Louis Scott
University of the Free State, Plant Sciences, Department Member
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Fossilized feces, termed coprolites, provide unique information on digestive systems, diets, and ecosystems of extinct animals, and are potentially useful for palynology, biostratigraphy and preservation of animal and plant remains.... more
Fossilized feces, termed coprolites, provide unique information on digestive systems, diets, and ecosystems of extinct animals, and are potentially useful for palynology, biostratigraphy and preservation of animal and plant remains. Despite this broad utility, scientific enquiry into coprolites has been relatively sparse. We carried out a systematic investigation into 23 significant South African fossil collections of the Evolutionary Studies Institute (ESI), University of the Witwatersrand, Johannesburg, in search of coprolites. This study spanned a temporal range from the Permian to the recent Cenozoic returning approximately 790 known coprolites in the collections. Of these, only four assemblages have appeared in six coprolite‐specific publications. Others have been mentioned to some extent in publications focused on fauna, palynology or simply mentioned that coprolites were present. Clearly, the coprolite collections at the ESI are understudied and require attention with the int...
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African grassy biomes evolved together with fire and have a long history of human manipulation of fire, yet few rangeland studies acknowledge the role of prehistoric fire in shaping contemporary ecological patterns. Nevertheless,... more
African grassy biomes evolved together with fire and have a long history of human manipulation of fire, yet few rangeland studies acknowledge the role of prehistoric fire in shaping contemporary ecological patterns. Nevertheless, prehistoric fire records have been used elsewhere as invaluable environmental contexts for practitioners in fire management, ecosystem restoration and climate change. Therefore, our aim is to collate prehistoric sedimentary charcoal studies from southern African grassy biomes and bring them to the attention of practitioners. We discuss how long-term data contribute to fire ecology and ecosystem functioning. Importantly, this contribution aims to give a reference point for stakeholders working at different temporal and spatial scales to improve our understanding and management of grassy ecosystems.
Research Interests: Geography, Plant Biology, Agroforestry, Ecology, Charcoal, and 3 moreEcosystem, Biome, and Rangeland
Recent zooarchaeological and aDNA analysis have produced conflicting evidence for the existence of early domestic stock at Blydefontein Rock Shelter. The anatomical analysis identified eight specimens as sheep or sheep/goats, the oldest... more
Recent zooarchaeological and aDNA analysis have produced conflicting evidence for the existence of early domestic stock at Blydefontein Rock Shelter. The anatomical analysis identified eight specimens as sheep or sheep/goats, the oldest of which was dated to 2860–2765 BP, while the aDNA results suggest that the oldest identified sheep specimen was either greater kudu or eland. Almost all of the other aDNA identifications conflicted with the anatomical assessments. The faunal and aDNA analyses are presented in separate papers in this journal. This paper provides background information on the site of Blydefontein, and frames the discussion in terms of the reliability and validity of the anatomical and aDNA evidence.
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Abstract In this study we investigate the timing and nature of moisture availability in the Late Holocene by examining a multiproxy paleoenvironmental record from Kathu Pan at the southern edge of the Kalahari. In a region where organic... more
Abstract In this study we investigate the timing and nature of moisture availability in the Late Holocene by examining a multiproxy paleoenvironmental record from Kathu Pan at the southern edge of the Kalahari. In a region where organic proxy records are scarce, Kathu Pan provides a unique record of changes in past environmental conditions. Pollen, spore, charcoal, and stable isotope records were obtained from organic deposits at Kathu Pan and examined within a radiocarbon-constrained chronological framework. The Kathu Pan record registers a relatively moist phase occurring between 4.8 ka and 2.5 ka cal BP. Local environmental conditions at Kathu Pan shift gradually beginning around the terminal Northgrippian ~4.8 ka cal BP. Kathu Pan reaches maximum moisture availability with marsh-like conditions signaled by increased organic content, dominance of Cyperaceae pollen, presence of freshwater fungi, and δ13C values consistent with local C3 vegetation, around the inception of the Meghalayan Stage, although due to uncertainties in the age-depth model these changes may have taken place 1–2 centuries on either side of the formal date for the onset of the Meghalayan at 4.2 ka cal BP. This interval also corresponds with the highest charcoal concentrations, indicating the importance of adequate moisture conditions to support the growth of biomass which eventually becomes a fuel source. The moist phase lasts ca. 2000 years until a hypothesized shift to arid conditions occurs c. 2.5 ka cal BP leading to a change in local hydroclimate that may have terminated the accumulation of organic-bearing sediments.
