Autumn phenology of plant communities in the Swedish mountains.

Although the autumn phenology of plants is important for a wide range of processes including primary production, carbon sequestration and food availability for herbivores, few studies have addressed spatial variation of autumn phenology and how it changes with climate change. The greatest increase of temperature is predicted near the pole and therefor it is important to estimate how this change will affect Arctic ecosystems. The phenology of vegetation is a valuable indicator of climate change and knowledge about phenology will give indications how the Arctic terrestrial ecosystems will react on climate changes. So far, the spring phenology is well-known compared to the autumn phenology. The aim of this study was to examine how autumn phenology varies among and within locations in forest-tundra ecotone in Northwestern Sweden. The phenology of the plant communities was measured spectrally with the Normalized Difference Vegetation Index [NDVI]. This allow me to directly compare the results of this study with the results from large scale studies using satellite-derived indices. I found that the timing of the autumn senescence varies among locations, topographic positions and vegetation types. These results are important because they contribute to a more nuanced understanding of the processes regulating primary production and food availability for herbivores in the Scandinavian mountains, and provide important information for forecasting the responses of these ecosystems to future climate changes.