33 research outputs found

    Sedimentological processes and environmental variability at Lake Ohrid (Macedonia, Albania) between 640 ka and present day

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    Lake Ohrid (FYROM, Albania) is thought to be more than 1.2 million years old and hosts more than 200 endemic species. As a target of the International Continental Scientific Drilling Program (ICDP), a successful deep drilling campaign was carried out within the scope of the Scientific Collaboration on Past Speciation Conditions in Lake Ohrid (SCOPSCO) project in 2013. Here, we present lithological, sedimentological, and (bio-)geochemical data from the upper 247.8 m of the overall 569 m long DEEP site sediment succession from the central part of the lake. According to an age model, which is based on nine tephra layers (1st order tie points), and on tuning of biogeochemical proxy data to orbital parameters (2nd order tie points) and to the global benthic isotope stack LR04 (3rd order tie points), respectively, the analyzed sediment sequence covers the last 640 ka

    Unbalanced social–ecological acceleration led to state formation failure in early medieval Poland

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    To understand the planet?s current crisis, we need in-depth understanding of how social?ecological change accelerated in the past and how it failed or stabilized. Our study contributes to this field by offering detailed evidence of the ecological, economic, social, and political change in a key region of medieval Central Europe, which underwent unprecedented intensification in all of these domains in the 10th c. CE. We show how social and ecological processes accompanied the consolidation of a new political formation, in turn triggered by earlier economic developments. Further, we analyze the new state?s collapse. The success (stabilization) of the acceleration necessitated simultaneous creation or integration of several networks (political, cultural, economic, etc.), which the polity?s elite failed to achieve. Rapid social?ecological intensification is a recurrent feature of human history. It occurred in different forms and contexts; its outcomes may have been sustainable or transient. Until recently, such intensifications usually accompanied state formation: Consolidation of political power was often coupled with exponential increase in human exploitation of the environment of a given area. Here, we study one such case, uniquely well-documented through our rich paleoecological, archaeological, numismatic, and literary data. Triggered by the Eurasian slave trade, the first ?Polish? polity was founded in Central Europe c. 900 common era. It undertook unprecedented ecological intensification in its core territory, connected with large construction projects, and engaged in rapid territorial expansion. We provide new crucial evidence on this process by publishing here a high-resolution pollen profile from a location close to the polity?s capital and by an application of social network analysis to numismatic data. This state collapsed within a few generations after its foundation. The collapse of the political elites, however, did not produce a complete social and ecological disintegration of the polity?s former core region. We thus show how collapse and continuity can remain closely intertwined. Last but not least, the rich evidence on the mechanism of the collapse reveals that successful maintenance of social?ecological intensification requires reliance on a number of cultural, economic, religious, and social networks underlying the political expansion. The polity?s elite lacked access to or failed to mobilize such networks, which led to its demise.Rapid Intensification of Land Use Followed by a Sudden Rewilding. Settlement Dynamics in the Core Lands. Territorial Dynamics and Military Construction Projects. Monetary Flows and Exchange Networks. Political Institutions and Ideology. Discussion: How the Piast Political-Ecological Intensification Failed Conclusions: Broader Insights from the Piast Case Study Materials and Methods The Age-Depth Model of Lake Lednica. Pollen and Charcoal Analysis of Lake Lednica. Settlement Dynamics Analysis in the Area of Lednica Lake and Kazanie Peatland. SNA of Coinage Data

    Consilience in practice: social–ecological dynamics of the Lake Volvi region (Greece) during the last two millennia

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    The Lake Volvi area, part of the region of Macedonia (northern Greece), is a biodiversity hotspot, located in the central part of a major communication corridor connecting the western and eastern parts of the Balkans. The sediment succession from Lake Volvi is investigated here to provide a unique high-resolution pollen and geochemical record for the last 2000 years combining palaeoecological and historical methods, implementing the concept of consilience. The palaeoecological data document the environmental dynamics since the occupation of the area by the Romans. The vegetation changes reveal the development of wetland habitats and the variations of the mixed deciduous oak and thermophilous–mesophilous forests, as well as cereal cultivation, grazing and arboriculture, whose intensity varied over time. Archaeological data are available for the 1st millennium ce, but detailed historical evidence becomes accessible from the 13th century ce onwards through Byzantine and Ottoman documents. Both historical and palaeoecological data indicate that the 16th century was the period of strongest population pressure on the environment of the Volvi region. However, for other periods, it is possible to observe disagreements between the proxies. We demonstrate that these contradictions can be resolved with a more complex understanding of the region's social–ecological dynamics.Introduction Study area Site description Climate and vegetation Historical setting Materials and methods Geochemistry, chronology and palynology of the sediment core Byzantine and Ottoman documentary sources Results Lake sediments Chronology and sediment analysis Pollen, NPPs and charcoals Documentary sources Agricultural activities and settlements detailed in the Byzantine monastic documents Demography and agriculture in the Ottoman registers Discussion Social–ecological dynamics in the first millennium CE Social–ecological dynamics in the second millennium CE Conclusio

