Subtropical South African hydroclimate during the mid-Piacenzian Warm Period recorded by fynbos vegetation as a test case for climate model performance
Final Report Abstract
To study Pliocene hydroclimate and vegetation of subtropical South Africa, we analyzed the pollen and spores in deep-sea marine sediments recovered southwest from Cape Town. The Pliocene vegetation of the southern Cape region was dominated by fynbos indicating wetter conditions during the Pliocene compared to the Pleistocene. Our finding corroborates that of other paleorecords from the subtropics, but is inconsistent with most climate modelling studies. The pollen record has a high temporal resolution (one sample every 3 thousand years) revealing the variability of the South African subtropical vegetation during the late Pliocene from 3.34 to 2.79 million years ago. This variability is mainly driven by orbital precession, which influences the latitudinal position and strength of the Southern Hemisphere westerlies and affect the balance between winter rainfall and summer rainfall in South Africa. However, sea surface temperatures along the coast and the position of the Antarctic Subtropical Front also had some influence on the vegetation.
Publications
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(2019) Hydroclimate change in subtropical South Africa during the mid-Piacenzian Warm Period recorded in fynbos vegetation at IODP Site U1479. 18.-20.03.2019: IODP/ICDP Kolloquium, Köln, Germany
Zhao X, Koutsodendris A, Dupont L
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(2019) Hydroclimate change in subtropical South Africa during the mid-Piacenzian Warm Period. 9.-13.12.2019: AGU Fall meeting, USA
Zhao X, Koutsodendris A, Caley T, Dupont L
