Activities carried out.
WP2 used two types of data: forest monitoring plots and forest patches in western Norway. The surveyed monitoring plots were located in Geitaknottane (a nature reserve in Hordaland County, Western Norway) and in Sigdal (Buskerud County, Eastern Norway). Both sites consisted of 40 plots, 50 x 50 metres. The resurvey in Geitaknottane was carried out in summer 2015 and covered vascular plants, mosses, polypores and lichens. The Sigdal monitoring plots were resurveyed in 2015 and covered vascular plants, polypores and lichens. Old and new data from both monitoring plots were digitized and delivered to WP4. The statistical analyses concentrated on changes in species richness and species composition of plants, lichens and mosses. Further analysis will be conducted, to assess vegetation changes in the light of changing climatic conditions. During the summer of 2015 some field work was carried out to supplement data from 25 broadleaved deciduous forest patches in Hordaland County in western Norway. The database with old and new datahas been delivered to WP4. The statistical analyses covered changes in species composition of vascular plants and focussed on the detection of the importance of different environmental gradients related to climate, atmospheric deposition and management. In the analyses we have focused on the challenges of resampling old data, particularly focusing on sampling intensity and how this influences species richness. A participatory manuscript is in the final stage of preparation (Schei et al. in prep.).
During the past century, changes in forest structure, dynamics and composition have been related to changing climatic conditions. However, most studies of temperate forest communities have not reported a response to recent climatic changes. Most studies which analyze the effect of climate change on temperate forest communities were conducted in areas geographically in the centre of their distribution range and not in their outer limits. Populations that inhabit the latitudinal margins of the distribution range are more likely to be influenced by climate change, as increases in temperature change their potential species pool and may allow new lower-latitude species to survive. We analyzed the effect of climate change on vegetation communities of temperate forest in the outer limit of the climatic distribution, the most northern broadleaved deciduous woods in Europe. These forest patches, woodlands, are only able to persist in this climatic region due to the microclimatic conditions found in steep and south-facing slopes along the Norwegian fjords. We found changes in species composition and shifting frequencies. These changes were not related to climatic variables such as temperature and precipitation, but to changes in light and soil nutrients. The observed changes are likely to be due to the combination of cessation of traditional forest management and an increased storm activity leading to wind disturbance in the woodlands, which had been affected by human activities for a long time.