Long-term land-cover/use change in a traditional farming landscape in Romania inferred from pollen data, historical maps and satellite images

Traditional farming landscapes in the temperate zone that have persisted for millennia can be exceptionally species-rich and are therefore key conservation targets. In contrast to Europe’s West, Eastern Europe harbours widespread traditional farming landscapes, but drastic socio-economic and political changes in the twentieth century are likely to have impacted these landscapes profoundly. We reconstructed long-term land-use/cover and biodiversity changes over the last 150 years in a traditional farming landscape of outstanding species diversity in Transylvania. We used the Regional Estimates of Vegetation Abundance from Large Sites model applied to a pollen record from the Transylvanian Plain and a suite of historical and satellite-based maps. We documented widespread changes in the extent and location of grassland and cropland, a loss of wood pastures as well as a gradual increase in forest extent. Land management in the socialist period (1947–1989) led to grassland expansion, but grassland diversity decreased due to intensive production. Land-use intensity has declined since the collapse of socialism in 1989, resulting in widespread cropland abandonment and conversion to grassland. However, these trends may be temporary due to both ongoing woody encroachment as well as grassland management intensification in productive areas. Remarkably, only 8% of all grasslands existed throughout the entire time period (1860–2010), highlighting the importance of land-use history when identifying target areas for conservation, given that old-growth grasslands are most valuable in terms of biodiversity. Combining datasets from different disciplines can yield important additional insights into dynamic landscape and biodiversity changes, informing conservation actions to maintain these species-rich landscapes in the longer term

Ice genesis and its long-term mass balance and dynamics in Scărişoara Ice Cave, Romania

The paleoclimatic significance of the perennial ice deposit in Scărişoara Ice Cave has been remarked on since the early 20th century, but a lack of understanding of the processes involved in the genesis, age and long-term dynamics and volume fluctuations of ice hampered all attempts to extract valuable data on past climate and vegetation changes. In this paper, we present a model of ice genesis and dynamics, based on stable isotopes, ice level monitoring (modern and archived) and radiocarbon dating of organic matter found in the ice. Ice in this cave mostly consists of layers of lake ice, produced as liquid water freezes from top to bottom in mid-autumn, and floor ice, produced as inflow water in winter freezes on top of the lake ice. This mechanism was also acting in the past, during the Medieval Warm Period and the Little Ice Age. The ice block is not stable in shape and volume, being continuously modified by ablation on top and sides, basal melting and lateral flow. Radiocarbon dating shows that the ice block is older than 1000 years, but ice flow and differential basal melting suggesting that the ice could be much older

Transfer of environmental signals from the surface to the underground at Ascunsă Cave, Romania

We present here the results of a 4-year environmental monitoring program at Ascunsă Cave (southwestern Romania) designed to help us understand how climate information is transferred through the karst system and archived by speleothems. The air temperature inside the cave is around 7 °C, with slight differences between the upper and lower parts of the main passage. CO2 concentrations in cave air have a seasonal signal, with summer minima and winter maxima. These might indicate the existence of an organic matter reservoir deep within the epikarst that continues to decompose over the winter, and CO2 concentrations are possibly modulated by seasonal differences in cave ventilation. The maximum values of CO2 show a rise after the summer of 2014, from around 2000 to about 3500 ppm, following a rise in surface temperature. Using two newly designed types of water–air equilibrators, we were able to determine the concentration of CO2 dissolved in drip water by measuring its concentration in the equilibrator headspace and then using Henry's law to calculate its concentration in water. This method opens the possibility of continuous data logging using infrared technology, without the need for costly and less reliable chemical determinations. The local meteoric water line (δ2H  =  7.7 δ18O + 10.1), constructed using monthly aggregated rainfall samples, is similar to the global one, revealing the Atlantic as the strongly dominant vapor source. The deuterium excess values, as high as 17 ‰, indicate that precipitation has an important evaporative component, possibly given by moisture recycling over the European continent. The variability of stable isotopes in drip water is similar at all points inside the cave, suggesting that the monitored drip sites are draining a homogenous reservoir. Drip rates, as well as stable isotopes, indicate that the transfer time of water from the surface is on the order of a few days

Climate Variability and Associated Vegetation Response throughout Central and Eastern Europe (CEE) between 60 and 8 ka

Records of past climate variability and associated vegetation response exist in various regions throughout Central and Eastern Europe (CEE). To date, there has been no coherent synthesis of the existing palaeo-records. During an INTIMATE meeting (Cluj Napoca, Romania) focused on identifying CEE paleo-records, it was decided to address this gap by presenting the palaeo-community with a compilation of high-quality climatic and vegetation records for the past 60–8 ka. The compilation should also serve as a reference point for the use in the modelling community working towards the INTIMATE project goals, and in data-model inter-comparison studies. This paper is therefore a compilation of up to date, best available quantitative and semi-quantitative records of past climate and biotic response from CEE covering this period. It first presents the proxy and archive used. Speleothems and loess mainly provide the evidences available for the 60–20 ka interval, whereas pollen records provide the main source of information for the Lateglacial and Holocene. It then examines the temporal and spatial patterns of climate variability inferred from different proxies, the temporal and spatial magnitude of the vegetation responses inferred from pollen records and highlights differences and similarities between proxies and sub-regions and the possible mechanisms behind this variability. Finally, it identifies weakness in the proxies and archives and their geographical distribution. This exercise also provides an opportunity to reflect on the status of research in the area and to identify future critical areas and subjects of research

Climate variability and associated vegetation response throughout Central and Eastern Europe (CEE) between 60 and 8 ka

Abstract Records of past climate variability and associated vegetation response exist in various regions throughout Central and Eastern Europe (CEE). To date, there has been no coherent synthesis of the existing palaeo-records. During an INTIMATE meeting (Cluj Napoca, Romania) focused on identifying CEE paleo-records, it was decided to address this gap by presenting the palaeo-community with a compilation of high-quality climatic and vegetation records for the past 60–8 ka. The compilation should also serve as a reference point for the use in the modelling community working towards the INTIMATE project goals, and in data-model inter-comparison studies. This paper is therefore a compilation of up to date, best available quantitative and semi-quantitative records of past climate and biotic response from CEE covering this period. It first presents the proxy and archive used. Speleothems and loess mainly provide the evidences available for the 60–20 ka interval, whereas pollen records provide the main source of information for the Lateglacial and Holocene. It then examines the temporal and spatial patterns of climate variability inferred from different proxies, the temporal and spatial magnitude of the vegetation responses inferred from pollen records and highlights differences and similarities between proxies and sub-regions and the possible mechanisms behind this variability. Finally, it identifies weakness in the proxies and archives and their geographical distribution. This exercise also provides an opportunity to reflect on the status of research in the area and to identify future critical areas and subjects of research