干旱区生态环境知识资源中心(Arid): Synchronous rise of African C-4 ecosystems 10 million years ago in the absence of aridification

Arid

DOI	10.1038/s41561-019-0399-2
	Synchronous rise of African C-4 ecosystems 10 million years ago in the absence of aridification
	Polissar, Pratigya J.1; Rose, Cassaundra 2; Uno, Kevin T.1; Phelps, Samuel R.2; deMenocal, Peter 1,2
通讯作者	Polissar, Pratigya J. ; Rose, Cassaundra
来源期刊	NATURE GEOSCIENCE
ISSN	1752-0894
EISSN	1752-0908
出版年	2019
卷号	12 期号:8 页码:657-+
英文摘要	Grasslands expanded globally during the late Cenozoic and the development of these ecosystems shaped the evolution of many faunal groups, including our hominin ancestors. The emergence of these ecosystems has been dated in many regions, but the origins of the iconic African C-4 savannah grasslands remain poorly known, as do the causal factors that led to their establishment. Here we document their origins with the distinct carbon isotope signature from the hot-, arid- and low-CO2-adapted C-4 grasses that dominate modern savannahs and grasslands. We use the carbon isotope values of leaf-wax molecules in deep-sea drill cores to measure the rise of African C-4 ecosystems. We also reconstruct African palaeohydroclimate change from leaf-wax hydrogen isotope values and dust deposition rates in these cores. We find that C-4-dominated ecosystems expanded synchronously across Northwestern and East Africa after 10 million years ago. This was not accompanied by substantial changes in palaeohydrology or dust deposition, precluding aridification as a causal factor. The expansion of C-4 grasses was coincident, however, with dramatic high-latitude cooling and increased pole-Equator temperature gradients. We suggest that declining atmospheric CO2 levels were a direct cause of the C-4 grassland expansion.
类型	Article
语种	英语
国家	USA
收录类别	SCI-E
WOS记录号	WOS:000477864200017
WOS关键词	HYDROGEN-ISOTOPIC COMPOSITION ; VEGETATION CHANGE ; TURKANA BASIN ; LATE MIOCENE ; CO2 DECLINE ; RECORD ; RECONSTRUCTIONS ; PHOTOSYNTHESIS ; BIOCHRONOLOGY ; BIOZONATION
WOS类目	Geosciences, Multidisciplinary
WOS研究方向	Geology
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/217755
作者单位	1.Lamont Doherty Earth Observ, Div Biol & Paleo Environm, Palisades, NY 10964 USA; 2.Columbia Univ, Dept Earth & Environm Sci, New York, NY 10027 USA
推荐引用方式 GB/T 7714	Polissar, Pratigya J.,Rose, Cassaundra,Uno, Kevin T.,et al. Synchronous rise of African C-4 ecosystems 10 million years ago in the absence of aridification[J],2019,12(8):657-+.
APA	Polissar, Pratigya J.,Rose, Cassaundra,Uno, Kevin T.,Phelps, Samuel R.,&deMenocal, Peter.(2019).Synchronous rise of African C-4 ecosystems 10 million years ago in the absence of aridification.NATURE GEOSCIENCE,12(8),657-+.
MLA	Polissar, Pratigya J.,et al."Synchronous rise of African C-4 ecosystems 10 million years ago in the absence of aridification".NATURE GEOSCIENCE 12.8(2019):657-+.