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Research Interests: Geography, Earth Sciences, Classification (Machine Learning), Data Analysis, Paleoenvironment, and 13 morePaleoenvironmental Change, Late Pleistocene to Early Holocene, South Africa, Pollen, History and archaeology, Grassland, Biomes, Quaternary Science Reviews, Vegetation dynamics, Vegetation Classification, Vegetation reconstruction, Biome, and Pollen datasets
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Horizontal cores from a large stalagmite and two tufa deposits in the entrance to Wonderwerk Cave, South Africa, dated by radiocarbon methods, have provided climate proxy data on late Holocene environments near the cave. The δ18O and δ13C... more
Horizontal cores from a large stalagmite and two tufa deposits in the entrance to Wonderwerk Cave, South Africa, dated by radiocarbon methods, have provided climate proxy data on late Holocene environments near the cave. The δ18O and δ13C time series from stalagmite Core WW1–3 and tufa Core WW3 correlate well with isotope records for other sites in the summer rainfall zone of southern Africa and suggest that late Holocene warm periods in the Northern Hemisphere, including the Medieval Warm period, Roman Warm period, and Minoan Warm period, were times of increased moisture in this rainfall zone. In contrast, late Holocene cold intervals in the Northern Hemisphere, including the Dark Ages Cold period and Sub-Atlantic Cold period, were times of drier climate in the summer rainfall zone. Comparison of the Wonderwerk records with information on human settlement patterns, agricultural expansion or decline, and population growth or decline, shows that growth occurred preferentially during wetter climate periods and declines, including the abandonment of the important town of Mupungubwe in the Shashe-Limpopo area of northeast South Africa and the fall of Great Zimbabwe, which occurred during periods of low precipitation.RésuméUne grande stalagmite venant de la grotte de Wonderwerk, en Afrique du Sud, a été carottée horizontalement et est comparée avec deux autres dépôts de tuf venant de la meme grotte pour comprendre la variation climatique aux alentours de la grotte durant la fin de l’Holocene. Ces archives geologiques ont été datés par la methode 14C. Les variations isotopiques, particulierement δ18O et δ13C de la carotte WW1–3 et celles du tuf WW3, presentent une bonne resemblance avec d’autres donnees paleoclimatiques obtenues des autres site climatiques de la zone chaude et humide de l’Afrique australe. La comparaison suggere que la periode chaude de la fin de l’Holocene connue dans l’hemisphere nord, comme la période chaude médiévale, Roman Période Chaude, et Minoan Période Chaude, correspond a une periode tres humide aux alentours de Wonderwerk. Par contre, les periodes froides de la meme interval, comprenant Dark Ages Période Froide et Sous-Atlantique Période Froide, correspondent a des periodes seches a Wonderwerk. Il est a noter que les types d'établissements humains, l'expansion ou le déclin agricole, et la croissance de la population ou de déclin, montre que la croissance ont eu lieu préférentiellement pendant les périodes et les baisses de climat plus humide, y compris l'abandon de l'importante ville de Mupungubwe dans la zone Shashe-Limpopo du nord-est en Afrique du Sud et la chute du Grand Zimbabwe, a eu lieu pendant les périodes de faibles précipitations.
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A new global synthesis and biomization of long (>40 kyr) pollen-data records is presented, and used with simulations from the HadCM3 and FAMOUS climate models to analyse the dynamics of the global terrestrial biosphere and carbon... more
A new global synthesis and biomization of long (>40 kyr) pollen-data records is presented, and used with simulations from the HadCM3 and FAMOUS climate models to analyse the dynamics of the global terrestrial biosphere and carbon storage over the last glacial–interglacial cycle. Global modelled (BIOME4) biome distributions over time generally agree well with those inferred from pollen data. The two climate models show good agreement in global net primary productivity (NPP). NPP is strongly influenced by atmospheric carbon dioxide (CO<sub>2</sub>) concentrations through CO<sub>2</sub> fertilization. The combined effects of modelled changes in vegetation and (via a simple model) soil carbon result in a global terrestrial carbon storage at the Last Glacial Maximum that is 210–470 Pg C less than in pre-industrial time. Without the contribution from exposed glacial continental shelves the reduction would be larger, 330–960 Pg C. Other intervals of low terrestri...
