Search Results (4)

Rapid urban growth leads to an extension of artificial surfaces and inefficient energy management, an increase in urban heat islands, and local climate change. This has increased the need for green infrastructure and urban trees are playing an important role. It is important to ensure that tree groups can withstand climate warming and disturbances. This study investigated the physiological parameters of Tilia tomentosa ‘Seleste’ trees situated in a medium-sized Hungarian city, examining their relationship with microclimatic differences observed on opposing sides of a street. Instruments placed on 10 trees recorded air temperature and humidity, revealing a significant difference in total insolation, which resulted in higher maximum daily temperatures on the sunny side. These microclimatic variations were found to significantly affect physiological attributes, particularly pigment content. Trees on the sunny side exhibited a higher relative water content and a higher ratio of chlorophyll a/b, indicative of light acclimatisation. Trees on the sunny side exhibited a higher relative water content and a higher ratio of chlorophyll a/b, indicating an acclimatisation to light. Furthermore, a positive correlation was observed between pigment content, total insolation, and growing degree days. The findings demonstrate how fine-scale microclimate differences influence tree physiology, providing crucial physiological indicators that inform the capacity of urban trees to provide vital ecosystem services, such as local climate regulation. This emphasises the importance of climate-conscious urban planning, as even small-scale climate change can have a broader impact. Full article

The treatment of wastewater and the utilization of the by-products of these processes are an important part of the circular economy. The sewage sludge, a result of wastewater treatment, could be used as a material for plant nutrient supply and/or soil-improving products. The city of Nyíregyháza, Hungary, with 120,000 citizens, has a well-planned water treatment plant operated by Nyírségvíz Ltd., which, in cooperation with the Research Institute of Nyíregyháza, developed a municipal sewage sludge compost (SSC). The closed loop of sewage water treatment and the agricultural utilization of its by-product has been developed and managed. The compost product called Nyírkomposzt was planned for acidic sandy soils. Beyond the agronomic benefits, the sustainable and environmentally sound utilization of SSC reduces sewage sludge disposal. This active involvement of a water utility company demonstrates the potential of cross-sectoral cooperation in solving environmental problems. The quality of the compost fits the Hungarian legislation. To study the effects of 0, 9, 18, and 27 t ha⁻¹ doses of compost on acidic sandy soil, a long-term small plot experiment was started in 2003. The cumulative effects of the regular (every third year, last treatment before sampling in 2021) application of the SSC showed positive changes in basic soil properties, depending on the doses used. Increasing values were found in the case of pH from 4.5 to 6, plant available P₂O₅ from 240 to 690 ppm, and plant available K₂O from 180 to 200 ppm. The plant-available zinc and copper content also increased. Soil organic matter and total N content stabilized at around 0.9% and 0.08%, respectively. The grain yields of winter rye also increased in both investigated years. The yields of 18 t ha⁻¹ treatment were about two times higher compared to the control, but only in 2022 was the difference significant. Our findings underscore the potential of well-planned SSC applications to improve the fertility of ploughed, acidic sandy soil, taking into account the theory of the circular economy by utilizing wastes and decreasing landfilling. Full article

The Hungarian water management plan has lately identified 185 groundwater bodies based on the concepts given by the European Water Framework Directive. Achieving and maintaining the good quantitative and chemical status of these groundwater bodies is of primary importance. It is demonstrated how innovative hydrogeophysical methods can be applied successfully to assess the Hungarian or other international groundwater bodies. By applying geoelectric methods, horizontal layering or large uniform rock units can be well characterized by Wenner–Schlumberger array, also enabling accurate depth determination of the shallow groundwater table. Horizontal variations in the rock type or its state can be well described by dipole–dipole array or, even better, by the newly developed quasi-null arrays. Their joint application may be very straightforward to investigate different aquifer types by giving high-resolution resistivity images as input for hydrogeological modeling. In the identification of porous formations, multivariate statistical interpretation of wireline logs using cluster analysis allows reliable lithological separation of potential aquifers. Their clay content is estimated by robust factor analysis, while their hydraulic properties are directly derived from the resistivity log. For a more effective interpretation, a combination of surface and borehole geophysical methods can be recommended for meeting challenges in hydrogeology and groundwater management. Full article

Observing wetland areas and monitoring changes are crucial to understand hydrological and ecological processes. Sedimentation-induced vegetation spread is a typical process in the succession of lakes endangering these habitats. We aimed to survey the tendencies of vegetation spread of a Hungarian lake using satellite images, and to develop a method to identify the areas of risk. Accordingly, we performed a 33-year long vegetation spread monitoring survey. We used the Normalized Difference Vegetation Index (NDVI) and the Modified Normalized Difference Water Index (MNDWI) to assess vegetation and open water characteristics of the basins. We used these spectral indices to evaluate sedimentation risk of water basins combined with the fact that the most abundant plant species of the basins was the water caltrop (Trapa natans) indicating shallow water. We proposed a 12-scale Level of Sedimentation Risk Index (LoSRI) composed from vegetation cover data derived from satellite images to determine sedimentation risk within any given water basin. We validated our results with average water basin water depth values, which showed an r = 0.6 (p < 0.05) correlation. We also pointed on the most endangered locations of these sedimentation-threatened areas, which can provide crucial information for management planning of water directorates and management organizations. Full article