Scots pine (Pinus sylvestris L.) ecosystem macronutrients budget on reclaimed mine sites—stand trees supply and stability

The aim of this study was to determine the sources, accumulation rate and relationships between macronutrients in reclaimed mine soils (RMS) and aboveground plant biomass on external slopes of lignite mines in central Poland. The study was conducted on two different types of sites with 10-year-old Scots (Pinus sylvestris L.) pine stands located on Quaternary loamy sands (QLS) and on Tertiary acidic carboniferous sands following neutralisation (TCS). The control plot was located in the same vicinity on an external slope in a natural pine ecosystem on a Haplic Podzol in a young mixed coniferous forest habitat (NPE). The nutrient resources, apart from N, were higher in RMS than in comparable Haplic Podzols, however, N primarily accumulated in the mineral horizons. In forest soils, the main macronutrient resources were accumulated in organic horizons, which in natural soils of coniferous forest habitats constitute the main source of nutrients. The proportion of individual macronutrients accumulated in the biomass vs. pools in soil was much lower on the external slope RMS than in the natural site, which in view of the potential richness of RMS, indicated poorer sorption and utilization of macronutrients in aboveground plant biomass than in natural habitats. Other important linear correlations (p = .05) were found between the sources of nutrients in RMS and elements accumulated in biomass (most clearly in case of K, Ca and Mg), which indicates important relationships between soil and vegetation in the first stages of ecosystem development as stimulated by reclamation.