DOI: 10.1016/j.quascirev.2015.05.009
Scopus记录号: 2-s2.0-84930671397
论文题名: Origin and dynamics of the northern South American coastal savanna belt during the Holocene - the role of climate, sea-level, fire and humans
作者: Alizadeh K. ; Cohen M. ; Behling H.
刊名: Quaternary Science Reviews
ISSN: 2773791
出版年: 2015
卷: 122 起始页码: 51
结束页码: 62
语种: 英语
英文关键词: Climate change
; ENSO
; Gallery forest
; Holocene
; Human impact
; ITCZ and SACZ shift
; Mangrove
; Pollen and charcoal analysis
; Savanna
; Vegetation change
Scopus关键词: Charcoal
; Climatology
; Forestry
; Plants (botany)
; Sea level
; Vegetation
; Wetlands
; Charcoal analysis
; ENSO
; Gallery forests
; Holocenes
; Human impact
; ITCZ and SACZ shift
; Mangrove
; Savanna
; Vegetation change
; Climate change
; anthropogenic effect
; charcoal
; climate change
; El Nino-Southern Oscillation
; Holocene
; intertropical convergence zone
; mangrove
; paleoenvironment
; palynology
; savanna
; sediment core
; vegetation dynamics
; Coasts
; Forest Fires
; Forests
; Seasonal Variation
; Swamps
; Brazil
; British Columbia
; Canada
; Euphorbiaceae
; Micropholis (angiosperm)
; Rhizophoraceae
; Sapotaceae
英文摘要: Presence of a coastal savanna belt expanding from British Guiana to northeastern Brazil cannot be explained by present-day climate. Using pollen and charcoal analyses on an 11.6k old sediment core from a coastal depression in the savanna belt near the mouth of the Amazon River we investigated the paleoenvironmental history to shed light on this question. Results indicate that small areas of savanna accompanied by a forest type composed primarily by the genus Micropholis (Sapotaceae) that has no modern analog existed at the beginning of the Holocene. After 11,200calyr BP, savanna accompanied by few trees replaced the forest. In depressions swamp forest developed and by ca10,000calyr BP replaced by Mauritia swamps. Between 8500 and 5600calyr BP gallery forest (composed mainly of Euphorbiaceae) and swamp forest succeeded the treeless savanna. The modern vegetation with alternating gallery forest and savanna developed after 5600calyr BP. We suggest that the early Holocene no-analog forest is a relict of previously more extensive forest under cooler and moister Lateglacial conditions. The early Holocene savanna expansion indicates a drier phase probably related to the shift of the Intertropical Convergence Zone (ITCZ) towards its northernmost position. The mid-Holocene forest expansion is probably a result of the combined influence of equatorwards shift of ITCZ joining the South Atlantic Convergence Zone (SACZ). The ecosystem variability during the last 5600calyr BP, formed perhaps under influence of intensified ENSO condition. High charcoal concentrations, especially during the early Holocene, indicate that natural and/or anthropogenic fires may have maintained the savanna. However, our results propose that climate change is the main driving factor for the formation of the coastal savanna in this region. Our results also show that the early Holocene sea level rise established mangroves near the study site until 7500calyr BP and promoted swamp formation in depressions, but did not influence the savanna vegetation. © 2015 Elsevier Ltd. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/59888
Appears in Collections: 过去全球变化的重建
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作者单位: Department of Palynology and Climate Dynamics, Albrecht-von-Haller-Institute for Plant Sciences, University of Göttingen, Untere Karspüle 2, Göttingen, Germany; Faculty of Oceanography, Federal University of Pará, Rua Augusto Corrêa, no 1, Guama, Belém, PA, Brazil
Recommended Citation:
Alizadeh K.,Cohen M.,Behling H.. Origin and dynamics of the northern South American coastal savanna belt during the Holocene - the role of climate, sea-level, fire and humans[J]. Quaternary Science Reviews,2015-01-01,122