Nutrient uptake efficiency and stoichiometry for different plant functional groups on spoil heap after hard coal mining in Upper Silesia, Poland

Various plant functional groups (PFGs) used in the reclamation of post-mining heaps may differ in their nutrient uptake efficiency and thus in their effect on the ecosystem development. The effect of PFGs may be additionally modified by the applied reclamation measures such as e.g. topsoiling. In this study we compared the nutrient uptake efficiencies and plant stoichiometry for two PFGs (grasses and forbs) growing on the sites reclaimed by applying topsoil (TS) and unreclaimed sites on carboniferous bare rock (BR) in hard coal spoil heap in Upper Silesia (southern Poland). Basic soil parameters, including pH, texture, soil organic carbon, and nutrients (N, P, K, Ca, and Mg), were measured, and the aboveground plant biomass and nutrient content in plant tissue were determined. Forbs were characterized by a larger biomass and higher nutrient concentrations (except for P) than grasses. The TS treatment supported higher concentrations of N and P in plant tissues but not to the level ensuring more significant primary biomass production. The nutrient concentration and elemental stoichiometry in plant tissue indicated that N was the primary limiting element. However, the major growth limitation for N-fixing forbs was from P. Forbs were much more efficient in nutrient uptake than grasses, independent of the reclamation treatment. Therefore, they stimulate nutrient cycling in the restored ecosystems more than grasses.

Biomonitoring of Mercury Contamination in Poland Based on Its Concentration in Scots Pine (Pinus sylvestris L.) Foliage

This work evaluates current mercury (Hg) contamination in Poland, represented by the Hg concentrations in Scots pine foliage. Samples were collected over 295 investigation plots in monitoring grids throughout Poland, from pines aged between 12 and 147 years. Analyses were conducted with consideration of bioclimatic factors and soil properties. Concentrations in the pine foliage did not exceed the values characteristic of an ecosystem unaffected by industrial pollution, ranging from 0.0032 to 0.0252 mg kg⁻¹ dry mass. However, pine stands located in western and central Poland, and in the northwest near the Baltic Sea, exhibited higher Hg concentrations in foliage than in eastern regions. Hg content in foliage depends on the mean temperature of the driest quarter, as well as on Hg content in soils. This indicates that the periods of drought observed in recent years in Poland may affect Hg concentrations in pine foliage.

The impact of alder litter on chemistry of Technosols developed from lignite combustion waste and natural sandy substrate: a laboratory experiment

Alders, as an N-fixing species, are widely used as a phytomelioration species at post-industrial sites. The paper presents the effects of litter decomposition of different alder species-black alder, gray alder, and green alder-on changes to the soil solution chemistry of Technosols developed from two types of substrates: lignite combustion waste and sandy substrates from a former sand quarry. Under controlled conditions, the 13-week experiment investigated pH, electrical conductivity (EC), and the chemical parameters-dissolved organic carbon (DOC), dissolved nitrogen (DON), and macroelements S, Ca, Mg, K, and Na content-of filtrates in composites consisting of substrate and litter from alder species was investigated. Alder litter accelerated nutrient leaching processes from soil substrates and had the greatest impact on sandy substrates because fast leaching was possible at low absorption capacity characteristics. Higher leaching rates in sandy substrates were also observed, especially in the cases of DOC, DON, K, and P, in comparison to combustion waste substrates. In the first phase of the experiment in sandy soil substrates, the dominant process is the leaching of DOC from dead organic matter, while in the case of combustion waste, calcium leaching prevails in the first phase. Among the investigated species, black alder had the greatest impact on the chemistry of substrates and solutions, and the dynamic of these processes has a different path at various substrates.

