Thuja plicata – establishment of four proveniences of western red cedar

Future climate changes may lead to an interest of alternative and foreign forest tree species in order to spread the risks in forestry. Douglas fir, Sitka spruce, Freemont cottonwood and hybrid aspen are examples of popular foreign tree species that along with western red cedar could have a future in the Swedish forests.Södra Skogsägarna and SLU have collaboration in establishment of foreign species in Swedish forests.The purpose of this study was to analyze and present the establishment of western red cedar, and to survey and illustrate injuries of freeze drying and other damages like deer browsing, vegetation and insect attacks. The study included four different provenances, and spruce as a reference, planted in two locations – Asa and Släne.Western red cedar is despite its name a conifer of the cupressaceae family with defined secondary characteristic and gets along well with an overstory. Western red cedar grows often in mixed stands with similar conifers and its natural habitat is within and in the area near to British Columbia.The study included two series of field inventories, one made in the summer and one in the autumn 2013, three growing seasons after plantation. Every second row in the western red cedar plantations were planted with hybrid larch, a cross between Japanese and European larch, to improve a favorable climate for the main trees which are sensitive to freeze, and also to spread the economic risks.The results showed that the reference spruce had a greater establishment than the western red cedar but the results also proves western red cedar to be a possible alternative tree species in these two locations. The study showed good growth even though western red cedar was affected by injuries from freeze and pine weevil.Of the four provenances there was one that had a lower survivorship than the others, Yola Creek, which was more coastal than the other reported provenances.Den här studien har jämfört etableringen av jättetuja med fyra olika provenienser och en referensgran på två olika lokaler samt studerat skador av frosttorka och övriga skador.Södra Skogsägarna och SLU har ett samarbete kring främmande trädslag med syftet att studera etableringsförsök. Jättetuja, Thuja plicata, ofta benämnt som western red cedar, är ett barrträdslag inom familjen cupressaceae och växer ofta i blandbestånd tillsammans med andra liknande barrträdslag.Syftet med studien var att undersöka etableringen för olika provenienser hos trädslaget jättetuja samt studera skador av frosttorka och övriga skador. Studien omfattar fyra provenienser samt ett trädslag som referens, gran, på två lokaler.Inventeringarna skedde i två omgångar, sommar och höst, tre tillväxtsäsonger efter planteringen 2011.Resultatet av den här studien visar att granen hade bäst överlevnadsprocent men att jättetuja är ett godkänt alternativ till gran rent etableringsmässigt på dessa lokaler