Life histories of Abies alba and Picea abies growing in old-growth forests driven by natural gap-phase dynamics

Abstract We analyzed growth trajectories recorded in the tree-ring series of Norway spruce Picea abies (L.) H. Karst. and silver fir Abies alba Mill. co-occuring with European beech Fagus sylvatica L. old-growth forests driven by natural stand dynamics. The study sites were localized five stands Western Carpathians (Central Europe). characterized life histories 218 individual trees using 25 metrics which refer to age trees, number release events, reaction releases, radial increment basal area increment. found a large variation dbh-age relationship. most included two or three (in single cases up seven) events. did not find tree as an important factor determining post-release response. maximal was frequently registered at terminal stage life. spruces firs significantly differ. concluded that gap-phase dynamics, history events is primary driver plays secondary role. After reaching overstory, can continue growing without significant symptoms aging until extrinsic forces cause their death. Our results indicate studied ecosystem persistence less shade-tolerant attributable niche differentiation site partitioning mechanism. An alternative hypothesis based on shifts densities, species composition climatic factors more probable.