The effects of late Quaternary climate and pCO2 change on C4 plant abundance in the south-central United States

摘要: The late Quaternary was a time of substantial environmental change, with the past 70,000 years exhibiting global changes in climate, atmospheric composition, and terrestrial floral faunal assemblages. We use isotopic data couple climate vegetation models to assess balance between C3 C4 Texas during this period. carbon isotope composition fossil bison, mammoth, horse tooth enamel is used as proxy for versus plant consumption, indicates that biomass remained above 55% through most from prior Last Glacial Maximum (LGM) into Holocene. These also reveal horses did not feed exclusively on herbaceous plants, consequently are reliable indicators C3–C4 grassland biomes. Estimates percentages coupled climate–vegetation illuminate relative roles dioxide (CO2) concentrations shaping regional signal. estimated using observed modern relationships variables (simulated by model) much lower than those indicated values fossils. When effect CO2 concentration competitive plants included numerical experiment, however, show better agreement estimates mammals soils. This result suggests low levels played role persistence throughout Quaternary.