fallen crown; more P. abies grew under a fallen crown in unburned stands. Conclusion: The post-treatment tree seedling density and distribution among microsites can be affected by restoration treatments. However, knowledge of local site characteristics and their interaction with different restoration treatments is needed to achieve the goals set for restoration at the stand and landscape levels.