The genetic variability and biodiversity of tree populations ensure the stability and sustainability of forest ecosystems. New research tools based on molecular DNA markers enable precise characterisation of forest genetic resources, i.e. detection of different allele frequencies in mature trees and progeny populations. The paper describes the genetic structure of mature stands of Scots pine (Pinus sylvestris L.) in Oława Forest District and Norway spruce (Picea abies L. Karst.) in Jawor Forest District and stands of their respective progeny. In the Scots pine stand, there was a slight increase (0.6%) in heterozygosity level and a larger increase (4.9%) in the inbreeding coefficient of progeny trees. In the Norway spruce stand, despite a small reduction (0.9%) in heterozygosity, a similar increase (4.6%) in the inbreeding coefficient of progeny was revealed. In both stands, allele richness and the partition probability of basic clustering were high. Both pine and spruce adults and progeny trees were characterised by high levels of genetic similarity (96% and 79%, respectively). Gene flow between the mature and progeny populations was high (Nm > 1) for both Scots pine and Norway spruce. Conservation of the gene pool within forest tree stands requires an increase in the proportion of natural regeneration. To estimate the extent to which genes are transmitted between adult trees and their progeny, more studies are needed, especially taking into account the influence of silviculture measures, like selective tree cutting, on the genetic variability of the younger generation. These results confirm that the gene pool was conserved when transmitted between the stands studied, as well as highlight the usefulness of such a study for silvicultural purposes

Szkody wyrządzone przez gołoledź i śnieg na przykładzie Nadleśnictwa Herby, na tle panujących warunków pogodowych w styczniu 2010 roku:

One of the tree species appearing after a decline of Norway spruce Picea abies (L.) H. Karst. in the Silesian Beskid Mountains is Silver Birch Betula pendula Roth. Therefore our study was aimed at evaluating this birch regeneration and the dynamics of changes resulting from experimental cutting. Measurements and inventories of trees were conducted on research plots located in a ten-year old birch regeneration site with either no cutting, partial cutting (50%) or clear cutting (100%) of birch. We observed an introduction of biocenotic species (rowan, willow, aspen) as well as the target species (spruce, fir, beech) under the birch canopy. Fir and beech were also planted, because of their slow natural regeneration. The clear cut treatment caused a great number of sprouts growing from birch stumps, reaching a height of about 2 m over 3 years, resulting in competition with the regeneration of other species. Partial cutting did not cause such a drastic amount of sprouting. Furthermore, we found that only the spruce height increment is significantly less under a birch canopy compared to open space. The obtained results indicate a necessity to adjust the density and species composition of regenerating tree species under a birch canopy, avoiding complete removal of the first generation birch cover and the need to moderately thin out birch.