Search

The research area is located in the Eastern Carpathians, Romania. This region is rich in various formations and indicates significant potential for paleo-environmental reconstruction. The present research was carried out on sediment cores collected at lake Bolătău-Feredeu, Feredeului Mountains (Eastern Carpathians, Romania). Preliminary examination of the sediment confirmed the possibility for data analysis with high temporal resolution. The aim of the research was to clarify and supplement the findings of previous research at this site, to explore the relationships between proxy parameters and to elucidate the cause for the changes. Core dating was carried out using 210Pb and radiocarbon isotopes and indicated that sediment cores span the past 500 years. The research uses a wide range of methodologies, including organic geochemistry with calculated n alkane indices (Phw and Pwax). Based on these proxies, the changes of woody and herbaceous coverage in the catchment can be estimated. Moreover, element concentration, weathering indices and particle size distribution assist to detect climate changes in the catchment area. The data and conclusions yielded by the analysis were compared with the regional modelled temperature profile, based on which five periods were separated. In addition to natural and anthropogenic events, the main factor among the natural processes is the change in annual temperature. Based on the obtained data, several parameters were found to be suitable for monitoring past temperature changes.

Dissolved organic matter (DOM) is a key soil quality property, indicative of the organic matter stored in the soil, which may also be a function of temporal variation. This study examines whether DOM is a robust property of the soil, controlling fertility, or if it may change with time. Altogether eight sets of soil samples were collected in 2018 and 2019 from the cultivated topsoil (0–10 cm) of cropland and from a nearby grassland near Martonvásár, Hungary. The study sites were characterized by Chernozem soil and were part of a long-term experimental project comparing the effects of manure application and fertilization to the control under maize and wheat monocultures. DOM was extracted from the samples with distilled water. The dissolved organic carbon (DOC), total dissolved nitrogen (DN), biological index (BIX), fluorescence index (FI), humification index (HIX), carbon nitrogen (C/N) ratio and specific ultraviolet absorbance at 254 nm (SUVA254) index were studied in the arable soils, and the results showed that all the DOM samples were humified, suggesting relevant microbiological contributions to the decomposition of OM and its conversion into more complex molecules (FI = 1.2–1.5, BIX = ~0.5, and HIX = ~0.9). Temporal variations were detected only for the permanent grassland where higher DOM concentration was found in spring. This increased DOM content mainly originated from humified, solid phase associated, recalcitrant OM. In contrast, there were no differences among fertilization treatments and sampling dates under cropfield conditions. Moreover, climatic conditions were not proven as a general ruler of DOM properties. Therefore, momentary DOM alone is not necessarily the direct property of soil organic matter under cropfield conditions. The application of this measure needs further details of sampling conditions to achieve adequate comparability.

The present dataset provides data on the pharmaceutically active compounds (PhACs) concentrations measured in the Danube and the drinking water abstraction wells (DWAW) in the Budapest region. Grab samples were collected during five periods. One hundred and seven water samples from the Danube and ninety water samples from the relevant DWAWs were analyzed to quantify physical-chemical parameters, trace element concentrations, and one hundred and eleven PhACs, including pharmaceutical derivatives, illicit drugs, and alkaloids. The ion concentrations were measured using dual channel ion chromatography, spectrophotometric and titrimetric methods, and inductively coupled plasma mass spectrometry. PhACs concentrations were measured after solid-phase extraction applying supercritical fluid chromatography coupled with tandem mass spectrometry. Fifty-two PhACs were quantified in the Danube, and ten PhACs were present in >80% of the samples. Whereas thirty-two PhACs were quantified in the DWAWs. The present dataset is useful for further comparisons and meta-analyses.

The volume of soil organic matter (SOM) changes, owing to variations in tillage systems. Conservation tillage (CT) is a useful method for recovering the SOM content of crop fields. However, little is known about the SOM composition of silt- and clay-associated and aggregate-occluded organic matter (OM). The present study aimed at determining the SOM compositions of various SOM fractions in the same Luvisol in a native forest and under ploughing and CT. SOM fractions (silt and clay associated; sand and aggregates associated; restricted OM) were characterized using diffuse reflectance Fourier transform infrared (FTIR) spectroscopy. The size of both the aggregate-occluded and resistant SOM pools increased, owing to the shift in the tillage system to CT for 15 years. As a general trend, the soil organic carbon content was inversely proportional to aromaticity under both crop fields, which supported the preferential mineralization of aliphatic components in each fraction. The shift in the tillage system could trigger rapid qualitative changes even in the stable restricted carbon pools; nevertheless, it was difficult to distinguish between the role of OM and the mineral composition in the FTIR spectra. In particular, the clay-related organic-mineral complexes could trigger difficulties in the traditional interpretation methods.