Bas van Geel

• Active 'pensionado' at University of Amsterdam

High-resolution studies of botanical microfossils and macroremains were performed on two Lateglacial sites in The Netherlands. Both sites showed a thin Sphagnum layer, formed during the transition from the relatively warm Bølling-Allerød interstadial to the cold Younger Dryas. Dendrochronological analyses revealed that pine trees survived into the...

Three hundred forty‐one radiocarbon dates from the Groningen radiocarbon database are compiled in this study. They show for the first time that organic sediment samples from the eastern Netherlands and mammal bones from Doggerland reflect shifts in the presence and the density of vegetation (food for herbivores) and mammal biomass during the last i...

The drift sand area near Hilversum, the Netherlands, holds a geo-archive with multiple drift sand phases and intercalated palaeosols. We studied this area to test earlier theories on the development of podzols in such aeolian sands, the occurrence of sand drifting, and the contemporary vegetation development, and to gain insight into the early huma...

Fungal spores that grew on the faeces of herbivores in the past can be extracted from sediments and used to identify the presence of herbivores in former ecosystems. This review: (i) examines the factors that should be considered when interpreting these fungal spores, (ii) assesses the degree to which they can be used to estimate past herbivore pop...

Alkaline fens are important Natura 2000 habitats, which harbor many endangered plant species. Alkaline fens are formed in areas with groundwater discharge and usually developed in a natural way in the early Holocene. We radiocarbon dated the base of three peat deposits from spring fens along the flanks of the ice-pushed ridge near the village of Oo...

In the Netherlands, several proxies of climate change during the Last Glacial-Interglacial Transition (LGIT) (c. 14,700 to 11,700 b2k) have been investigated in detail over the last few decades. The present paper presents two tree-ring chronologies LETR-A (n = 16, timespan 106 rings) and LETR-B (n = 24, timespan 201 rings) from in situ subfossil pi...

We studied the pollen content of a well-preserved coprolite of a Late-Glacial giant ground sloth (Mylodon darwinii) from the Mylodon Cave, province Última Esperanza, southern Chile. The specimen was obtained in 1909 and has been stored in a museum in the Netherlands since. It was radiocarbon dated to 13,140 ± 55 BP (15,927–15,522 cal BP), which fit...

The study of faecal samples to reconstruct the diets and habitats of extinct megafauna has traditionally relied on pollen and macrofossil analysis. DNA metabarcoding has emerged as a valuable tool to complement and refine these proxies. While published studies have compared the results of these three proxies for sediments, this comparison is curren...

Non-pollen palynomorphs (NPPs) form a large group of biological objects found in palynological slides besides pollen grains. This includes various remains of algae and fungi, shells, resting stages and eggs of invertebrates, among others. Publications of NPP-types started in the 1970s with studies of BvG and colleagues, and large numbers of new typ...

We studied twelve late Holocene organic deposits in West-Frisia, The Netherlands. Pollen, spores, non-pollen palynomorphs, mosses, other botanical macrofossils and insect remains were recorded for reconstructions of changing environmental conditions. Eastern West-Frisia was a cultivated landscape during the Bronze Age, but it became a freshwater we...

In 1492 CE Columbus landed in the "New World". In 1494 CE he founded La Isabela, the first colonial town in the Americas, located at the northern coast of the current Dominican Republic (Haytí island). Five hundred years of colonial exploitation followed, which had far-reaching impacts for the Indigenous people and local landscapes. Paleoecological...

Wetlands have been attractive environments for early communities worldwide. In China, wetlands offered natural ecological settings for the start of rice cultivation in the Lower Yangtze Region. Besides rice, Typha has been suspected to be an available wetland resource in previous studies at the Kuahuqiao site. Based on our pollen analyses of coprol...

