Enno Schefuß's research while affiliated with Universität Bremen and other places

Publications (262)

Article
Abrupt changes in the Atlantic meridional overturning circulation (AMOC) are thought to affect tropical hydroclimate through adjustment of the latitudinal position of the intertropical convergence zone (ITCZ). Heinrich Stadial 1 (HS1) involves the largest AMOC reduction in recent geological time; however, over the tropical Indian Ocean (IO), proxy...
Article
The scarcity of suitable high-resolution archives, such as ancient natural lakes, that span beyond the Holocene, hinders long-term late Quaternary temperature reconstructions in southern Africa. Here we target two cores from Mfabeni Peatland, one of the few long continuous terrestrial archives in South Africa that reaches into the Pleistocene, to g...
Article
Full-text available
Leaf wax n -alkane biomarkers are widely used to infer past vegetation dynamics and hydroclimate changes. The use of these compounds strongly relies on the characterization of modern plants. However, few studies have explored leaf waxes of modern plants and their application to reconstructing climate and environmental changes in the Iberian Peninsu...
Article
Full-text available
The forested swamps of the central Congo Basin store approximately 30 billion metric tonnes of carbon in peat1,2. Little is known about the vulnerability of these carbon stocks. Here we investigate this vulnerability using peat cores from a large interfluvial basin in the Republic of the Congo and palaeoenvironmental methods. We find that peat accu...
Article
The aim of the present study was to characterize the distribution and sources of terrigenous organic matter (OM) in surface sediments of a subtropical estuarine-lagoon system surrounded by the Atlantic Rainforest. n-Alkanes and their isotopic composition were evaluated in 20 surface sediment samples, as well as in leaves from nine representative pl...
Article
It is well accepted that global circulation models equipped with stable water isotopologues help us better understand the relationships between atmospheric circulation changes and isotope records in paleoclimate archives. Still, isotope-enabled models do not disentangle the different processes affecting precipitation isotopic compositions. Furtherm...
Article
Full-text available
Sedimentary organic matter (OM) analyses along a 130 km long transect of the Mkhuze River from the Lebombo Mountains to its outlet into Lake St Lucia, Africa's most extensive estuarine system, revealed the present active trapping function of a terminal freshwater wetland. Combining bulk OM analyses, such as Rock-Eval®, and source-specific biomarker...
Article
Despite its great ecological importance, the main factors governing tree cover in tropical savannas as well as savanna-forest boundaries are still largely unknown. Here we address this issue by investigating marine sediment records of long-chain n-alkane stable carbon (δ¹³Cwax) and hydrogen (δDwax) isotopes from a core collected off eastern tropica...
Article
Lipid biomarker proxies from terrigenous sediments have been extensively used to understand variations in paleoenvironmental conditions, but many of the mechanisms affecting these proxies during riverine transport are still poorly understood. Here, we analyze glycerol dialkyl glycerol tetraether (GDGT) distributions and n-alkane isotopic compositio...
Conference Paper
Full-text available
Palynological studies were carried out on cored late Holocene sediments from the Mkhuze Swamp at the northern shore of Lake St. Lucia located in the Indian Ocean Coastal Belt Biome of KwaZulu-Natal, eastern South Africa. The project is part of TRACES (Tracing Human and Climate Impacts in South Africa, coordinated by MARUM, University of Bremen,...
Conference Paper
The dearth of high-resolution climate records for the past millennium has largely limited our understanding of the impacts of natural (e.g., the Little Ice Age: LIA) and anthropogenic climate perturbations (i.e., the ongoing global warming) on the arid regions of West Asia (also referred to as the Middle East). Here, we present multiproxy records i...
Article
Full-text available
Particulate pyrogenic carbon (PyC) transported by rivers and aerosols, and deposited in marine sediments, is an important part of the carbon cycle. The chemical composition of PyC is temperature dependent and levoglucosan is a source‐specific burning marker used to trace low‐temperature PyC. Levoglucosan associated to particulate material has been...
Article
Full-text available
Historic droughts document the strong spatio‐temporal variability of the South American Monsoon System, which currently provides more than two thirds of the rainfall in tropical South America. The drivers of this variability have remained not well understood due to the lack of continuous, high‐resolution paleorecords, especially from the more arid...
Preprint
Full-text available
Sedimentary organic matter (OM) analyses along a 130 km-long transect of the Mkhuze River from the Lebombo Mountains to its outlet into Lake St. Lucia, Africa’s most extensive estuarine system, revealed the present active trapping function of a terminal freshwater wetland. A combination of organic bulk parameters, thermal analyses, and determinatio...
