Vegetation History Reconstructed from Anthracology and Pollen Analysis at the Rescue Excavation of the MO Motorway, Hungary
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Cent. Eur. J. Geosci. • 3(4) • 2011 • 358-367 DOI: 10.2478/s13533-011-0036-0 Central European Journal of Geosciences Vegetation history reconstructed from anthracology and pollen analysis at the rescue excavation of the MO Motorway, Hungary Research article Katalin Náfrádi1∗, Elvira Bodor1, Tünde Törocsik˝ 1, Pál Sümegi1 1 Department of Geology and Palaeontology, University of Szeged, Szeged 6722, Egyetem utca 2-6, Hungary Received 20 July 2011; accepted 26 September 2011 Abstract: The significance of geoarchaeological investigations is indisputable in reconstructing the former environment and in studying the relationship between humans and their surroundings. Several disciplines have developed during the last few decades to give insight into earlier time periods and their climatic conditions (e.g. palynology, malacology, archaeobotany, phytology and animal osteology). Charcoal and pollen analytical studies from the rescue excavation of the MO motorway provide information about the vegetation changes of the past. These methods are used to reconstruct the environment of the former settlements and to detect the human impact and natural climatic changes. The sites examined span the periods of the Late-Copper Age, Late-Bronze Age, Middle- Iron Age, Late-Iron Age, Sarmatian period, Late Sarmatian period, Migration period, Late-Migration period and Middle Ages. The vegetation before the Copper Age is based only on pollen analytical data. Anthracological results show the overall dominance of Quercus and a great number of Ulmus, Fraxinus, Acer, Fagus, Alnus and Populus/Salix tree fossils, as well as the residues of fruit trees present in the charred wood assemblage. Keywords: charcoal analysis • palynology • geoarchaeology • MO motorway • Hungary © Versita Sp. z o.o. 1. Introduction [5]. Its significance is that it allows for the reconstruc- tion of woody plants, so that the reconstruction of the former local vegetation can be completed. Several studies from recent years [6–12] show that anthracological analy- Pollen analysis and anthracology are suitable methods sis has become a very important method in palaeoecolog- for the reconstruction of the vegetation cover of the past. ical studies. In Hungary, even in the first part of the 20th The data gained from the two methods complement each century very important wood anatomical [13–16] and an- other in order to give a broader and more accurate picture thracological [17–20] papers were published, and during about the former vegetation and the changes of woodland the last few decades palaeoecological studies have also history [1–4]. The anatomical analysis of wood charred been prominent [21–25]. The analysis of palaeovegeta- remains is called charcoal analysis or anthracology, and tion gives us information about the natural environment of is vitally important method in geoarchaeological studies a certain human population, the relationship between hu- mans and their environment, the changes in the vegetation ∗E-mail: nafradi@geo. u- szeged. hu composition, the preferred species and the climatological 358 Katalin Náfrádi, Elvira Bodor, Tünde Törocsik,˝ Pál Sümegi and ecological conditions of an area. cavations took place on the border of the alluvial plain of Pest and the Hills of Gödöll˝o, on the Maglód ridge. The analysis of archaeological charcoals is an applied The archaeological data of the sites show that the ear- method for the vegetation reconstruction of dry environ- liest habitation level is linked to the Ludanice culture in ments because of the lack of the well preserved pollen the Early-Copper Age in the Ecser-6 archaeological site. sequences [7, 26, 27]. The archaeological context is very Nevertheless more intensive habitation can be observed important in reconstructing the former environment. Re- from the level of the Baden culture in the Late-Copper searchers differentiate short and long-term deposits [28] Age. The human settlements were continuous until the relating to archaeological charcoal assemblages. Short- Middle ages in the area under study. term deposits or primary refuse (e.g. hearths) may not re- flect long-term deposited charcoal assemblages, but they The geological, soil and vegetation features of the regions are remains of the last episodic use. On the contrary, differ so the former human population settled on these long-term deposits or secondary refuse (e.g. charcoals different, close to each other mosaic sites. Furthermore, from middens, fills etc.) accumulated over a longer period the roads leading to the east and the trade-routes meet of time thus reflect firewood selection [9]. The number of here, leading to the area being a significant site of human charcoal samples is very important in every palaeoecolog- settlement [31]. ical study. It is proposed that 100 fragments per sample The altitude of the alluvial plain of Pest is between 98 and and 300-400 fragments per stratigraphic level [29] or 250 250 m a.s.l. Its elevation increases from the Duna valley