Increased atmospheric CO2 concentrations may affect competition for resources between reproduction and shoot growth in forest species. Han et al. examine mature beech (Fagus sylvatica) trees in masting and non-masting years with or without long-term CO2 enrichment and find that a reduction in shoot growth associated with masting is not observed under elevated CO2. Competition for resources is therefore reduced and rising atmospheric CO2 concentrations shift the balance of allocation witin the shoots.
