Viscario vulgaris-Quercetum petraeae Stöcker (1965) in the Opawskie Mts (Eastern Sudetes)

Results of phytosociological studies conducted in the southern part of Opole Silesia within the Sudetes mountain range in 2014-2015 are presented. The main aim of our research was to confirm the occurrence of Viscario vulgaris-Quercetum petraeae Stöcker 1965, which had previously been noted in Poland only within the Central Sudetes Foothills in Lower Silesia province. Two additional sites of this extremely rare in Poland plant association were confirmed, located within the Opawskie Mts in Opole province. The association develops on steep slopes, near rocky outcrops, on southern or western expositions at altitudes between 350 and 410 m a.s.l. All plots of the association consists of several diagnostic taxa and the share of thermophilous plants is clear. The Viscario vulgaris-Quercetum petraeae is rather species poor forest phytocoenosis with the herb layer abundance shrink by a scree downslides. The most frequent taxa contributing to the sampled plots were: Luzula luzuloides, Galeopsis ladanum, Hieracium laevigatum, Lembotropis nigricans, Vaccinium myrtillus, Deschampsia flexuosa and Viscaria vulgaris. In all forest plots the Quercus petraea apparently dominates and shrub layer is scarce.

Effect of conventional and whole-tree clear-cutting on concentrations of some micronutrients in coniferous forest soil and plants

Effect of conventional and whole-tree clear-cutting on concentrations of some micronutrients in coniferous forest soil and plants Increasingly intensive and mechanized clear-cutting may deplete the forest ecosystem of essential nutrients. A clear-cut area near Växjö, southern Sweden, was investigated for changes in Mn, Cu and Zn in soil (NH4NO3 extractable and HNO3 soluble) and wavy hair grass (Deschampsia flexuosa) after conventional (CC) and whole-tree clear-cutting (WTC). The soil samples were mostly iron podzols. The area consisted of four clear-cut sites, respectively 2, 4, 6 and 8 years old, and an uncut forest reference stand. Each of the clear-cuts was split in two parts representing WTC and CC sites. Manganese showed the most definite trends after clear-cutting, exhibiting higher extractable concentrations in Oe, Oa and E horizons (4-8 years after clear-cutting) and B horizons (6-8 years after clear-cutting). The increase of exchangeable Mn in the E (2-8 years) and B (4-8 years) horizons was particularly strong. Zn concentrations tended to fluctuate with time. There was a tendency to higher Mn and Zn concentrations in the humus layer especially 2 years after CC-treatment compared with WTC, whereas the opposite trend was apparent for Cu. Mn, Cu and Zn concentrations decreased in Deschampsia flexuosa 2 years after clear-cutting, possibly due to increased soil pH.