Molars of eight large herbivore species (Megaloceros giganteus, Cervus elaphus, Rangifer tarandus, Alces alces, Bison priscus, Ovibos moschatus, Coelodonta antiquitatis and Stephanorhinus kirchbergensis) were collected ex situ from Pleistocene and Holocene sands dredged in the North Sea, and from Dutch inland sites. Folds in many molars contained c...

In contrast to conventional pollen records from natural sediments, pollen spectra from animal dung are less susceptible to long-distance wind and water transport and therefore have been used as indicators of local and regional vegetation, providing an opportunity to examine micro-environmental patterns relating to human impacts, especially when ass...

What combination of DNA metabarcoding primers works best to reconstruct changing species composition of Arctic vegetation over time? How do pollen, macro-fossil and DNA results from Pleistocene coprolites compare?

Scientific dissemination paper published in Geografie, a magazine of the Royal Dutch Geography Society (KNAG). Link to the paper: https://geografie.nl/artikel/columbus-voetafdruk

We analyzed intestinal contents of two late-glacial mastodons preserved in lake sediments in Ohio (Burning Tree mastodon) and Michigan (Heisler mastodon). A multi-proxy suite of macrofossils and microfossils provided unique insights into what these individuals had eaten just before they died and added significantly to knowledge of mastodon diets. W...

Suppl._Info._Table_S1 – Supplemental material for Columbus’ environmental impact in the New World: Land use change in the Yaque River valley, Dominican Republic

The carbon sink potential of peatlands depends on the balance between carbon uptake by plants and microbial decomposition. The rates of both these processes will increase with warming but it remains unclear which will dominate the global peatland response. Here we examine the global relationship between peatland carbon accumulation rates during the...

Columbus’ arrival in the New World in AD 1492 on the northern coast of Hispaniola was followed by a suite of changes in land-use. We reconstruct environmental change from a 225-cm-long sediment core from site Los Indios from an abandoned and sediment-filled meander of the Yaque River, Cibao Valley, northeastern Dominican Republic. The sediment reco...

Lake Uddelermeer (The Netherlands) is characterized by turbid conditions and annual blooms of toxic cyanobacteria, which are supposed to be the result of increased agricultural activity in the twentieth century AD. We applied a combination of classic palaeoecological proxies and novel geochemical proxies to the Holocene sediment record of Lake Udde...

Middens (nests and caches) of Late Pleistocene arctic ground squirrels ( Urocitellus parryii ) that are preserved in the permafrost of Beringia archive valuable paleoecological data. Arctic ground squirrels selectively include the plant material placed in middens. To account for this selectivity bias, we used a multi-proxy approach that includes an...

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 dur...

One of the most significant Late Holocene climate shifts occurred around 2800 years ago, when cooler and wetter climate conditions established in western Europe. This shift coincided with an abrupt change in regional atmospheric circulation between 2760 and 2560 cal years BP, which has been linked to a grand solar minimum with the same duration (th...

In the Monnikenberg estate, built in the mid-19th century in a Pleistocene coversand area to the south of Hilversum (the Netherlands), a depression with a small man-made mire was found to contain the remains of a complex peaty fill of a larger mire. Microfossil study and radiocarbon dating showed that its development started at the beginning of the...

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 dur...

Needles, wood and pollen of Larix, recorded in a peat deposit from Kotelny Island, northern Siberia, indicate the local occurrence of larch around 38 000 cal. a BP, which is during the Middle Pleniglacial (Greenland Interstadial 8) of the Weichselian last glacial period. The pollen record, dominated by Cyperaceae, Poaceae, Betula, Alnus, Salix and...

High-resolution Early Holocene palynological records from the middle Meuse River valley were missing until recently. In order to investigate environmental and inferred climate changes during the Preboreal, sediments from a former residual channel of the Meuse River near Haelen were studied. Detailed multi-proxy analyses, including microfossils, mac...

Lake Meerfelder Maar (MFM) is the northernmost W European sediment record with annual laminations across the Younger Dryas (YD), and the onset of the YD in the record of MFM has previously been defined as an increase in non-arboreal pollen abundance at ca 12,680 varve a BP. Here we present a palynological record at unprecedented subdecadal-resoluti...

