This study presents selected tree stand features and stand productivity of the English oak (Quercus robur L.) growing in the conditions of a reclaimed external dump of Piaseczno sulfur mine in Tarnobrzeg mining area. Following 40 years of growth in the dump, the oak trees reached first and second bonitation class and good growth parameters. The oak obtained the highest stand volume and basal area on sandy soils and loamy-sand substrates. A significant negative correlation between high clay content in soil cores and tree stand parameters was observed, indicating unfavourable impact on tree growth. The results confirmed the usefulness of the English oak as the main (target) species in the conditions of sulfur dumps, and the suitability of its introduction with preliminary identification of micro-habitat differentiation.
The research was conducted on the external spoil heap of the ‘Piaseczno’ Sulphur Mine (southern Poland). This paper is aimed to compare the selected properties of macrostructure and density of wood of Scots pine trees planted onto the external spoil heap of the mine, in the scope of forest reclamation, depending on the soil substrate and employed reclamation treatments. The annual rings of pine trees on the Quaternary sands and Tertiary Krakowieckie clays (S&C) were significantly wider than those of the individuals on the Quaternary loose sands (S) and Quaternary sands and Tertiary clays after an intense initial fertilization (F). However, the share of latewood zone and density of wood of the pine trees growing on the substrate F were significantly greater in comparison to those of substrates S and S&C.
The stability of introduced stands depends not only on aboveground but also on the belowground biomass. Results from reclaimed sites often indicate good growth of the aboveground part of stands, but data on the development of root systems are still lacking. Our aim was to assess the vitality of trees, their biomass and the morphology of the root systems of Scots pine (Pinus sylvestris L.) introduced on reclaimed landfill waste after zinc and lead flotation in Bukowno (southern Poland). The landfill site was reclaimed 20 years ago and reclamation treatments involved isolation and covering with mineral substrate layers (110–150 cm thickness) which formed a technogenic soil profile. Four research plots (10 m × 10 m) were set up in pure pine stands where soil profiles consisted entirely of flotation waste. Trees on the plots were assayed according to the Kraft and IUFRO classification system. In total, 15 trees of average growth parameters and bio-sociological position (I and II Kraft class) were selected for biomass and root system analyses and the root systems were excavated, washed, measured, weighed and photographed.
Our results support pine as a useful species in reforestation of post-mining areas. However, although pine trees were characterised by good vitality, their root systems were shallow and their depth reduced by up to 60 cm due to strong skeletal loamy substrate. Individual root biomass ranged from 1.2 to 9.1 kg and was comparable to pine root biomass on other reclaimed mining sites. This indicates that during restoration, the thickness of the substrate covering the flotation waste should be increased or the amount of skeletal substrate in the top layers of technosol reduced.