Article
Full-text available
Significance Explaining the greening of the Sahara during the Holocene has been a challenge for decades. A strengthening of the African monsoon caused by increased summer insolation is usually cited to explain why the Sahara was vegetated from 14,000 to 5,000 y ago. Here, we provide a unique climate record of quantified winter, spring, and summer p...
Article
Full-text available
The transitional regions between the low and high latitudes of the Northern Hemisphere are highly vulnerable to future climate change yet most of the current climate models usually diverge in their projections. To better understand the dynamics in these regions, the reconstruction of past hydrological fluctuations and precipitation patterns is of p...
Article
Mpondoland on the South African east coast is a particularly dynamic region in terms of climate change as it is influenced by both temperate and tropical circulation and climate systems. We present a sediment record that indicates regional climatic change and anthropogenic influence during the last ~5500 yr. Catchment data allow an understanding of...
Article
Tropical and subtropical rivers deliver large quantities of terrestrial organic carbon (OCterr) to the ocean, acting as a crucial part of the global carbon cycle, but little is known about the timescale and efficiency of its transport to and in the adjacent coastal sea. Here we examined source-specific biomarker (fatty acids, FAs) contents and isot...
Article
Full-text available
Modern precipitation over northeastern (NE) South America is strongly controlled by the seasonal meridional migration of the Intertropical Convergence Zone (ITCZ). Ample evidence from the Northern Hemisphere suggests a mid- to late Holocene southward migration of the ITCZ. Such a shift would be expected to increase precipitation over semi-arid nort...
Article
Full-text available
Significance Terrestrial organic-carbon reservoirs (vegetation, soils) currently consume more than a third of anthropogenic carbon emitted to the atmosphere, but the response of this “terrestrial sink” to future climate change is widely debated. Rivers export organic carbon sourced over their watersheds, offering an opportunity to assess controls o...
Article
One of the central assumptions of paleoenvironmental research using lipid biomarker isotope compositions in sedimentary archives is the isotopic stability of these compounds after deposition. If this indeed applies for open marine sediments with low sedimentation rates and strong biodegradation is, however, not well constrained. Here we study lipid...
Article
Waterfall Bluff, in Eastern Mpondoland (Eastern Cape Province, South Africa), is a recently excavated archaeological site with deposits spanning Marine Isotope Stage (MIS) 3 to the Middle Holocene. Here, we present preliminary results of a multi-proxy palaeoenvironmental study combining macro-botanical remains, charcoal, phytoliths, pollen and plan...
Article
Full-text available
Northern Africa’s past climate is characterized by a prolonged humid period known as the African Humid Period (AHP), giving origin to the “Green Sahara” and supporting human settlements into areas that are now desert. The spatial and temporal extent of climate change associated with the AHP is, however, subject to ongoing debate. Uncertainties aris...
Article
Full-text available
The distribution and isotopic composition (δ¹³C and δD) of lipids are proxies used to determinate paleoenvironmental conditions including precipitation regimes, vegetation changes and sources of organic matter, among others. This data article describes five datasets of distribution (n-alkanes, fatty acids, n-alkanols and sterols) and isotopic compo...
Article
Full-text available
Fire causes dramatic energy and matter exchanges between biosphere and atmosphere on a regional to global scale. Predicting fires, however, is hindered by the complex interplay of fire, climate, and vegetation. Paleo-fire records provide critical information beyond instrumental records that cover only the past few decades and may be used to assess...
Article
Full-text available
Rapid North Atlantic cooling events during the last deglaciation caused atmospheric reorganizations on global and regional scales. Their impact on Asian climate has been investigated for monsoonal domains, but remains largely unknown in westerly wind-dominated semiarid regions. Here we generate a dust record from southeastern Iran spanning the peri...
Article
To identify environmental causes for past changes in vegetation in subtropical East Asia, we present carbon isotope compositions of plant-wax n-alkanes and provide estimates of the C4-plant contribution across the past four glacial terminations and interglacials, based on cores recovered from the northern South China Sea. Our results show a compara...
Article
The youngest and one of the largest saline deposits of Earth history formed in the Mediterranean during the Messinian salinity crisis (MSC; 5.97–5.33 Ma, Late Miocene), when global climate was experiencing a trend of cooling and aridification. However, recent paleoclimate reconstructions indicate strong climate gradients across the Mediterranean Ba...
