Pál Balázs

Due to the changing climate, there has been a growing interest in solutions to reduce the carbon dioxide content of the atmosphere in recent decades. The utilization of the natural potential and the applied land uses in a given area directly affect the sequestration of carbon dioxide from the atmosphere. Within the framework of our research, we aim to estimate the carbon sequestration and carbon storage capacity of the Austrian-Hungarian border region based on land use.We utilized the land cover categories of the CORINE database, which is available for a significant portion of Europe. Based on the literature sources and our own measurement results for the border region, we assigned potential carbon storage values to the land cover categories, which allows us to estimate the amount of stored carbon for the entire region. In addition to determining the current carbon storage capacity value, the database also allows us to track past changes in the region's carbon storage using the CORINE land cover maps, which are updated every six years.The research was carried out within the framework of the CS4Region project, identification number ATHU-0100046, with the support of the INTERREG AT-HU 2021-2027 program.

The application of biochar (a stable carbon-rich material produced by pyrolysis under oxygen-limited conditions) in forests can simultaneously contribute to improving soil water-retention capacity and mitigating climate change. In forest soils, biochar’s fine pore structure and large specific surface area may have beneficial effects on soil structure: it can increase porosity, enhance the aggregation of soil particles, and provide more “micro-storage” sites for water. This may be particularly important in coarser-textured soils that dry out rapidly, where biochar can help a portion of precipitation remain longer in the root zone, thereby reducing drought stress and improving the survival prospects of natural regeneration and seedlings. Beyond water, biochar may also support nutrient retention: in certain cases, it can reduce nutrient leaching and create more favorable microhabitats for soil biota, which can indirectly enhance the stability of the soil water–nutrient balance.From a climate-mitigation perspective, the key benefit of biochar is that it can “lock” part of the plant-derived carbon into a more persistent form in the soil: instead of quickly returning to the atmosphere as carbon dioxide, it can contribute to increasing soil carbon stocks over longer time scales. In addition, if biochar is produced from local biomass residues and applied in a well-considered manner, it can become part of a circular economy approach and support forest climate adaptation (for example, by improving resilience during drier periods). In our studies, the optimal dose determined in laboratory germination-inhibition tests and pot experiments is being applied to three forest sites with different soil types. Even from our measurements so far, it has become evident that the effect strongly depends on the biochar feedstock and production conditions, the soil type, and the application method and rate. Therefore, in forest settings, small-scale pilot trials and monitoring are especially justified to ensure that water-management benefits are actually realized.The research was supported by the INTERREG AT-HU 2021-2027 CS4Region "A green and resilient border region" project.

One of the most important causes of global climate change is the increased CO2 content of the atmosphere. The most important CO2 sinks on Earth are terrestrial ecosystems, particularly forests, whose organic carbon reserves are stored approximately half in the soil in temperate zones. By changing land use, we have the opportunity to increase carbon dioxide and carbon sequestration. In our research, we investigated the possibility of increasing carbon sequestration in the Austrian-Hungarian border region, primarily through geoinformatics data processing. To validate the geoinformatics data, we measured the amount of organic carbon stored in the soil in 40 forest stands in the area. In the selected forest stands, we took samples every 10 cm from the top 40 cm layer of soil to determine the organic carbon content. During sampling, we took both undisturbed and disturbed samples. In addition to soil samples, we also took litter samples and recorded forest stands. The samples were examined in the soil science laboratory of the University of Sopron. The pH of the examined soils ranged from 3.9 to 8.1 pH(H2O). The average pH of the individual layers, from top to bottom, was 4.93, 4.78, 4.84, and 4.97 pH(H2O).As the results show, the top layer of soil was affected by leaching. We also examined the physical properties of the soil by the proportion of silt+clay particles that ranged from 11 to 65%, with an average of 43.55, 44.95, 46.78, and 48.45% from top to bottom. Loam was the main physical texture, and due to clay migration, the clay content increased downward, but there were also layers with coarse sand physical texture. The physical composition of the soils depended largely on the bedrock. The organic matter content (SOM) of the soil layers examined ranged from 0.54 to 2.16%. Naturally, the higher values were found in the top 10 cm layer, while the lower values were found between 30 and 40 cm. The amount of organic carbon stored in the top 40 cm layer of soil varied between 16 and 81 C t/ha, with an average of 44 C t/ha. The bedrock, soil quality, and forest composition greatly influenced the amount. Our data can contribute to the refinement of carbon stock estimates obtained using geoinformatics methods. This research was funded by the Interreg CS4Region (ATHU-0100046) project "Analysis and utilization of natural and technical carbon sinks in the Hungarian-Austrian border region." Some of the tools used in the research were acquired as part of the project "Investigation of the conditions for woody biomass production - GINOP-2.3.3-15-2016-00039".

