Consequences of Future Expansion at the Arctic Treeline in Northernmost Norway

Seedlings from eight seed populations of mountain birch(Betula pubescens var.tortuosa),were transplanted to a site close to the town Vard?,in the Arctic part of the Varanger area in Northernmost Norway,in order to investigate the adaptation to climate change in different birch provenances and the implications for the treeline ecosystem and the local population.A comparable site was established at Kilpisj?rvi(500 masl)in Northern Finland close to treeline.Five replicates with 20 plants per replicate were established per site.The Vard?site was partly snow-free,sheltered by a willow thicket,and partly exposed on a ditched peat bog with thick snow cover from a nearby snowfence.Annual measurements were carried out on survival and growth parameters.The preliminary conclusion from this study is that local climate may be more important than the overall climatic variation in the adaptation and reforestation process in Northernmost Fennoscandia.In this process,the subarctic willow and shrub vegetation seems to be an important factor influencing the microclimate and seedling establishment.Species and provenances originating from areas with similar latitudes and climatic conditions as the reforestation area,were most successful.The Varanger area has always been a meeting place between different cultures,i.e.,the Sami,Norwegian,Finnish and Russian population.The study indicates that in a changed climate the birch forest area would expand because there will be more willow growth and consequently more safe sites for birch seedling establishment and growth,which would also create a better local climate for the human population.In this process local birch populations that are adapted to a more coastal climate,would have an advantage.Since birch has been shown to be an important resource for all these cultures,this would decrease the level of conflicts between the different groups of stakeholders about the resources in the area.