DOI: 10.1016/j.quascirev.2013.04.004
Scopus记录号: 2-s2.0-84878144678
论文题名: Vegetation changes and human settlement of Easter Island during the last millennia: A multiproxy study of the Lake Raraku sediments
作者: Cañellas-Boltà N. ; Rull V. ; Sáez A. ; Margalef O. ; Bao R. ; Pla-Rabes S. ; Blaauw M. ; Valero-Garcés B. ; Giralt S.
刊名: Quaternary Science Reviews
ISSN: 2773791
出版年: 2013
卷: 72 起始页码: 36
结束页码: 48
语种: 英语
英文关键词: Deforestation
; Easter Island
; Human settlement
; Late Holocene
; Paleoecology
; Verbena litoralis
Scopus关键词: Easter island
; Human settlements
; Late Holocene
; Paleoecology
; Verbena litoralis
; Catchments
; Charcoal
; Climatology
; Deforestation
; Ecology
; Lakes
; Sedimentology
; Vegetation
; climate variation
; growth rate
; human activity
; human settlement
; lacustrine deposit
; palynology
; vegetation classification
; vegetation cover
; vegetation dynamics
; vegetation type
; weed
; Charcoal
; Deforestation
; Ecology
; Lakes
; Meteorology
; Plants
; Easter Island
英文摘要: Earlier palynological studies of lake sediments from Easter Island suggest that the island underwent a recent and abrupt replacement of palm-dominated forests by grasslands, interpreted as a deforestation by indigenous people. However, the available evidence is inconclusive due to the existence of extended hiatuses and ambiguous chronological frameworks in most of the sedimentary sequences studied. This has given rise to an ongoing debate about the timing and causes of the assumed ecological degradation and cultural breakdown. Our multiproxy study of a core recovered from Lake Raraku highlights the vegetation dynamics and environmental shifts in the catchment and its surroundings during the late Holocene. The sequence contains shorter hiatuses than in previously recovered cores and provides a more continuous history of environmental changes. The results show a long, gradual and stepped landscape shift from palm-dominated forests to grasslands. This change started c. 450 BC and lasted about two thousand years. The presence of Verbena litoralis, a common weed, which is associated with human activities in the pollen record, the significant correlation between shifts in charcoal influx, and the dominant pollen types suggest human disturbance of the vegetation. Therefore, human settlement on the island occurred c. 450 BC, some 1500 years earlier than is assumed. Climate variability also exerted a major influence on environmental changes. Two sedimentary gaps in the record are interpreted as periods of droughts that could have prevented peat growth and favoured its erosion during the Medieval Climate Anomaly and the Little Ice Age, respectively. At c. AD 1200, the water table rose and the former Raraku mire turned into a shallow lake, suggesting higher precipitation/evaporation rates coeval with a cooler and wetter Pan-Pacific AD 1300 event. Pollen and diatom records show large vegetation changes due to human activities c. AD 1200. Other recent vegetation changes also due to human activities entail the introduction of taxa (e.g. Psidium guajava, Eucalyptus sp.) and the disappearance of indigenous plants such as Sophora toromiro during the two last centuries. Although the evidence is not conclusive, the American origin of V. litoralis re-opens the debate about the possible role of Amerindians in the human colonisation of Easter Island. © 2013 Elsevier Ltd.
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/60603
Appears in Collections: 过去全球变化的重建
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作者单位: Palynology and Paleoecology Lab, Botanic Institute of Barcelona (IBB-CSIC-ICUB), Passeig del Migdia s/n, E-08038 Barcelona, Spain; Department of Stratigraphy, Paleontology and Marine Geosciences, Universitat de Barcelona, Marti Franques s/n, E-08028 Barcelona, Spain; Institute of Earth Sciences Jaume Almera (ICTJA-CSIC), Lluís Solé Sabarís s/n, E-08028 Barcelona, Spain; Faculty of Sciences, University of A Coruña, Campus da Zapateira s/n, 15071 A Coruña, Spain; Biogeodynamics and Biodiversity Group, Center for Advanced Studies of Blanes (CEAB-CSIC), Cala St. Francesc 14, E-17300 Blanes, Spain; Centre for Ecological Research and Forestry Applications (CREAF), Cerdanyola del Vallès, E-08193 Barcelona, Spain; School of Geography, Archaeology and Palaeoecology (GAP), Queen's University Belfast, Belfast BT7 1NN, United Kingdom; Pyrenean Institute of Ecology (IPE-CSIC), Apdo. 13034, E-50080 Zaragoza, Spain
Recommended Citation:
Cañellas-Boltà N.,Rull V.,Sáez A.,et al. Vegetation changes and human settlement of Easter Island during the last millennia: A multiproxy study of the Lake Raraku sediments[J]. Quaternary Science Reviews,2013-01-01,72