High-resolution patterns of palaeoenvironmental changes during the Little Ice Age and the Medieval Climate Anomaly in the northwestern Iberian Peninsula  

作　　者：Daniel Castro Martin Souto Maria Isabel Fraga Eduardo Garcia-Rodeja Sebastian Perez-Diaz Jose Antonio Lopez Saez Xabier Pontevedra-Pombal 

机构地区：[1]Dpto.Botanica,Fac.Bioloxia,Universidade de Santiago de Compostela,Galicia,Spain [2]Dpto.Edafoloxia e Quimica Agricola,Fac.Bioloxia,Universidade de Santiago de Compostela,Galicia,Spain [3]Dpto.Geografia,Urbanismo y Ordenacion Del Territorio,ETS Caminos,Canales y Puertos,Universidad de Cantabria,Spain [4]GI Arqueobiologia,Instituto de Historia,CCHS–CSIC,Madrid,Spain

出　　处：《Geoscience Frontiers》2020年第5期1461-1475,共15页地学前缘（英文版）

基　　金：the support of the Xunta de Galicia government(Spain)through projects INCITE09-200-019-PR and Consolidacion e Estructuracion 2018 GRC GI-1243-GEMAP,ED431C 2018/32。

摘　　要：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.Analysis:of 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 of Sphagnum species(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

关 键 词：Last millennium Raised bog Plant macrofossil Humification analysis Southwest Europe Climate change 

分 类 号：P532[天文地球—古生物学与地层学]