Colluvial deposits in loess gullies of southwestern Poland as an indicator of palaeoenvironmental changes and human impact

Abstract

Assessing the interactions between natural environmental change and land degradation due to human impact is crucial for palaeoenvironmental analysis in loess areas. However, the reconstruction of relief evolution in loess regions of SW Poland in relation to human impact of the first agrarian cultures, is not well understood by comparison with other loess areas in Poland. Therefore, our study aims to reconstruct land-use changes based on a palaeosol-bearing sedimentary sequence in a loess gully in this region. The research was conducted in the hilly region of SW Poland, where loess patches occur. To investigate prehistoric human impact in this area, we analysed dry valley systems near the village of Nowolesie, employing a combination of lithostratigraphic analysis and dating (radiocarbon and OSL) techniques. Within a 4.0 m-thick sedimentary succession filling the bottom of the gully, we identified loess-palaeosol sequences that represent a record of environmental changes during the Holocene. Our findings suggests that deforestation and dry valley transformation occurred during the Neolithic/early Bronze Age transition. Subsequently, erosional processes intensified during the Middle Ages. During this period, sediment dating to the Neolithic/Bronze Age was deposited in the upper parts of the gully and was later transported to the lower part of the main gully and redeposited in several episodes.