title: Elevation-induced climate change as a dominant factor causing the late Miocene C(4) plant expansion in the Himalayan foreland.
abstract: During the late Miocene, a dramatic global expansion of C4 plant distribution occurred with broad spatial and temporal variations. Although the event is well documented, whether subsequent expansions were caused by a decreased atmospheric CO2 concentration or climate change is a contentious issue. In this study, we used an improved inverse vegetation modeling approach that accounts for the physiological responses of C3 and C4 plants to quantitatively reconstruct the paleoclimate in the Siwalik of Nepal based on pollen and carbon isotope data. We also studied the sensitivity of the C3 and C4 plants to changes in the climate and the atmospheric CO2 concentration. We suggest that the expansion of the C4 plant distribution during the late Miocene may have been primarily triggered by regional aridification and temperature increases. The expansion was unlikely caused by reduced CO2 levels alone. Our findings suggest that this abrupt ecological shift mainly resulted from climate changes related to the decreased elevation of the Himalayan foreland.
authors.affiliation: Key Laboratory of Cenozoic Geology and Environment, Institute of Geology and Geophysics, Chinese Academy of Sciences, P.O. Box 9825, Beijing, 100029, China.
authors.forename: Haibin
authors.initials: H
authors.lastname: Wu
authors.forename: Zhengtang
authors.initials: Z
authors.lastname: Guo
authors.forename: Joël
authors.initials: J
authors.lastname: Guiot
authors.forename: Christine
authors.initials: C
authors.lastname: Hatté
authors.forename: Changhui
authors.initials: C
authors.lastname: Peng
authors.forename: Yanyan
authors.initials: Y
authors.lastname: Yu
authors.forename: Junyi
authors.initials: J
authors.lastname: Ge
authors.forename: Qin
authors.initials: Q
authors.lastname: Li
authors.forename: Aizhi
authors.initials: A
authors.lastname: Sun
authors.forename: Deai
authors.initials: D
authors.lastname: Zhao
mesh_terms: D001272:Atmosphere / Q000032:analysis; D044822:Biodiversity; D002244:Carbon / Q000378:metabolism; D002245:Carbon Dioxide / Q000032:analysis*; D057231:Climate Change; D017753:Ecosystem; D008954:Models, Biological; D009390:Nepal; D010163:Paleontology; D010944:Plants / Q000378:metabolism; D012621:Seasons
chemical_list: D002245:Carbon Dioxide; D002244:Carbon
keywords: C4 plant expansion; inverse vegetation model; late Miocene; paleoclimate reconstruction; pollen biome