%0 Research article
%T Seedling survival and establishment in small canopy openings in drained spruce mires in Northern Finland
%A Hökkä, Hannu
%A Repola, Jaakko
%A Moilanen, Mikko
%A Saarinen, Markku
%D 2011
%J Silva Fennica
%V 45
%N 4
%R doi:10.14214/sf.97
%U https://silvafennica.fi/article/97
%X A large proportion of drained spruce mire stands is currently  approaching regeneration maturity in Finland. Traditional regeneration  methods with effective site preparation and planting generally result in  satisfactory seedling stands also in spruce mires. However, natural  regeneration methods may be more appropriate in protecting watercourses  and minimizing regeneration costs. We studied the survival of advance  growth and establishment of new seedlings in small canopy openings that  were cut at three different diameters in two experimental drained spruce  mire stands in Northern Finland (Tervola and Oulu) in 2004. The number  of seedlings was repeatedly surveyed from five small circular plots (one  10 m<sup>2</sup> and four 5 m<sup>2</sup> plots in size) located within  the opening. Advance growth which survived the cutting and new  seedlings were separated in the surveys. The density of advance growth  was on average 9000 ha<sup>–1</sup> after cutting, and it decreased by  30% during the five-year monitoring period (2006–2010) due to natural  mortality. The number of new seedlings increased rapidly within the  three years after cutting the openings. In 2010, 11 000–26 000 new  seedlings ha<sup>–1</sup> in Tervola and 12 000–16 000 ha<sup>–1</sup> in Oulu on average were observed. The size of the opening had no clear  effect on the regeneration result. The proportion of birch of the new  seedlings increased with time and opening size in Tervola. The results  show that Norway spruce regenerates naturally in small canopy openings  cut in mature drained spruce mire stands.