Reclamation of a lignite combustion waste disposal site with alders (Alnus sp.): assessment of tree growth and nutrient status within 10 years of the experiment

Combustion wastes are characterised by extremely low N contents. Therefore, introduction of nitrogen-fixing species at the first stage of their biological reclamation is required. This paper presents an assessment of the growth parameters of alders (Alnus sp.) 10 years after their introduction to a disposal site of lignite combustion waste in Central Poland. Black (Alnus glutinosa) and grey alders (Alnus incana) were planted directly in the combustion waste. The soil amendment included three variants: control with pure combustion waste, admixture of lignite culm and addition of acid sand. Both alder species displayed good growth parameters comparable to those of alders in natural habitats. However, black alder had better growth parameters, such as stand density index (SDI), diameter at breast height (DBH) and height (H) than grey alder. The lignite amendment exerted a positive effect on tree growth, reflected in a higher SDI and H, whereas the acid sand amendment did not affect any of the growth parameters of the studied alder species. Despite the good growth parameters, the measured N:P and N:K ratios in the alder leaves largely differed from the optimal values indicating insufficient P and K supply at the combustion waste disposal site. This may pose a threat to further development of the introduced tree plantings. The introduction of alders along with the lignite addition into the planting holes seems to be a successful method of combustion waste revegetation.

Simulation of Birch and Pine Litter Influence on Early Stage of Reclaimed Soil Formation Process under Controlled Conditions

The impact of litter decomposition on chemical substrate properties and element leaching during early soil formation in afforested post-mine sites and the influence of different tree species are key issues in new ecosystem development. Scots pine ( L.) and common birch ( Roth) are important pioneering species used in afforestation of post-mine sites in central and eastern Europe. The aim of this study was to assess the impact of litter decomposition of these species on the chemical properties of mine soil substrates. The impact of litter decomposition on soil properties was tested on quaternary and neogene substrates with different textures (sands, loams, and mixtures of clays and sands) in a controlled incubation experiment using PVC columns. Simulation of precipitation and leaching was undertaken for 10 wk at a temperature of 16°C with distilled water (200 mL wk) through cylinders with litter, substrate + litter, and control substrate (no litter). Filtrated water solution was collected once a week for laboratory analysis, and the concentrations of dissolved organic C, total N, K, Ca, Mg, and P were determined. The study results indicate a stronger impact of the common birch on the chemical properties of reclaimed mine soils compared with pine. After the experiment, birch litter caused significant changes in pH in quaternary sands, concentration of P in quaternary loams (Ql) and mixtures of neogene clays and quaternary sands (QsNc), exchangeable Ca in QsNc, and Mg in Ql and QsNc compared with pine litter. Birch, in comparison to pine, may affect the intensity of early-stage soil-forming processes by increasing nutrient availability and transport into the soil profile, which may affect the development of soil microbial communities. This process results in different soil properties under the two tree species.

Scots pine needles macronutrient (N, P, K, CA, MG, and S) supply at different reclaimed mine soil substrates--as an indicator of the stability of developed forest ecosystems

A main objective of restoration and afforestation at post-mining sites is establishing a long-term sustainable ecosystem which depends on adaptations of tree species and which in turn depends on the soil nutrient flux. The nutrient concentration (nitrogen (N), P, K, Ca, Mg, and sulfur (S)) of Scots pine needles was investigated in reclaimed mine soils (RMS) located at the following post-mining sites: a sand mine pit, spoil heap from a lignite mine, spoil heap from a S mine, and a carbonaceous spoil heap from an underground coal mine. The control plots were arranged on natural forest sites adjacent to the post-mining sites. A higher level of foliar nutrients was noted in the carbonaceous RMS, while lower levels were found in RMS on the spoil heap following lignite mining. The characteristics of the substrate were found to exert greater effect than mineral fertilization (performed at the onset of reclamation) on the tree stand characteristics, needle length and foliar nutrient concentration. While the soils and trees were most deficient in N, negative symptoms have not been noted to this date in tree stands at reclaimed mine sites. Trophic ratings were recommended based on statistical correlations and groupings between N and P contents in needles and needles length (mean length of 300 needles) while nutrient ratings were recommended from statistical differences and groupings of the RMS substrates.