Stefan Skiba

New international long-term ecological research on air pollution effects on the Carpathian Mountain forests, Central Europe

An international cooperative project on distribution of ozone in the Carpathian Mountains, Central Europe was conducted from 1997 to 1999. Results of that project indicated that in large parts of the Carpathian Mountains, concentrations of ozone were elevated and potentially phytotoxic to forest vegetation. That study led to the establishment of new long-term studies on ecological changes in forests and other ecosystems caused by air pollution in the Retezat Mountains, Southern Carpathians, Romania and in the Tatra Mountains, Western Carpathians on the Polish-Slovak border. Both of these important mountain ranges have the status of national parks and are Man & the Biosphere Reserves. In the Retezat Mountains, the primary research objective was to evaluate how air pollution may affect forest health and biodiversity. The main research objective in the Tatra Mountains was to evaluate responses of natural and managed Norway spruce forests to air pollution and other stresses. Ambient concentrations of ozone (O(3)), sulfur dioxide (SO(2)), nitrogen oxides (NO(x)) as well as forest health and biodiversity changes were monitored on densely distributed research sites. Initial monitoring of pollutants indicated low levels of O(3), SO(2), and NO(x) in the Retezat Mountains, while elevated levels of O(3) and high deposition of atmospheric sulfur (S) and nitrogen (N) have characterized the Tatra Mountains. In the Retezat Mountains, air pollution seems to have little effect on forest health; however, there was concern that over a long time, even low levels of pollution may affect biodiversity of this important ecosystem. In contrast, severe decline of Norway spruce has been observed in the Tatra Mountains. Although bark beetle seems to be the immediate cause of that decline, long-term elevated levels of atmospheric N and S depositions and elevated O(3) could predispose trees to insect attacks and other stresses. European and US scientists studied pollution deposition, soil and plant chemistry, O(3)-sensitive plant species, forest insects, and genetic changes in the Retezat and Tatra Mountains. Results of these investigations are presented in a GIS format to allow for a better understanding of the changes and the recommendations for effective management in these two areas.

CLAY-MINERAL FORMATION IN SOILS DEVELOPED IN THE WEATHERING ZONE OF PYRITE-BEARING SCHISTS: A CASE STUDY FROM THE ABANDONED PYRITE MINE IN WIESCISZOWICE, LOWER SILESIA, SW POLAND

Intense mineral transformations that produce acid soils from weathering zones of pyritebearing rocks, including alterations of layer silicates, are of critical importance to agricultural and environmental interests in various regions of the world. To date, the transformations of layer silicates in these soils have not been studied in detail. The aim of the present investigation was to examine the weathering pathways controlling processes of clay-mineral formation in acidic soils developed near the abandoned pyrite mine in Wieściszowice (Lower Silesia, SW Poland). A sequence of soils, from weakly developed technogenic soils (located on the mine dumps) to well developed natural soils, was selected. Bulk soil material and separated clay fractions were analyzed using X-ray diffractometry, Fouriertransform infrared spectroscopy, and scanning electron microscopy-energy dispersive spectrometry. The profiles analyzed were developed on pyrite-bearing schists containing trioctahedral Mg,Fe-chlorite and dioctahedral micas (muscovite and paragonite). Because of pyrite weathering, all the soils studied were strongly acidic (pH 2.8–4.4). Inherited chlorite and micas (K- and Na-mica) predominated in the clay fractions of soils developed on the mine dumps, whereas clays from natural soils were rich in pedogenic minerals (i.e. smectite, vermiculite, and mixed-layer minerals containing hydrated interlayers). The formation of both vermiculite and smectite at the expense of chlorite was observed in the soils studied. The transformation probably led to smectite formation via intermediate stages of mixed-layer minerals (i.e. chlorite-vermiculite, chlorite-smectite, and/or vermiculite-smectite). The process of chlorite dissolution took place simultaneously with the transformation. Micas were mainly transformed to smectite and mixedlayer mica-smectite. Neoformation of kaolinite occurring in A horizons of the soils investigated was also documented. Metal-hydroxy interlayers in Bw horizons of well developed soils were found. The process of interlayer development appeared to be pH dependent and took place at pH ⩾4.2. The processes of claymineral formation in soils developed in the weathering zone of a pyrite-bearing schist are similar to those occurring in podzols (Spodosols).

Concentrations of 137Cs and 40K radionuclides and some heavy metals in soil samples from the eastern part of the Main Ridge of the Flysch Carpathians

The aim of the study is to present the results of determination of radioactivity of artificial 137Cs and natural 40K and certain heavy metals in soil samples collected from the eastern part of the Main Ridge of Carpathians, including the Beskid Niski Mts and the Bieszczady Mts. The evaluation of level of radionuclides was based on the bulk density analysis of the soil. A valuable finding of the study was a good linear correlation between the level of 137Cs concentration and bulk density of the soil as well as an inverse correlation between radioactivity of natural 40K and tested soil density. This might indicate though a high competitiveness of these elements between each other. Moreover, a good correlation between the concentrations of artificial element 137Cs and Pb has been also observed in soil samples collected from the Beskid Niski Mts. In most cases, the level of artificial 137Cs was lower comparing to an average 137Cs concentration established for soils in Poland.

PREPUBLICATION: Formation of NH4-illite-like phase at the expense of dioctahedral vermiculite in soil and diagenetic environments – an experimental approach

Selective sorption and/or fixation of cations with low hydration energies (e.g. K+, NH4+, Rb+, Cs+) by vermiculites is a well known phenomenon in soil science and it has been described by many investigators since the 1950s. Because most of the available studies deal with trioctahedral vermiculites, cation fixation in dioctahedral vermiculites is not as well understood as fixation by trioctahedral structures. The objective of the present study was to investigate the influence of NH4+ saturation on the structure of a natural dioctahedral vermiculite. Because no dioctahedral vermiculite standard reference material was available, two natural dioctahedral vermiculite-rich soil clay samples were used in the study. The clays were saturated with NH4+ using different protocols to simulate natural processes that likely take place in soils. The degree of NH4+ fixation by the dioctahedral vermiculite was evaluated using X-ray diffraction, elemental N analysis, and infrared spectroscopy. All the treatments that involved NH4+ saturation caused NH4+ fixation and irreversible collapse (i.e. contraction to ~10 Å) of at least a portion of the previously hydrated (vermiculitic) interlayers. Air drying of the NH4+-saturated samples greatly enhanced the degree of the collapse. The results indicated that the collapse of dioctahedral vermiculite leads to the formation of a NH4-illite-like phase that is likely to occur in some soils and sediments that are rich in organic matter. The formation of a NH4-illite-like phase by NHNH4+ fixation in vermiculitic interlayers needs to be taken into consideration in studies that deal with the clay mineralogy of sedimentary basins.