TY - JOUR
T1 - Describing a drowned Pleistocene ecosystem
T2 - Last Glacial Maximum vegetation reconstruction of the Palaeo-Agulhas Plain
AU - Cowling, Richard M.
AU - Potts, Alastair J.
AU - Franklin, Janet
AU - Midgley, Guy F.
AU - Engelbrecht, Francois
AU - Marean, Curtis W.
N1 - Funding Information:
CWM, RMC and JF recognize the support of a grant from the National Science Foundation ( BCS-0524087 , BCS-1138073 and BCS-1460376 ). CWM further acknowledges the support the Hyde Family Foundation , the Institute of Human Origins ( IHO ) at Arizona State University, and the John Templeton Foundation to the Institute of Human Origins at Arizona State University. AJP acknowledges the support of the National Research Foundation (Grant No. 91452 ). RMC and AJP are grateful for the support from Nelson Mandela University. This work used the Extreme Science and Engineering Discovery Environment (XSEDE), which is supported by National Science Foundation grant number ACI-1548562 . This work used the XSEDE Bridges and Stampede resources through XSEDE allocation DBS140003.
Funding Information:
CWM, RMC and JF recognize the support of a grant from the National Science Foundation (BCS-0524087, BCS-1138073 and BCS-1460376). CWM further acknowledges the support the Hyde Family Foundation, the Institute of Human Origins (IHO) at Arizona State University, and the John Templeton Foundation to the Institute of Human Origins at Arizona State University. AJP acknowledges the support of the National Research Foundation (Grant No. 91452). RMC and AJP are grateful for the support from Nelson Mandela University. This work used the Extreme Science and Engineering Discovery Environment (XSEDE), which is supported by National Science Foundation grant number ACI-1548562. This work used the XSEDE Bridges and Stampede resources through XSEDE allocation DBS140003. The opinions expressed in this publication are those of the author(s) and do not necessarily reflect the views of any of these funding organizations. All authors thank the participants of the Palaeoscape I, II and III workshops for their valuable discussions on this topic.
Publisher Copyright:
© 2019
PY - 2020/5/1
Y1 - 2020/5/1
N2 - Pleistocene ecosystems provided the stage for modern human emergence. Terrestrial vegetation communities structure resources for human foragers, providing plant food, wood for fuel and tools, and fibre, as well as habitat for animal prey. The Pleistocene distribution of vegetation communities is seldom considered as a key constraint on hunter-gatherers foraging across the landscape. We used modern vegetation patterns along the Cape south coast to develop a rule-based model of the expected vegetation for a given soil type, precipitation regime and fire regime. We then applied this ruleset to present-day environmental conditions to test and validate the model. We also scaled the climate-vegetation ruleset to account for likely effects of low atmospheric [CO2] and lower temperature in the Last Glacial Maximum (LGM) on plant water use efficiency. The model was then used to postdict vegetation patterns for the LGM using palaeo-landscape reconstruction of geological substrata and soils, and palaeoclimate simulations. This palaeoscape comprised the extensive Palaeo-Agulhas Plain (PAP), which was exposed at lower sea levels during glacial periods. Our model predicts that the PAP was dominated by limestone fynbos in its southern part, and by shale grassland with cappings of dune fynbos-thicket mosaic in the north. Shale and sandstone fynbos were restricted to the western zone, which experienced a stronger winter rainfall regime during the LGM than at present. The entire PAP was dissected by broad and shallow floodplains supporting a mosaic of woodland and grassland on fertile, alluvial soils. This savanna-like vegetation, as well as shale grassland, are poorly represented in the modern landscape, and would have been capable of supporting the diverse megafauna typical of glacial periods. These Pleistocene periods would have presented a very different resource landscape for early modern human hunter-gatherers than the interglacial landscape such as is found in the Cape coastal lowlands today.
AB - Pleistocene ecosystems provided the stage for modern human emergence. Terrestrial vegetation communities structure resources for human foragers, providing plant food, wood for fuel and tools, and fibre, as well as habitat for animal prey. The Pleistocene distribution of vegetation communities is seldom considered as a key constraint on hunter-gatherers foraging across the landscape. We used modern vegetation patterns along the Cape south coast to develop a rule-based model of the expected vegetation for a given soil type, precipitation regime and fire regime. We then applied this ruleset to present-day environmental conditions to test and validate the model. We also scaled the climate-vegetation ruleset to account for likely effects of low atmospheric [CO2] and lower temperature in the Last Glacial Maximum (LGM) on plant water use efficiency. The model was then used to postdict vegetation patterns for the LGM using palaeo-landscape reconstruction of geological substrata and soils, and palaeoclimate simulations. This palaeoscape comprised the extensive Palaeo-Agulhas Plain (PAP), which was exposed at lower sea levels during glacial periods. Our model predicts that the PAP was dominated by limestone fynbos in its southern part, and by shale grassland with cappings of dune fynbos-thicket mosaic in the north. Shale and sandstone fynbos were restricted to the western zone, which experienced a stronger winter rainfall regime during the LGM than at present. The entire PAP was dissected by broad and shallow floodplains supporting a mosaic of woodland and grassland on fertile, alluvial soils. This savanna-like vegetation, as well as shale grassland, are poorly represented in the modern landscape, and would have been capable of supporting the diverse megafauna typical of glacial periods. These Pleistocene periods would have presented a very different resource landscape for early modern human hunter-gatherers than the interglacial landscape such as is found in the Cape coastal lowlands today.
KW - Cape Floristic Region
KW - Cape south coast
KW - Fynbos
KW - Hunter-gatherers
KW - Palaeoscape
KW - Pleistocene vegetation change
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U2 - 10.1016/j.quascirev.2019.105866
DO - 10.1016/j.quascirev.2019.105866
M3 - Article
AN - SCOPUS:85070784558
SN - 0277-3791
VL - 235
JO - Quaternary Science Reviews
JF - Quaternary Science Reviews
M1 - 105866
ER -