The effect of climate on vegetation cover in Swedish mountain regions

Abstract: Climate change, with a higher temperature, is making the snow covered period shorter in the Swedish mountain region. This represents a threat towards plant species at high altitudes which, due to their sensitivity to temperature changes, will likely lead to a change in plant species composition. The purpose of this study was to determine if there has been any change in vegetation cover in the Swedish mountain region and if temperature has changed, based on data from a long-term monitoring program called National Inventory of Landscapes in Sweden (NILS), and data collected from the Swedish Meteorological and Hydrological Institute (SMHI). The NILS program has conducted three different inventories from 2003 – 2018 in which Sweden is divided into 10 stratums. Further, NILS divided Sweden into 631 survey quadrates (5x5 km), which of 145 were distributed across the Swedish mountain region. Linear regression analysis was used to determine if there had been any change in the average vegetation cover, or in the cover of lichens, mosses and herbs, and to assess if there had been any change in temperature during the sample years 2003 – 2018. The results showed that the vegetation cover in both the sample blocks of 20 m radius and smaller sample areas 0.252 m had no significant change. Neither did the cover of herbs or the average temperature. The period of 2003 – 2018 might have been too short of a period to see any kind of difference in the temperature and the herbs might have a difficult time surviving due to a long drought period and hence they have not been able to increase their average cover. Results of lichens and mosses showed a significant increase in cover which could be because they can withstand drought better than herbs and therefore have a better chance of surviving the rise in temperature. In conclusion I observed no change in the cover of vegetation but there is an increasing cover of lichens and mosses in the Swedish mountain regions.