Preprint
Full-text available
Abstract. We present a continuous and well-resolved record of climatic variability for the past 100,000 yrs from a marine sediment core taken in Delagoa Bight, off southeastern Africa. In addition to providing a sea surface temperature reconstruction for the past ca. 100,000 yrs, this record also allows a high-resolution continental climatic recons...
Poster
Sea ice proxies are used to reconstruct the climate and environmental history in both polar regions. In the Southern Ocean, the biomarker IPSO25 ‒a highly branched isoprenoid (HBI) diene‒ is produced by sea ice diatoms (Belt et al., 2016). We evaluated the abundance and distribution of IPSO25 in recent ocean surface sediments through comparisons wi...
Article
Full-text available
Late Holocene hydroclimate variations have been extensively recognized in Amazonia, but the effects of such changes on riverine discharge within the Amazon lowlands are still poorly understood. We investigated a sediment core covering circa 4,000 to 300 cal yr BP collected in the lower valley of the Xingu River (Xingu Ria) in an area under the infl...
Article
Full-text available
Organic geochemical and micropaleontological analyses of surface sediments collected in the southern Drake Passage and the Bransfield Strait, Western Antarctic Peninsula, enable a proxy-based reconstruction of recent sea ice conditions in this climate-sensitive area. We study the distribution of the sea ice biomarker IPSO25, and biomarkers of open...
Poster
Full-text available
The Arabian Sea is affected by an extremely dynamical climate system characterized by a pronounced seasonal monsoonal atmospheric circulation associated to changes in ocean circulation. Seasonal reversals and intensity changes of wind systems drive the development/suppression of strong coastal upwellings. High surface productivity, linked to upwell...
Data
The Maritime Continent, home to widespread tropical rainforest and millions of people, is the primary region of deep atmospheric convection on the Earth. However, debate exists whether the isotopologues of water reflect rainfall amount during the Last Glacial Maximum (LGM), resulting in different interpretations of the LGM climate of the Maritime C...
Article
The Maritime Continent, home to widespread tropical rainforest and millions of people, is the primary region of deep atmospheric convection on the Earth. However, debate exists whether the isotopologues of water reflect rainfall amount during the Last Glacial Maximum (LGM), resulting in different interpretations of the LGM climate of the Maritime C...
Article
The relative abundance of the C32 1,15 long-chain alkyl diol (LCD) is an emerging proxy for the input of riverine aquatic particulate organic carbon (POC) into coastal oceans. This compound has the potential to complement other established proxies reflecting riverine terrestrial POC input and allows for a more nuanced assessment of riverine POC exp...
Article
Full-text available
The scarcity of continuous, terrestrial, palaeoenvironmental records in eastern South Africa leaves the evolution of late Quaternary climate and its driving mechanisms uncertain. Here we use a ∼7 m long core from Mfabeni peatland (KwaZulu-Natal, South Africa) to reconstruct climate variability for the last 32 000 years (cal ka BP). We infer past ve...
Article
The South China Sea (SCS), characterized by a large continental shelf, is located at the edge of the Asian monsoon domain. In this study, two marine sediment cores from the northern SCS (NSCS) continental slope were investigated to construct composite vegetation and precipitation isotopic composition records based on the d 13 C and dD values of pla...
Article
Full-text available
Recent paleoclimatic studies suggest that changes in the tropical rainbelt across the Atlantic Ocean during the past two millennia are linked to a latitudinal shift of the Intertropical Convergence Zone (ITCZ) driven by the Northern Hemisphere (NH) climate. However, little is known regarding other potential drivers that can affect tropical Atlantic...
Article
Full-text available
Recent paleoclimatic studies suggest that changes in the tropical rainbelt across the Atlantic Ocean during the past two millennia are linked to a latitudinal shift of the Intertropical Convergence Zone (ITCZ) driven by the Northern Hemisphere (NH) climate. However, little is known regarding other potential drivers that can affect tropical Atlantic...
Article
Full-text available
Biomass burning on the African continent is widespread, and interactions with climate, vegetation dynamics, and biogeochemical cycling are complex. To obtain a better understanding of these complex relationships, African fire history has been widely studied, although mostly on relatively short timescales (i.e., years to kiloyears) and less commonly...
Conference Paper
The P5 Project is an international and interdisciplinary team of researchers studying hunter-gatherer adaptations in persistent coastal contexts in the Eastern Cape Province of South Africa. Since 2015, excavations at the site of Waterfall Bluff (A2SE-1) have revealed stratified and well-preserved remains of coastal hunter-gatherer occupations dati...