Terrestrialization stages of mire vegetation are important to Dutch nature conservancy because of high biodiversity, particularly of base-rich fens. In recent turbaries, terrestrialization has however not shown development of such a stage, while existing rich fens show accelerated development towards species-poor Sphagnum-dominated vegetation, due...

We studied a Holocene peat fill of a small depression in Pleistocene coversand, in the western border zone of Het Gooi, to assess the early local and regional vegetation history in relation to sea-level rise, soil development and potential human impact. In the fourth millenium BC, a podzol which had formed in the depression became stagnative, leadi...

A sudden decline of solar activity around 850 calendar years BC caused a shift to a cool and wet climate in northwest Europe. Food production suddenly became problematic because of shorter, wetter growing seasons and increased night frost. This climate change triggered innovation and the development of a new agricultural system in continental north...

The Uddelermeer is a unique lake for The Netherlands, containing a sediment record that continuously registered environmental and climatic change from the late Pleistocene on to the present. A 15.6-m-long sediment record was retrieved from the deepest part of the sedimentary basin and an age–depth model was developed using radiocarbon dating, 210Pb...

Depositional systems such as lagoons and estuaries are natural archives of information about coastal and environmental changes that occurred in the past. In the particular case of the Portuguese coastal fringe an evolutionary model based on sedimentological, palaeoecological and geochronological data has been proposed. To improve the resolution of...

We present quantitative reconstructions of regional vegetation cover in north-western Europe, western Europe north of the Alps, and eastern Europe for five time windows in the Holocene (around 6k, 3k, 0.5k, 0.2k, and 0.05k calendar years before present (BP)) at a 1° x 1° spatial scale with the objective of producing vegetation descriptions suitable...

Historic carbon accumulation rates in four bogs on a north to south transect from Sweden to Germany were calculated by using the bulk densities and carbon concentrations of 1-cm peat layers and a fine-resolution radiocarbon chronology. Carbon accumulation rates were compared to environmental data to explore the effects of climatic factors. Carbon a...

The nature and cause of the so-called 2.8 kyr BP event have been a subject of much debate. Peat sequences have provided much of the evidence for this event, but the process link between climate and peatland response is not well understood. Multiproxy, high-resolution analysis of a core from Bargerveen in the eastern Netherlands based on pollen, non...

The last meal of a horse that lived in the northern part of the Sakha Republic (Russia) c. 5400 years ago was studied using pollen, spores, botanical macroremains, lipid composition, and ancient DNA in order to reconstruct its components. Pollen of Poaceae was superabundant, but this may be because of over-representation as a consequence of grazed...

Here, we present results from the most comprehensive compilation of Holocene peat soil properties with associated carbon and nitrogen accumulation rates for northern peatlands. Our database consists of 268 peat cores from 215 sites located north of 45 degrees N. It encompasses regions within which peat carbon data have only recently become availabl...

Castellum Fectio was one of the largest fortifications along the Limes, the northern border of the Roman Empire. The castellum, situated 5 km southeast of Utrecht, the Netherlands, was occupied from around the start of our Era to ca. a.d. 260. It was situated along a river bend of the Rhine that was cut off from the main stream during the occupatio...

Lake Nussbaumersee, located SW of Lake Constance (Switzerland/Germany), was studied at high temporal resolution for non-pollen palynomorphs (NPPs) within a calcareous gyttja sediment core from the deepest part of the lake. At the Nussbaumersee lakeshore, three pile-dwelling settlements have been excavated and dendrochronologically dated (to the Neo...

Pollen, botanical macrofossils, chemical components and ancient DNA were studied in samples from the rumen of a frozen Yakutian bison (Bison priscus) that lived ca. 10,500 cal a BP. The dialkyl glycerol ether lipid archaeol (2,3-di-O-phytanyl-sn-glycerol) was detected and is interpreted to have been derived from methanogenic Archaea in the rumen. T...

