Vegetation Changes Caused by Agricultural Societies in the Great Mazurian Lake District
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Acta Palaeobotanica 52(1): 59–104, 2012 Vegetation changes caused by agricultural societies in the Great Mazurian Lake District AGNIESZKA WACNIK 1, TOMASZ GOSLAR 2,3, and JUSTYNA CZERNIK 2 1 W. Szafer Institute of Botany, Polish Academy of Sciences, Lubicz 46, 31-512 Kraków, Poland; e-mail: [email protected] 2 Poznań Radiocarbon Laboratory, Foundation of the A. Mickiewicz University, Rubież 46, 61-612 Poznań, Poland 3 Faculty of Physics, A. Mickiewicz University, Umultowska 85, 61-614 Poznań, Poland Received 14. May 2012; accepted for publication 31 May 2012 ABSTRACT: The results of pollen analysis and radiocarbon datings of bottom sediments of four lakes: Lakes Miłkowskie, Wojnowo, Łazduny, and former Lake Staświńskie, situated in the eastern part of the Great Mazu- rian Lake District, were the basis for the reconstruction of vegetation changes during the last 4 millennia. In addition to the local pollen assemblage zones, which represent transformations of forest vegetation at the local level, three regional pollen assemblage zones were described, as were also the changes of plant communities developing in water basins. In the case of Lake Miłkowskie the variations in the composition of fossil green algae showed its evolution from an oligotrophic to strongly eutrophic water body as early as the 11th century AD. The present studies have confi rmed that the vegetation transformations in the Miłki-Staświny microregion differed from those in Szczepanki vicinity. In the fi rst case, human activity, besides climate, proved decisive agent in vegetation cover development, in the second one it was a natural process of lake terrestrialization. Pollen record showed that a characteristic short-lasting phase of the intensive Picea development about 2000 –1600 BC was delayed for at least a century compared to the Suwałki region. It was confi rmed that the fi rst Carpinus spread in the forests occurred about 1350 BC. The data provided evidence for metachronous beginning of forma- tion and long-term persistence of anthropogenic forest communities dominated by birch in different parts of the area (1200 BC – 1100 AD in Miłki and Staświny regions, 200 BC – 1500 AD in Lake Łazduny region). The investigations documented the spread of local cereal cultivation (Triticum and Hordeum types) during the middle Bronze Age. The phases of more intensifi ed human impact on microregional vegetation were identi- fi ed with the middle Bronze Age settlement (Lusatian culture); with the activity period of the West Baltic Bur- row culture population; with the societies of the Bogaczewo culture and Prussian Galindians. The last phase of the very strong agricultural exploitation of the area that lasts to the present time, was initiated in the Middle Ages, about 1100 AD in Lakes Wojnowo and Miłkowskie regions and in the 16th century near Lake Łazduny. The datings of sediments deposited in the Middle Ages confi rmed the asynchronous beginnings of the large- scale deforestations. Of special interest was the dating of the deforestation time in the surroundings of Lakes Miłkowskie and Wojnowo (in the Staświny settlement centre) to the earlier time than it was deduced from written sources and the presentation of arguments for the foundation of permanent settlement units prior the arrival of the Teutonic Order Knights. The stages of anthropogenic disturbances of vegetation distinguished in individual pollen diagrams in the most cases well refl ected the history and intensity of settlement confi rmed by archaeological fi ndings and historical data. KEYWORDS: palynology, vegetation history, human impact, radiocarbon chronology, adoption of agriculture, fi re, large-scale clearings, settlement history, late Holocene, NE Poland INTRODUCTION The signifi cant natural potential of the palaeoenvironmental changes. Among the Great Mazurian Lake District for palaeoeco- sites that were palynologically investigated logical studies, resulting from the abundance after the second World War, only a few of lakes and peat bogs, was hitherto little included pollen sequences reaching to mod- exploited in the analysis of the late Holocene ern times. These were pollen profi les from the 60 following lakes: Mikołajskie (Ralska-Jasiewi- leadership of W. Gumiński from the Warsaw czowa 1966, Ralska-Jasiewiczowa & Latałowa University, worked on the sites Szczepanki 1996), Kruklin, Mamry, Tałty (Stasiak 1967, and Dudka. 