Trees at the treeline: Stillberg afforestation research

At Stillberg, we study the growth of trees at the forest line and the interaction between the trees, snowpack and avalanches. While the principal focus of the research was, at one time, on avalanche pretection, we are now increasingly conduction experiments relating to climate change.

Our research at Stillberg in Davos began back in the 1950s. The field site was established as part of the first joint research programme between the former EAFV ("Swiss Federal Institute for Forest Research", now the WSL) and the SLF. The principal aim was to find suitable methods for afforestation in avalanche starting zones in the treeline area. In 1975, we systematically planted around 92,000 saplings on the field site. Ever since, the steep site has provided information on the long-term impact of various environmental factors on the Alpine treeline.

A selection of our research activities

  • Long-term monitoring of trees at the treeline (SLF / WSL)
    From 1975 to 1995, we intensively monitored the Swiss stone pine, mountain pine and larch that had been planted. Since 1995, these monitoring activities have continued on a more extensive scale. A comparison with earlier records allows us to examine the effect of location factors and neighbouring interactions over space and time.
  • Alpine treelines in a warm, CO2-rich future (WSL/SLF and other partners)
    We study the reactions of plants and soil at the treeline in relation to future climate scenarios by subjecting trees and ground vegetation to increased CO2 concentration and warmer soil temperatures.
  • Experiment on nutrient limitation (SLF)
    In this fertilisation experiment, we examine whether nutrients limit tree growth at the treeline, whether growth promotion is actually possible with the addition of nutrients in an extreme climate, and whether the trees become more sensitive to stress and disturbance as a result of increased nutrient availability.
  • Climate change in winter – how do plants react? (SLF),
    By manipulating the snowpack, we cause it to melt prematurely. We then study the plants' lifecycle, growth and reproduction. These studies are conducted in both Alpine dwarf shrub heathland at Stillberg, and in the subarctic tundra in Alaska.

Research group

Mountain Ecosystems

Activities of the group “Mountain Ecosystems” focus on mountain ecosystems above and below the treeline.