Dr Krupski: – The work of a geoarchaeologist is similar to a criminal investigation

• Until now, no one has conducted such extensive and interdisciplinary research in the Białowieża Forest
• Examining the soil, the micromorphological researcher from the UPWr is able to determine the processes occurring in it over the centuries
• Among others, traces of human activity and former settlements in the forest were analysed
• Scientists only began to research the forest 200 years ago
• Another project of the UPWr scientist concerns kurgans in Silesia

Thanks to his unique competences, Dr. Mateusz Krupski from the Institute of Soil Sciences, Plant Nutrition and Environmental Protection of the UPWr was invited to join the "Cultural and natural heritage of the Białowieża Forest" research programme. Coordinated by the Institute of Archaeology at Cardinal Stefan Wyszynski University in Warsaw, the four-year project financed by the National Science Centre, which ended last year, was of an interdisciplinary nature: it combined historical, natural, geographical, geological and geophysical sciences.

The first tests of this kind

– Until now, there has been no such systematic and extensive research in the Białowieża Forest. They covered the entire Polish part of the forest, creating an archaeological map of the area, from the Stone Age to modern times – says the archaeologist. – We were looking for traces of human activity, because contrary to popular belief, it was not always a completely natural area. A similar myth also concerns the Amazon Forest, often considered to be untouched, while in the pre-Columbian era there were extensive villages surrounded by cultivated fields. Humans have been present in both the Amazon and Białowieża Forests for a long time, affecting the environment to a different extent. It is worth taking a closer look at these processes, among other reasons in order to avoid mistakes made in the past.

Of particular interest to scientists in the Białowieża Forest were field forms that bear evidence of human activity from as far back as prehistoric times. At the Postołowo archaeological site, in the Szczekotowo archaeological and natural reserve, one of the most distinctive areas was selected for research. There are over a hundred mounds dating to the prehistoric, early medieval (7th-9th century AD), medieval (11th-13th century AD) and modern times. This time, however, the remnants of a former agricultural landscape were examined: cultivated fields divided by earth banks and situated on a gentle slope. They do not stand out in the landscape, tourists are unlikely to notice them in a forest covered with dense old oak and hornbeam trees. Using aerial laser scanning, researchers distinguished a clear system of rectangular plots surrounded by embankments several dozen centimetres high and 3-5 metres wide.

– The work of an archaeologist is like a criminal investigation: we try to solve a series of questions and puzzles. The system of old fields and strips of land in the forest is an interesting area for us. When did humans first appear in this area? For a long time or only periodically? How did they live, what did they do? To what extent has agriculture changed the environment? Until when did they use this land and why did they leave? – asks the scientist. Some of these questions have been answered using methods applied by modern science, including micromorphology, in which Mateusz Krupski specialises.   

Micromorphology – what does it concern?

It is a branch of soil science that, using microscopic techniques, describes the composition and structure of soil and makes it possible to determine the processes that have taken place in it. – In Poland, it is quite a rare discipline. Archaeology is rather associated with excavations and analysis of acquired artifacts: ceramic objects, for example fragments of vessels, stone, bone and metal. Less attention is paid to the soil from which they were taken. Meanwhile, the soil at archaeological sites is formed by both natural factors and former human activity – explains Dr. Krupski.

– There is a concept called 'soil memory', which also refers to all the changes resulting from human presence in a particular place – he adds. – Sometimes during a walk in the forest you might come across the remains of a recent campsite: the ragged remains of a campfire, with charcoal and dissolved ash, and around it, on a partially trodden area, you usually see a variety of waste, some of it very small, and you might even come across a 'sanitary' zone. In simple terms, the soils here will show a variation of physical and chemical properties resulting from different types of 'camping activity'. The types of anthropogenic soils distinguished by soil scientists, sometimes called cultural layers, are actually artifacts in themselves. People can really 'disturb' the soil, and some of these changes are visible only under a microscope, hence the enormous importance of micromorphological analyses in archaeology – says Dr. Krupski.