fragments per sample and 400-500 fragments per strati- towards east the Hills of Gödöll˝o, which have an aver- graphic level [28] is necessary for palaeoecological studies age altitude is 130-134 m a.s.l. [31]. The ground surface in order to be statistically meaningful [9]. of the alluvial plain is covered by a significant thickness Palynology is the most popular discipline to study the of Quaternary sediments, primarily fluvial deposits, which vegetation development of an area, since pollen grains are are covered by loess sediments. This area is bordered by the most abundant microfossils in Quaternary sediments the Hills of Gödöll˝o, which are a Neogene plateau [32]. [30]. Depending on the size of the sedimentary basin, the The area is divided up into blocks as a consequence of a results of the analysis give information about the regional considerable fault network [31]. The climate of the area is and occasionally local vegetation. Opposite to it the lo- transitional between temperate warm and temperate cold. cally deposited wood fossils show the local buried veg- The mean annual temperature is 10-10.5 °C and the mean etation picture so it provides site related information [4]. annual precipitation is 550-600 mm. On the highest sur- At the same time pollen analysis allows us to examine the faces are wastelands, on wind-blown sand areas leptosols, vegetation picture with high taxonomical resolution and on the loess covered areas brown forest soils and cher- with a well established chronology [4], while anthracolog- nozem brown forest soils developed. In valleys and on ical data give information only about ligneous genera or deeper areas hydromorph soils evolved [31]. species [3]. The potential vegetation communities of the area are pan- This study aims to reconstruct the former vegetation on the nonic inland sand dune thickets (Junipereto-Populetum basis of the identification of wood macro remains derived albae), oak-ash-elm gallery forest (Querco-Ulmetum hun- from Hungarian archaeological sites and to compare the garicum), ash-alder carr (Fraxino pannonicae-Alnetum obtained results with palynological results. The charcoal hungaricum) and oak forest with lily-of-the-valley data is evaluated in terms of considering the human effect (Convallario-Quercetum roboris danubiale). As regards to on the plant communities, such as selecting plants and the non-arbor vegetation, brome-grass (Bromus sąuarro- modifying the environment. sus, Bromos tectorum), sedge (Carex pilosa, Carex silvat- ica, Carex elata), fescue-grass (Festuca vaginata, Festuca sulcata, Festuca pseudovina) and needle-grass (Stipa 2. Study area sabulosa) dominate [32]. On the basis of the tempera- ture and precipitation records, it can be interpreted that originally closed deciduous forest developed on the study The archaeological sites of the MO motorway (Ecser 6 area. and 7; Maglód 1; Ulló 5 and 9) are situated in Central Hungary, at the transitional region between the North From the beginning of cultivation activities in the Ne- Hungarian Mountain Range and the Great Hungarian olithic and as a consequence of soil erosion humans have Plain (Fig.1). The south foreland of the North Hun- had an effect on the region in regards to soil and veg- garian Mountain Range and the north border of the Great etation development and this is taken into consideration Hungarian Plain frame the archaeological sites. The ex- during vegetation reconstruction [31]. 359 Vegetation history reconstructed from anthracology and pollen analysis at the rescue excavation of the MO Motorway, Hungary Figure 1. The location of the archaeological sites and drilled core in Central Hungary. 3. Methods cording to the archaeological objects excavated from the level of a certain archaeological culture. We concentrated on charcoal samples with a sum total higher than 200 3.1. Sampling and methods for anthracologi- fragments per archaeological stratigraphic level. During cal analysis charcoal analysis pieces larger than 4 mm were the most useful, as smaller fragments are in most cases unidentifi- The archaeobotanical material was obtained from samples able [9, 28, 29]. of archaeological profiles and the deposits of the archaeo- logical features. The sampled objects were both short (e.g. The microscopic identification of wood is possible by hearth) and long- term deposits (e.g. midden, refuse pit, knowing the unique tissue map of the given genera or fills, well fills, ceramic filling). The chronology of the sam- species. Cross-sectional, radial and tangential sections pled archaeological features are as follows: Late-Copper were prepared when analysing charcoals [13], created by Age, Late-Bronze Age, Middle-Iron Age, Late- Iron Age, breaking new surfaces by hand or with a scalpel. The Sarmatian period, Late Sarmatian period, Migration pe- charcoal pieces were placed in fine sand for ease of ma- riod, Late Migration period and Middle Ages. In obtaining nipulation. The three directional sections were analysed and processing the samples we followed the guidelines of using a petrographic microscope, at 10x, 20x, 50x and 100x the German standards [33] and Ferenc Gyulai [34] regard- objectives.