To analyse the capacity of a soil to sequester organic carbon and the impact that deforestation and reforestation can have on its physical and chemical properties, specific laboratory analyses are necessary. According to a standard methodology, a number of 16 samples were taken from two different depths (0–10 cm, 10–20 cm) and from two different areas (degraded area and forest area) to identify if the type of land use and sampling depth are the key factors in changing the obtained values and also to prove the hypothesis according to which forest lands may have a higher carbon sequestration capacity. The highest value of soil organic carbon was identified in the forest area at a depth of 0–10 cm. The organic carbon values relative to the surface indicated a higher average in the forest area with a value of 36.19 t/ha, compared to the degraded area, with a value of 32.07 t/ha which indicated a greater capacity of carbon sequestration in forest lands. The forest lands also indicated the highest water holding capacity, with values of up to 100% at a depth of 0–10 cm. The higher values of organic carbon, its sequestration capacity and water holding capacity values in the forest lands compared to the values obtained on the degraded lands and at the surface of 0–10 cm compared to the depth of 10–20 showed that the type of land use and sampling depth influences the physico-chemical properties of the soil and leads to a visibly greater capacity to sequester carbon. These results match the expected ones and support our hypothesis

This study aims to assess the pollution history of persistent organic pollutants (POP) in lake Muntinu, Carpathian Mountains, Romania. Gamma spectrometry was used to measure 210Pb and 137Cs radionuclides in order to determine the age of sediment layers. The target compounds were isolated from sediment samples by ultrasound-assisted extraction method, followed by purification of extracts using open-column chromatography. 16 polycyclic aromatic hydrocarbons (PAHs), 20 organochlorine pesticides (OCPs) and 12 polychlorinated biphenyls (PCBs) were analysed in each dated sediment layer using gas chromatography coupled with mass spectrometry or electron capture detector. The results show that, over the past 100 years, POP concentrations from sediment samples ranged from 2.53 to 156.27 ng/g for PAHs, from 1.78 to 71.12 ng/g for OCPs, and from not detected to 76.03 ng/g for PCBs. PAHs diagnostic ratios such as ƩLMW/ƩHMW, ANT/(ANT+PHE) and FLT/(FLT+PYR) show that the main source of PAHs in the sediment is of pyrogenic nature, especially from biomass and coal combustion. The sources of OCPs and PCBs could not be determined due to the lack of data obtained. However, the study demonstrates that the analysis of POP residues in sediments is a suitable method for reconstructing the history of surface water pollution.

The Cluj Metropolitan Area is located in Cluj County, the north-western development region of Romania. The strategic option of polycentric territorial development was adopted on the basis of the principles outlined in the NDP (National Development Plan)- on spatial development at regional level. This involves supporting development processes within urban growth pole. The associative structure at the Cluj Metropolitan Area (CMA) was formed at the end of 2008, continuing the efforts to establish a metropolitan area with economic specificity, initiated by Cluj County Council in 2006. Communes included in Cluj Metropolitan Area are also part of different micro-regional associations with relatively homogeneous characteristics. These associations were formed at the initiative of city halls and they have legal personality.

This paper aims to investigate the environmental impact of uncontrolled urban sprawl on the peri-urban Fagetul Clujului wooded area. This area is a partially conserved peri-urban forest and a ROSCI Natura 2000, located in the southwestern part of Cluj-Napoca Municipality in Romania. To assess the environmental impact, a standardized checklist based on national regulations and a modified rapid impact assessment matrix (RIAM) were used to obtain environmental scores for 30 key points in the area. The QGIS and IDW (Inverse Distance Weighting) methods were used to combine the main assessment scores to create a general impact map. The assessment outcomes confirm that there are significant negative impacts on environmental components in this peri-urban wooded area, such as abiotic and biotic components, in those peripheral areas that are recently built, developed, or expanding. This study provides an effective, transparent, and integrated methodology for assessing the impact of uncontrolled urban sprawl on the environment. It can help local decision-makers and experts in designing and developing sustainable strategies for environmental management and urban planning.

Groundwater quality is a key factor and a critical determinant of public health, agriculture, and socio-economic development, particularly in regions where private wells and mineral springs constitute the primary water sources. This study presents an integrated hydrochemical, radiological, and toxicological assessment of groundwater in the Sângeorz-Băi area, Romania, a spa region where mineral waters hold both therapeutic and economic significance. Samples from mineral springs, the municipal supply system, and private wells were analyzed to evaluate compliance with national and international standards and to assess their suitability for drinking, therapeutic, and agricultural purposes. The results reveal distinct hydrochemical contrasts between sources. Mineral springs are characterized by elevated salinity, hardness, and Na–HCO₃ facies, whereas the municipal network and private wells are dominated by Ca–HCO₃ facies. More than half of the private wells exceeded permissible limits for NO₃⁻, NO₂⁻, NH₄⁺, Pb, and Fe, with one well posing a significant nitrite-related health risk. Trace metal analysis indicated localized enrichment in Cu, Fe, and Pb. Radon and radium activities generally complied with regulations, although radium occasionally exceeded the more stringent WHO guidelines. Seasonal variation was minimal, reflecting stable groundwater chemistry. Health risk and irrigation assessments suggest that municipal supply water is largely safe for consumption, while private wells require targeted monitoring and mitigation. Despite elevated Na⁺ and Cl⁻, mineral springs retain therapeutic value under controlled use. This study provides a replicable framework for groundwater quality assessment in spa regions and offers critical insights for public health protection, sustainable tourism, and agricultural resilience.

Land leveling deep-seated landslides for agricultural use alters soil profile integrity and soil functionality. In the mid-20th century, such interventions in the Transylvanian Basin (Romania) involved grading and converting landslide bodies into arable land. This study evaluates the consequences of interventions on soil physicochemical properties and erosion susceptibility in the case of two deep-seated landslides. Soil samples collected from leveled landslide bodies were analyzed for pH, total nitrogen, available phosphorus (P-AL), available potassium (K-AL), calcium carbonates, humus content, and texture. The results, in the case of the two studied deep-seated landslides, indicate contrasts between areas where the Ah horizon is preserved and where leveling exposed the C horizon or parental material at the surface. Exposed zones exhibit reduced nitrogen and humus content, altered textures, and higher carbonate influence, indicating lower fertility potential despite 65 years of pedogenesis. Spatial assessment using Sentinel-2-derived NDMI and USLE-based erosion modelling confirms increased moisture stress and higher erosion susceptibility in areas with exposed substratum. These findings demonstrate that the leveling of the two studied deep-seated landslide bodies, although effective in expanding arable surfaces, leads to persistent soil degradation patterns and reduced agro-ecological resilience. Sustainable cultivation of such terrains requires targeted soil conservation measures, including erosion control and adapted land management practices. The results provide important implications for land-use planning in landslide-prone agricultural landscapes.