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Leaf waxes have been assumed to be the dominant source of wax delivered to sediment. However, wooden branches and twigs have not been widely considered in this context and could be a potential source of wax lipids in fire places or combustion structures. Black sedimentary layers are the main material of open-air archaeological combustion structures and represent either carbonized fuel (wood) or the charred ground beneath the fire (mainly leaves) and it is difficult to discern between the two sources. To identify different plant parts as components of combustion residues, fresh and charred leaves, branches and twigs (bark and xylem) of the Celtis australis tree were analyzed for aliphatic and aromatic hydrocarbons and fatty acid concentrations, as well as the carbon isotopic composition of n -alkanes (δ 13 C alkane ). Charred biomass was produced under limited oxygen conditions at 150, 250 (3 and 5 h), 350 and 450 °C for 1 h. The n -alkyl profiles in different parts of C. australis are sufficiently distinct to allow their identification as components of combustion structures under low combustion temperature conditions. Average chain lengths and carbon preference index ratios decrease with increasing temperature and vary among plant parts. The δ 13 C alkane values remained slightly unaltered up to 350 °C and changed by 3–4‰ at 450 °C. Our results provide new information on the molecular and isotopic changes that occur upon burning different plant parts, which in turn show potential for good preservation of organic matter in archaeological black layers and for positive identification of burned leaf and wood residues in them. [ABSTRACT FROM AUTHOR]

Mountain lakes are particularly sensitive to global change as their oligotrophic conditions may be rapidly altered after reaching an ecological threshold, due to increasing human impact and climate change. Sanabria Lake, the largest mountain lake in the Iberian Peninsula and with a recent history of increased human impact in its watershed, provides an opportunity to investigate recent trends in an oligotrophic, hydrologically-open mountain lake, and their relationship with climate, hydrological variability and human pressure. We conducted the first systematic and detailed survey of stable isotope compositions of Sanabria Lake and Tera River together with limnological analyses during 2009–2011. δ 18 O lakewater and δD lakewater seasonal fluctuations are strongly linked to river discharges, and follow the monthly mean isotopic composition of precipitation, which is controlled by NAO dynamics. δ 13 C POM and δ 13 C DIC revealed higher contribution of allochthonous organic matter in winter and spring due to higher river inflow and lower primary productivity. Increased phytoplankton biomass in late summer correlated significantly with higher pH and Chl- a , and higher nutrient input and lower river inflow. However, the small δ 13 C POM seasonal amplitude underlines the stability of the oligotrophic conditions and the isotopic variation in POM and DIC reflect small seasonal fluctuations mostly as a consequence of strong throughflow. The stability of hydrology and productivity patterns is consistent with Holocene and last millennium reconstructions of past limnological changes in Sanabria Lake. The results of this study indicate that trophic state in this hydrologically-open mountain lake is strongly controlled by climate variability, but recent changes in human-land uses have increased sediment delivery and nutrients supply to the lake and have to be considered for management policies. Monitoring surveys including isotope techniques provide snapshots of modern isotope variability, and serve as a benchmark for assessing the environmental impacts of future developments and long-term climate changes in mountain lakes. [ABSTRACT FROM AUTHOR]

This study presents a hydroclimatic reconstruction from Crvena Stijena (Montenegro, Balkan Peninsula), a rock shelter that has yielded evidence for Middle Paleolithic human occupation. The integration of lipid biomarkers, hydrogen (δD) isotopic compositions of n -alkanes, and organic elemental geochemistry in the 7-m deep vertical sedimentary sequence enables reconstruction of the main hydrological and environmental changes during the MIS 3 and their correlation with the presence at the site. We apply agglomerative hierarchical clustering and principal component analysis to the geochemical, molecular, and stable isotopic data to obtain a robust hydrological record. We find evidence of three aridity trends from the studied period, one of them correlated with the Heinrich Event 5, and humid and cold-temperate conditions in archaeology-rich layers. Our dataset also contributes to the knowledge of past hydrological variability in the Balkan Peninsula, a sensitive area to short-lived climatic shifts, and overall, in the Mediterranean region during the last glacial/interglacial cycle. • Hydrogen isotopes from sedimentary leaf waxes as a paleohydrological proxy. • Hydroclimatic reconstruction in the Middle Paleolithic site of Crvena Stijena. • Three aridity trends in the 7 m-deep sedimentary sequence (MIS 4/3 to MIS 2). • Archaeology-rich layers show depleted sedimentary n -alkanes δD values. [ABSTRACT FROM AUTHOR]

