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The sediment deposits of northwestern Tripura, northeast India, revealed the enhanced proximity to the marginal marine environments, forest cover variations and anthropogenic influences. We infer the palaeo-vegetation and palaeo-environmental conditions between 9900 and 1800 cal B.P. through a 1.80 m deep sediment profile, from the remote location of Charilam, Tripura, using biotic (fossil pollen) and abiotic (mineral magnetism) proxies. The sediment profile recorded warm and humid conditions between 8300 and 6200 cal B.P., which later shifted towards less humid phase until 4900 cal B.P. The lower part of the sediment profile provided evidence of enhanced sea-level in this region, as manifested by mangrove taxa found between 9900 and 4900 cal B.P. But later, these taxa were minimal and thereafter, diminished in the sediments during the Late Holocene (4100–1800 cal B.P.).The occurrence of fewer tree taxa and dominance of larger grass pollen signify the enhancement of anthropogenic activities in the region, during the recent times. The shifts in mineral magnetic content towards fine-grained anti-ferrimagnetic hematite components, as exhibited by relatively high Hard IRM, SIRM/ΧLF, ARM/SIRM ratio and low S–ratio towards the end of the Middle Holocene, resonate with the climate variations concurrent to the vegetation changes. These interpretations lead to the perception of a reduction in the Indian Summer Monsoon (ISM) strength during the Late Middle Holocene. The inception of anthropogenic activities has also induced the changes in the vegetation cover, leading to increased soil erosion and land-use changes during the Late Holocene in the region, which are well observed in the pollen and mineral magnetic records. This study focuses on multi-proxy analyses of the Holocene sediments in this part of northeast India, which has no such previous records. [ABSTRACT FROM AUTHOR]

The research on the spatial distribution and evolution of ancient settlements from the Neolithic Age to the Bronze Age in Dalian area is of great significance for a profound understanding of the prehistoric human-land relationship in Dalian area. The results showed that: ① The number of settlement sites in Dalian area showed an overall upward trend from the Mid-Neolithic to the Bronze Age. Most sites during the three periods studied were to be found 0–50 m above sea level (asl), with a significant increase in the number of sites located >50 m asl during the Bronze Age. In terms of gradient of slope, all settlements were concentrated on coastal plains or in low-altitude, hilly areas on relatively gentle slopes ranging between 0 and 6°. Settlements from each period faced in all directions, and were mainly located in river valleys or low-altitude mountain valleys with low terrains.② The proximity of ancient settlements to river courses during the Mid Holocene evolved, with Mid and Late Neolithic settlements usually distributed in the range beyond 3 km of the river buffer zone; the distribution of Bronze Age sites was relatively uniform, reflecting an increasing demand for water resources; the density of settlements was clustered between the Mid Neolithic and the Bronze Age, Neolithic sites being both the smallest in number and the most concentrated. ③ The spatiotemporal distribution and evolution of settlements in the Dalian area were influenced by the contemporary climate: the Mid Neolithic climate was warm and humid, and settlements were distributed principally on the various islands near present-day Dalian, and especially Guanglu Island; the Late Neolithic climate became increasingly drier and cooler, stimulating cultural advances and a slight increase in the number of ancient settlements, which gradually developed in the areas in and around present-day Dalian; during the cold and dry Bronze Age, the number of settlements across the Dalian region reached their peak, and it is widely distributed in various areas of Dalian. To a certain extent, this reflected a continuous improvement in the ability of the human population to adapt to the natural environment.

In this paper we evaluate the role of human strategies in the Andean Piedmont from northern Patagonia across the Holocene. Specifically, we present the analysis of the Early Holocene-Late Holocene archaeological record of Salamanca cave (Mendoza-Argentina). We identified technological changes that occurred during the Late Holocene and the implications of a human occupation hiatus in the Middle Holocene. We follow a multiproxy approach by the analysis of radiocarbon dates, archaeofaunal remains, ceramic, lithics and XRF obsidian sourcing. We also discuss a detailed stratigraphic sequence by geomorphological descriptions, the construction of a radiocarbon sequence model and summed probability distributions, compared with other archaeological sites in the region. We conclude that after the Middle Holocene archaeological hiatus, human populations grew while guanaco populations dropped. The imbalance between demography and resources boosted the incorporation of new technologies such as ceramics and the bow and arrow, allowing people to exploit lower-ranked resources.