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An ongoing re-investigation of the early Miocene Saldanha Bay (South Africa) palynoflora, using combined light and scanning electron microscopy (single grain method), is revealing several pollen types new to the African fossil record. One... more
An ongoing re-investigation of the early Miocene Saldanha Bay (South Africa) palynoflora, using combined light and scanning electron microscopy (single grain method), is revealing several pollen types new to the African fossil record. One of the elements identified is Loranthaceae pollen. These grains represent the first and only fossil record of Loranthaceae in Africa. The fossil pollen grains resemble those produced by the core Lorantheae and are comparable to recent Asian as well as some African taxa/lineages. Molecular and fossil signals indicate that Loranthaceae dispersed into Africa via Asia sometime during the Eocene. The present host range of African Loranthaceae and the composition of the palynoflora suggest that the fossil had a range of potential host taxa to parasitise during the early Miocene in the Saldanha Bay region.
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Research Interests: Palaeoclimatology, Archaeology, Earth Sciences, Geology, Palaeolithic Archaeology, and 12 morePalynology, Levant Prehistory, Paleoclimate, Middle to Upper Paleolithic Transition, Pleistocene, Upper Paleolithic, Middle East, Middle Paleolithic, Quaternary Science, History and archaeology, Anthracology, and Quaternary Science Reviews
Palynology of marine sediment core SBQW4, Saldanha Bay (South Africa), early Miocene, supplement to: Neumann, Frank Harald; Roberts, David; Cawthra, Hayley C; Carr, Andrew S; Scott, Louis; Durugbo, Ernest; Humphries, Marc; Cowling, Richard; Bamford, Marion; Musekiwa, Chiedza; Machutchon, Michael ...more
A multi-proxy study of an offshore core in Saldanha Bay (South Africa) provides new insights into fluvial deposition, ecosystems, phytogeography and sea-level history during the late Paleogene-early Neogene. Offshore seismic data reveal... more
A multi-proxy study of an offshore core in Saldanha Bay (South Africa) provides new insights into fluvial deposition, ecosystems, phytogeography and sea-level history during the late Paleogene-early Neogene. Offshore seismic data reveal bedrock topography, and provide evidence of relative sea levels as low as -100 m during the Oligocene. 3D landscape reconstruction reveals hills, plains and an anastomosing river system. A Chattian or early Miocene age for the sediments is inferred from dinoflagellate taxa Distatodinium craterum, Chiropteridium lobospinosum, Homotryblium plectilum and Impagidinium paradoxum. The subtropical forest revealed by palynology includes lianas and vines, evergreen trees, palms and ferns, implying higher water availability than today, probably reduced seasonal drought and stronger summer rainfall. From topography, sedimentology and palynology we reconstruct Podocarpaceaedominated forests, Proto-Fynbos, and swamp/riparian forests with palms and other angiosper...
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Poor pollen preservation in cave deposits is due to oxidation and increasing scarcity of pollen with distance from the cave entrance. After an attempt to obtain pollen grains from the sediments in Azokh 1 (Lesser Caucasus) failed, two... more
Poor pollen preservation in cave deposits is due to oxidation and increasing scarcity of pollen with distance from the cave entrance. After an attempt to obtain pollen grains from the sediments in Azokh 1 (Lesser Caucasus) failed, two coprolites from Unit II were investigated for their microfossil contents. They contained few diatoms (including the rare Pliocaenicus), even less pollen but numerous phytoliths that were compared with those in selected levels of cave deposits and modern soil from outside. Grass silica short cell phytoliths give evidence of vegetation typical of a temperate climate for Unit II, which included C3 grasses. Not only the coprolites from Azokh are useful but the whole sequence of deposits has good potential for palaeoclimatic reconstruction based on for phytolith studies. The diatoms observed indicate feeding from a relatively moist terrestrial environment and availability of lake and/or running water.