The multiproxy study (sedimentology, geochemistry and diatoms) of sediment cores from Sanabria Lake (42°07′30″ N, 06°43′00″ W, 1000 m a.s.l.) together with a robust 14C chronology provides the first high-resolution and continuous sedimentary record in the region, extending back the last 26 ka. The development of a proglacial lake before 26 cal ka BP demonstrates the onset of deglaciation before the global Last Glacial Maximum, similarly to other alpine glaciers in southern European mountains. Rapid deglaciation occurred at the beginning of the Greenland Interstadial GI-1e (Bølling, 14.6 cal ka BP). Following a short-lived episode of glacier re-advance (14.4–14.2 cal ka BP, GI-1d), a climatic improvement at 13.9 cal ka BP suggests the glaciers retreated from the lake basin during the GI-1c. Another glacier reactivation phase occurred between ca 13.0–12.4 ka, starting earlier than the onset of GS-1 (Younger Dryas). Rapid deglaciation during the Early Holocene (11.7–10.1 cal ka BP) was followed by a period of higher river discharge (10.1–8.2 cal ka BP). After 8.2 ka, the Holocene is characterized by a general decreasing trend in humidity, punctuated by the driest phase during the Mid Holocene (ca 6.8–4.8), a wetter interval between 4.8 and 3.3 cal ka BP, and a relatively decline of rainfall since then till present, with a minor increase in humidity during some phases (ca 1670–1760) of the Little Ice Age. Discrete silt layers intercalated in the organic-rich Holocene deposits reflect large flooding events of the Tera River (ca 10.1, 8.4, 7.5, 6.2, 5.7–5.6, 4.6, 4.2, 3.7, 3.3, 3.1, 2.7, 2.5 and 2.0 cal ka BP). Their synchronicity with a number of cold and humid events described in the Atlantic demonstrates a strong control of NW Iberian climate by North Atlantic dynamics at centennial–millennial scale. Comparison with Western Mediterranean records points to similar regional dynamics during the Holocene, although modulated in the NW Iberian Peninsula by the stronger Atlantic influence. [ABSTRACT FROM AUTHOR]

This paper presents a multiproxy palaeoenvironmental study from Abric del Pastor (Alcoy, Spain), a rock shelter which has yielded evidence for Middle Palaeolithic human occupation. The sedimentary sequence has been analysed for lipid biomarker n -alkane abundances (ACL, CPI), compound specific leaf wax δ2H and δ13C, and bulk organic geochemistry (TOC, %N, %S), providing a record of past climate and local vegetation dynamics. Site formation processes have been reconstructed through the application of soil micromorphology. Analyses of anthracological, microvertebrate and macrofaunal assemblages from selected subunits are also presented here. Our data indicates that a variable climate marked by predominantly cold conditions persisted through most of the sequence and that Neanderthal occupations in stratigraphic unit IVd, assigned to MIS 4 or late MIS 5, occurred in a landscape setting characterised by a mosaic of biotopes. The presence of key resources inside the ravine where the site is located suggests that the occupation of the rock shelter may have been strategically motivated by a subsistence and mobility strategy which focused on zones of localised ecological resilience, such as intra-mountainous valleys or ravines, during periods of global or regional environmental downturn. • New palaeoenvironmental data for Neanderthal site of Abric del Pastor is presented. • Degradation of n -alkanes linked to anthropogenic fire. • Occupations in S.U. IVd occurred in generally cold and dry conditions. • The Barranc del Cinc acted as a vegetation refugium. • Occupation of rock shelter may have been strategically motivated by its location. [ABSTRACT FROM AUTHOR]