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Predicting the impact of sea-level (SL) rise on coral reefs requires reliable models of reef accretion. Most assume that accretion results from vertical growth of coralgal framework, but recent studies show that reefs exposed to hurricanes consist of layers of coral gravel rather than in-place corals. New models are therefore needed to account for hurricane impact on reef accretion over geological timescales. To investigate this geological impact, we report the configuration and development of a 4-km-long fringing reef at Punta Maroma along the northeast Yucatan Peninsula. Satellite-derived bathymetry (SDB) shows the crest is set-back a uniform distance of 315 ±15 m from a mid-shelf slope break, and the reef-front decreases 50% in width and depth along its length. A 12-core drill transect constrained by multiple 230Th ages shows the reef is composed of an ~2-m thick layer of coral clasts that has retrograded 100 m over its back-reef during the last 5.5 ka. These findings are consistent with a hurricane-control model of reef development where large waves trip and break over the mid-shelf slope break, triggering rapid energy dissipation and thus limiting how far upslope individual waves can fragment corals and transport clasts. As SL rises and water depth increases, energy dissipation during wave-breaking is reduced, extending the clast-transport limit, thus leading to reef retrogradation. This hurricane model may be applicable to a large sub-set of fringing reefs in the tropical Western-Atlantic necessitating a reappraisal of their accretion rates and response to future SL rise.

Morphological analysis of plant remains from archaeological sites provides evidence regarding the domestication process of crop species, and the changing economic behaviors of humans during the foundation and intensification of agriculture. In contexts from the Neolithic and early state periods of Henan, China, morphometry of genus Setaria millet seeds is shown to provide data on production versus consumption contexts of archaeological deposits, in connection with site function and settlement hierarchy. Comparative morphometry of modern Setaria seeds sheds light on larger archaeobotanical issues, including problematizing the distinction between domesticated and wild/weedy seeds. Statistical analysis suggests that subdivision of archaeological millets below the genus level is less useful in some cases than consideration and comparison of genus-level populations. [ABSTRACT FROM AUTHOR]

Neste trabalho são analisados os resultados de um conjunto de simulações que permite avaliar as variações climáticas no Holoceno Médio (HM) com relação ao clima atual na América do Sul (AS). Utiliza-se o MCGA do CPTEC com resolução T062 e 28 níveis na vertical (T062L28). Realizaram-se as simulações climáticas a partir da modificação dos parâmetros orbitais e da concentração de CO2 para valores típicos do HM. Os resultados foram comparados com simulações do PMIP e com os indícios paleoclimáticos na América do Sul, para avaliar a resposta do MCGA à variação dos parâmetros climáticos característicos do HM e avaliar diferenças do clima no presente e HM. Observou-se um comportamento mais úmido no nordeste da AS no HM. Na região central, sul e sudeste do continente o HM foi marcado por uma redução da precipitação. Quanto à temperatura verificou-se um sinal de resfriamento no HM que concorda com as evidencias paleoclimáticas observacionais. Observou-se um aumento da intensidade do fluxo médio do vento em 850 hPa, sobre o continente, no HM, devido diminuição na variação sazonal da insolação no Hemisfério Sul, que leva a menores gradientes de temperatura. Também se verificou a intensificação da circulação da alta subtropical do Atlântico Sul e enfraquecimento da circulação de norte a leste dos Andes durante todas as estações do ano. Esse enfraquecimento tem impacto significativo no transporte de umidade da bacia Amazônica para a bacia do Prata, e consequentemente sobre a formação da ZCAS.An ensemble of climate simulations with the CPTEC T062L28 AGCM is performed in order to obtain the present and Mid-Holocene (MH) climate in South America. The climatological characteristics simulated by the model are compared with PMIP models and paleoclimate records, and emphasis is given to the Southern Hemisphere and South America (SA). The orbital parameter and the CO2 concentration are changed for typical MH values. In general, the model simulations indicate a wetter Northeast. In the central region, south and southeast of the continent, the MH climate was marked by reduced precipitation in comparison with the present model climate. A cooling signal is observed in the MH according to the paleoclimatic evidences. A increase of the intensity of the 850 hPa flow over the continent is produced by the model in the MH climate in comparison with the present model climate. The South Atlantic subtropical high intensity is increased and less intense climatological northerly flow east of the Andes during all seasons. This weakening of the northerly flow has a significant impact on the moisture transport from the Amazon to the La Plata basin, and consequently over the SACZ.

