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There has been considerable debate about the degree to which climate has driven societal changes in the eastern Mediterranean region, partly through reliance on a limited number of qualitative records of climate changes and partly reflecting the need to disentangle the joint impact of changes in different aspects of climate. Here, we use tolerance-weighted, weighted-averaging partial least squares to derive reconstructions of the mean temperature of the coldest month (MTCO), mean temperature of the warmest month (MTWA), growing degree days above a threshold of 0 ∘ C (GDD0), and plant-available moisture, which is represented by the ratio of modelled actual to equilibrium evapotranspiration (α) and corrected for past CO 2 changes. This is done for 71 individual pollen records from the eastern Mediterranean region covering part or all of the interval from 12.3 ka to the present. We use these reconstructions to create regional composites that illustrate the long-term trends in each variable. We compare these composites with transient climate model simulations to explore potential causes of the observed trends. We show that the glacial–Holocene transition and the early part of the Holocene was characterised by conditions colder than the present. Rapid increases in temperature occurred between ca. 10.3 and 9.3 ka, considerably after the end of the Younger Dryas. Although the time series are characterised by centennial to millennial oscillations, the MTCO showed a gradual increase from 9 ka to the present, consistent with the expectation that winter temperatures were forced by orbitally induced increases in insolation during the Holocene. The MTWA also showed an increasing trend from 9 ka and reached a maximum of ca. 1.5 ∘ C greater than the present at ca. 4.5 and 5 ka, followed by a gradual decline towards present-day conditions. A delayed response to summer insolation changes is likely a reflection of the persistence of the Laurentide and Fennoscandian ice sheets; subsequent summer cooling is consistent with the expected response to insolation changes. Plant-available moisture increased rapidly after 11 ka, and conditions were wetter than today between 10 and 6 ka, but thereafter, α declined gradually. These trends likely reflect changes in atmospheric circulation and moisture advection into the region and were probably too small to influence summer temperature through land–surface feedbacks. Differences in the simulated trajectory of α in different models highlight the difficulties in reproducing circulation-driven moisture advection into the eastern Mediterranean. [ABSTRACT FROM AUTHOR]

This paper aims to reconstruct Middle Bronze Age (MBA; 1600–1250 BCE) land use practices in the northwestern Alpine foreland (SW Germany, Hegau). We used a multi-proxy approach including the analysis of biogeochemical proxies from colluvial deposits and buried topsoils in the surroundings of the well-documented settlement site of Anselfingen and off-site pollen data from two peat bogs. This approach allowed for in-depth insights into the MBA subsistence economy and shows that the MBA in the northwestern Alpine foreland was a period of establishing settlements with sophisticated land management and land use practices. The reconstruction of phases of colluvial deposition was based on ages from optically stimulated luminescence (OSL) and radiocarbon (AMS 14 C) dating from multi-layered colluvial deposits and supports the local archaeological record with the first phase of major colluvial deposition occurring during the MBA followed by phases of colluvial deposition during the Iron Age, the Medieval period and modern times. The on-site deposition of charred archaeobotanical remains and animal bones from archaeological features, as well as polycyclic aromatic hydrocarbons (PAHs), charcoal spectra, phytoliths, soil microstructure, urease enzymatic activity, microbial biomass carbon (C mic) and heavy metal contents from colluvial deposits, were used as proxies for on-site and near-site land use practices. The charcoal spectra indicate MBA forest management which favored the dominance of Quercus in the woodland vegetation in the surrounding area north of the settlement site. Increased levels of 5 β stanols (up to 40 %) and the occurrence of pig bones (up to 14 %) support the presence of a forest pasture mainly used for pig farming. In the surrounding area south of the settlement, an arable field with a buried MBA plow horizon (2Apb) could be verified by soil micromorphological investigations and high concentrations of grass phytoliths from leaves and stems. Agricultural practices (e.g., plowing) focussed on five staple crops (Hordeum distichon/vulgare , Triticum dicoccum , Triticum monococcum, Triticum spelta , Triticum aestivum/turgidum), while the presence of stilted pantries as storage facilities and of heat stones indicate post-harvest processing of cereal crops and other agrarian products within the settlement. In the area surrounding the settlement, increased levels of urease activity, compared to microbial biomass carbon (up to 2.1 µ g N µ g C mic-1), and input of herbivorous and omnivorous animal faeces indicate livestock husbandry on fallow land. The PAH suites and their spatial distribution support the use of fire for various purposes, e.g., for opening and maintaining the landscape, for domestic burning and for technical applications. The off-site palynological data support the observed change in on-site and near-site vegetation as well as the occurrence of related land use practices. During the Early and Middle Bronze Age, fire played a major role in shaping the landscape (peak of micro-charcoal during the MBA), and anthropogenic activities promoted Quercus -dominated forest ecosystems at the expense of natural beech forests. This indicates a broader regional human influence in the northwestern Alpine foreland at low- and mid-altitude inland sites during the Middle Bronze Age. [ABSTRACT FROM AUTHOR]

Mountain vegetation is facing more rapid changes in temperature than the global average with the risk of losing essential ecosystem services in higher elevation environments. Therefore, it is important to thoroughly understand the sensitivity of mountain vegetation to climatic and anthropogenic induced changes. Although a general framework of Holocene tree-line evolution in Southwestern Bulgaria has already been established in previous research, data on higher elevations spanning the entire Holocene was still lacking. To provide this data, a multi-proxy analysis (comprising plant macro-remains, pollen and charcoals), covering the entire Holocene, was performed on a core from a peat bog near the tree-line of the Rila Mountains (Southwestern Bulgaria). The results of this study were subsequently interpreted in the framework of other palaeoecological records from the region providing information on tree-line shifts. The resulting reconstruction, supported by radiocarbon chronology, revealed the climatic and anthropogenic impact on the development of the postglacial vegetation. From this reconstruction can be concluded that our data is well in agreement with the general vegetational and environmental changes in the region. After the end of the last glaciation (around 11,500 cal. BP) open vegetation developed, which was gradually replaced by pioneer tree species. This phase was followed by the establishment of a coniferous belt (around 6700 cal. BP) as a response to an increase in humidity in the Atlantic. During the next period, the Subboreal (after 4800 cal. BP), the tree-line underwent major changes in composition as a response to a decrease in average temperatures and a rise in average precipitation. This signal is however biased during the Subatlantic (after 2400 cal. BP) because of the intensification of anthropogenic disturbance in the form of deforestation, burning and animal husbandry. Human impact in the area is still playing a significant role, threatening the peat bogs that provide valuable ecosystem services and serve as unique palaeoenvironmental archives. This study provides a more complete insight in the sensitivity of mountain vegetation to climatic and anthropogenic driven changes, in order to anticipate the likely future responses in tree-line position and diversity. In this way, it will contribute to the choice of more effective conservation strategies for the protection of the biodiversity and other ecosystem services in these ecological hotspots. [ABSTRACT FROM AUTHOR]