%0 Research article
%T Seedling establishment and growth after direct seeding with Pinus sylvestris: effects of seed type, seed origin, and seeding year
%A Wennström, Ulfstand
%A Bergsten, Urban
%A Nilsson, Jan-Erik
%D 2007
%J Silva Fennica
%V 41
%N 2
%R doi:10.14214/sf.298
%U https://silvafennica.fi/article/298
%X The early effects of seed type, seed origin, and seeding year on  seedling emergence, survival, and growth after one to four years was  quantified and examined. Two experimental series of Scots pine located  at 61°N and 64°N and six orchard seed lots and six stand seed lots of  adequate geographical origins in each series were used. Both series were  replicated at five sites for up to five years. On average, orchard seed  lots had 16% and 12% higher seedling emergence, in relation to sown  germinable seeds, than stand seed lots in the northern and southern  series. The survival from year 1 to year 4 was also higher for orchard  seedlings than for stand seedlings; there was a 77% and 72% survival  rate in the northern series and a 58% and 49% survival rate in the  southern series for orchard and stand seedlings respectively. On  average, after four years orchard seedlings were 26% taller in the  northern series and 13% taller in the southern series. The gain in  height growth for the orchard seeds was positive at all seeding years,  at all sites, and at all seedling ages. If survival was calculated to  the height of a four-year-old seedling, the survival of orchard  seedlings increased by 3% in the northern and 1% in the southern series  as the result of the higher growth of orchard seedlings. Using orchard  seeds resulted in 6 percent units higher growth gain when the clear cuts  were regenerated with direct seeding than with plants using the same  seed material. Changes in the ranking of seed lots and seed types at  different sites and seeding years for seedling emergence is an effect of  external factors such as grazing and foraging that cannot be related  directly to the tested factors.