Gap-cuttings in the framework of a continuous cover forestry system have an ecological effect on the chemical soil properties. The Pilis Gap Experiment (https://piliskiserlet.ecolres.hu/en) starting in 2019 in the Pilis Mountains in Hungary, investigates the effect of gap size and shape on soil properties in a mature oak-hornbeam forest. This study analyses the soil samples from 2023 regarding the effect of treatments on the pH value, the humus, and soil water content.A full-factorial design was applied for gap size (small: 150 m2 or large: 300 m2) and shape (circular or elongated) including an uncut control. For each treatment, six replicates were used in block design (five treatments, six replicates, altogether 30 plots). From each plot, two 20 cm deep soil samples were taken in the spring of 2023.The statistical analysis concludes that the effect of the different treatments is not significant on the pH-value, on the humus content of the soil and the soil water content.The pH value, measured in H2O, ranges between 4.2 and 5.3 with a mean of 4.60. The values in the circular gaps are higher than the values in the elongated gaps, but the models are not significant. Due to less litter, the soil could be less acidic in circular gaps, where the tree crown is less able to reach the middle of the gap.The result is similar in the humus content with a mean of 2.8 %. Here, the values in the elongated gaps are higher than the values in the circular gaps, but not significantly. This also can be explained by the amount of litter that reaches the soil. Therefore, with more litter more organic material can be degraded into humus.Also, the soil water content did not significantly differ from each other. The values are higher in circular gaps than in the elongated gaps and the control. This can be explained by the lower evapotranspiration and interception effect in the circular gaps, where neither the roots nor the crowns of the neighbouring trees can reach the gap centre compared to the elongated ones.We can conclude that gap-cutting in these dimensions does not modify the soil conditions. In circular gaps, a moderate soil water increment is detectable which can accelerate the regeneration processes.This article was made in the frame of the project TKP2021-NKTA-43 which has been implemented with the support provided by the Ministry of Innovation and Technology of Hungary (successor: Ministry of Culture and Innovation of Hungary) from the National Research, Development and Innovation Fund, financed under the TKP2021-NKTA funding scheme.

One of the greatest challenges of the 21st century is combating global climate change and adapting to its effects. In addition to reducing CO2 emissions, natural processes capable of absorbing CO2 are of paramount importance. Forest ecosystems play a critical role in this regard as they are the largest terrestrial absorbers of CO2 and organic carbon reservoirs. Our research revealed that in recent decades, systematic surveys of soil (and litter layer) organic carbon content have not been conducted in Hungary. Existing soil data are often incomplete (e.g., lack measurements of bulk density), were obtained using different analytical methods (e.g., determining soil humus content), and do not always include forest stand data. Data on litter layers are even more scarce. Consequently, our primary goal was to expand this dataset. To achieve this, we began assessing the effects of tree species, site conditions, and silvicultural interventions on the organic carbon stocks of soils and litter layers in Hungarian forest stands.Soil samples were collected using a motorized auger to a depth of 1–1.1 meters. The undisturbed samples were divided into 10 cm sections rather than genetic horizons, and for each section, a 100 cm³ cylinder was used to extract undisturbed samples for bulk density determination. The remaining soil in each section was retained for further analysis. From a 5-meter radius around each sampling point, litter samples were randomly collected from three locations per stand. The litter included all decomposing leaves and small to medium-sized twigs above the raw soil surface. Each sample was placed in a separate bag, resulting in 25 samples per location.This study focuses on results from beech (Fagus sylvatica) stands, as laboratory analyses are still ongoing. The collected soil samples were analyzed for bulk density, pH, lime content, acidity, particle size distribution, and organic carbon content. For the litter samples, in addition to dry mass, pH, the proportions of various fractions, and C/N content were determined.In the approximately 40 examined beech stands, the average soil pH was 5.17 pHH2O, with minimum and maximum values of 3.87 pHH2O and 8.4 pHH2O, respectively. Humus content in individual layers ranged from 0.16% to 15.65%. The average organic carbon stock of the 10 cm soil layers was 6.39 C t/ha, with a minimum of 1.46 C t/ha and a maximum of 34.03 C t/ha.Based on the results, the carbon stocks under beech stands in Hungary, which are retreating due to climate change, are likely to disappear if the pace of climate change accelerates in the Carpathian Basin.This article was made in the frame of the project TKP2021-NKTA-43 which has been implemented with the support provided by the Ministry of Innovation and Technology of Hungary (successor: Ministry of Culture and Innovation of Hungary) from the National Research, Development and Innovation Fund, financed under the TKP2021-NKTA funding scheme. Some of the tools used during the research were acquired within the framework of the "Investigation of the conditions for the cultivation of wood biomass - GINOP-2.3.3-15-2016-00039" project.

