Sheltered or suppressed? Tree regeneration in unmanaged European forests

Abstract Tree regeneration is a key demographic process influencing long‐term forest dynamics. It driven by climate, disturbances, biotic factors and their interactions. Thus, predictions of tree are challenging due to complex feedbacks along the wide climatic gradients covered most species. The stress gradient hypothesis (SGH) provides framework for assessing such across species ranges, suggesting that competition between trees more frequent under favourable conditions, whereas reduced (i.e. positive interactions) likely stress. Moreover, life‐history strategies (LHS) may shed light on how whether SGH explains different To address these topics, we developed statistical models based >50,000 recruitment events observed 24 in an extensive permanent plot network (6540 plots from 299 unmanaged European temperate, boreal subalpine forests) covering gradient. We found effects Leaf Area Index (as proxy competition) changed but species‐specific manner. Competition predominates, with its intensity decreasing stressful conditions species, as predicted SGH. However, interactions were only evident few Additionally, ability explain patterns differed among some differences exceptions be related varying LHS. Synthesis . Our study shows toward decreases systematically depends tolerance climate shade. These findings within‐ between‐species temperate forests. our imply projections dynamics change must accommodate both interactions, they strongly affect rates community turnover.