Humans colonized the Balearic Islands 5–4 ka ago. They arrived in a uniquely adapted ecosystem with the Balearic mountain goat Myotragus balearicus (Bovidae, Antilopinae, Caprini) as the only large mammal. This mammal went extinct rapidly after human arrival. Several hypotheses have been proposed to explain the extinction of M. balearicus. For the...

A unique complex of multiphased Holocene drift sands and paleosols, with at least two lacustrine phases, was discovered during a major sanitation project in the Laarder Wasmeren area near Hilversum, the Netherlands. The complex could be studied in detail, highly facilitated by the excellent and large-scale exposure of the various deposits and soils...

Discrete reddish-brown, predominantly minerogenic detrital layers along the Holocene, annually laminated sediment sequence of Lake Meerfelder Maar represent extreme runoff events. We conducted detailed microfacies analyses and a high-resolution palynological investigation, focusing on ten detrital layers throughout the Holocene. We studied triad sa...

For the understanding of current and future climate change it is a basic pre requisite to properly understand the mechanisms, which controlled climate change after the Last Ice Age. According to the IPCC 5th assessment report (in prep.) the Sun has not been a major driver of climate change during the post-Little Ice Age slow warming, and particular...

The complete microfossil record of 30 samples from Meerfelder Maar. Percentages are expressed relative to a pollen sum, including trees, shrubs and upland herbs

This study compares age estimates of recent peat deposits in 10 European ombrotrophic (precipitation-fed) bogs produced using the C-14 bomb peak, Pb-210, Cs-137, spheroidal carbonaceous particles (SCPs), and pollen. At 3 sites, the results of the different dating methods agree well. In 5 cores, there is a clear discrepancy between the C-14 bomb pea...

Peatlands are a major terrestrial carbon store and a persistent natural carbon sink during the Holocene, but there is considerable uncertainty over the fate of peatland carbon in a changing climate. It is generally assumed that higher temperatures will increase peat decay, causing a positive feedback to climate warming and contributing to the globa...

A range of mire and peat macrofossils which can be found in northwest European peat bog (ombrotrophic) and fen (minerotrophic peatland) deposits are illustrated in an extensive series of figures. Methodologies commonly used to pretreat samples are described, in addition to the paleoecological indicator value of a wide selection of botanical/zoologi...

Peatlands are a major terrestrial carbon store and a persistent natural carbon sink during the Holocene, but there is considerable uncertainty over the fate of peatland carbon in a changing climate. It is generally assumed that higher temperatures will increase peat decay, causing a positive feedback to climate warming and contributing to the globa...

Peatlands are a major terrestrial carbon store and a persistent natural carbon sink during the Holocene, but there is considerable uncertainty over the fate of peatland carbon in a changing climate. It is generally assumed that higher temperatures will increase peat decay, causing a positive feedback to climate warming and contributing to the globa...

Peat, especially from acidic mires (bogs), is a natural archive of past environmental change. Reconstructions of past climate from bogs commenced in the 19th Century through examination of visible peat stratigraphy, and later formed the basis for a postglacial climatic scheme widely used in Northwest Europe. Nevertheless, misconceptions as to how b...

Natural climate change currently acts in concert with human-induced changes in the climate system. To disentangle the natural variability in the climate system and the human-induced effects on the global climate, a critical analysis of climate change in the past may offer a better understanding of the processes that drive the global climate system....

Large changes in solar ultraviolet radiation can indirectly affect climate by inducing atmospheric changes. Specifically, it has been suggested that centennial-scale climate variability during the Holocene epoch was controlled by the Sun. However, the amplitude of solar forcing is small when compared with the climatic effects and, without reliable...

