Modelovanie dopadov prirodzenej a umelej obnovy na genetickú truktúru: 1. nezmie any smrekovy porast

The paper focuses on the analysis and assessment of spatial and temporal variation in male and female fertility and their effect on the genetic structure of progeny in a managed stand of a pure Norway spruce. The program package Eco-Gene (Degen & Gregorius & Scholz 1996) was used to model genetic structures and to assess the influence of various regeneration systems based on natural and artificial regeneration on the formation of spatial genetic structure, allelic richness, diversity and genotype structure of progeny, and its differentiation from the maternal stand. The research plot was established in the site Vy né Hágy with 200 adult trees. For each tree, position in the stand, crown size and its ground projection, and seed fertility were scored in the field. Besides, a multilocus genotype of each tree was determined by isozyme analyses of dormant buds. Based on the modelling, we compared various silvicultural systems, which should result in a progeny reproducing genetic structures of maternal stands. An important indicator for the evaluation of silvicultural treatments was the formation of spatial genetic structures, as a secondary criterion, we used the differentiation of progeny against mother stand. Finally, we also considered genetic variation of progenies. Considering these criteria, the most appropriate silvicultural treatment in pure spruce stands appears to be the two-phase edge shelterwood cutting. On the other hand, intensive single tree selection is maybe unexpectedly the least appropriate option. The other tested systems - single-phase edge, group, progressive group shelterwood cutting and moderate single tree selection have an equivalent, intermediate position.