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标题：High-resolution patterns of palaeoenvironmental changes during the Little Ice Age and the Medieval Climate Anomaly in the northwestern Iberian Peninsula
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作者：Daniel Castro ; Martín Souto ; María Isabel Fraga 等
期刊名称：Geoscience Frontiers
印刷版ISSN：1674-9871
出版年度：2020
卷号：11
期号：5
页码：1461-1475
DOI：10.1016/j.gsf.2020.05.015
语种：English
出版社：Elsevier
摘要：AbstractA high resolution core (9.7 yr cm−1) from the Chao de Veiga Mol raised bog (NW Iberian Peninsula) was analyzed to identify plant macrofossils, estimate peat humification and calculate hydroclimatic indices based on current bog species, with the overall aim of determining the climate conditions associated with evolution of the bog during the Medieval Climate Anomaly and the Little Ice Age. These proxies, together with historical and climate data, proved to be good indicators of the changes in bog surface wetness.Analysisof the core led to identification of 9 different periods: two corresponding to the so-called Medieval Climate Anomaly (930 to 1345 AD, 1075–665 calibrated years before present [cal. yr BP]); four corresponding to the Little Ice Age (1345 to 1905 AD; 665–105 cal yr BP); and three corresponding to the last century (1905 to 2000 AD). The findings revealed a generally dry climate that lasted until the 14th century, followed by a transition to a long period with a more humid, but characteristically very variable climate, which ended at the beginning of the 20th century and was followed by a rapid transition to more humid conditions and finally, a change to drier conditions.The Medieval Climate Anomaly was indicated by the abundance of dry-adapted mosses (Leucobryum glaucum,Hypnum cupressiforme) and characterized by warm dry conditions and high levels of peat humification, with alternating wet phases. The LIA period was dated by a large abundance ofSphagnumspecies (an indicator of wetness) and a gradual increase in the humification index. However, four different climate phases were differentiated in this period.High-resolution reconstruction of the evolution of the CVM bog and the multiproxy approach have together enabled a more detailed identification of climatic variations in this area, which are generally consistent with the global models, as well as better definition of the elusive climatic oscillations in the last millennium and confirmation of the importance of local modulation of global models.The study provides new information and a detailed chronology of climatic events that will help to refine local modulation of the climate evolution model in the still quite unexplored region of the NW Iberian Peninsula, a key area for understanding the paleoclimatic dynamics in SW Europe.Graphical abstractDisplay OmittedHighlights•High resolution ombrotrophic peat core obtained in the NW Iberian Peninsula.•Multi-proxy approach explore the Late Holocene climate in the Iberian Peninsula.•Studies mire enabled detection of new inhomogeneities in well-known climate periods (LIA and MCA).•Three climate periods identified between the 10th and 14th centuries AD.•Arid phase identified between the 17th and 19th centuries AD in the LIA.
关键词：KeywordsenLast millenniumRaised bogPlant macrofossilHumification analysisSouthwest EuropeClimate change