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Tijdens de afgelopen ruim 20 jaar heb ik door grote herbivoren geconsumeerd materiaal, met name feces en plantenresten uit kiesplooien, kunnen onderzoeken. In de meeste gevallen ging het om een samenwerkingsverband met Dick Mol en een team van andere experts. Het betrof monsters van pleistocene, in sommige gevallen uitgestorven zoogdieren uit Siberië, Noordwest-Europa, Noord-Amerika en zuidelijk Zuid-Amerika. In deze uitgebreide samenvatting wordt een overzicht gegeven van resultaten uit eerder gepubliceerde artikelen. Van het onderzoek aan pollen uit kiesplooien afkomstig uit de Noordzee (Van Geel et al., 2018, 2019) werd al eerder in Cranium verslag gedaan (Van Geel et al., 2020). Voor het onderzoek aan mammoetmest wordt verwezen naar Van Geel et al. (2008, 2011a, b) en Polling et al. (2021). Recentelijk verscheen een artikel (Van Geel et al., 2022) over onderzoek aan mest van de uitgestorven reuzenluiaard Mylodon darwinii Owen, 1840. Over de hieronder besproken resultaten van het paleo-botanisch onderzoek van voedselresten van de Siberische wolharige neushoorn ‘Sasha’ (Coelodonta antiquitatis (Blumenbach, 1799)) werd niet eerder verslag gedaan.

Molaren van acht soorten grote herbivoren (reuzenhert Megaloceros giganteus, edelhert Cervus elaphus, rendier Rangifer tarandus, eland Alces alces, steppewisent Bison priscus, muskusos Ovibos moschatus, wolharige neushoorn Coelodonta antiquitatis en bosneushoorn Stephanorhinus kirchbergensis) werden ex situ verzameld uit opgebaggerde pleistocene en Holocene zandafzettingen uit de Noordzee en uit Nederlandse vindplaatsen in het binnenland. In de plooien van vele molaren bevonden zich gekauwde plantenresten en daarbij ook microfossielen. We determineerden pollen (stuifmeel) en sporen en interpreteren op basis hiervan voedselkeuzes en de mogelijke effecten op de pollenspectra als een deel van het bloeiseizoen vertegenwoordigd is. We bediscussiëren ook de effecten van de veranderende vegetatiesamenstelling in relatie tot het klimaat en de ouderdom van de molaren. Verschillende factoren hebben bijgedragen aan de samenstelling van het pollen. Toch geven de pollenspectra een beeld van de vegetatie en kunnen we de voedselkeuze en de ouderdom afleiden en krijgen we een beeld van de landschapstypen, van subarctische open gebieden tot interglaciaal bos. Ecologische en statistische analyses van de resultaten laten verschillen zien tussen de voedselkeuze van, en de beschikbaarheid van plantensoorten voor de verschillende zoogdiersoorten. Deze bijdrage is gebaseerd op een artikel dat eerder in Quaternary Science Reviews verscheen. -- 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 compacted masticated plant remains, and also microfossils. We identified pollen, spores, and non-pollen palynomorphs and on this basis interpret food preferences, represented flowering seasons, or parts of flowering seasons. We also discuss effects of changing vegetation composition in relation to climate and age of the molars, based on the pollen spectra. Various confounding factors have contributed to the recorded pollen composition, but nevertheless the pollen spectra show valuable aspects of vegetation composition, food choice, age, and landscapes, from subarctic open areas to interglacial forest. Ecological and statistical analysis of the results shows dietary differences between the mammal species analyzed. This contribution is based on a paper that appeared in Quaternary Science Reviews.

Non-pollen palynomorphs (NPP) in pollen slides form a large, inhomogeneous group of remains of organisms that represents a memory of former, often strictly local environmental conditions. A systematic approach of NPP documentation led to a strong development of the field in the last 40 years, and the total amount of NPP exceeds 1300. A large number of NPP remains unknown and identified NPP belong to a wide variety of taxonomic groups such as Ascomycetes, Basidiomycetes, Hyphomycetes, Zygomycetes, Cyanobacteria, green algae, cysts of dinoflagellates, roundworms, flatworms, testate amoebae, rotifers, and tardigrades. We give an overview, illustrate and discuss the palaeoenvironmental indicator value of a selection of NPP important for environmental reconstructions at, or close to, archaeological sites in connection with human impact.

The molar of a giant deer, Megaloceros giganteus (Blumenbach, 1799), was discovered in sandy deposits of the North Sea, about 10 km west of the present shoreline of the Netherlands. Compacted masticated plant remains were preserved in the molar's deep folds. A palaeoecological analysis of these plant remains shows the complete dominance of pollen from Artemisia (sage) and other Asteraceae Tubuliflorae (Compositae), indicating that the animal foraged in a steppe environment, and may have preferred to eat Artemisia, which contain a high level of nutrients such as calcium and phosphorous components, which are important for antler building. Radiocarbon dating indicates that the plant remains are of mid‐Weichselian age [38 570 (+300, −290) 14C a BP, Greenland Interstadial‐11]. This is the first study of the food choice of M. giganteus based on palaeoecological evidence. We hypothesize about links between the extirpation of M. giganteus at the onset of the Holocene in North‐West Europe and the transition from a landscape with highly dynamic geomorphological processes and consequently prevalence of immature and nutrient‐rich soils, to a less dynamic landscape with stable, leached and acidifying soils, and the decline of Artemisia and other calciphilous plants.