    Spatial competition in a global disturbance minimum; the seabed under an Antarctic ice shelf

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    The marine habitat beneath Antarctica's ice shelves spans ∼1.6 million km2, and life in this vast and extreme environment is among Earth's least accessible, least disturbed and least known, yet likely to be impacted by climate-forced warming and environmental change. Although competition among biota is a fundamental structuring force of ecological communities, hence ecosystem functions and services, nothing was known of competition for resources under ice shelves, until this study. Boreholes drilled through a ∼ 200 m thick ice shelf enabled collections of novel sub-ice-shelf seabed sediment which contained fragments of biogenic substrata rich in encrusting (lithophilic) macrobenthos, principally bryozoans – a globally-ubiquitous phylum sensitive to environmental change. Analysis of sub-glacial biogenic substrata, by stereo microscopy, provided first evidence of spatial contest competition, enabling generation of a new range of competition measures for the sub-ice-shelf benthic space. Measures were compared with those of global open-water datasets traversing polar, temperate and tropical latitudes (and encompassing both hemispheres). Spatial competition in sub-ice-shelf samples was found to be higher in intensity and severity than all other global means. The likelihood of sub-ice-shelf competition being intraspecific was three times lower than for open-sea polar continental shelf areas, and competition complexity, in terms of the number of different types of competitor pairings, was two-fold higher. As posited for an enduring disturbance minimum, a specific bryozoan clade was especially competitively dominant in sub-ice-shelf samples compared with both contemporary and fossil assemblage records. Overall, spatial competition under an Antarctic ice shelf, as characterised by bryozoan interactions, was strikingly different from that of open-sea polar continental shelf sites, and more closely resembled tropical and temperate latitudes. This study represents the first analysis of sub-ice-shelf macrobenthic spatial competition and provides a new ecological baseline for exploring, monitoring and comparing ecosystem response to environmental change in a warming world

    The Hominin Sites and Paleolakes Drilling Project:Inferring the environmental context of human evolution from eastern African rift lake deposits

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    Funding for the HSPDP has been provided by ICDP, NSF (grants EAR-1123942, BCS-1241859, and EAR-1338553), NERC (grant NE/K014560/1), DFG priority program SPP 1006, DFG-CRC-806 “Our way to Europe”, the University of Cologne (Germany), the Hong Kong Research Grants Council (grant no. HKBU201912), the Peter Buck Fund for Human Origins Research (Smithsonian), the William H. Donner Foundation, the Ruth and Vernon Taylor Foundation, Whitney and Betty MacMillan, and the Smithsonian’s Human Origins Program.The role that climate and environmental history may have played in influencing human evolution has been the focus of considerable interest and controversy among paleoanthropologists for decades. Prior attempts to understand the environmental history side of this equation have centered around the study of outcrop sediments and fossils adjacent to where fossil hominins (ancestors or close relatives of modern humans) are found, or from the study of deep sea drill cores. However, outcrop sediments are often highly weathered and thus are unsuitable for some types of paleoclimatic records, and deep sea core records come from long distances away from the actual fossil and stone tool remains. The Hominin Sites and Paleolakes Drilling Project (HSPDP) was developed to address these issues. The project has focused its efforts on the eastern African Rift Valley, where much of the evidence for early hominins has been recovered. We have collected about 2 km of sediment drill core from six basins in Kenya and Ethiopia, in lake deposits immediately adjacent to important fossil hominin and archaeological sites. Collectively these cores cover in time many of the key transitions and critical intervals in human evolutionary history over the last 4 Ma, such as the earliest stone tools, the origin of our own genus Homo, and the earliest anatomically modern Homo sapiens. Here we document the initial field, physical property, and core description results of the 2012–2014 HSPDP coring campaign.Publisher PDFPeer reviewe
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