DOI: 10.1016/j.palaeo.2012.11.002
论文题名: The significance of modern diatoms as paleoenvironmental indicators along an altitudinal gradient in the Andean piedmont of central Argentina
作者: Hassan G.S. ; De Francesco C.G. ; Dieguez S.
刊名: Palaeogeography, Palaeoclimatology, Palaeoecology
ISSN: 0031-0182
出版年: 2013
卷: 369 起始页码: 349
结束页码: 360
语种: 英语
英文关键词: Argentina
; Diatoms
; Holocene
; Paleoenvironmental reconstruction
; Pleistocene
英文摘要: The objectives of this study were to (a) analyze the distribution pattern of diatom assemblages in freshwater systems from central-western Argentina, (b) investigate the key climatic and limnological factors affecting the species distributions, and (c) evaluate the extent and limitations of diatoms as Quaternary paleoenvironmental indicators in the area. Diatoms were sampled and physical and chemical variables were quantified in a total of 45 lotic and lentic sites. Altitude, annual precipitation, and summer (January) temperature data were obtained from a world climate database. Previously published data from an adjacent region was incorporated into the modern dataset. Environmental variables significantly influencing diatom assemblage composition were identified through partial canonical correspondence analyses (CCAs). In order to assess the degree of analogy between modern and fossil assemblages, the modern analog technique (MAT) was applied. Diatom taxa showed distinct abundance patterns in relation to altitude, with a shift from communities dominated by periphitic and benthic taxa in lower sites to communities dominated by small benthic-tychoplanktonic taxa in high elevated waterbodies. The pH was the strongest variable explaining the variance within the diatom dataset, followed by log-conductivity and summer air temperature. The comparison of modern diatom assemblages with fossil sequences allowed reconstruction of the evolution of shallow, lentic and vegetated habitats. A good analogy between modern and Pleistocene diatom assemblages was found. The strong relationship between diatoms and climate-driven environmental variables, such as pH, conductivity and summer temperature, enhances the importance of the diatom floras as paleoclimatic indicators in the area and encourages future development of quantitative inference models for the region. © 2012 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/69913
Appears in Collections: 过去全球变化的重建
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作者单位: Instituto de Investigaciones Marinas y Costeras, CONICET-Universidad Nacional de Mar del Plata, Juan B. Justo 2550 1 Piso, Mar del Plata, cc 7600, Buenos Aires, Argentina; Departamento de Geología, Museo de Historia Natural de San Rafael, Parque Mariano Moreno, cc. 5600, San Rafael, Mendoza, Argentina
Recommended Citation:
Hassan G.S.,De Francesco C.G.,Dieguez S.. The significance of modern diatoms as paleoenvironmental indicators along an altitudinal gradient in the Andean piedmont of central Argentina[J]. Palaeogeography, Palaeoclimatology, Palaeoecology,2013-01-01,369