Abundantly available catfish otoliths excavated from the ruins of the Indus civilization, in the coastal regions of Western India, are expected to preserve a detailed paleoclimatological record of the mid- to late-Holocene. In this study, we analyzed saltwater catfish otoliths recovered from the Gulf of Kutch, Western India. Stable isotopes (oxygen and carbon) and elemental ratios (Ba/Ca and Sr/Ca) were measured by isotope ratio mass spectrometry (IRMS) and high-resolution laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS), respectively. Oxygen isotopes of a modern otolith (δ 18 O) indicates the interval when the catfish would have dwelt in the sea and appear to record seasonal temperature variability with a precision of 1 C°. Calculated temperatures from δ 18 O of a fossil otolith dated to 4.3 cal ka BP indicates that the minimum temperature in winter was ∼2.5 C° lower than that of the present. Although comparison to alkenone results from the northwestern Arabian Sea indicates potential temperature underestimation, further measurements of modern and fossil samples would lead to more precise reconstruction of temperature history during mid- to late- Holocene. [ABSTRACT FROM AUTHOR]

A sediment core has been retrieved from Vanevan peat (south-eastern shore of Lake Sevan, Armenia), which is today disconnected from Lake Sevan thanks to an artificial shallowing of the lake. Based on 5 radiocarbon dates, Vanevan record covers the Mid Holocene (from ca. 7800 to ca. 5100 cal. BP). The Late Holocene is today absent in the peat stratigraphy due to modern peat exploitation by surface mining. This study focuses on a multi-proxy approach including pollen, charcoals, and pollen-inferred climate reconstruction. An open-land, steppic vegetation is recorded up to ca. 7700 cal. BP, followed by a more forested landscape during the Mid Holocene (up to ca. 5700 cal. BP), and ending again with an open-land vegetation (to the end of record, 5100 cal. BP). This vegetation dynamics responds to general climate changes documented in the Near East. Whether human activities are documented since ca. 7500 cal. BP (Late Neolithic) in Vanevan, they remain marginal and probably did not affect the area. Early Holocene dry climate, which caused the steppic environment to be widespread through the Near East, is strongly related to low late spring precipitation (P May–Jun = 180 mm). Mid Holocene forested landscape and increasing lake-level seem related to late spring precipitation (+28%), which is the main change in estimated climate parameters. This has to be linked with reinforcement of the Westerlies and less active Siberian High, which are inversely involved in the following, dry phase starting at ca. 5700 cal. BP. [ABSTRACT FROM AUTHOR]

Despite having a moderately large distributional area, both the pink fairy armadillo ( Chlamyphorus truncatus ) and particularly the Chacoan fairy armadillo ( Calyptophractus retusus ), which are among the least known xenarthrans, appear to be rare or patchily distributed. Although low density in species with large range sizes has been associated with large body size, this is not the case for fairy armadillos. We propose that past climate variations may have caused their current low densities, and evaluate retractions and expansions of suitable areas of fairy armadillos by extrapolating the consensus of habitat suitability models fitted with current climatic conditions to past conditions. We found great variation in suitable area along time in both species, with a drastic reduction in the Last Interglacial (LIG) period when compared with current situation. Both the variations and the reduction during LIG were more pronounced in Calyptophractus than in Chlamyphorus . We postulate that past extreme reductions in suitable areas could cause a delay in the recovery of the populations, resulting in low densities despite climatic conditions during more benign times allowing a more widespread distribution. [ABSTRACT FROM AUTHOR]

