Fig. 2

Rolling front landscape breeding. Phenotyping/genotyping in all stands (four assumed in the graphical illustration) is followed by combined multi-trait/site/age BLUP or GBLUP analysis, conducted periodically. Genetically superior individuals from the candidate population (exceeding the selection age) may enter the RESERVOIR subset of the arboretum. Genotypes in the RESERVOIR can either remain—with the possibility of either reaching reproductive age and joining the CORE subset or being removed during any evaluation stage. Genotypes in the CORE subset have two potential outcomes: they may either be retained or removed, with the latter occurring for reasons such as genetic inferiority or surpassing the reproductive age. Except for the initial period, the size of the CORE subset is dynamic, but it must meet a minimum \({N}_{CR}\). The quantity and specific identity of individuals shifted at each step (arrows) are periodically determined by mathematical optimization