2026/07/01 by Christian Ammer, Peter Schall, Dominik Mütze +2
Environmental Science · #Ecology and Vegetation Dynamics Studies #Seedling growth and survival studies #Plant Water Relations and Carbon Dynamics
paper · doi:10.1111/1365-2745.70407
Abstract In even‐aged tree stands, asymmetric competition for light usually leads to clear dominance structures. However, it is unclear whether the differences in individual tree size develop gradually or manifest themselves very early on, that is in the year of germination, and whether formerly suppressed trees can rise in rank while dominant trees fall. Using two experimental plots in which European beech ( Fagus sylvatica ) seeds were sown under the canopy of mature Norway spruce ( Picea abies ) trees in 1997, we studied the survival and height development of 2214 numbered seedlings on 324 subplots (0.5 m 2 in size) over a period of more than 25 years. We found that the survival probability of the tallest individuals at their seed site in the year of germination was significantly higher than that of smaller plants. We further found that these early dominance structures became increasingly consolidated over the years, reducing the mortality risk of the dominant trees. In a supplementary seed experiment, we showed that the height growth and biomass production of seedlings achieved in the first vegetation period depended largely on seed mass. Synthesis . Our study illustrates how intense intraspecific competition processes operate at very early developmental stages among even‐aged tree cohorts, following the general pattern of self‐thinning. We showed that the underlying dominance structures develop surprisingly early and that they persist. Our study also clearly indicates that dominance reversal, that is the fall of formerly dominant trees to lower ranks and the rise of formerly suppressed trees to the dominant layer, occurs infrequently, at least in the first 25 years of an even‐aged cohort.