The geochemistry preserved in coral skeletons provides access to pre-instrumental records of environmental changes. While a variety of proxies have been established for coral paleoclimatology, their applications to the use of Acropora to generate longer-term reconstructions have been studied less. Here, we examine the geochemical proxies (i.e., Sr/Ca, Li/Mg, δ18O, δ13C, δ11B, and B/Ca) of dead Acropora assemblages collected from a fringing reef off Hainan Island in the northern South China Sea. These samples have been precisely dated using U Th isotopes and record reef development episodes since the mid-Holocene, allowing us to assess their potential as paleoclimate archives. The sea surface temperature (SST) trend reconstructed by Sr/Ca and Li/Mg exhibits better consistency with each other, and they have recorded the SST shifts around 5–4 ka BP and the subdued variability during the Medieval Climate Anomaly (MCA), whereas the δ18O-SST record exhibits less clear variations over the past 7000 years. However, the universal Li/Mg-SST calibration tends to underestimate the SST reconstruction from tropical corals, highlighting the importance of using a site- and species-specific calibration of the Li/Mg-SST. Boron systematics are used to reconstruct the carbonate chemistry of coral calcifying fluid (CF), which reveals significant differences between the ancient and modern corals. The pH of the coral CF (pH cf) is significantly lower in the modern Acropora compared to the ancient corals, with a mean difference of ~0.08 pH, corroborating the pronounced influence of ocean acidification on the coral CF chemistry. The dissolved inorganic carbon of the coral CF (DIC cf) is also lower for modern Acropora , and this decreasing trend seems to have persisted over the past 7000 years. In addition, the skeletal δ13C is closely related to the CF carbonate chemistry, highlighting the intrinsic relationship between the coral internal carbon pool used for calcification and the up-regulation of the pH cf. • Acropora -derived SST reconstruction using Sr/Ca has registered SST shifts around 4–5 ka BP and the modern warming. • The universal Li/Mg-SST calibration tends to underestimate the SST reconstruction. • Reduced pH cf is found for the post-industrial corals compared to the ancient corals. • Coral DIC cf exhibits a progressive decrease since the mid-Holocene. • Skeletal δ13C is intrinsically linked to the coral CF carbonate chemistry. [ABSTRACT FROM AUTHOR]

The Earth's climate response to the rapid vegetation collapse at the termination of the African Humid Period (AHP) (5.5–5.0 kyr BP) is still lacking a comprehensive investigation. Here we discuss the sensitivity of mid-Holocene Arctic climate to changes in albedo brought by a rapid desertification of the Sahara. By comparing a network of surface temperature reconstructions with output from a coupled global climate model, we find that, through a system of land-atmosphere feedbacks, the end of the AHP reduced the atmospheric and oceanic poleward heat transport from tropical to high northern latitudes. This entails a general weakening of the mid-latitude Westerlies, which results in a shift towards cooling over the Arctic and North Atlantic regions, and a change from positive to negative Arctic Oscillation-like conditions. This mechanism would explain the sign of rapid hydro-climatic perturbations recorded in several reconstructions from high northern latitudes at 5.5–5.0 kyr BP, suggesting that these regions are sensitive to changes in Saharan land cover during the present interglacial. This is central in the debate surrounding Arctic climate amplification and future projections for subtropical precipitation changes. [ABSTRACT FROM AUTHOR]

The Song Keplek 5 (SK5) specimen was found in 1998 at the Song Keplek site, located in the Gunung Sewu (Southern Mountains) karst region, East Java. SK5 is a burial dated within direct sample with an AMS date from its fragments bones of c. 3053 ± 65 calBP (AA96775). This paper will discuss the archaeological and biological context of SK 5. Biological information includes estimation of age, sex determination, height, and any indicators of systemic pathology. Discussion of archaeological context will include cultural practices during this individual’s life, and subsequent funerary practices post-mortem. This exploration of the cultural and biological context of SK 5 will not only begin to flesh out an “osteobiography” for this individual, but also improve our understanding of living conditions during the mid Holocene in Java, in the time of early Austronesian occupation in this island.

