Keski-Alppien alpiinisen kasvillisuuden muutosherkkyys lämpenevässä ilmastossa

The last few decades have been the warmest since the beginning of meteorological measurements, and the mean temperatures are expected to increase at least a further 1.1 K by the end of the 21st century. Temperature is the main influencing factor of the life conditions of the alpine plants and climate warming is estimated to be higher than average in the alpine areas of the mountain ranges. Also the precipitation and snow cover occurrence and timing will change in the future. The aim of this study was to investigate the observed changes of the vegetation of the high areas of the Alps during the recent decades and the responses of the vascular plants to changing growth conditions, as well as researchers' estimates for the fate of the alpine plants in the future, as the climate change continues. This thesis was conducted as a literature review and the research data was phased out from scientific journals using various search criteria. The data consisted of 12 reports which pertained alpine vascular plants and their responses to climate change impacts, and were performed in the Central Eastern Alps or Swiss Central Alps. The method used was qualitative metasummary, where abstracted findings were formatted from the relevant discoveries and conclusions of each study. To assess the relative magnitude of the abstracted findings, as well as the similarities of the results of different reports, frequency effect sizes were calculated. In addition, abstracted findings were used to assess the intensity of each report in relation to the research questions. The most frequent abstracted findings stated that the observed changes of the vegetation have been small (75% of the reports) and the species richness has increased (67% of the reports). For example, the upward migration of the plants, the lower altitudinal index of increased species and species-specific responses of the plants to the climate change were mentioned in every other article. Two reports with the strongest intensity effect size were Pauli et al. (2007) and Cannone & Pignatti (2014), which both contributed the changes of the species richness and plant communities in relation to the climate warming. It was discovered that the future of the alpine vegetation is partly contradictory: alpine areas were found to be susceptible and the climate change threatens them greatly (25 % of the reports), but many potentially variable factors were found to have only minor effects on the alpine plants (25 % of the reports). The current alpine and nival species were estimated to disappear – or at least suffer – due to the invasion of species from lower altitudes (42 % of the reports), and especially the cold-adapted species were predicted to decrease, as a result of the loss of the suitable habitats (33% of the reports). The final fate of the species was found to be dependent on their capacity of persistence and adaptation, and their seed bank (42 % of the reports).