Schematic removal of planted trees for example in
complete rows is unlikely to have strong effects on
genetic structures since the phenotypes have no impact
on the probability of survival. Schematic thinning is
often conducted during the pole wood age. Stands are
still dense with a high number of individuals left after
the thinning. Thus, neither drift nor selection are
expected to induce strong changes of genetic structures
as a result of schematic thinning.
The pioneering work of Hosius (1993) proved
changes of genetic structures as a result of selective
thinning in Norway spruce (Picea abies). Different
isozyme gene loci were significantly affected by two
types of thinning strategies: Thinning from above
resulted in significantly different genotypic structures
of the removed and the remaining trees at three
enzyme gene loci Thinning from below yielded significant genotypic
differences at Aat-B and 6-Pgdh-B.