Copyright of Revista Chilena de Antropologia is the property of Universidad de Chile and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The objective of our research was to define the main human–environment interactions during the Neolithic period (6500–3700 bc) in the Apulia region of southeastern Italy based on available published and unpublished data. Knowledge of these interactions is crucial to understanding the cultural and social dynamics of the period, particularly concerning the earliest farmers. Using a multidisciplinary approach, paleoenvironmental and paleoclimatological data at the regional and Mediterranean scales were compared with the results of analyses performed on natural deposits and deposits in Neolithic settlements. The following data sets were used: (1) 121 14C dates for settlements, from which probability curves (%) of the Apulian Archaeological Occupation (AAO) were developed; (2) offshore data obtained from analyses performed on two offshore sediment cores drilled in the Adriatic Sea; (3) offsite data from studies conducted in two natural coastal contexts; and (4) onsite archaeobotanical data from 35 settlements. This study allowed us to tentatively define the main climatic features between 6200 and 3700 bc. We identified two dry phases (one between 5000 and 4600 bc and a second that peaked c. 4000 bc) and two wet intervals (one between 6200 and 5500 bc and a second that peaked around 4400 bc). Climate changes appear to have been relatively gradual. The use of archaeobotanical data allowed us to determine a direct link between paleoclimatic and archaeological sequences. These data highlight the variations in agricultural strategies (species used and harvest times) as humans responded to changes in the rainfall regime. [ABSTRACT FROM AUTHOR]

Grassland and savanna are globally important ecosystems, both ecologically and economically. These grass-dominated systems are at risk from current and future climate change and increasing anthropogenic impact. Key questions for understanding the resilience and variability of grass-dominated ecosystems under current and future environmental conditions include: How have these systems responded to climate change and disturbance in the past? What are the principal driving agents responsible for their present-day composition and distribution? Do the palaeoecological data provide evidence for feedbacks between climate, fire and anthropogenic activities? In this study, the temporal dynamics of grassland, savanna and forest in the summer rainfall region of northern South Africa were reconstructed for the last ~6500 years. Palaeoecological techniques used include analyses of fossil pollen, charcoal and stable isotopes. Data from two sites located at the present-day grassland-savanna ecotone in Mpumalanga province of South Africa are reported. Results indicate that a mosaic of grassland, savanna and Podocarpus forest occupied the landscape throughout the late Holocene, with grassland and forest dominating higher altitudes, and savanna and forest lower altitudes. Podocarpus forest retreated and grass-dominated vegetation expanded its range around 1800 cal. yr BP at the lower altitude site (Lowveld) and 600 cal. yr BP at the higher altitude site (Highveld), representing a change from a stable state forest savanna/grassland mosaic to an increasingly grass-dominated system. Climatic stress, changes in fire regime and anthropogenic impact led to the vegetation transitions recorded, and resulted in changes in water and nutrient cycles. In an increasingly warm world, with fluctuating water availability and heightened anthropogenic use of natural resources, the future of grass-dominated ecosystems appears far from stable. [ABSTRACT FROM PUBLISHER]