On the trail of agriculture

In Postołowo, scientists were looking for traces of former agriculture. Survey trenches were set perpendicular to the course of two strips of land and within several ancient plots. The excavations resulted in the discovery of fragments of prehistoric and early medieval pottery, while a series of soil samples were taken from the exposed sections at various depths. Packed in plastic bags, they were sent to laboratories where their physical and chemical composition was determined and the content of plant residues was checked. Radiocarbon dating was also performed on selected organic remains. A separate type of specimen was that of an intact structure, cut from ground sections in the form of blocks of earth not much larger than a packet of cigarettes, with the natural arrangement of grains and free spaces preserved. The samples were fixed with synthetic resin, then cut and ground to obtain microscopic preparations after sticking to the slides. Under a microscope they showed traces of soil mixing, probably as a result of former cultivation and progressive flushing down the slope, and scattered charcoal – the result of burning vegetation. Nie było natomiast pozostałości po nawożeniu, na przykład w postaci resztek odchodów zwierzęcych.

– We have been able to establish the extent and time of past human activity in Postolov. We know that the original vegetation was cleared and burnt and then crops were grown on the plots so prepared. Radiocarbon dates, including from two uncovered burnt rye grains, have shown us two episodes of such agricultural activity: in the so-called Roman period, i.e. around the 2nd century AD, and in the early Middle Ages, around the 10th century. It was then that at least some of the strips of land visible today were formed. We also noted that early medieval farmers failed to prevent erosion of the land they used. During heavy rainfall or thawing it was successively washed off the exposed field surface forming a deposit called deluvium at the foot of the slope. The effects of this process can be seen today in the differing soil morphology in the higher and lower parts of the former field system. Our research at Postołowo clearly shows that human activity at this site has left its mark on the landscape, but was rather incidental. Forest regeneration occurred between the 3rd and 9th centuries and the 12th and 17th centuries. The period between the 17th and 18th centuries AD saw limited settlement and charcoal production on the banks of the Łutownia River, after which the area was abandoned. So it was not a continuous settlement – explains the archaeologist.

– I must admit that this was my first experience with the Białowieża Forest. What attracted me to work on this project in the first place was the fact that we worked as a team, that archaeologists, soil scientists, geomorphologists, botanists, geophysicists and palynologists, i.e. pollen specialists, could complement each other's knowledge. You won't be able to solve many puzzles on your own, or understand the past so well – says the Wrocław researcher.

The forest – a unique place

The project, headed by Prof. Przemysław Urbańczyk, an archaeologist from the Cardinal Stefan Wyszyński University in Warsaw, involved scientists from the Department of Soil Science at the Warsaw University of Life Sciences, the Department of Geology and Geomorphology at the University of Łódź, the Earth Museum of the Polish Academy of Sciences and the Institute of Geography of the Russian Academy of Sciences.

The Bialowieża Forest is an extremely valuable research area for scientists due to its low degree of human interference, in comparison with urbanised areas and more intensively exploited agricultural areas. From the 15th century it was the exclusive hunting ground of Polish kings, Russian tsars and later a national park, which protected it from excessive human influence: developed settlements, logging and ploughing.

It is the largest 'primary' forest in Central Europe, and a UNESCO World Heritage Site. Archaeologists have access here to an original cultural landscape shaped over millennia: numerous kurgans, productive mounds and ancient farmland systems have been preserved. The history of archaeological research in the forest dates back to 1825, but initially these were mainly random, amateur findings. The first regular work was carried out in the early 20th century by the German archaeologist Alfred Götze. In the 1960s, the Institute of History of Material Culture of the Polish Academy of Sciences began excavations, among others, at prehistoric and early medieval cemeteries.

According to scientists, previous work was rather ad hoc, limited in time and space, and its results were fragmentary. This time they worked comprehensively, using many modern methods. The current programme has resulted in a three-volume catalogue, which contains information on more than 1,840 anthropogenic sites and locations: mounds of various character, kurgans, charcoal piles, tar kilns, former fields and other sites of an unspecified nature.

Kurgans in Silesia

Mateusz Krupski is already in charge of another project funded by the National Science Centre, which is being carried out at Wrocław University of Environmental and Life Sciences. – We are examining original prehistoric soils that are preserved under kurgans in several forest complexes in Silesia. These constitute a wonderful archive of information on the ancient environment and its changes, including those resulting from human activity – says the researcher. – I am glad that during this project I can make myself more at home at the Institute of Soil Science, Plant Nutrition and Environmental Protection, because the long-term cooperation with Prof. Cezary Kabala is important to me and has taught me a lot. I perceive my work with the Archaeologists.org Foundation team, which specialises in research using geophysical, geoarchaeological, traseological and physical anthropological methods, in a similar way. There are new discoveries every year.