1971), and Dgał Wielki (Filbrandt-Czaja 2000). The questions connected with the process The insuffi cient number of radiocarbon dates of the neolithization of north-eastern Poland, of the late Holocene sediments resulted in including the very beginning of the transfor- a very generalized chronology of vegetation mation from foraging to (partly) producing changes presented in these papers. This fact economy type, are as yet not fully understood. restricts the possibility of the reconstruction of A particular feature of this area, is contrary to the rates of environmental changes and their the rest of Poland, was a prolonged existence correlation with archaeological-historical and of foraging and a very late acceptance of farm- climatic data. The investigations of the envi- ing as the basis for food procurement. Hitherto ronmental history of the Great Mazurian Lake existing palynological studies of bottom sedi- District and its connection with the appear- ments of Lakes Miłkowskie and Staświńskie, ance of agricultural societies during the last which are to a high degree representative millennia require on one hand the selection of for this region, have demonstrated that the deposits suitable for palaeoecological analyses impact of local Mesolithic and Neolithic popu- and on the other, the information about the lations on vegetation was insignifi cant, while changing in time forms of local economic and climate remained the main agent controlling settlement activities. The good recognition of the dynamics of plant community changes. radiocarbon and archaeological chronologies is The use of fi re for clearing small surfaces for of key signifi cance in these studies. The time economic and settlement purposes, and since frames for the present investigations, which ca 3800 BC also sporadically for farming, focus on the impact of agricultural societies caused only small and temporary disturbances on vegetation, were established on the basis of the structure and taxonomic composition of of the fi rst appearance of Cerealia type pol- forest communities. It was only the increased len grains about 3800 BC in the sediments of signifi cance of producers’ economy based on Lake Miłkowskie (Wacnik 2009a) and approxi- plant cultivation and animal raising, recorded mately at the same time in Lake Dgał Wielki in the middle Bronze Age from about 1400 BC, (Filbrandt-Czaja 2000) as well as in cultural that resulted in more pronounced environmen- layers from an archaeological site Szczepanki 8 tal changes (Wacnik 2005, 2009a). The char- (Wacnik & Ralska-Jasiewiczowa 2008, Madeja acter of anthropogenic disturbances during et al. 2009). These data indicate a likely begin- the early and middle Holocene that can be ning of the interference in vegetation of people observed in this area, resembles those known who were engaged, though on a very limited from the majority of the Baltic countries. scale, in cultivating plants and raising live- The basic aim of the present paper was to stock. In order to recognize anthropogenic veg- describe the main stages of palaeoenviron- etation changes in the late Holocene several mental changes, which occurred in the Great new localities, situated a few to a dozen or so Mazurian Lake District from the onset of agri- kilometers apart, were investigated. Thanks culture to modern times and to confi rm that to their different dimensions, pollen records the large-area deforestations and enlargement showed differences refl ecting the unequal sizes of surfaces taken under cultivation were not of source areas for pollen transported to the synchronous over the whole area. sedimentation basins, which made possible the differentiation of local and regional phenom- ena. The region Staświny-Miłki-Szczepanki THE STUDY REGION was selected for palynological investigations because human settlement in this terrain was The Great Mazurian Lake District (1730 km²) well known due to the intensive archaeologi- lies in a depression between the Mrągowo cal explorations carried out by two teams. One Lake District to the west and Ełk Lake District of them, under the leadership of M. Karcze- to the east. To the north it borders upon the wski and M. Karczewska from the University Węgorapa District and to the south upon the of Bialystok, studied the region of Paprotki Mazurian Plain, where the border is marked Kolonia and Staświny, another one, under the by marginal forms (moraines and kames) 61 Fig. 1. Location of studied sites in the eastern part of the Great Mazurian Lake District. Main localities mentioned in the paper are marked on the map. Names of the studied palynological sites are framed of the Pomeranian stage of the Vistula gla- exaration basins were formed, which gave rise ciation, running north of Ruciane, and south to the network of modern channel lakes includ- of Lakes Śniardwy, and Orzysz (Kondracki ing Lakes Miłkowskie, Wojnowo, and Łazduny 1972). In respect of geomorphology the region (Fig. 1). Front moraines were formed at that is situated within the reach of the last glacia- time as well as local accumulations of kame tion formations and forms, between the I and sands and gravels. During the glacier