Environmental reconstruction of a Roman Period settlement site in Uitgeest (The Netherlands), with special reference to coprophilous fungi
Introduction
Human impact on past vegetation can be deduced from pollen records, preferably in combination with the study of macroremains. An important anthropogenic environmental change at or near settlement sites is eutrophication resulting from the production of dung by high densities of domesticated herbivores. Also leaf-foraging, grazing, deforestation and crop cultivation could have a considerable impact on the natural landscape. Man and domesticated animals could have been responsible for a range of new habitats, and also the mycoflora of settlement sites and the surrounding arable land, pastures and hay-meadows could have different fungal assemblages relative to undisturbed natural ecosystems.
Pollen slides may contain a wide range of other microfossils, the study of which is a long-term research project of van Geel. Several hundreds of ‘Types’ have been distinguished in various deposits (peat, lacustrine sediments, samples from archaeological sites). Among the microfossils are fungal and algal spores and remains of cyanobacteria ([12], and references therein). Palaeoecological studies including the fungal remains show that some fungi represent a new and valuable category of anthropogenic indicators. In the present paper, we emphasise the indicator value of spores produced by Ascomycetes, which occur on the dung of mammals.
Section snippets
Site description
From 1980 to 1983 the Dutch State Service for Archaeological Investigations (ROB) carried out large-scale excavations of a Roman Period settlement site near the village of Uitgeest, location Dorregeest, in the province of Noord-Holland, The Netherlands [41], [42], [2], [9]. The landscape development in this area was strongly determined by geological events occurring in the former IJ estuary [38], [43]. The Roman Period habitation traces at the excavated site were concentrated on top of a small,
Material and methods
Sixteen samples of sod-surfaces were prepared for the analysis of microfossils [10]. Only four samples contained sufficient material for a complete analysis (Table 1). The microfossil slides of the other 12 samples were screened for the presence of coprophilous fungi (which were common in most of the samples). For microfossil types not illustrated in Plate 1 reference is made to descriptions and illustrations by van Geel [11], van Geel et al. [14], [15], [18] and Pals et al. [31]. Ascospores of
Botanical micro and macrofossils (Tables 1–3)
The pollen records indicate a treeless landscape (total tree pollen percentages varying between 3.2 and 9.1%). The construction of the wells with sods instead of wood may relate to the scarceness of trees in the surroundings. The presence of Cerealia pollen is not surprising in this anthropogenic context. They do not necessarily point to the presence of arable fields, but may originate from threshing of cereals. The relatively high pollen percentages of Poaceae, Asteraceae liguliflorae,
Discussion and conclusions
The pollen record shows that the region around the settlement was largely treeless. Macrofossils give more detail about local conditions at the sites where the sods were taken from. Soil disturbance by trampling, and grazing in salt marshes combined with temporary inundations by brackish water characterised the site. Additional evidence for grazing comes from the fungal spore record, this is dominated by dung-inhabiting taxa.Coprophilous fungi may be host-specific in the choice of their
Type 55A: Sordaria-type, ascospores(Plate 1, 22–27)
These ascospores are one-celled, ellipsoidal, brown, 16–31×10–17 μm in size, with an apical pore about 1.5 μm wide. Wall around the apical pore is relatively thick and dark. The basal end of the spore is slightly flattened.
Type 55A spores probably were produced by various different species belonging to the (mostly coprophilous) Sordariales. Van Geel et al. [14], Willemsen et al. [40] and Buurman et al. [3] have recorded numerousType 55A ascospores, together with spores of other coprophilous taxa,
Acknowledgments
The authors thank Dr P.J. Woltering and H. ter Schegget (ROB) for careful sampling of the sods as indispensable prerequisite for the subsequent research. The authors thank Dr Rob Marchant for help with improvements to the text.
References (43)
Spores of the dung fungus Sporormiella: increased abundance in historic sediments and before Pleistocene megafaunal extinction
Quaternary Research
(1987)- et al.
Palynological evidence for the historic expansion of Juniper and desert shrubs in Arizona, U.S.A.
Review of Palaeobotany and Palynology
(1986) A palaeoecological study of Holocene peat bog sections in Germany and the Netherlands
Review of Palaeobotany and Palynology
(1978)- et al.
A Late Holocene deposit under the Westfriese Zeedijk near Enkhuizen (Prov. of N-Holland, The Netherlands): palaeoecological and archaeological aspects
Review of Palaeobotany and Palynology
(1983) - et al.
An Upper Eemian lake deposit from Twente, eastern Netherlands
Review of Palaeobotany and Palynology
(1986) - et al.
Palaeoecology and stratigraphy of the Late glacial type section at Usselo (the Netherlands)
Review of Palaeobotany and Palynology
(1989) - et al.
Paleoecological studies in the Klokkeweel bog near Hoogkarspel (prov. of Noord Holland)
Review of Palaeobotany and Palynology
(1980) The reconstruction of local environments on the basis of remains of oribatid mites (Acari; Oribatida)
Journal of Archaeological Science
(1990)A palaeoecological study of a section from the foot of the Hazendonk (Zuid-Holland, The Netherlands), based on the analysis of pollen, spores and macroscopic plant remains
Review of Palaeobotany and Palynology
(1982)- et al.
Environmental change during the medieval reclamation of the raised-bog area Waterland (The Netherlands): a palaeophytosociological approach
Review of Palaeobotany and Palynology
(1996)