Land use effects on soil organic carbon sequestration in calcareous Leptosols in former pastureland : a case study from the Tatra Mountains (Poland)

The purpose of the paper is to describe soil organic carbon (SOC) sequestration rates in calcareous shallow soils in reforested areas in the Tatra Mountains with a particular focus on different forms of organic matter (OM) storage. Three plant communities creating a mosaic on the slopes of the studied valley were taken into account. Fifty years since the conversion of pastureland to unused grassland, dwarf pine shrub and larch forest have emerged in the study area, along with the development of genetic soil horizons as well as SOC sequestration in the soil despite the steepness of slopes. SOC stock was measured to be the highest in soils under larch forest (63.5 Mg ha−1), while in soil under grassland and under dwarf pine shrub, this value was found to be smaller (47.5 and 42.9 Mg ha−1, respectively). The highest amount of mineral-associated OM inside stable microaggregates (MOM FF3) was found in grassland soil (21.9–27.1 % of SOC) and less under dwarf pine shrub (16.3–19.3 % of SOC) and larch forest (15.3–17.7 % of SOC). A pool of mineral-associated OM inside transitional macroaggregates (MOM FF2) was found in soil under dwarf pine shrub (39.2–59.2 % of SOC), with less under larch forest (43.8–44.7 % of SOC) and the least in grassland soil (37.9–41.6 % of SOC). The highest amount of the free light particulate fraction (POM LF1) was found in soil under dwarf pine shrub (6.6–10.3 % of SOC), with less under larch forest (2.6–6.2 % of SOC) and the least in grassland soil (1.7–4.8 % of SOC)

Application of various standards of pH measurement to determine reaction classes of selected soils in the upper San valley

The paper presents a study of different procedures of soil reaction measurement carried out on selected soil profiles in the Upper San Valley. It is also aimed to assess the usefulness of pH-based indices used in various national and international soil classification systems that can be applied to classify the soils of the Western Bieszczady Mts

Linking snow, soil, and stream during snowmelt and rain-on-snow events : storage and transport of NO3−NO_{3}^{-} ions in an acid-sensitive alpine catchment (Tatra Mountains, Poland)

The purpose of the study was to examine the storage and transport of $NO_{3}^{-}$ ions through snowpack, soils, and stream water in an acid-sensitive alpine catchment (Tatra Mountains, Poland) during snowmelt and rain-on-snow events. Samples of snowpack layers, near-surface soil horizons, and stream water were collected in the winter and snowmelt seasons of 2019. A laboratory experiment was conducted to determine the effect of temperature on the rate of soil nitrogen mineralization and nitrification. Our study has shown that snowpack is an important source of $NO_{3}^{-}$ ions in the catchment. As the snow melts, the release of $NO_{3}^{-}$ ions from snowpack occurs. A gradual and slow melting of snow starts even before the first snowmelt-induced increase in stream discharge. $NO_{3}^{-}$ ions eluted from available snowpack are temporarily stored in soil, which is shown by a large increase in the concentration of water-soluble $NO_{3}^{-}$ in the soil at that time. $NO_{3}^{-}$ ions are washed out of soils and supplied to streams during the first snowmelt event. This is demonstrated by a large increase in the stream water $NO_{3}^{-}$ concentration, termed an "$NO_{3}^{-}$ pulse." The $NO_{3}^{-}$ ion is a key acid anion responsible for the acidification of the studied stream during snowmelt season, as the $NO_{3}^{-}$ pulse coincides with a decrease in bicarbonate alkalinity. Our field research and laboratory experiment have shown a minor role of mineralization and nitrification in $NO_{3}^{-}$ production in soils in the winter and $NO_{3}^{-}$ pulse formation in stream water during the early stages of the snowmelt season

Headwater chemistry in subarctic areas with different plant communities (Finnish Lapland)

The study determines the differences in the chemistry of small headwater streams located in areas with different plant communities in Finnish Lapland. Water samples from 76 catchments with four different plant communities were collected and analyzed. The statistical analyses of water temperature, water specific electric conductivity and the concentration of main ions, revealed the greatest variation in ion concentrations related to rock weathering: Ca2+, Mg2+, HCO3- in the studied catchments. Enrichment of water with these ions occurred in catchments representing forest communities with thick soils, especially in the boreal forest community. This suggests that future changes in the northern treeline may affect the surface water chemistry depending on the direction of changes. In case of the expansion of the treeline to the north due to climate warming, an increase in water mineralization and a shift of hydrochemical facies towards a Ca-Mg-HCO3-type can be expected. On the other hand, the regression of the northern treeline could be expected to result in a reduction of nutrient pools and leaching them into streams. Eventually, it could result in the depletion of soils and the dominance of atmosphere-derived ions in waters, and the hydrochemical facies will shift towards Na-Cl-type.Peer reviewe