In this study we investigate pollen and oxygen isotopes of moss cellulose from the peat bog ‘Dürres Maar’ in the Eifel low mountain range, Germany (450 m a.s.l.) to quantitatively infer mid-Holocene climate change for the period between ~7000 and 3800 cal. BP. Pollen was analysed on the same samples from which Sphagnum leaves were isolated to extract cellulose for the determination of its oxygen isotope composition (δ18OSphagnum). To quantitatively estimate January and July temperature and annual precipitation from the pollen data, we applied a probabilistic indicator taxa method (‘pdf-method’). The pollen-based reconstructions indicate July temperatures ~1°C higher around 6000 cal. BP than after ~5500 cal. BP, which is consistent with a ~1‰ decrease in δ18OSphagnum during the same period. While the pollen-based climate reconstructions indicate little variability in summer temperature after ~5500 cal. BP, winter temperature shows several pronounced cold excursions of ~2–4°C in this period, which was likely accompanied by changes in precipitation patterns. Test reconstructions leaving out specific taxa indicate that not only larger climate trends, but also relatively small-scale climate variability can robustly be reconstructed with the pdf-method. This is of particular importance for reliable reconstructions of climate variability not only during the Holocene, but also in former interglacials, for which archives are rare and pollen is often the only suitable proxy in terrestrial records. The stable isotope values agree with the reconstructions based on pollen for the time between ~4500 and 3500 cal. BP, but not for the period before 4500 cal. BP. We explain this difference by atmospheric circulation patterns being different in the mid and late Holocene, respectively. [ABSTRACT FROM PUBLISHER]

Results from a new mid holocene site in the central-western torres Strait, north-eastern australia are presented. AMS determinations from Dabangai on Mabuyag provide evidence for two settlement periods. Phase 1 (7180-4960 calBP) is associated with recurring/ permanent occupation involving marine-based subsistence during the poorly documented period of marine transgression. Phase 2 (230BP-present) is a period of increased site use including an escalation of marine subsistence activities. results provide the first direct evidence for marine settlement and subsistence practices on torres Strait islands after their initial formation. [ABSTRACT FROM AUTHOR]

Mid-Holocene (7000—4000 yr BP) paleoclimate conditions were reconstructed for the eastern Mediterranean region through a high-resolution (3—20 yr) oxygen and carbon isotopic record in a speleothem from Soreq Cave, Israel. Mid-Holocene climate change is characterized by sinusoidal cycles lasting ~1500 years, that represent changes of ~400 mm (between ~700 and ~300 mm) in annual rainfall, coincident with major cultural changes. Two major cultural changes occurred during wet events at 6550—6450 yr BP and 4800—4700 yr BP, associated with the transitions from mid-Chalcolithic to late-Chalcolithic period and from the early Bronze II to early Bronze III, respectively. The transition from late Chalcolithic to early Bronze I occurred during a dry period at 5700—5600 yr BP. Superimposed on these cycles, several short-lived decadal- to centennial-scale climatic events were identified. Dry events occurred at 6650—6600 yr BP, 6250—6180 yr BP, 5700—5600 yr BP, 5250—5170 yr BP and 4200—4050 yr BP. The last two events coincide with the cultural collapse of the Uruk society in Mesopotamia and the Akkadian Empire. Short climatic wet events occurred at 6700—6680 yr BP, 6170—6100 yr BP, 5760—5740 yr BP and 5500—5450 yr BP. [ABSTRACT FROM AUTHOR]

This paper presents evidence for the nature of early and middle Neolithic farming activity, its impact upon the landscape and environment, and its vulnerability to climatic change, at a sub-peat field system at Belderg Beg, North Co. Mayo, Ireland. Pollen analyses of a 14C dated peat deposit close to the field system indicates that basin peat accumulated from c. 5590 to 5330 cal. BP, probably triggered by farming activities. The palynological evidence indicates that the field system was constructed for pastoral farming, surrounded by woodland. Sediment-stratigraphic analyses show that the soil in the field system was subject to significant erosion, which may have been a causal factor in the local cessation of agriculture in the late sixth millennium cal. BP. Peat humification analyses indicate that surface wetness was greatest at c. 4940 cal. BP, several centuries after abandonment of the field system, coincident in age with evidence for higher precipitation from other sites in North Mayo. Comparison with other records of early and mid-Neolithic agricultural activity and abandonment in the region suggests that the well-recognised mid-Neolithic agricultural decline occurred in the broad context of a shift to a more oceanic climate, but that local factors such as soil quality may have been more important in the exact timing of local agricultural abandonment. [ABSTRACT FROM PUBLISHER]

