DOI: 10.1016/j.quascirev.2013.09.001
Scopus记录号: 2-s2.0-84885231470
论文题名: Moisture and temperature changes associated with the mid-Holocene Tsuga decline in the northeastern United States
作者: Marsicek J.P. ; Shuman B. ; Brewer S. ; Foster D.R. ; Oswald W.W.
刊名: Quaternary Science Reviews
ISSN: 2773791
出版年: 2013
卷: 80 起始页码: 129
结束页码: 142
语种: 英语
英文关键词: Abrupt change
; Climatic change
; Fossil pollen
; Hemlock (Tsuga canadensis) decline
; Holocene
; Lake levels
; Northeastern U.S.
Scopus关键词: Abrupt change
; Climatic changes
; Fossil pollens
; Holocenes
; Lake levels
; Northeastern U.S
; Tsuga canadensis
; Drought
; Moisture
; Population statistics
; Vegetation
; Water supply
; Lakes
; abundance
; climate change
; coastal zone
; fossil record
; Holocene
; moisture content
; population decline
; precipitation (climatology)
; sediment core
; temperature effect
; vegetation cover
; Cape Cod
; Massachusetts
; United States
英文摘要: A decline of hemlock (Tsuga) populations at ca5.5ka (thousands of calibrated radiocarbon years before 1950AD) stands out as the most abrupt vegetation change of the Holocene in North America, but remains poorly understood after decades of study. Recent analyses of fossil pollen have revealed a concurrent, abrupt oak (Quercus) decline and increases in the abundance of beech (Fagus) and pine (Pinus) on Cape Cod in eastern Massachusetts, but the replacement of drought-tolerant oaks by moisture-sensitive beeches appears inconsistent with low lake levels in the region at the same time. The oak and beech changes are also limited to coastal areas, and the coastal-inland differences require an explanation. Here, we develop a new lake-level reconstruction from Deep Pond, Cape Cod by using a transect of sediment cores and ground-penetrating radar (GPR) profiles to constrain the past elevations of the sandy, littoral zone of the pond. The reconstruction shows that a series of multi-century episodes of low water coincide with the abrupt hemlock and oak declines, and interrupt subsequent phases of hemlock recovery. The lake-level variations equal precipitation deficits of ~100mm superimposed on a Holocene long moisture increase of >400mm. However, because moisture deficits do not easily explain the oak and beech changes, we also evaluate how the climate preferences of the regional vegetation changed over time by matching the fossil pollen assemblages from Deep Pond with their modern equivalents. Reconstructions of the precipitation requirements of the vegetation correlate well even in detail with the lake-level record (r=0.88 at Deep Pond), and indicate close tracking of effective moisture (precipitation minus evapotranspiration) by the vegetation despite the abrupt species declines, which could have decoupled climate and vegetation trends. Reconstructions of the temperature preferences of the vegetation indicate that coastal sites may have cooled by 0.5-2.5°C after ca5.5 ka, while inland sites warmed by 0.5-1C. The change in coastal temperature preferences agrees with sea surface cooling in the western Atlantic Ocean of 1°C. Consequently, the persistence of low hemlock abundance after 5.5 ka in the northeast U.S. may have resulted from oceanic changes that produced multi-century droughts and thus delayed the post-decline recovery of hemlock populations. © 2013 Elsevier Ltd. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/60466
Appears in Collections: 过去全球变化的重建
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作者单位: Department of Geology and Geophysics, University of Wyoming, Dept. 3006, 1000 E. University Ave., Laramie, WY 82071, United States; Department of Geography, University of Utah, Salt Lake City, 260 S. Central Campus Dr., UT 84112, United States; Harvard Forest and Department of Organismic and Evolutionary Biology, Harvard University, Petersham, 324 North Main St., MA 01366, United States; Department of Communication Sciences and Disorders, Emerson College, Boston, 120 Boylston St., MA 02116, United States
Recommended Citation:
Marsicek J.P.,Shuman B.,Brewer S.,et al. Moisture and temperature changes associated with the mid-Holocene Tsuga decline in the northeastern United States[J]. Quaternary Science Reviews,2013-01-01,80