Molecular and isotopic approaches offer the chance to identify combustion residues and substrate components of archaeological combustion features to infer past fire-related activities. Analysis of fatty acid methyl esters by gas chromatography-combustion-isotope ratio mass spectrometry have been successfully used to distinguish among different animal fat groups. However, plant oils from different tissues have not been widely investigated even though organic residues from leaf, root, and wood tissues are preserved in sediments from archaeological combustion structures. Our analyses of plant residues from controlled laboratory heating sequences and experimental hearths involving wood and animal residues, provide references to discern anatomical parts of fresh and charred plants and to differentiate contributions of terrestrial plants and animal sources in open air hearths. This information is compared with charred organic residues from combustion structures from three Middle Palaeolithic sites: El Salt (Spain), Abric del Pastor (Spain) and Crvena Stijena (Montenegro). The occurrence of n -alkyl nitriles in our samples corroborates their potential as combustion temperature biomarkers and the δ13C 16:0 and δ13C 18:0 values allow us differentiate between charred and fresh plant anatomical parts and between fresh plant oils and animal fats. • δ13C 16:0 and δ13C 18:0 values from modern fresh and charred plant plants were obtained. • Animal fat residues are enriched in 13C (≈4‰) compared to plant residues. • n -Alkyl nitriles are preserved in sediments from Neanderthal combustion structures. • n -Alkyl nitriles have potential as combustion temperature biomarkers. [ABSTRACT FROM AUTHOR]

Lipid biomarker analysis focused on steroids has shown to have great potential for discriminating between animal faecal inputs in archaeology. This is particularly interesting when applied to stabling deposits to assess herding strategies and livestock composition. Here we present the results of a sedimentary faecal biomarker study conducted at Belmaco Cave, a pre-European archaeological site in La Palma (Canary Islands). The site was occupied by indigenous pastoralist groups over the course of five centuries prior to the first arrival of the Europeans in the 15th century. Previous soil micromorphological data indicates recurrent sheep and/or goat penning and periodic burning of the pen in the central area of the cave. We selected bulk sediment samples from unburned, charred and ashed dung layers and carried out sterol, stanol and bile acid analysis. Our results suggest that the main source of faecal matter is sheep. We also found that even though charred and dung ash layers contained lower concentrations of the biomarker compounds, these were still sufficient to provide information on the origin of the faecal remains. These data add to our current knowledge of the aboriginal Canary Island pastoralist economy. [ABSTRACT FROM AUTHOR]

The Carbon Preference Index (CPI) is a molecular ratio often used to assign the biological source and maturity of organic matter. This parameter is frequently employed in paleoenvironmental studies and archaeological applications. In this paper, we have evaluated the different results for this index using peak areas or concentrations from calibration curves. For this purpose, plant reference samples (Celtis Australis L.) and sediments from two archaeological sites were analysed. The results show that the values obtained depend on the method employed and, thus, interpretations may differ significantly. Consequently, the method used must be clearly stated in each particular application and results can only be compared when using the same protocol. [ABSTRACT FROM AUTHOR]

Tropical dry islands are currently facing major challenges derived from anthropogenic and climatic pressures. However, their trajectories of environmental change, which could provide relevant information applicable to biodiversity conservation, remain understudied. This is mainly due to poor micro-fossil preservation and irregular sediment deposition. Multi-proxy palaeoecological analyses spanning decades to 1000s of years can add perspective as to how vegetation, fungal communities, and the fauna responded to previous natural and anthropogenic disturbances. In São Nicolau, Cabo Verde, we used palaeoecological methods to analyse a highland soil profile (1000 m asl) dated to 5900 cal yr BP. We analysed how vegetation (abundances in pollen of native and introduced species, and leaf wax n -alkanes), ferns and fungal communities (abundance of non-pollen palynomorphs) varied over time in relation to fire (charcoal concentration) and erosion regimes (grain sizes and elemental composition). Between 5000 and 400 cal yr BP the highlands held native woody taxa such as Euphorbia tuckeyana , Dracaena draco subsp. caboverdeana , and Ficus , taxa that can be used for future reforestation programmes. From 400 cal yr BP to the present day, replacement of native taxa by introduced and cultivated taxa (Pinus , Eucalyptus , Asystasia , Opuntia) has occurred. Vegetation burning and grazing caused loss of vegetation and erosion, acting as conjoined drivers of scrubland degradation. This dataset helps to set historically contextualised restoration goals such as the re-introduction of native species, monitoring of recently introduced species and control of free grazing. This can serve as a model system for the conservation of tropical dry islands' biodiversity. Unlabelled Image • Palaeoecological analyses reveal 5900-yr of ecological change in São Nicolau. • Fern-rich endemic-dominated scrublands present (5000–410 cal yr BP) even after fire. • Introduced grazers and vegetation burning caused erosion and landscape opening. • Results are used to set historically-contextualised conservation/restoration goals. • Methods are applicable in other dry tropical islands in Cabo Verde and beyond. [ABSTRACT FROM AUTHOR]