High-resolution grain size analyses of three AMS 14C-dated cores from the Southeastern Brazilian shelf provide a detailed record of mid- to late-Holocene environmental changes in the Southwestern Atlantic Margin. The cores exhibit millennial variability that we associate with the previously described southward shift of the Inter Tropical Convergence Zone (ITCZ) average latitudinal position over the South American continent during the Holocene climatic maximum. This generated changes in the wind-driven current system of the SW Atlantic margin and modified the grain size characteristics of the sediments deposited there. Centennial variations in the grain size are associated with a previously described late-Holocene enhancement of the El Niño-Southern Oscillation (ENSO) amplitude, which led to stronger NNE trade winds off eastern Brazil, favouring SW transport of sediments from the Paraiba do Sul River. This is recorded in a core from off Cabo Frio as a coarsening trend from 3000 cal. BP onwards. The ENSO enhancement also caused changes in precipitation and wind pattern in southern Brazil, allowing high discharge events and northward extensions of the low-saline water plume from Río de la Plata. We propose that this resulted in a net increase in northward alongshore transport of fine sediments, seen as a prominent fine-shift at 2000 cal. BP in a core from ∼24°S on the Brazilian shelf. Wavelet- and spectral analysis of the sortable silt records show a significant ∼1000-yr periodicity, which we attribute to solar forcing. If correct, this is one of the first indications of solar forcing of this timescale on the Southwestern Atlantic margin. [ABSTRACT FROM AUTHOR]

Coupled high-resolution Sr/Ca and δ18O records of a modern and a mid-Holocene coral from Sanya in the southern Hainan Island, northern South China Sea (SCS), were reported and the residual δ18O (δδ18O) were calculated to indicate precipitation change in this region. Unlike other paleoclimate studies, this study focused on changes of precipitation time rather than precipitation amount. As negative Δδ18O peaks in coral generally correspond to peak precipitations or rainy seasons in the surrounding region, the time offsets between negative Δδ18O peaks and other seasonal indicators, such as sea surface temperature (SST), can well indicate the time of rainy seasons, and the precise time offsets can be estimated by the method of cross spectral analysis. The results of the modern coral indicate that the variation of the coral Δδ18O lags that of the instrumental measured precipitation by about 2 months, and about 3 months to the SST derived from coral Sr/Ca ratios. This agrees well with the modern observation that the salinity change in the southern coastal regions generally lags that of the precipitation in Hianan Island by about 2 months, and the precipitation change lags about 1 month behind the SST in this region. Thus, coral Δδ18O records can be a reliable proxy for the change of rainy seasons in this region. The results of the mid-Holocene coral show about 2.5 months' leading of the Δδ18O variation ahead of the SST. By compensating the approximate 3 months' lag of the Δδ18O variation behind the SST in modern time, the occurrence of rainy seasons during the mid Holocene may have advanced about 5-6 months. In detail, it may start around December and end around April to May with maximum occurring around February. Therefore, rainy seasons mainly occur in winter through early spring during the mid Holocene, compared with that from May through October in modern times. Such precipitation patterns appear to agree with the mid-Holocene pollen records in this region. Variations of large-scale circulation may possibly result in such a different precipitation pattern. Further studies, in particular climate model studies collaborated with meteorologists, are required for a better understanding of the mechanism. [ABSTRACT FROM AUTHOR]

