Spatial analyses of medieval fields geochemistry reveals past land use management - preliminary results
Abstract
Our study is focused on human impact on nature and on the inter-relationships between these two entities. As there was always a huge shift towards interdisciplinarity in environmental archaeology, we aim on the complex study of medieval fields.
Our research is performed in touch with nature sciences, mainly soil geochemistry, and also with archaeology and history. Our research is methodically based on broad spatial sampling of soil samples and mapping of basic soil conditions.
We use XRF spectrometry as a main tool for multi-elemental analyses. The crucial factor of our methods is also a design of sampling based on a respect to historical land and land use features like parts of village field system or possesions of the households.
Since there were performed many researches in the built up areas of villages and also of houses, we focus more on the fields systems. Some of our sampling reached ca 2 kms from the village households, depending on the field system area.
Also macroscopic visual method of getting data and knowledge of the site is crucial. We present the final or preliminary results of our researches of five villages: Spindelbach (Ore Mountains, North-Western Bohemia), Hol (near Prague, Central Bohemia), Lovětín and Regenholz (near Třešť, Czech-Moravian Upland) and Goschwitz (near Wroclaw, Poland).
It was revealed that generally used and acknowledged human indicator - Phosphorus - can be present at only very low levels of concentration, or undetectable, even in the nearness of households. The natural conditions cannot be the causing factor at all cases.
This situation is caused also by last human activity intensity and by its spatial manifestation. In such cases, multi-elemental analysis is very useful.
Zinc is usually correlated with Phosphorus, which is also connected to Lead. The past human activity indicators are usually connected to modern pollution indicators.
These two inputs can be sometimes distinguished by statistical analyses and by spatial visualisation of data. Working with just concentrations can be misleading.
Past land use management and its strategies were important for spatial distribution of soil geochemical indicators. Therefore, we can use them not only as quantifiers of human impact on nature, but we can also detect different management or knowledge and experience.
As it was revealed e. g. by analyses of households' possessions differences. For example, generally presumed decreasing gradient of management intensity (e.g. manuring) along the distance from village can be found on on the level of a whole field system, but it varies a lot between the possessions' parcels.