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Treeline research area Stillberg

Aufforstung Stillberg
Aufforstung Stillberg
Research area Stillberg
Photos: U. Wasem (WSL)

The research area Stillberg at the alpine treeline has been established in the 1950s in a collaboration between the WSL-sites Birmensdorf and Davos (“Gebirgsprogramm”). The original aim of this research program was to find appropriate methods for afforestations in potential avalanche starting zones near treeline. Since the year 1975, the research area Stillberg has been systematically planted with 92’000 trees (Larches, Stone pines, Mountain pines) and provides unique information about long term effect of different environmental factors for treeline trees. The experiences from the Stillberg have helped to afforestate high altitude sites more appropriate. During the last decades the Stillberg research area has also increasingly served as experimental basis for different experiments focusing on questions about climate change effects on treelines.
Outline of some of the recent research activities on Stillberg:

  • Long term monitoring Stillberg (SLF / WSL)
    From 1975 until 1995, an intensive monitoring of the planted trees have been conducted and repeated in 2005. A comparison of different stages of the afforestation allows to study and disentangle the influences of different environmental factors and how they change in space and time.
  • Alpine treelines in a CO2-rich and warmer world (WSL/SLF and other partners)
    The response of plants and soils near treeline on future climate scenarios is simulated by exposing them to higher CO2-concentrations (+200 ppm) and warmer soil temperatures (+4°C).
  • Experiments on nutrition limitations near treeline (SLF)
    In this fertilization experiment, we investigate if nutritions play a role as limiting factors for trees and dwarf shrubs near treeline, if their growth is increased and/or if they are more susceptible to other stressors.
  • Plant responses to winter climate change? (SLF)
    In order to simulate effects of climate change on plants, we manipulated and artificially shortened the duration of the snow cover. We then investigated responses of this treatment on live cycles, growth and reproduction of plants. These experiments have been conducted on Stillberg and in tundra ecosystems in Alaska.
  • Plantation of exotic species (WSL)
    Between 1984 and 1985, exotic treeline species from other mountain ranges have been planted on Stillberg (and 3 other sites in Switzerland). This allows the comparison of their growth and survival with autochthon treeline species.