DOI: 10.1016/j.quascirev.2016.04.005
Scopus记录号: 2-s2.0-84968912270
论文题名: Reconstruction of full glacial environments and summer temperatures from Lago della Costa, a refugial site in Northern Italy
作者: Samartin S. ; Heiri O. ; Kaltenrieder P. ; Kühl N. ; Tinner W.
刊名: Quaternary Science Reviews
ISSN: 2773791
出版年: 2016
卷: 143 起始页码: 107
结束页码: 119
语种: 英语
英文关键词: Chironomids
; Climate
; Heinrich events
; Last glacial
; LGM
; Mediterranean
; Northern Italy
; Paleoclimatology
; Paleoecology
; Refugia
; Vegetation
Scopus关键词: Atmospheric temperature
; Climatology
; Forestry
; Lakes
; Sediments
; Temperature
; Vegetation
; Chironomids
; Climate
; Heinrich Events
; Last glacial
; Mediterranean
; Northern Italy
; Paleoclimatology
; Paleoecology
; Refugia
; Glacial geology
; air temperature
; autochthon
; climate conditions
; gyttja
; Heinrich event
; ice sheet
; lacustrine deposit
; Last Glacial
; Last Glacial Maximum
; paleobotany
; paleoclimate
; paleoecology
; paleotemperature
; reconstruction
; sediment core
; summer
; temperate forest
; Euganean Hills
; Italy
; Italy
; Padova
; Veneto
; Abies alba
; Acer
; Carpinus
; Castanea
; Chironomidae
; Fagus sylvatica
; Fraxinus excelsior
; Quercus
; Tilia
; Ulmus
英文摘要: Vegetation and climate during the last ice age and the Last Glacial Maximum (LGM, ~23,000-19,000 cal BP) were considerably different than during the current interglacial (Holocene). Cold climatic conditions and growing ice-sheets during the last glaciation radically reduced forest extent in Europe to a restricted number of so-called "refugia", mostly located in the southern part of the continent. On the basis of paleobotanical analyses the Euganian Hills (Colli Euganei) in northeastern Italy have previously been proposed as one of the northernmost refugia of temperate trees (e.g. deciduous Quercus, Tilia, Ulmus, Fraxinus excelsior, Acer, Abies alba, Fagus sylvatica, Carpinus and Castanea) in Europe. In this study we provide the first quantitative, vegetation independent summer air temperature reconstruction for Northern Italy spanning the time ~31,000-17,000 cal yr BP, which covers the coldest periods of the last glacial, including the LGM and Heinrich stadials 1 to 3. Chironomids preserved in a lake sediment core from Lago della Costa (7m a.s.l.), a small lake at the south-eastern edge of the Euganean Hills, allowed quantitative reconstruction of Full and Late Glacial summer air temperatures using a combined Swiss-Norwegian temperature inference model based on chironomid assemblages from 274 lakes. Chironomid and pollen evidence from Lago della Costa derives from finely stratified autochthonous organic gyttja sediments, which excludes major sediment mixing or reworking. After reconstructing paleo-temperatures, we address the question whether climate conditions were warm enough to permit the local survival of temperate tree species during the LGM and whether local expansions and pollen-inferred contractions of temperate tree taxa coincided with chironomid-inferred climatic changes. Our results suggest that chironomids at Lago della Costa have responded to major climatic fluctuations such as temperature decreases during the LGM and Heinrich stadials. The vegetation of the Euganean Hills shows responses to these climatic oscillations although the effects of temperature changes were probably also strongly influenced by changes in humidity. Reconstructed July air temperatures at Lago della Costa never fell below 10-13 °C (error range of reconstruction ~ ±1.5-1.6 °C), which is considerably above the limit considered necessary for forest growth (8-10 °C). Instead rather mild climatic conditions prevailed ~31,000-17,000 cal yr BP with average summer temperatures between ~12 and 16 °C, which most likely allowed survival of temperate tree taxa in the warmest (and moistest) microhabitats of the Euganean Hills during the LGM. Only assuming local survival is it possible to explain the repeated expansions and collapses of temperate trees at Lago della Costa which faithfully accompanied the climatic oscillations. © 2016. 资助项目: We thank Brigitta Ammann for her steady support and Stephen Brooks for providing access to calibration data. We also thank the Swiss National Science Foundation, who funded the study within PP00P2-114886.
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/59578
Appears in Collections: 过去全球变化的重建
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作者单位: Oeschger Centre for Climate Change Research and Institute of Plant Sciences, University of Bern, Altenbergrain 21, Bern, Switzerland; Steinmann-Institute of Geology, Mineralogy and Paleontology, University of Bonn, Nussallee 8, Bonn, Germany
Recommended Citation:
Samartin S.,Heiri O.,Kaltenrieder P.,et al. Reconstruction of full glacial environments and summer temperatures from Lago della Costa, a refugial site in Northern Italy[J]. Quaternary Science Reviews,2016-01-01,143