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Lake sediments are valuable archives and can help construct a chronology of event deposits induced by seismic events. Such a chronology can be used to better understand the recurrence times between seismic events over longer periods than those covered by historical seismicity catalogs. However, only a few studies in lake palaeoseismology have focused on areas with moderate seismicity. This study aims to improve the catalog of paleoseismological archives in the front of the Western Alps. In this part, new multi-proxy data from the sedimentary archives of Lake Aiguebelette (France) allow the identification of 32 homogenites (thickness ≥ 0.5 cm) interpreted as of coseismic origin over the Holocene. An age model based on short-lived radionuclides, paleomagnetic data and radiocarbon ages constrains the chronology of sedimentary deposits in the deep basin of Lake Aiguebelette. Among these homogenites, several were deposited at time intervals compatible with historical seismic events. To correlate the historical seismic events likely to have generated the event deposits identified in the sedimentary sequences of the deep basin of Lake Aiguebelette, the Earthquake Sensitivity Threshold Index (ESTI) method is used. Historical seismicity catalogs with uncertainties about intensities and epicenter coordinates for earthquakes make correlations to event deposits difficult. To better understand which seismic events may have been archived, a relative comparison was conducted between the pseudospectral acceleration (PSA) values calculated for each event in the FCAT-17 seismic catalog and for two distinct frequencies. Based on this PSA approach, for higher frequencies (5 Hz), the contribution of nearby and moderate events is significantly stronger than that of strong and distant events in the lake sequence of Aiguebelette. Thus, the chronicle established based on the event deposits archived in Lake Aiguebelette sediment is interpreted as representative of local events (epicentral distance to the lake < 50 km). Recurrence intervals between the deposition of event layers do not follow a specific distribution (log-normal, Weibull, gamma or exponential) but might be a combination of several distributions. This suggests possible coexistence of several processes over the Holocene, impacting the evolution of the seismicity in this area. [ABSTRACT FROM AUTHOR]

The trajectories of mountain socio-ecosystems are complex and influenced by numerous factors (climate, human practices, slope, etc.). This study combined methods used in palynology, ecology and history to produce complementary data to improve understanding of the trajectories of an alpine socio-ecosystem over the last 500 years. Past changes in vegetation cover and land use were reconstructed along with their impacts on erosion dynamics in Montainmont, a commune in the French Alps. A paleoenvironmental analysis (pollen, coprophilous fungi, sedimentology, geochemistry) was conducted on lake sediment, providing a 500-year record of vegetation and erosion dynamics, and mixed farming history. The historical analysis focused on the reconstruction of the customs and habits of the community of Montaimont through the examination of the historical archives of their administrative district. The historical records provided quantitative data on changes in the forest at the plot scale and qualitative information on landscape management. The ecological approach focused on land use analyses using photo-interpretation of aerial ortho-photographs since the 1950s. This data set was used to conduct a spatially explicit analysis of social-environmental interactions in the past. By combining the three approaches, we were able to document changes in vegetation cover over time as well as changes in forestry and agricultural activities. Our analyses reveal a key tipping point during the past century. The community of Montaimont originally used its landscape for mixed farming activities coupled with intensive exploitation of the forest. During the twentieth century, a major socio-ecological change occurred when crop farming ceased, and forest use decreased. This land abandonment led to spontaneous reforestation. This study demonstrates that an interdisciplinary approach bridges the blind spots inherent to each disciplinary approach, facilitating a better understanding of socio-ecological trajectories. [ABSTRACT FROM AUTHOR]

This paper presents the results of archaeobotanical studies carried out on the Late Mesolithic layer at Melnychna-Krucha (6460–6100 cal BC) and the Linearbandkeramik (LBK) site of Kamyane-Zavallia (5295–4960 cal BC), close to the Southern Bug River. Despite the relatively modest dataset presented in this paper, these preliminary results provide new data for a region where the environmental setting and the uses of plant resources during the Early Atlantic period are poorly understood. The main taxa used for firewood are quite similar at Melnychna-Krucha and Kamyane-Zavallia, although they were occupied 1000 years apart. Fraxinus (ash) and Quercus (oak) dominate both charcoal assemblages. These taxa, as well as Ulmus (elm), could have grown together in the alluvial deciduous forest, probably on the Southern Bug riverbank, close to both sites. Carpinus (hornbean) was present but probably still not abundant around Kamyane-Zavallia at the end of the 6th millennium. Macroremains and phytoliths demonstrate that the plant production economy (cultivation, cereal processing) was well developed and very similar to other European LBK sites. At Melnychna-Krucha, plant macro- and microremains did not indicate a productive subsistence. [ABSTRACT FROM AUTHOR]

