%0 Research note
%T Biomass production of dense direct-seeded lodgepole pine (Pinus contorta) at short rotation periods
%A Backlund, Ingegerd
%A Bergsten, Urban
%D 2012
%J Silva Fennica
%V 46
%N 4
%R doi:10.14214/sf.914
%U https://silvafennica.fi/article/914
%X Lodgepole pine (Pinus contorta) is a fast-growing species that is  suitable for producing woody biomass in Nordic countries. Direct seeding  of this species is cheaper than planting and creates dense, stable  stands. The objective of this study was to quantify the stem volume and  biomass production of direct seeded lodgepole pine stands grown under  different site conditions with different stem densities, at an age that  would permit extensive harvesting of biomass. A circle-plot inventory  was performed in 16 of the oldest direct seeded lodgepole pine stands in  mid-northern Sweden. Stemwood production of almost 200 m<sup>3</sup>/ha was achieved on average on the best sites, rising to about 300 m<sup>3</sup>/ha  for the best circle-plots within 30 years of direct seeding despite the  fact that pre-commercial thinning was made once or twice. This  corresponds to 100 and 140 tons of dry weight biomass/ha, respectively.  Higher stand stem densities (≥3000 st/ha) yielded more biomass with only  slight reductions in diameter at breast height. The development of stem  volume with respect to dominant height in direct seeded stands was  becoming comparable to that in planted stands with similar spacing. It  therefore seems that there is an unutilized potential for  cost-effectively growing lodgepole pine in dense stands for biomass  production after direct seeding. It may be possible to devise regimes  for short(er) rotation forestry that would yield substantial amount of  inexpensive biomass for biorefineries within a few decades.