Central European populations of woody plants differ widely in age. For this reason, they may have reached different degrees of adaptedness to their habitats and have been subjected to different degrees of human influence. This condition must be accounted for in the declaration of gene resources. Both in the past and in the present, man has had an impact not only on the state of the populations but also on their genetic systems. Particularly in the widely practiced conservation in situ, the functioning of the genetic system must be maintained or even restored. Some problems in the current procedures for choosing stands for conservation are addressed.
Under anthropogenic environmental change, some genetic systems of species and species spectra are no longer fully adapted because of reduced population density. This has consequences on the methodology of gene conservation. The more specific these methods are, to take into account the negative influence of human activities, the more efficient they can be. This establishes the need for population genetic research.