We model the past and future distribution of Pinus sylvestris in the Iberian Peninsula using the random forest algorithm, a machine learning technique that implements an automatic combination of tree predictors. In order to model the past, we chose two of the most climatically significant events recognized affecting the species distribution: the last glacial maximum (LGM, 21 000 cal. BP), and the mid Holocene (6000 cal. BP). In order to model the distributions, we based the future scenarios of climate change upon the four storylines projected by the Intergovernmental Panel on Climate Change (A1, A2, B1 and B2). The results obtained for the past show a contraction in the distribution area during the LGM and a subsequent expansion, coinciding with an improvement in climate in the mid Holocene. The presence of isolated populations of Pinus sylvestris at low altitudes could support the existence of refuges for Northern European taxa. The results obtained for the future, even in the least aggressive scenario, show a rapid decrease in this species' distribution and a vertical migration as a response to climate change. Pinus sylvestris populations would be restricted in the future to the higher altitudes of the mountains in the north of the Iberian Peninsula (mainly the Pyrenees), and the species would disappear from the central and southern mountain ranges. These results identify a risk to high-mountain forest species in the Iberian Peninsula from the effects of global warming. [ABSTRACT FROM AUTHOR]

Climate change has been analysed for the mid Holocene (MH, 6000 years BP) over South America. Simulations have been performed through modification of the orbital parameters and the CO2 concentration typical of the MH within the CPTEC T062L28 atmospheric general circulation models (AGCM). The results were compared with previous simulations performed by various climate centres around the world and with palaeoclimate indicators. The MH climate simulation shows a wetter behaviour in northeastern South America with a northward shift of the Intertropical Convergence Zone (ITCZ). In central and southeastern South America the simulations show a reduction in precipitation. Some important changes were detected during the MH: (a) the increase in the intensity of the circulation of the South Atlantic subtropical high; (b) the intensification of the northerly flow east of the Andes, south of 20°S; (c) the decrease in moisture transport from the Amazon basin to central and south-southeastern Brazil, which can influence the formation and intensity of the South Atlantic Convergence Zone (SACZ); (d) the reduced intensity of the northeasterly trade winds north of 20°S, which can explain the northward positioning of the ITCZ; and (e) the weakening of the low-level convergence over the Amazon region, which can explain the reduction in precipitation in this region during the MH. A cooling signal was verified during the MH simulation, in accordance with palaeoclimate evidence, that was related to cold air surges coming from the South, which cooled regions east of the Andes and were more common during summer and autumn during the MH. [ABSTRACT FROM AUTHOR]

What was the environmental setting for changes in the settlement pattern of Adaïma, a mid-fourth to early-third millennium site in the Egyptian Nile valley? Analysis of charcoal collected from the archaeological soil was performed on contexts from several periods. The settlement was set up in an environment where the vegetation was probably more extended, with more wooded desert margins. Over 600 years, changes in the charcoal spectrum reflect a possible local desertification and the impact of human activities on the vegetation of the floodplain, perceptible in particular through the development of ruderal Calotropis procera. [ABSTRACT FROM AUTHOR]

Abstract: Excavations at the archaeological site of Encosta de Sant''Ana (Lisbon, Portugal) uncovered a mid-Holocene buried alluvial soil associated with early Neolithic occupation layers. Routine laboratory analyses and micromorphological observations were undertaken on the soil material. Humic acids from its Ab horizon, as well as Neolithic ecofacts, were radiocarbon dated. The dates obtained indicate that soil was formed between c. 8.0 and 6.0cal ka BP and that the pedological evidence fits the record of the North Atlantic Holocene IRD events (“Bond events”) and the so-called “Holocene climate optimum”. The geoarchaeological record reveals that Neolithic inhabitants settled upon a stable surface, still affected by soil formation that was suddenly interrupted by slope wasting, probably in correspondence to Bond event 4, at c. 6.0cal ka BP. [Copyright &y& Elsevier]

Evidence for cultivated wheat at 4650 cal. yr BP, as part of a broadening agricultural-based society (4650–4300 cal. yr BP), is presented from Xishanping in northwest China. This was established from archaeobotanical evidence and radiocarbon dating. Crops from SW Asia had therefore been adopted in China about 2500 years earlier than previously thought, and long before the ‘Silk Road’ route was known to be used. The data show that the early infiltration and blending of agriculture involving rice, buckwheat, barley, millet and wheat occurred in this region. This raises questions as to why crops from China do not appear further westward at this time and how the blending of agricultural practices contributed to the development of Chinese civilization. [ABSTRACT FROM AUTHOR]