气候变化领域集成服务门户(CCPortal): Ecological dynamic equilibrium in an early Miocene (21.73 Ma) forest; Ethiopia

CCPortal

DOI	10.1016/j.palaeo.2019.109425
	Ecological dynamic equilibrium in an early Miocene (21.73 Ma) forest; Ethiopia
	Currano E.D.; Jacobs B.F.; Bush R.T.; Novello A.; Feseha M.; Grímsson F.; McInerney F.A.; Michel L.A.; Pan A.D.; Phelps S.R.; Polissar P.; Strömberg C.A.E.; Tabor N.J.
发表日期	2020
ISSN	0031-0182
卷号	539
英文摘要	Miocene paleoecology of East Africa has implications for human origins and understanding the vicariant legacy forests found today on either side of the East African Rift. Fossil leaves preserved in 21.73 million year old lacustrine sediments from the Mush Valley, Ethiopia, provide a unique opportunity to investigate forest composition and dominance-diversity patterns at an ecological scale. We classified and analyzed 2427 leaves in total from two to three quarries within each of six stratigraphic levels, spanning 7 m of section; we estimate each quarry census represents one to three centuries, and 50–60 kyrs separate the oldest and youngest levels. Pollen, phytolith, and compound-specific organic geochemical data were also collected in a detailed stratigraphic context to provide independent, integrated lines of evidence for landscape evolution and lacustrine paleoecology of the system that preserves the macrofossils. Forty-nine leaf morphotypes were documented, and Legume 1 dominated all samples. Nonmetric multidimensional scaling, Jaccard similarity analyses, and diversity and evenness indices demonstrate a degree of change comparable to community ecology dynamics, likely illustrating a dynamic stable state in forest vegetation surrounding the lake. Taxonomic assessments of leaves, phytoliths, and pollen are consistent with a closed canopy forest with limited palm diversity. A high abundance of des-A ring triterpenoid molecules (diagenetic products formed by microbial degradation under anoxic conditions) and very negative δ13C values (<−45‰) of several hopanoid compounds point to anoxic conditions at the lake bottom, consistent with exquisite fossil preservation. The proportion of mid-chain n-alkanes is low, signifying relatively few submerged plants, but increases up-section, which signals shallowing of the paleolake. The Mush Valley locality is unique in Africa with regard to its very early Miocene age and the abundance and quality of organic remains. This densely forested landscape in an upland volcanic region of the Ethiopian Plateau showed resilience amid volcanic eruptions and had botanical affinities with species found today in West, Central, and eastern Africa. © 2019 The Authors
英文关键词	Africa; Mush Valley; n-Alkanes; Paleobotany; Paleoenvironmental proxies; Phytoliths
语种	英语
scopus关键词	alkane; carbon isotope; dominance; estimation method; fossil record; macrophyte; Miocene; paleobotany; paleoecology; paleoenvironment; phytolith; pollen; species diversity; Africa; East African Rift; Ethiopian Highlands
来源期刊	Palaeogeography, Palaeoclimatology, Palaeoecology
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/150633
作者单位	Departments of Botany and Geology & Geophysics, University of Wyoming, 1000 E. University Avenue, Laramie, WY 82072, United States; Roy M. Huffington Department of Earth Sciences, Southern Methodist University, 3225 Daniel Avenue, Dallas, TX 75275-0395, United States; Department of Earth and Planetary Sciences, Northwestern University, 2145 Sheridan Avenue, Evanston, IL 60208, United States; Aix‐Marseille University, CNRS, IRD INRA, Coll France, CEREGEAix en Provence, France; Department of Biology, Burke Museum of Natural History & Culture, University of Washington, Seattle, WA 98195, United States; Paleoanthropology and Paleoenvironment Program, College of Natural Sciences, Addis Ababa University, Addis Ababa, Ethiopia; Department of Botany and Biodiversity Research, University of ViennaVienna, Austria; Department of Earth Sciences and Sprigg Geobiology Centre, University of Adelaide, Adelaide, SA 5005, Australia; Department of Earth Sciences, Tennessee Tech University, 1 William L Jones Drive, Cook...
推荐引用方式 GB/T 7714	Currano E.D.,Jacobs B.F.,Bush R.T.,等. Ecological dynamic equilibrium in an early Miocene (21.73 Ma) forest; Ethiopia[J],2020,539.
APA	Currano E.D..,Jacobs B.F..,Bush R.T..,Novello A..,Feseha M..,...&Tabor N.J..(2020).Ecological dynamic equilibrium in an early Miocene (21.73 Ma) forest; Ethiopia.Palaeogeography, Palaeoclimatology, Palaeoecology,539.
MLA	Currano E.D.,et al."Ecological dynamic equilibrium in an early Miocene (21.73 Ma) forest; Ethiopia".Palaeogeography, Palaeoclimatology, Palaeoecology 539(2020).