Over the past hundred years, Hungary's forest area has increased from 12% to 24%, thanks to afforestation efforts. Accordingly, it is crucial to examine the impact of forests on soils.In our study, we compared 1. a cropland, 2. a 19-year-old pedunculate oak stand, and 3. a 79-year-old pedunculate oak stand at the Szentkirály area of the Great Hungarian Plain to investigate changes in the soil. On adjacent areas with calcareous chernozem soil, undisturbed soil samples were taken every 10 cm down to a depth of 110 cm and analyzed in the laboratory.By examining the soil pH, it was determined that the soil under the cropland and the young stand was weakly alkaline to alkaline (7.9 (pHH2O) to 8.6 (pHH2O)). In contrast, the upper soil layers under the old forest exhibited an acidic pH (5.4 (pHH2O)). Intensive leaching was observed, affecting the upper 50 cm layer. The soil carbonate content values also corresponded to the pH levels. Based on particle size distribution analysis, the soil was classified as sandy loam, with no differences observed under the various land uses.The humus content in the soil samples ranged from 0.1% to 3.5%. The lowest humus content (0.1%-1.7%) was found in the cropland, while the highest humus content was observed in the old oak forest, where the top layer contained 3.0% humus. Overall, it can be concluded that the nearly 80 years of afforestation significantly impacted soil development. Leaching intensified, and following the cessation of plowing, organic matter accumulation began in the soils. Field observations also indicated a marked improvement in soil structure. The forest improved the soil properties, creating conditions more favorable for itself.This article was made in the frame of the project TKP2021-NKTA-43 which has been implemented with the support provided by the Ministry of Innovation and Technology of Hungary (successor: Ministry of Culture and Innovation of Hungary) from the National Research, Development and Innovation Fund, financed under the TKP2021-NKTA funding scheme. Some of the tools used during the research were acquired within the framework of the "Investigation of the conditions for the cultivation of wood biomass - GINOP-2.3.3-15-2016-00039" project.

Increasing carbon presence in the atmosphere prompts scientists to understand carbon sequestration processes better. Forest is one of the most promising ecosystems where this sequestration can take place with higher efficiency. In this research, we analysed long-term land use change processes and carbon content of soils in present Hungarian forests, searching for the answer: is there any relationship between the former land use and the carbon content of soils?We selected 183 forest stands scattered across the country, where the age of the trees were approximately 60-70 years old. Soil samplings were carried out in the depth of 40-110 cm (in 10 cm layers). In order to derive long-term land use change information, we used historical map series dating back to the 18th century.Results will contribute to the understanding of the carbon sequestration processes of terrestrial ecosystems.This article was made in frame of the project TKP2021-NKTA-43 which has been implemented with the support provided by the Ministry of Innovation and Technology of Hungary (successor: Ministry of Culture and Innovation of Hungary) from the National Research, Development and Innovation Fund, financed under the TKP2021-NKTA funding scheme.

Aiming at a deeper understanding of long-term feedback and interactions, here we reconstructed the changing socio-ecological system of a 9931 km2 wetland landscape over the last millennium. The study area is situated in the steppe-forest zone representing a major part of World Heritage inland salt grasslands in Europe.Merging GIS-based historico-geographical and archaeo-topographical records from the 11th–mid-16th centuries, detailed spatiotemporal dynamics of settlement patterns, and random information on vegetation and economic activities were reconstructed. Testing the mean elevation of archaeological remains of settlements (sites) and the average soil agro-suitability in their buffer zones by non-parametric t-tests we found an extensive dispersion of settlements in the fertile deep floodplains at the turn of the 11th and 12th centuries but this reclaimed flood zone had been abandoned by the early 14th century. Statistical test results also suggested that the late medieval (LMA) (14th–mid-16th centuries) group was situated significantly higher than the high medieval (HMA) group (late 10th–13th centuries), and the deserted settlements were situated lower than the permanently settled group. Certain geomorphological formations, floodplain islands, and low fluvial ridges became scenes of settlement abandonment, while a dynamic concentration took place on high ridges. These outcomes suggest that the settlement pattern shrunk and vertically displaced significantly by the 14th-century beginning of the Little Ice Age (LIA) when hydrological challenges emerged all over Europe.Testing the statistical-based settlement-indicated-flood-zone method in a 237 km2 area by an integrated hydrological model concerning the elevation of sites, we simulated the HMA, LMA, and late 18th-century extension of flood zones.However, not only climatic conditions but anthropogenic transformation in runoff conditions of the upper catchment may also have triggered hydrological challenges in the low-lying plains. The reconstructed transformation of medieval settlement patterns in the Tisza basin (157000 km²) suggests that tens of thousands of square kilometers of virgin forests could have been destroyed in that age. Adapting to a changing hydro-climatic and socio-economic environment a complex community-based ‘livestock-water-crop farming’ trinity evolved, and livestock breeding and export became the strategic sector in the plain over the next centuries.The socio-economic basis of mixed farming collapsed by the 18th century. As a response to chronic socio-economic backwardness and emerging hydro-climatic challenges, the aristocratic elite began the biggest river regulation in 19th-century Europe, which transformed the plain into a homogenous agricultural area (1950s cropland covering ~70 %). However, this adaptation strategy failed, and the land use regime of the plain has fallen into a longstanding crisis today. To demonstrate this transformation between the late 18th century (water cover ~30 %) and today (water cover