Since the last glacial maximum, soil formation related to ice‐cover shrinkage has been one major sink of carbon accumulating as soil organic matter (SOM), a phenomenon accelerated by the ongoing global warming. In recently deglacierized forelands, processes of SOM accumulation, including those that control carbon and nitrogen sequestration rates and biogeochemical stability of newly sequestered carbon, remain poorly understood. Here, we investigate the build‐up of SOM during the initial stages (up to 410 years) of topsoil development in 10 glacier forelands distributed on four continents. We test whether the net accumulation of SOM on glacier forelands (i) depends on the time since deglacierization and local climatic conditions (temperature and precipitation); (ii) is accompanied by a decrease in its stability and (iii) is mostly due to an increasing contribution of organic matter from plant origin. We measured total SOM concentration (carbon, nitrogen), its relative hydrogen/oxygen enrichment, stable isotopic (13C, 15N) and carbon functional groups (C‐H, C=O, C=C) compositions, and its distribution in carbon pools of different thermal stability. We show that SOM content increases with time and is faster on forelands experiencing warmer climates. The build‐up of SOM pools shows consistent trends across the studied soil chronosequences. During the first decades of soil development, the low amount of SOM is dominated by a thermally stable carbon pool with a small and highly thermolabile pool. The stability of SOM decreases with soil age at all sites, indicating that SOM storage is dominated by the accumulation of labile SOM during the first centuries of soil development, and suggesting plant carbon inputs to soil (SOM depleted in nitrogen, enriched in hydrogen and in aromatic carbon). Our findings highlight the potential vulnerability of SOM stocks from proglacial areas to decomposition and suggest that their durability largely depends on the relative contribution of carbon inputs from plants. [ABSTRACT FROM AUTHOR]

The nature and timing of environmental changes throughout the last glacial-interglacial transition in the South Caucasus, and more widely in eastern Europe, are still not fully understood. According to certain pollen records, forest expansion occurred in many areas several millennia after what is considered worldwide as the onset of the Holocene. The current problem we face is that the time lag in forest expansion varies from one sequence to another, sometimes with no delay at all. Moreover, the potential forcing/controlling factors behind this complex pattern, contrary to the almost synchronous global Holocene warming, are still a matter for debate. Accordingly, we revisit the issue of forest expansion through vegetation history obtained in the South Caucasus using a new pollen record, retrieved from the Nariani paleolake (South Georgia). These data attest to a steppic phase, initially dominated by Amaranthaceae-Chenopodiaceae (12,700–10,500 cal yr BP), then by Poaceae (10,500–9000 cal yr BP), culminating with a more forested phase (9000–5000 calyrBP). Although some palaeoclimatic regional reconstructions show a wet early Holocene, we interpret the delay in forest expansion recorded in Nariani (2500 years) as the result of reduced spring precipitation, which would have limited forest development at that time. [ABSTRACT FROM PUBLISHER]

This paper contributes to understand the palaeoenvironment and the exploitation of vegetal resources during the Mid-Holocene in the southern Crimean Mountains. To address these questions, we apply a multi-proxy approach based on charcoal, seeds/fruits and phytoliths analyses from Neolithic layers (5800-5300 cal BC) of Buran-Kaya IV, a rock-shelter located in the south of Crimean Peninsula. Charcoal analysis shows that the Neolithic groups have exploited the Quercus petraeae forest belt composed mainly of Quercus, Carpinus and Acer. The identification of Fagus and a fragment of gymnosperm, which developed in upland areas, suggests the mobility of inhabitants of BK IV. According seed and phytolith analyses, it is more likely that the Neolithic groups did not practice agriculture on the site, and that their diet was not based on crop production. Furthermore, considering the probable absence of domestic animals in the layer 2, the economy may essentially be based on hunting-gathering at Buran Kaya IV. [ABSTRACT FROM AUTHOR]

The aim of this study is to directly radiocarbon date pottery from prehistoric rock-art shelters in the Tassili n'Ajjer (central Sahara). We used a combined geochemical and microscopic approach to determine plant material in the pottery prior to direct 14C dating. The ages obtained range from 5270 ± 35 BP (6276-5948 cal BP) to 8160 ± 45 BP (9190-9015 cal BP), and correlate with the chronology derived from pottery typology. Our results document the transition from pre-Pastoral to Pastoral contexts, dated to the early-mid Holocene transition, and confirm that vegetal temper in pottery can provide reliable 14C ages within Saharan contexts. [ABSTRACT FROM AUTHOR]

The Shi'bat Dihya 1 site in western Yemen, dated by optically stimulated luminescence to 55 ka, provides insight into the Middle Paleolithic peopling of the Arabian Peninsula. The archaeological layer is interstratified within thick, sandy silt floodplain deposits filling a piedmont basin. Luminescence dates, lack of soil development, and gypsum precipitation indicate a high accretion rate of the floodplain during Marine Isotope Stage 3, in connection with a (semi)-arid environment. Rapid overbank sedimentation was likely a result of the remobilization of loess material deposited on the Yemeni Great Escarpment at the periphery of the adjacent Tihama coastal sand desert or of other sources. Fabric and size analyses of the lithic artifacts, together with spatial projections, indicate site modifications by floods. Primary modifications include (1) selective accumulation of medium-sized lithic pieces as a result of hydraulic sorting, (2) bimodal orientation of artifacts, and (3) ripple-like arrangement of lithics and bone/tooth fragments. The overrepresentation of teeth may also be a consequence of sorting. Although floods have distorted the original site patterning, long-distance transport of artifacts by water can be excluded, as indicated by relatively high refitting rate, close proximity of artifacts derived from the same block of raw material, and lack of abrasion of the pieces. Therefore, the site is considered 'geologically' in situ because its remobilization by water occurred shortly after human abandonment. This study also stresses that the effective preservation of a site cannot be assessed without careful taphonomic study, even in a potentially favorable depositional context such as silty alluvium. [ABSTRACT FROM AUTHOR]

The article cities a research study that reconstructs 600 years of ecosystem dynamics on a sub-Antarctic island to determine how long do ecosystems require to reach a new equilibrium and also identifies the impact of invasive rabbits. It used environmental DNA extracted from a lake sediment core, coprophilous fungi and sedimentological analysis for the study.