In this special issue we publish a series of articles which summarise the results of ten years research on four study sites in mountain forests in the Swiss Alps. The study sites were set up after the 1990 blow-down caused by the storm Vivian. Each site was divided into the following three treatments: (1) uncleared with natural regeneration, (2) cleared with natural regeneration, and (3) planted (cleared with natural and planted regeneration). Special projects studied and compared the soils, the dynamics of the ground vegetation, the natural and artificial forest regeneration, the mycorrhiza, the impact of ungulates, the diversity of insects, the spread of bark beetles, the formation of avalanches, the surface erosion, and the timber decay in the different treatments. This paper summarises the common objectives of the projects and the characteristics of the four study sites.