Data for: Climate changes in the eastern Mediterranean over the last 5000 years and their links to the high-latitude atmospheric patterns and Asian monsoons

Bulk geochemistry (TOC, δ13C), relative abundances of n-alkanes, n-alkane δD values. Data from the Lerna core, NE Peloponnese, Greece

Data for: Climate changes in the eastern Mediterranean over the last 5000 years and their links to the high-latitude atmospheric patterns and Asian monsoons

Bulk geochemistry (TOC, δ13C), relative abundances of n-alkanes, n-alkane δD values. Data from the Lerna core, NE Peloponnese, Greece.THIS DATASET IS ARCHIVED AT DANS/EASY, BUT NOT ACCESSIBLE HERE. TO VIEW A LIST OF FILES AND ACCESS THE FILES IN THIS DATASET CLICK ON THE DOI-LINK ABOV

Eemian geochemical data (biomarkers, isotopes) from Sokli, Northern Finland

Bulk geochemical data (TOC, TN, δ13Corg, δ15N), n-alkane abundances and δD values of individual n-alkanes from the Eemian Sokli sequence in Northern FinlandTHIS DATASET IS ARCHIVED AT DANS/EASY, BUT NOT ACCESSIBLE HERE. TO VIEW A LIST OF FILES AND ACCESS THE FILES IN THIS DATASET CLICK ON THE DOI-LINK ABOV

Data for: Eastern Mediterranean hydroclimate reconstruction over the last 3600 years based on sedimentary n-alkanes, their carbon and hydrogen isotope composition and XRF data from the Gialova Lagoon, SW Greece

Bulk organic matter properties (δ13Corg and TOC), n-alkane abundances, δ13C and δD composition of n-alkanes, and X-ray fluorescence (XRF) core scanning data from the Gialova sediment core

Chemotaxonomy in some Mediterranean plants and implications for fossil biomarker records

The increasing utilization of n-alkanes as plant-derived paleo-environmental proxies calls for improved chemotaxonomic control of the modern flora in order to calibrate fossil sediment records to modern analogues. Several recent studies have investigated long-chain n-alkane concentrations and chain-length distributions in species from various vegetation biomes, but up to date, the Mediterranean flora is relatively unexplored in this respect. Here, we analyse the n-alkane concentrations and chain-length distributions in some of the most common species of the modern macchia and phrygana vegetation in south western Peloponnese, Greece. We show that the drought adapted phrygana herbs and shrubs, as well as some of the sclerophyll and gymnosperm macchia components, produce high concentrations of n-alkanes, on average more than double n-alkane production in local wetland reed vegetation. Furthermore, the chain-length distribution in the analysed plants is related to plant functionality, with longer chain lengths associated with higher drought adaptive capacities, probably as a response to long-term evolutionary processes in a moisture limited environment. Furthermore, species with relatively higher average chain lengths (ACL) showed more enriched carbon isotope composition in their tissues (δ13Cplant), suggesting a dual imprint from both physiological and biochemical drought adaptation. The findings have bearings on interpretation of fossil sedimentary biomarker records in the Mediterranean region, which is discussed in relation to a case study from Agios Floros fen, Messenian plain, Peloponnese. The 6000 year long n-alkane record from Agios Floros (ACL, δ13Cwax) is linked to the modern analogue and then evaluated through a comparison with other regional-wide as well as local climate and vegetation proxy-data. The high concentration of long chain n-alkanes in phrygana vegetation suggests a dominating imprint from this vegetation type in sedimentary archives from this ecotone. © 2017 The Author(s

Evaluation of anhydrosugars as a molecular proxy for paleofire activity: A case study on a Holocene sediment core from Agios Floros, Peloponnese, Greece

