Publikationsdatum:
2024-02-14
Beschreibung:
The dominant forcing factors for past large-scale changes in vegetation are widely debated. Changes in the distribution of C4 plants-adapted to warm, dry conditions and low atmospheric CO2 concentrations (Collatz et al., 1998, doi:10.1007/s004420050468) -have been attributed to marked changes in environmental conditions, but the relative impacts of changes in aridity, temperature (Pagani et al., 1999, doi:10.1126/science.285.5429.876; Huang et al., 2001, doi:10.1126/science.1060143) and CO2 concentration (Cerling et al., 1993, doi:10.1038/361344a0; Kuypers et al., 1999, doi:10.1038/20659) are not well understood. Here, we present a record of African C4 plant abundance between 1.2 and 0.45 million years ago, derived from compound-specific carbon isotope analyses of wind-transported terrigenous plant waxes. We find that large-scale changes in African vegetation are linked closely to sea surface temperatures in the tropical Atlantic Ocean. We conclude that, in the mid-Pleistocene, changes in atmospheric moisture content - driven by tropical sea surface temperature changes and the strength of the African monsoon - controlled aridity on the African continent, and hence large-scale vegetation changes.
Schlagwort(e):
175-1077B; Accumulation rate, mass; AGE; Benguela Current, South Atlantic Ocean; Calculated, see reference(s); Carbon Preference Index, n-Alkanes (C25-C33); Depth, composite; DEPTH, sediment/rock; DRILL; Drilling/drill rig; DSDP/ODP/IODP sample designation; Gas chromatography - Mass spectrometry (GC-MS); GeoB; Geosciences, University of Bremen; Intercore correlation; Joides Resolution; Leg175; n-Alkane, average chain length; n-Alkane, C31/(C29+C31) ratio; n-Alkane C25-C35, flux; n-Alkane C29, δ13C; n-Alkane C31, δ13C; n-Alkane C4 plant, reference to C29; n-Alkane C4 plant, reference to C31; Ocean Drilling Program; ODP; Sample code/label; Sum n-alkanes C25-C35; Sum odd numbered n-alkanes C25-C35; Sum odd numbered n-alkanes C25-C35, flux
Materialart:
Dataset
Format:
text/tab-separated-values, 2492 data points
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