Kreyling, J; Henry, HAL: Vanishing winters in Germany: soil frost dynamics and snow cover trends, and ecological implications, Climate Research, 46, 269–276 (2011)
Key words: EVENT 4
Current climate models are very capable of projecting trends in mean winter temperature. However, other ecologically relevant parameters, such as snow cover and soil frost dynamics are less well investigated. Changes in these parameters are expected to have strong ecological implications, especially in the temperate zone, where the question arises if snow and soil frost will occur at all with any regularity at some point in the future. We explored trends in days with snow on the ground (snowdays), minimum soil temperature (MST), and number of soil freeze thaw cycles (FTC, i.e. changes in sign from negative to positive at any pair of consecutive soil temperature records at -5 cm) at 177 German weather stations. Future trends were explored by statistical modelling based on climatic and topographic predictors. Snowdays decreased uniformly at a rate of 0.5 days per year. This trend is projected to continue to a point where significant parts of Germany will no longer exhibit snow cover regularly in the future. MST has already been increased and is projected to do so in the future, mainly in southern Germany. FTC have been decreasing uniformly in the recent past. No evidence for increased FTC or decreased MST with decreasing insulation due to missing snow cover was found. FTC are projected to decrease over-proportionally in the north-east where frequencies in the past were higher. Ecological implications of the strong decrease in occurrence and magnitude of the studied climate parameters include changes in nutrient cycling, productivity and survival. Ecological research is clearly needed, as the effects of diminished winters on ecosystems are not well understood.

last modified 2011-11-09