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 dating, and Bayesian modeling. Lake-level change was reconstructed using a novel combination of high-resolution palaeoecological proxies (e.g. pollen, non-pollen palynomorphs, chironomids), quantitative determinations of lake-level change (ground-penetrating radar), and estimates of changes in precipitation (lipid biomarker stable isotopes). We conclude that lake levels were at least as high as present-day water levels from the late glacial to 3150 cal. yr BP, with the exception of at least one lake-level lowstand during the Preboreal period. Lake levels were ca. 2.5 m lower than at present between 3150 and 2800 cal. yr BP, which might have been the result of a change in moisture source region prior to the so-called 2.8-kyr event. Increasing precipitation amounts around 2800 cal. yr BP resulted in a lake-level rise of about 3.5–4 m to levels that were 1–1.5 m higher than at present, in line with increased precipitation levels as inferred for the 2.8-kyr event from nearby raised bog areas as well as with reconstructions of higher lake levels in the French Alps, all of which have been previously attributed to a phase of decreased solar activity. Lake levels decreased to their present level only during recent times, although the exact timing of the drop in lake levels is unclear.

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 study of pollen and a few easily recognisable spores; however, a variety of other microfossils can be studied in peat deposits and can provide information on past environmental conditions. Among the so-called non-pollen palynomorphs (NPPs) are fungal and algal spores that can be used as indicators for local hydrological changes and trophic conditions. This article provides an overview of aspects to consider and sample preparation methods for pollen, spores and other non-pollen palynomorph microfossils in peat deposits; advice on aids to pollen identification and counting; and a brief guide to the range of NPPs that can be counted from prepared subfossil-pollen microslides.

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. We present a brief overview of the sample pre-treatment procedure and available techniques for estimating macrofossil composition, and we recommend identification guides.

In persons with multiple sclerosis (MS) a lowered self-efficacy negatively affects physical activities. Against this background we studied the relationship between self-efficacy and cognitive performance in the early stages of MS. Thirty-three patients with Clinically Isolated Syndrome (CIS) and early Relapsing Remitting MS (eRRMS) were assessed for self-efficacy (MSSES-18), cognition (CDR System), fatigue (MFIS-5), depressive symptoms (BDI), disease impact (MSIS-29), and disability (EDSS). Correlative analyses were performed between self-efficacy and cognitive scores, and stepwise regression analyses identified predictors of cognition and self-efficacy. Good correlations existed between total self-efficacy and Power of Attention (r= 0.65;P< 0.001), Reaction Time Variability (r= 0.57;P< 0.001), and Speed of Memory (r= 0.53;P< 0.01), and between control self-efficacy and Reaction Time Variability (r= 0.55;P< 0.01). Total self-efficacy predicted 40% of Power of Attention, 34% of Reaction Time Variability, and 40% of Speed of Memory variabilities. Disease impact predicted 65% of total self-efficacy and 58% of control self-efficacy variabilities. The findings may suggest that in persons with CIS and eRRMS self-efficacy may positively affect cognitive performance and that prevention of disease activity may preserve self-efficacy.

Accurate chronologies are essential for linking palaeoclimate archives. Carbon-14 wiggle-match dating was used to produce an accurate chronology for part of an early Holocene peat sequence from the Borchert (The Netherlands). Following the Younger Dryas-Preboreal transition, two climatic shifts could be inferred. Around 11 400 cal. yr BP the expansion of birch (Betula) forest was interrupted by a dry continental phase with dominantly open grassland vegetation, coeval with the PBO (Preboreal Oscillation), as observed in the GRIP ice core. At 11 250 cal. yr BP a sudden shift to a humid climate occurred. This second change appears to be contemporaneous with: (i) a sharp increase of atmospheric C-14; (ii) a temporary decline of atmospheric CO2; and (iii) an increase in the GRIP Be-10 flux. The close correspondence with excursions of cosmogenic nuclides points to a decline in solar activity, which may have forced the changes in climate and vegetation at around 11 250 cal. yr BP. Copyright (C) 2004 John Wiley Sons, Ltd.

The cornerstone of palaeoecological research, concerned with vegetation dynamics over the recent geological past, is a good understanding of the present-day ecology and distribution of the taxa. This is particularly necessary in areas of high floral diversity such as Latin America. Vegetation reconstructions, based on numerous pollen records, now exist with respect to all major vegetation associations from Latin America. With this ever-increasing number of sedimentary records becoming available, there is a need to collate this information and to provide information concerning ecology and distribution of the taxa concerned. The existing Latin American Pollen Database (LAPD) meets the first of these needs. Information concerning the ecology and distribution of the parent taxa responsible for producing the pollen, presently lodged within the LAPD, is the focus of this paper. The ‘dictionary’ describes the ecology and distribution of the parent taxa responsible for producing pollen identified within sedimentary records. These descriptions are based on a wide range of literature and extensive discussions with members of the palaeoecological community working in different parts of Latin America investigating a range of different vegetation types.