Steppe development on the Northern Tibetan Plateau inferred from Paleogene ephedroid pollen

被引:21
作者
Han, Fang [1 ,2 ]
Rydin, Catarina [3 ]
Bolinder, Kristina [3 ]
Dupont-Nivet, Guillaume [4 ,5 ]
Abels, Hemmo A. [6 ]
Koutsodendris, Andreas [7 ]
Zhang, Kexin [8 ]
Hoorn, Carina [2 ]
机构
[1] East China Univ Technol, Sch Earth Sci, Nanchang 330013, Peoples R China
[2] Univ Amsterdam, Inst Biodivers & Ecosyst Dynam, Amsterdam, Netherlands
[3] Stockholm Univ, Dept Ecol Environm & Plant Sci, S-10691 Stockholm, Sweden
[4] Univ Potsdam, Inst Earth & Environm Sci, Potsdam, Germany
[5] Univ Rennes 1, Geosci Rennes, Rennes, France
[6] Univ Utrecht, Dept Earth Sci, Utrecht, Netherlands
[7] Heidelberg Univ, Inst Earth Sci, Paleoenvironm Dynam Grp, Heidelberg, Germany
[8] China Univ Geosci, Wuhan 430074, Peoples R China
基金
瑞典研究理事会;
关键词
pollen morphology; Eocene; climate; Ephedripites; Distachyapites; Gnetaceaepollenites; monsoon; WESTERN QAIDAM BASIN; DRILL CORE SG-1; MIDDLE EOCENE; ASIAN MONSOON; PALYNOLOGICAL ASSEMBLAGES; CLIMATE-CHANGE; XINING BASIN; UPLIFT; EVOLUTION; ARIDIFICATION;
D O I
10.1080/00173134.2015.1120343
中图分类号
Q94 [植物学];
学科分类号
071001 [植物学];
摘要
Steppe vegetation represents a key marker of past Asian aridification and is associated with monsoonal intensification. Little is, however, known about the origin of this pre-Oligocene vegetation, its specific composition and how it changed over time and responded to climatic variations. Here, we describe the morphological characters of Ephedraceae pollen in Eocene strata of the Xining Basin and compare the pollen composition with the palynological composition of Late Cretaceous and Paleocene deposits of the Xining Basin and the Quaternary deposits of the Qaidam Basin. We find that the Late Cretaceous steppe was dominated by Gnetaceaepollenites; in the transition from the Cretaceous to the Paleocene, Gnetaceaepollenites became extinct and Ephedripites subgenus Ephedripites dominated the flora with rare occurrences of Ephedripites subgen. Distachyapites; the middle to late Eocene presents a strong increase of Ephedripites subgen. Distachyapites; and the Quaternary/Recent is marked by a significantly lower diversity of Ephedraceae (and Nitrariaceae) compared to the Eocene. In the modern landscape of China, only a fraction of the Paleogene species diversity of Ephedraceae remains and we propose that these alterations in Ephedreaceae composition occurred in response to the climatic changes at least since the Eocene. In particular, the strong Eocene monsoons that enhanced the continental aridification may have played an important role in the evolution of Ephedripites subgen. Distachyapites triggering an evolutionary shift to wind-pollination in this group. Conceivably, the Ephedraceae/Nitrariaceae dominated steppe ended during the Eocene/Oligocene climatic cooling and aridification, which favoured other plant taxa.
引用
收藏
页码:71 / 100
页数:30
相关论文
共 155 条
[1]
Step-wise change of Asian interior climate preceding the Eocene-Oligocene Transition (EOT) [J].
Abels, Hemmo A. ;
Dupont-Nivet, Guillaume ;
Xiao, Guoqiao ;
Bosboom, Roderic ;
Krijgsman, Wout .
PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY, 2011, 299 (3-4) :399-412
[2]
Late Cretaceous palynostratigraphy in the Gongola Basin (Upper Benue Trough, Nigeria) [J].
Abubakar, M. B. ;
Luterbacher, H. P. ;
Ashraf, A. R. ;
Ziedner, R. ;
Maigari, A. S. .
JOURNAL OF AFRICAN EARTH SCIENCES, 2011, 60 (1-2) :19-27
[3]
Akkiraz MS, 2008, TURK J EARTH SCI, V17, P317
[4]
[Anonymous], CUENCAS SEDIMENTARIA
[5]
[Anonymous], 2002, CHIN ACAD SCI
[6]
[Anonymous], POLLEN CRETACE MOYEN
[7]
[Anonymous], 1982, Bol. Inst. Geociencia. Univ. USP, DOI DOI 10.11606/ISSN.2316-8978.V13I0P116-128
[8]
[Anonymous], GRANA
[9]
[Anonymous], 1984, GEOLOGY REV
[10]
[Anonymous], 1950, PALAEONTOGRAPHICA B