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Quaternary records provide an opportunity to examine the nature of the vegetation and fire responses to rapid past climate changes comparable in velocity and magnitude to those expected in the 21st century. The best documented examples of... more
Quaternary records provide an opportunity to examine the nature of the vegetation and fire responses to rapid past climate changes comparable in velocity and magnitude to those expected in the 21st century. The best documented examples of rapid climate change in the past are the warming events associated with the Dansgaard-Oeschger (D-O) cycles during the last glacial period, which were sufficiently large to have had a potential feedback through changes in albedo and greenhouse gas emissions on climate. Previous reconstructions of vegetation and fire changes during the D-O cycles used independently constructed age models, making it difficult to compare the changes between different sites and regions. Here we present the ACER (Abrupt Climate Changes and Environmental Responses) global database which includes 93 pollen records from the last glacial period (73-15 ka) with a temporal resolution better than 1,000 years, 32 of which also provide charcoal records. A harmonized and consistent chronology based on radiometric dating (14C, 234U/230Th, OSL, 40Ar/39Ar dated tephra layers) has been constructed for 86 of these records, although in some cases additional information was derived using common control points based on event stratigraphy. The ACER database compiles metadata including geospatial and dating information, pollen and charcoal counts and pollen percentages of the characteristic biomes, and is archived in Microsoft ACCESS(TM).
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This dataset is associated with Phelps et al. (2020, DOI: 10.1111/ecog.04990), and is comprised of paleoecological information from African subfossil pollen assemblages over the past 20,000 years. Data includes the following... more
This dataset is associated with Phelps et al. (2020, DOI: 10.1111/ecog.04990), and is comprised of paleoecological information from African subfossil pollen assemblages over the past 20,000 years. Data includes the following information:Appendix 1: a list of collated sites from the APD, EPD, and other publicationsAppendix 2: a list of collated entities from the APD, EPD, and other publicationsAppendix 3: a list of citations for each entity in appendix 2, whether analyzed or notAppendix 4: a harmonized taxa list with original taxa names and numbersAppendix 5: a list of collated samples from the APD, EPD, and other publicationsAppendix 6: a list of counts from the APD, EPD, ACER, and other publicationsAppendix 7: a list of dates (14C, etc) from the APD, EPD, ACER, and other publicationsAppendix 8: a list of CLAM outputs calculated (Blaauw 2010) from the list of radiocarbon datesAppendix 9: a harmonized biomization scheme for "direct" and "indirect" methodsFor use o...
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Organic material from the Noordhoek area on the western margin of the Cape Peninsula, South Africa, was obtained from a ~ 50 m-long drill-core dominated by fluvio-lacustrine siliciclastic sediments. The aim of this study is to constrain... more
Organic material from the Noordhoek area on the western margin of the Cape Peninsula, South Africa, was obtained from a ~ 50 m-long drill-core dominated by fluvio-lacustrine siliciclastic sediments. The aim of this study is to constrain fluctuations in climate and the decline of tropical vegetation elements along the southwestern coast and the Cape Peninsula of South Africa, during the Late Cenozoic phase, when the Benguela upwelling system was established. The approach was to combine palynological, biogeochemical (tetraether lipids) and stable isotope (C, N) studies of the organic-bearing record from the Noordhoek area on the western margin of the Cape Peninsula. Bulk C and N isotope data of sediment organic matter, point to a predominantly C3 higher plant source vegetation. Mean annual air temperature (MAT) from the analyses of tetraether lipids (MBT′–CBT index) was compared with palynomorphs from partly unpublished data of a previously drilled core adjacent to the study site. The palynomorphs are of subtropical affinities, and suggest that an open riparian forest would have existed in the early to middle Miocene of the southwestern coast of South Africa. Together these data sources allow vegetation and climate reconstructions of subtropical conditions during the early to middle Miocene, which comprised fluctuating open riparian forest and swamp vegetation. Temperatures rose in the middle Miocene and were higher than those of the present day.
Research Interests: Evolutionary Biology, Palaeogeography, Earth Sciences, Geology, Sedimentology, and 15 moreBiogeochemistry, Stable Isotope Analysis, Palynology, Stable Isotope Geochemistry, Ecology, Biogeography, Palaeoclimate, Palynofacies, Paleogeography, Miocene, Cenozoic, Southern Hemisphere, Palynostratigraphy, Palynomorphs, and peninsula
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ABSTRACT