Natural and anthropogenic impacts reflected by paleoclimate proxy parameters in a lake-forest system in Bukovina, Romania

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.

Vertical differentiation of pedogenic iron forms – a key of hydromorphic soil profile development

This paper focuses on the vertical distribution and characterisation of pedogenic iron forms in a Gleysol- Histosol transect developed in a marshy area in the Danube-Tisza Interfluve, Hungary. Four soil profiles were investigated along a series of increasing waterlogging and spatial and temporal patterns of hydromorphic pedofeatures (characteristics of pedogenic iron forms) were recorded. Frequent and wide-range redox potential (Eh) changes caused the emergence of many types of redoximorphic iron features, including mottles, plaques and nodules. The forms of these features depended on the micro-environments determined by the vertical position in the soil profile and the presence of plant roots. The greatest iron enrichment occurred in the zone of most intensive and widest-range redox fluctuations. Increasing water saturation resulted the extension of gleyic pattern due to the existence of permanent reduction. Most of the features also showed annual variations during the varying periods of water saturation and aeration.

The role of temperature and the NAO index in the changing snow-related variables in European regions in the period 1900-2010

Snow-related variables are analysed in the present paper in the period 1901‒2010 on the basis of the ERA-20C dataset. Relationships between different snow characteristics, temperature and the NAO index are investigated on monthly, yearly and decadal scales for eight regions within Europe representing different climatic types (i.e. oceanic, continental, polar) to analyse the differences and similarities between them depending on the climatic conditions. According to our results, the ratio of snow (i.e. snowfall compared to total precipitation) can reach 1 in winter in the colder, northern regions, whereas it is about 0.6 in the continental areas of Central Europe, even in the coldest months. During a strong positive phase of NAO more snow falls in the northern regions of Europe due to the large-scale circulation characteristics. When a negative NAO phase occurs, the temperature and snowfall anomalies are the opposite in northern Europe. The highest temperature values generally occurred after 2000, and the snowfall amount was smaller in the first decades of the 21st century compared to the previous decades. The relationship between temperature and snowfall is the strongest in autumn in the colder regions; in spring in the continental areas and in winter in the oceanic climate.

Green infrastructure-based hydrological modelling, a comparison between different urban districts, through the case of Szeged, Hungary

Because of the climate uncertainties caused by climate change and the growing urban areas, today’s cities face new environmental challenges. The impervious artificial elements change the urban water cycle. Urban districts with inadequate water infrastructure and treatment can be a major source of environmental risks, like urban flash floods. Modern cities need to be prepared for the changing environment in a sustainable way, which can be realised with the help of green infrastructure. The primary role of the green infrastructure is mitigation, such as surface runoff reduction and retainment. The aim of our research is to examine urban district scale data about the role of green infrastructure in urban water management. Hydrological models can provide adequate data about the surface runoff, infiltration and the mitigating effect of vegetation (interception and evaporation). We compared two significantly different urban districts (downtown and housing estate area), based on land cover and vegetation data. The analysis of the districts of Szeged (Hungary) suggests that the vegetation can significantly contribute to the reduction of surface runoff. Differences between these urban districts can be quantified, thus, these data can serve as a basis for urban water management planning processes.

Residential suburbanisation in the hinterland of Bratislava – a case study of municipalities in the Austrian border area

This paper provides an overview of the process of residential suburbanisation in the hinterland of Bratislava. The study focuses on the municipalities around the Austrian border area. The main aim of the paper is to investigate the characteristics of cross-border suburbanisation, which is a significant spatial phenomenon in the municipalities of northern Burgenland and the south-eastern part of Lower Austria. The analysis has a spatio-temporal dimension, as it depicts the time-space characteristics of the phenomenon – both for a single time point, as well as for a time series from the approximate beginning of the onset of suburbanisation up to the present. While monitoring the growth of the number of Slovaks in the study area, we observed a gradual increase in all the selected municipalities of the Austrian border area, with the distance from Bratislava being a significant factor here. The analysis of migration in the surveyed municipalities showed predominantly positive migration efficiency – immigration was negated by emigration only to a small extent (compared to suburbanisation in the Slovak hinterland of Bratislava, which is, however, relatively high). The structural characteristics of Slovak immigrants, where the younger age group of 30 to 44 years followed by a child component up to 14 years predominated, attest to the ongoing process of suburbanisation. The research confirmed the advancing residential suburbanisation and expansion of the cross-border suburban hinterland of Bratislava.

Natural reduction of Ukraine’s population: Regional dimensions of the national threat

A significant decline in Ukraine’s population is mainly due to its natural decrease, which began in the 1970s and 1980s in the rural areas and had been determined by the objective trends in demographic transition, the inertia effect of the demographic losses in the past and the social policy of the political regime at that time. Likewise, the social and economic crisis of the 1990s deepened the depopulation processes. In the present research, correlation analysis demonstrated a relationship between the current dimensions of natural population decline and a number of socio-demographic factors (proportion of the rural population, mean age of the population, divorce rate and the mean age at first marriage). In recent years, the effects of the demographic crisis have been particularly acute in North-eastern and Central Ukraine, due to the deepening disproportions in the age and sex structures of the population. However, in the capital of Ukraine, Kyiv, and in some western regions, the natural decrease in population is less acute because of more balanced social and demographic indicators. Although religious and ethnic factors contribute to some extent to greater natural population growth, especially in the western and south-western regions, their impact on the processes of population reproduction in Ukraine is generally not significant. To sum up, in order to stop natural population decline in Ukraine, it is important to ensure more favourable conditions for demographic development in the economic, social, informational and cultural spheres of society. Furthermore, in areas of acute demographic crisis, it is important to raise the issue of rural reconstruction involving a variety of organisational and economic mechanisms.