Genetic structure of spruce population and forest management

Genetic diversity and spatial structure of a young planted Norway spruce (Picea abies Karst.) stand, localized in the Giant Mts. near Špindlerův Mlýn, was investigated. Average tree height was 15.1 m, average diameter at breast height was 245 mm. The spatial distribution of trees was random. Spruce branches of all trees in the selected part of the stand were sampled in order to accomplish isozyme analysis. One–dimensional horizontal electrophoresis on starch gel was used to determine the alleles of isozyme loci G–6–PDH, GDH, SDH–A, SDH–B, PGM–A, IDH–B, AAT–B and AAT–C. Subsequently, allele numbers per loci, allelic frequency and heterozygosity were evaluated. Genotype combinations were a basis to calculate coefficients of genetic diversity: Shannon's index and Rao's quadratic entropy. Further, three variants of thinning with removal of 30% of the trees in each case were simulated: trees with the highest diameter were removed in the variant v1, 15 % of the trees with the highest and 15 % with the lowest diameter in the variant v2, and the trees with the lowest diameter in the variant v3. The genetic diversity is affected by the simulated thinning. Differences in heterozygosities and diversities between the whole population and subpopulations were statistically tested using the Monte–Carlo randomization test.