The anhydrosugars, levoglucosan, mannosan and galactosan, are regarded as suitable molecular indicators of natural biomass combustion. Here, we evaluate summed anhydrosugars (SAS) as a paleofire indicator in a 6000 year-long fossil core from Agios Floros fen, Peloponnese, Greece, by analyzing charcoal fragments in parallel, throughout the sediment sequence. Modern surface soil samples from the same region were analysed for the presence of SAS, confirming the biomarker as an indicator of recent fire activity. The highest SAS concentrations in the fossil core were found in sections representing periods of wet conditions, both on local and regional scales and regionally widespread arboreal vegetation. Low amounts, or the absence, of SAS in the fossil core were associated with periods of dryness, regional dominance of non-arboreal vegetation and the presence of a fen rather than a lake ecosystem at the site. Micro-charcoal fragments were generally more abundant under these conditions. This suggests that SAS yield and deposition may vary with fuel availability and fire behavior, which in turn is affected by climate, local moisture and vegetation type. Forest fires result in more SAS compared to grass fires. SAS yield is also favored by low-temperature fires sustained under wet climate conditions. Preservation of SAS is likely to be compromised in the only seasonally wet fen ecosystem under the dry and warm Mediterranean climate conditions. The moist and shallow conditions in the wetland during hot summer months probably promote oxidation and biodegradation of the labile SAS molecules, compared to the more robust charcoal fragments. Thus, a multiproxy approach - using several proxies, both for fire, hydroclimate and vegetation change - is preferred when aiming to reconstruct past biomass burning from wetland ecosystems in a Mediterranean environment. The micro-charcoal record from Agios Floros reveals significant fire activity between 4400 and 2800 cal yr BP. This partly overlaps the Bronze Age period, associated with intense human environmental interaction and climate change in this area of Peloponnese, Greece. © 2021 The Author

Mid-late Holocene vegetation history of the Argive Plain (Peloponnese, Greece) as inferred from a pollen record from ancient Lake Lerna

This study provides a high-resolution reconstruction of the vegetation of the Argive Plain (Peloponnese, Greece) covering 5000 years from the Early Bronze Age onwards. The well dated pollen record from ancient Lake Lerna has been interpreted in the light of archaeological and historical sources, climatic data from the same core and other regional proxies. Our results demonstrate a significant degree of human impact on the environments of the Argive Plain throughout the study period. During the Early Bronze Age evidence of a thermophilous vegetation is seen in the pollen record, representing the mixed deciduous oak woodland of the Peloponnesian uplands. The plain was mainly used for the cultivation of cereals, whereas local fen conditions prevailed at the coring site. Towards the end of this period an increasing water table is recorded and the fen turns into a lake, despite more arid conditions. In the Late Bronze Age, the presence of important palatial centres modified the landscape resulting in decrease of mixed deciduous oak woodland and increase in open land, partly used for grazing. Possibly, the human management produced a permanent hydrological change at Lake Lerna. From the Archaic period onwards the increasing human pressure in association with local drier conditions caused landscape instability, as attested by a dramatic alluvial event recorded in the Pinus curve at the end of the Hellenistic Age. Wet conditions coincided with Roman times and favoured a forest regeneration pattern in the area, at the same time as we see the most intensive olive cultivation in the pollen record. The establishment of an economic landscape primarily based on pastures is recorded in the Byzantine period and continues until modern times. Overgrazing and fires in combination with arid conditions likely caused degradation of the vegetation into garrigue, as seen in the area of the Argive Plain today

The socio-environmental history of the Peloponnese during the Holocene: Towards an integrated understanding of the past

Published archaeological, palaeoenvironmental, and palaeoclimatic data from the Peloponnese in Greece are compiled, discussed and evaluated in order to analyse the interactions between humans and the environment over the last 9000 years. Our study indicates that the number of human settlements found scattered over the peninsula have quadrupled from the prehistoric to historical periods and that this evolution occurred over periods of climate change and seismo-tectonic activity. We show that societal development occurs both during periods of harsh as well as favourable climatic conditions. At some times, some settlements develop while others decline. Well-known climate events such as the 4.2 ka and 3.2 ka events are recognizable in some of the palaeoclimatic records and a regional decline in the number and sizes of settlements occurs roughly at the same time, but their precise chronological fit with the archaeological record remains uncertain. Local socio-political processes were probably always the key drivers behind the diverse strategies that human societies took in times of changing climate. The study thus reveals considerable chronological parallels between societal development and palaeoenvironmental records, but also demonstrates the ambiguities in these correspondences and, in doing so, highlights some of the challenges that will face future interdisciplinary projects. We suggest that there can be no general association made between societal expansion phases and periods of advantageous climate. We also propose that the relevance of climatic and environmental regionality, as well as any potential impacts of seismo-tectonics on societal development, need to be part of the interpretative frameworks. © 2015 The Authors