Intra-annual diameter growth variation of six common European tree species in pure and mixed stands

Studies of intra-annual growth are particularly useful for understanding tree growth because of their high temporal resolution. This study was performed in Austria and included hourly band dendrometer data of 244 annual tree recordings from six tree species ( (L.) Karst., L., Mill., Mill., L., spp. ( (Matt.) Liebl., L.) sampled on five sites with contrasting site conditions in pure and mixed stands and on trees of different social position. Measurements encompassed 1â7 years. Cumulative diameter increment was modelled by logistic mixed-effects models with random effects at the tree and year level. The results showed large differences in seasonal growth patterns between sites, with a clearly shorter growing season at the drier sites. Species specific response on dry sites could be linked to drought characteristics, whereas response on more humid sites was related to light requirements or successional status. The deciduous trees showed earlier growth culmination and shorter growing periods than the evergreen species. Individual tree growth of spp., , and was positively affected by mixture whereas , and showed no or adverse mixture effects. Mixture effects differed between years and social position. Furthermore, increment culmination was earlier in mixed stands, but shifts were minor. Tree growth differed by social position with dominant trees showing the largest increment and the longest growth duration, with shifts in tree growth patterns due to social position being as large as those between different sites.Picea abiesPinus sylvestrisLarix deciduaAbies albaFagus sylvaticaQuercusQuercus petraeaQuercus roburQuercusP. abiesF. sylvaticaL. deciduaP. sylvestrisA. alb