A doctoral student in the Professorship of Forest Ecology at ETH Zurich… together with the European Forest Research Initiative, have taken a look at regeneration in protected European forests for the first time. In a new study recently published in Journal of Ecology, the researchers show how natural regeneration develops without human influence. …They analyzed how regeneration of the forest works under a wide range of environmental conditions. This involved examining the complex interplay between the different features of the tree species, forest density, disturbances and climate. …This study shows that positive interactions between trees only occur in a few species, and are therefore rarer than previously assumed. The features of the species concerned and the varying stress factors determine whether trees protect each other from cold or dry conditions during regeneration or whether they compete with each other instead.