Late-Quaternary records of vegetation and fire in southeastern North Carolina from Jones Lake and Singletary Lake

QUATERNARY SCIENCE REVIEWS

卷:174

Article

Spencer, Jessica¹  Jones, Kaylee B.¹  Gamble, Douglas W.¹  Benedetti, Michael M.¹  Taylor, Audrey K.¹  Lane, Chad S.¹ 

[1] Univ North Carolina Wilmington, Dept Earth & Ocean Sci, Wilmington, NC 28403 USA

关键词: Lake sediment;    Macroscopic charcoal;    North America;    Paleoenvironmental;    Paleolimnology;    Pollen;    Quaternary;    Stable isotopes;   

DOI  :  10.1016/j.quascirev.2017.09.001

来源: Elsevier

【 摘 要 】

We conducted fossil pollen, charcoal, and geochemical analyses of sediment cores from Jones Lake and Singletary Lake spanning the last similar to 50,000 cal yr B.P. to examine the linkages between climate, vegetation, and fire activity on the Atlantic Coastal Plain, and particularly emphasize changes since the Last Glacial Maximum. Application of the modern analog technique (MAT) to fossil pollen data allowed for quantitative estimates of Holocene climate, but Pleistocene assemblages had no modern analogues preempting their use for quantitative reconstructions. The MAT data indicate markedly lower mean annual precipitation and temperatures during the late Pleistocene relative to the Holocene. Increased charcoal accumulation during interstadials indicates increased fire activity during these warm intervals. Geochemical data (delta C-13, delta N-15, C:N) and pollen concentrations indicate a sparsely-vegetated Pleistocene landscape that produced few fires followed by an increase in biomass and fire activity around the lakes during the Holocene transition. A Quercus spp. maximum in the early Holocene is associated with low charcoal abundances, while increased dominance of Pinus spp. during the middle Holocene is associated with dramatic increases in charcoal. It is unclear if the Quercus-Pinus transition was the result of changing fire regimes or if the fire regime changed in response to vegetation. The regional asynchronicity of the Quercus-Pinus transition may indicate another forcing mechanism besides climate change, such as prehistoric human activity, is responsible for the ecological change. Macroscopic charcoal and C:N ratios reach unprecedented values during the late Holocene, possibly as a result of deforestation by both prehistoric Native Americans and later immigrant populations. (C) 2017 Elsevier Ltd. All rights reserved.

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