DOI: 10.1002/2014GB004822
Scopus记录号: 2-s2.0-84907711204
论文题名: The impact of neogene grassland expansion and aridification on the isotopic composition of continental precipitation
作者: Chamberlain C ; P ; , Winnick M ; J ; , Mix H ; T ; , Chamberlain S ; D ; , Maher K
刊名: Global Biogeochemical Cycles
ISSN: 8866236
出版年: 2014
卷: 28, 期: 9 起始页码: 992
结束页码: 1004
语种: 英语
英文关键词: grasslands
; oxygen isotopes
; precipitation
Scopus关键词: aridification
; aridity
; cooling
; forest ecosystem
; grassland
; isotopic composition
; Miocene
; Neogene
; oxygen isotope
; paleoclimate
; paleoecology
; precipitation (climatology)
; Poaceae
英文摘要: The late Cenozoic was a time of global cooling, increased aridity, and expansion of grasslands. In the last two decades numerous records of oxygen isotopes have been collected to assess plant ecological changes, understand terrestrial paleoclimate, and to determine the surface history of mountain belts. The δ18O values of these records, in general, increase from the mid-Miocene to the Recent. We suggest that these records record an increase in aridity and expansion of grasslands in midlatitude continental regions. We use a nondimensional isotopic vapor transport model coupled with a soil water isotope model to evaluate the role of vapor recycling and transpiration by different plant functional types. This analysis shows that increased vapor recycling associated with grassland expansion along with biomechanistic changes in transpiration by grasses themselves conspires to lower the horizontal gradient in the δ18O of atmospheric vapor as an air mass moves into continental interiors. The resulting signal at a given inland site is an increase in δ18O of precipitation with the expansion of grasslands and increasing aridity, matching the general observed trend in terrestrial Cenozoic δ18O records. There are limits to the isotopic effect that are induced by vapor recycling, which we refer to here as a "hydrostat." In the modern climate, this hydrostatic limit occurs at approximately the boundary between forest and grassland ecosystems. © 2014. American Geophysical Union. All Rights Reserved. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/77458
Appears in Collections: 气候变化事实与影响
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作者单位: Department of Environmental Earth Systems Science, Stanford University, Stanford, CA, United States; Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY, United States; Department of Geological and Environmental Sciences, Stanford University, Stanford, CA, United States
Recommended Citation:
Chamberlain C,P,, Winnick M,et al. The impact of neogene grassland expansion and aridification on the isotopic composition of continental precipitation[J]. Global Biogeochemical Cycles,2014-01-01,28(9)