Relationships between tree size and density are important to defi ne the growing space utilization in a stand. Although a universal slope for the maximum size-density relationships (MSDRs) has been previously suggested, recent research have highlighted that these relationships are species-specifi c. Oriental beech (Fagus orientalis Lipsky), Trojan fi r (Abies nordmanniana subsp.equi-trojani), black pine (Pinus nigra Arnold) and Scots pine (Pinus sylvestris L.) represent different crown architecture, growth rate and shade tolerance; however, MSDRs have not been developed for these tree species in northern Turkey. In this study, average maximum density (DAM) slopes for these tree species were determined. Results suggested that MSDRs varied among the species, and that their slope differed from the universal slope of -1.605. The MSDRs described in this study are useful for managing stand density in natural stands of the species analyzed.