The presence of soil fauna is essential for healthy soil life. As part of the soil mesofauna, Collembola are significant contributors to humus formation and the spread of mycorrhizal fungi, which are of major importance for plants, and they also help to decompose organic matter and mineralise the soil. Among the soil parameters, organic matter content is one of the most significant determinants of the abundance and diversity of Collembola. Our study aimed to explore these relationships in a forest-open landscape mosaic in a dry, sandy area in the Danube-Tisza Mid-Region of Hungary. Soil samplings were carried out in different forest types and nearby open areas (grassland and abandoned cultivated habitats). Five non-destructive soil samples of 100 cm3 were taken at each site using a soil corer with a 3.6 cm diameter and a 10 cm depth for the soil fauna survey. In total, 2,018 specimens from 13 families, and 49 species were sampled and identified. We used a multivariate ordination method (CCA) to investigate the relationship of individual species and life forms to specific soil parameters. It was found that mainly hemiedaphic species (such as Appendisotoma franzi, A. juliannae, Lepidocyrtus nigrescens) showed the strongest connection to soil organic matter. In contrast, euedaphic species (e.g., Doutnacia xerophila, Mesaphorura krausbaueri, Protaphorura cancellata) showed a weaker binding. The epedaphic, soil surface-dwelling species (e.g., Entomobrya multifasciata, Orchesella cincta) did not show a strong preference for soil organic matter content or other soil parameters. Based on similarity analyses (cluster analysis, Bray-Curtis distance), open habitats showed a distinct separation according to the Collembola species composition and abundance.This article was made in frame of the project TKP2021-NKTA-43 which has been implemented with the support provided by the Ministry of Innovation and Technology of Hungary (successor: Ministry of Culture and Innovation of Hungary) from the National Research, Development and Innovation Fund, financed under the TKP2021-NKTA funding scheme.

The beech stands ratio of Hungarian forests barely reaches 6%. However, beech is a native tree species with high production capacity; therefore, its importance in nature conservation and economy is significant. Due to global climate change, the focus is on the ability of carbon fixing and storage capacity in beech forest ecosystems. While we can estimate the amount of biomass above ground with relative precision, we have little data about organic carbon in soils.The primary goal of our work was to collect as much data as possible on the amount of organic carbon stored in the soil of these native forest stands. Furthermore, the most significant factors were determined that influenced the sequestration.During the research, undisturbed and disturbed soil samples were collected from every 10 cm layer in 40 beech stands. The depth depended on the bedrock. On loessy or sandy bedrock, the depth was 110 cm. In the case of rocky structure, samples were taken from 0-40 cm depth. Moreover, litter samples were taken and analyzed. The properties of the stands were also recorded on the sampling sites (tree species, diameter, etc.).The soil pH was 5.17 on average, while the minimum value was 3.87 and the maximum was 8.4. The humus content varied between 0.16 and 15.65% because it decreased with depth. The average organic carbon stock was 6.39 C t/ha (Cminimum 1.46 C t/ha, Cmaximum 34.03 C t/ha). Moisture determines the organic carbon stock of the soil most of all.This article was made in the frame of the project TKP2021-NKTA-43 which has been implemented with the support provided by the Ministry of Innovation and Technology of Hungary (successor: Ministry of Culture and Innovation of Hungary) from the National Research, Development and Innovation Fund, financed under the TKP2021-NKTA funding scheme. Some of the tools used during the research were acquired within the framework of the "Investigation of the conditions for the cultivation of wood biomass - GINOP-2.3.3-15-2016-00039" project.