Abstract Available from http://www.agu.org

Records of the past climate and vegetation of Australia are frequently constructed using data generated from the analysis of pollen and pteridophyte spores alone, or in association with sedimentology. We demonstrate that theorganic residue prepared for pollen analysis yields other organic-walled microfossils that can be used to provide additional a...

_______________________________________________________________________________________ SUMMARY Peat deposits are valuable archives for studying palaeoclimate, the history of local and regional vegetation, and human impact. The most widely applied laboratory analytical technique has been palynology (pollen analysis), which is often limited to the s...

Dung from a mammoth was preserved under frozen conditions in Alaska. The mammoth lived during the early part of the Late Glacial interstadial (ca 12,300 BP). Microfossils, macroremains and ancient DNA from the dung were studied and the chemical composition was determined to reconstruct both the paleoenvironment and paleobiology of this mammoth. Pol...

In the light of the currently increasing drought frequency and water scarcity on oceanic islands, it is crucial for the conservation of threatened insular vertebrates to assess how they will be affected. A 4000 yr old fossil assemblage in the Mare aux Songes (MAS), southwest Mauritius, Mascarene Islands, contains bones of 100 000+ individual verteb...

This paper presents an illustrated guide to the identification of non-pollen palynomorphs (NPPs) preserved in lake-sediment archives from equatorial East Africa. Modern NPPs were recovered from recently deposited surface sediment in 20 small crater lakes in western Uganda, located along environmental gradients of vegetation (moist evergreen and sem...

Here we developed a composite pollen-based record of altitudinal vegetation changes from Lake Fúquene (5° N) in Colombia at 2540m elevation. We quantitatively calibrated Arboreal Pollen percentages (AP%) into mean annual temperature (MAT) changes with an unprecedented ~60-year resolution over the past 284 000 years. An age model for the AP% record...

The Noordoostpolder is an archaeologically rich area in the central Netherlands. A sediment profile, situated on a dune slope, was sampled near a Neolithic settlement site on the former island of Schokland. To reconstruct the local and regional vegetation around a Neolithic settlement, pollen, non-pollen palynomorphs and macrofossils were analyzed....

Botanical microfossils, macroremains and oribatid mites of a Weichselian interstadial deposit in the central Netherlands point to a temporary, sub-arctic wetland in a treeless landscape. Radiocarbon dates and OSL dates show an age between ca. 54.6 and 46.6 ka cal BP. The vegetation succession, starting as a peat-forming wetland that developed into...

Palynological studies including records of non-pollen palynomorphs (NPP) are uncommon in the Neotropics, in spite of their demonstrated usefulness in other regions. Modern analog studies to improve palaeoecological interpretations of NPP are even more scarce. Here, we report the NPP assemblages recorded in modern surface samples from an altitudinal...

Analyses of plant macrofossils can be used to reconstruct the development of the local vegetation on peatlands, and thus to elucidate successional processes. In the case of ombrotrophic peatlands, such analyses can also be used to generate palaeoclimate data. Identification of plant macrofossils in peat deposits is essential for accurate 14C dating...

Understanding the influence of solar variability on the Earth’s climate requires knowledge of solar variability, solar-terrestrial interactions and the mechanisms determining the response of the Earth’s climate system. We provide a summary of our current understanding in each of these three areas. Observations and mechanisms for the Sun's variabili...

Tropical montane biome migration patterns in the northern Andes are found to be coupled to glacial-induced mean annual temperature (MAT) changes; however, the accuracy and resolution of current records are insufficient to fully explore their magnitude and rates of change. Here we present a ~60-year resolution pollen record over the past 284 000 yea...

Table of contents 1. Introduction.Setting the Scene: How Do We Get to a Fitting Future?- 2.Impacts of Climate Change on Terrestrial Ecosystems and Adaptation Measures for Natural Resource Management.- 3.Fire in the Earth System.- 4.Vanishing Polar Ice Sheets.- 5.Climate and Peatlands.- 6.Climate and Lacustrine Ecosystems.- 7.Rivers.- 8.Climate Ch...