The aim of this paper is to present some lessons from multi-disciplinary, large-scale and long-term field experiments on reforestation conducted in Central Europe. The first experiment is an afforestation of a snow avalanche catchment observed during 20 years, the second consists of several case studies on windthrow areas observed during 10 to 15 years. The afforestation experiment showed a great impact of the relief on the survival and growth of planted coniferous saplings on sub-alpine sites. It promoted the use of the micro-site concept in mountain forests in general. The windthrow experiments showed a great impact of the pre-storm stand history on forest ecosystem dynamics. In both cases, the results were successfully implemented, despite difficulties to extrapolate the results to other sites and longer time periods. When designing manipulative field studies, differences in scale between sub-processes of interest should be carefully taken into account. To improve the potential for generalising results from field experiments, more use should be made of meta-analytic approaches, and of combining extensively studied field experiments with less extensive research on many areas.