The influence of experimental warming on flowering phenology of Moss Campion, Silene acaulis / Experimentel hiting ávirkar blóming hjá leggstuttari túvublómu (Silene acaulis)

Urtak I niggju ar kannaðu vit, a hvonn hatt experimentel hiting avirkar tey ymisku stigini i blomingini hja leggstuttari tuvublomu, Silene acaulis i Foroyum. Hitin varð experimentelt oktur við smaum sekshyrntum vakstrarhusum, ið eru gjord ur polycarbonate. Tey eru opin i erva og ti navnið „Open top Champers“ (OTC). Kanningarnar vorðu gjordar i fjallaoki i 600 m haedd, har blomustigini hja leggstuttari tuvublomu regluliga vorðu matað i vakstrartiðini fra mai til juli manað i tiggju OTC og tiggju kontrollum. Kanningarnar, ið vit skriva um i hesi grein, eru fra 2001 og hvort ar fra 2007­2010. Vit skrivaðu upp tiðarskeiðið, ta fyrsti blomuknubbin var sjonligur, tiðarskeiðið ta fyrsta bloman var utsprungin, ta fyrsta og seinasta krunublað folnaði. Kanningarnar eru ein partur av altjoða samstarvinum „International Tundra Experiment“ ITEX, ið er eitt samstarv millum fleiri stoð serliga a norðraru halvu, har kanningar verða gjordar. Kanningarnar hava til endamals at granska arinið av veðurlagsbroytingum a plantuvokstur. Urslitini fra hesari kanning visa greiðar munir millum OTC og kontrollarnar. Sum heild komu oll stigini i blomingini umleið eina viku fyrr i OTC enn i kontrollunum. Longdin a ollum blomingartiðarskeiðinum var ikki ymisk i OTC og kontrollunum. Okkara OTC oktu bara hitan umleið 1°C um summarið og broyttu neyvan vetrarhitan. Hetta og ymisk onnur viðurskifti gera, at urslitini ikki siga okkum alla soguna um broytingarnar i foroyskum plantuvokstri, sum fara at koma av globalu upphitingini. A bstract Over a period of nine years we studied the influence of experimental warming on the flowering phenology of Moss Campion , Silene acaulis in the Faroes. The temperature was experimentally elevated with hexagonal greenhouses called open top chambers (OTC´s) made by polycarbonate. The experiment was conducted in an alpine area at 600 m a.s. l. where the flowering stage of Silene acaulis was measured regularly during the growing season from May to July in ten OTC´s and ten control plots. In this paper, we present observations from 2001 and every year from 2007 to 2010. We measured four events in the flowering stage: first visible bud (FB), first flowering date (FO), first petal drop (FPD) and last petal drop (LPD). This experiment is a part of „The International Tundra Experiment“ (ITEX) that is a collaborative, multisite experiment using a common temperature manipulation to examine the influence of climate change on vegetation. The results from our experiment showed statistically significant changes between the OTC´s and the control plots for all four events. Typically, the events occurred about one week earlier in the OTC´s. The length of the flowering period from FB to LPD was not significally different in the OTC´s from the control plots. The warming induced by the OTC´s in our experiment was only about 1oC in the summer and less than that in the winter. This and other confounding effects such as sheltering imply that care should be taken when using our results to predict phenological in the Faroes changes induced by global warming.