Changes of soil properties of basins without outlets in the young glacial landscape as an effect of antropoghenic denudation and erosion

The aim of the study is to examine and identify the scale of changes of soil properties occurring in basins without outlets in north-western Poland as a result of erosion and anthropogenic denudation. These processes are conditioned by a diversified relief, slope reduction, texture and land use and modify the physico-chemical properties and morphology of soils of closed basins.

Soil cover, especially in arable land with varied relief, is subject to degradation. In morainic landscapes, characteristic soil sequences are often seen, with eroded soils on slopes, deluvial soils in the lower parts of the slopes and organic soils in depressions. For predicting future peneplanation of Quaternary landscapes and changes of soil properties, it is necessary to identify the main factors responsible for intensified erosion and anthropogenic denudation: soil texture, slope gradient, plant cover and land use. Agricultural slopes devoid of vegetation cover or poorly covered respond intensively or restrainedly to strong rainfall events which impoverish the soil as well as to anthropogenic denudation. Sediments and minerals move down the slope along with runoff, supplying the lower parts of the area with components such as clay, silt, organic carbon, total nitrogen, etc. Closed basins are very abundant in the landscape of morain uplands. These numerous depressions have unique natural values and are also reservoirs of knowledge about past geomorphologic events.

The study area is located within the Drawsko Lakeland, which is a part of the West Pomeranian Lakeland in north-western Poland. The study was conducted in six toposequences located in three selected basins without outlets in a young glacial landscape within a ground morainic plateau near Czaplinek.

With a closed water cycling, the soil material is retained inside the catchment despite erosion processes. The area of deluvial soils in a young glacial landscape in north-western Poland is increasing because of soil erosion and improper agrotechnical practices. The basic effect of anthropogenic denudation is increased thickness of the humus horizon from 10-15 cm in forest to 25-30 cm in arable land and compaction of soil material. Erosion processes underlie the formation of deluvial soils. Eroded soils which occur on higher parts of the slopes in basins without outlets are more compacted and drier than deluvial soils. Soil texture and flora are one of the most important factors that determine the intensity of erosion processes. Denudation markedly diversifies the soil cover of morainic landscapes in Poland. To protect the soil cover and geodiversity in these specific types of land forms, it is necessary to implement appropriate agrotechnical practices.