Conference Paper
A marine core (GeoB 20615) from Maputo Bay, offshore of Mozambique, reveals vegetation fluctuations during the last c. 16,000 years. The chronology is based on 12 radiocarbon dates from planktonic foraminifera, terrestrial organic remains, e.g., seeds, and gastropod shells. Until c. 15 ka Before Present (BP) high percentages of fynbos elements, esp...
Conference Paper
Full-text available
A marine core (GeoB 20615) from Maputo Bay, offshore of Mozambique, reveals vegetation fluctuations during the last c. 16,000 years. The chronology is based on 12 radiocarbon dates from planktonic foraminifera, terrestrial organic remains, e.g., seeds, and gastropod shells. Until c. 15 ka Before Present (BP) high percentages of fynbos elements, esp...
Article
Full-text available
The scarcity of continuous, terrestrial, palaeoenvironmental records in eastern South Africa leaves the evolution of late Quaternary climate and its driving mechanisms uncertain. Here we use a ~7-m long core from Mfabeni peatland (KwaZulu-Natal, South Africa) to reconstruct climate variability for the last 32 thousand years (kaBP). We infer past ve...
Article
There is increasing evidence that abrupt vegetation shifts and large-scale erosive phases occurred in Central Africa during the third millennium before present. Debate exists as to whether these events were caused by climate change and/or intensifying human activities related to the Bantu expansion. In this study, we report on a multi-proxy investi...
Article
Full-text available
In the version of this Article originally published, the units of the x and y axes in Fig. 3a were incorrectly given as ‘mg km–2 yr–1’; the correct units are ‘Mg km–2 yr–1’. These errors have now been corrected in the online versions.
Data
The southern Benguela upwelling system near the St Helena Bay has been proposed to be affected by various factors, while few investigations about the late-Holocene oceanic conditions has been carried out in this area. To determine the oceanic variability and its forcing mechanisms in the southern Benguela region during the late-Holocene, we examine...
Article
Full-text available
The southern Benguela upwelling system near the St Helena Bay has been proposed to be affected by various factors, while few investigations about the late-Holocene oceanic conditions has been carried out in this area. To determine the oceanic variability and its forcing mechanisms in the southern Benguela region during the late-Holocene, we examine...
Poster
Full-text available
Recent satellite mapping and coring of the peatland complex of the Congo Basin’s Couvette Centrale region underscores the global significance of this area. Freshwater tropical peatlands in the Congo Basin make up one of Earth’s largest terrestrial carbon sinks (Dargie et al. 2017) which forms an important nexus between global climate, biogeochemica...
Article
Full-text available
The past two million years of eastern African climate variability is currently poorly constrained, despite interest in understanding its assumed role in early human evolution. Rare palaeoclimate records from northeastern Africa suggest progressively drier conditions or a stable hydroclimate. By contrast, records from Lake Malawi in tropical southea...
Article
Full-text available
Wildfires and incomplete combustion of fossil fuel produce large amounts of black carbon. Black carbon production and transport are essential components of the carbon cycle. Constraining estimates of black carbon exported from land to ocean is critical, given ongoing changes in land use and climate, which affect fire occurrence and black carbon dyn...
Article
Precipitation isotope reconstructions derived from speleothems and plant waxes are important archives for understanding hydroclimate dynamics. Their climatic significance in East Asia, however, remains controversial. Here we present terrestrial plant-wax stable hydrogen isotope (δDwax) records over periods covering the last four interglacials and g...
Data
The past two million years of eastern African climate variability is currently poorly constrained, despite interest in understanding its assumed role in early human evolution1,2,3,4. Rare palaeoclimate records from northeastern Africa suggest progressively drier conditions2,5 or a stable hydroclimate6. By contrast, records from Lake Malawi in tropi...
Data
There is increasing evidence that abrupt vegetation shifts and large-scale erosive phases occurred in Central Africa during the third millennium before present. Debate exists as to whether these events were caused by climate change and/or intensifying human activities related to the Bantu expansion. In this study, we report on a multi-proxy investi...
Article
Full-text available
Terrestrial signals in marine sediment archives are often used for paleoclimatic reconstructions. It is therefore important to know the origin of the different terrestrial sedimentary components. The proximity to a river mouth is often the key location to determine the source. Especially in regions with strong ocean currents, such an assumption mig...
Article
The combined use of plant wax n-alkane δD values and branched glycerol dialkyl glycerol tetraether lipid (brGDGT) distributions provides a novel approach for paleoaltitude reconstruction. Studies from East Africa revealed, however, inconsistent results between the proxy estimates and altitudinal parameters. Here, we explore these proxies in soils o...