Department of Soil Sciences and Landscape Management

ABSTRACT Human-induced erosion is one of the key factors leading to the soil degradation. Agricultural, undulating or hilly morainic areas of North-Eastern Poland are exposed to this negative process. This paper elucidates the influence of accelerated soil erosion on soil cover in young morainic landscapes of North-Eastern Poland (Brodnica Lake District). Detailed pedological investigation (21 soil pits and 375 augerholes) were carried out within two study sites (forest and agricultural). A comparison of fully developed forest reference soil pedons with arable soil has been made. Five classes of soil truncation have been distinguished. According to the identified degrees of truncation, maps of soil cover transformation, caused by accelerated erosion, were generated and overlapped on Digital Elevation Models (DEMs). Eroded soils overlap 39.5% of agricultural area and 2.5% of forest site. The widespread occurrence of strongly and completely eroded pedons (respectively 7.4% and 5.4%), only in the agricultural areas, provides intense anthropogenic impact on soil cover in the agriculture areas of North-Eastern Poland. The average values of soil reduction are about 40–50 cm. In the case of completely eroded soils it exceeds even 100 cm. Truncation of pedons with abrupt textural change due to the slope processes leads to the disappearance of vertical textural contrasts and the formation of new soil units. The evidence of erosion from the topsoils is mainly the decrease in the content of organic matter and calcium carbonate enrichment. The effect of intensive slope processes is widespread occurrence of thick (up to 3 m) colluvial deposits.

The aim of the study was to assess the suitability of aerial photos for mapping the soils of dwindling lakes catchment areas. The study area is located in the North Poland, within the Brodnica Lakeland and it includes the direct catchment area of dwindling Sumowskie Lakes. There were three test area established for soil mapping. The photointerpretation was based on both immediate properties (colour of topsoil) for ploughed cultivated fields, and intermediate properties (vegetation and relief) for the areas of forests, shrubs or permanent pasture. The obtained results confirm the high usability of the cartographic materials such as aerial photographs and topographic maps for studies on specifications of areas such as the vicinities of dwindling lakes.

The aim of the study was to assess suitability of colour aerial photographs for mapping of soil cover transformed due to effect of anthropogenic denudation. The investigation was carried out in south-western part of the Brodnica Landscape Park, within the boundaries of rolling and hilly moraine plateau, used for agricultural purposes. The soil cover of that area is exposed to intensive influence of slope processes triggered by human agricultural activity. The anthropogenic denudation leads to truncation of soil profiles of top convex sections of slopes and hills' summits. Soil material moved down the slopes is accumulated in the form of diluvium in hollows and lower sections of slopes. Two study sites were selected -Sumówko and Zbiczno. Within the boundaries of both study sites, detailed soil mapping took place consisting in preparation of irregular boreholes projection. Next, four sites were selected for soil pits, representing broad spectrum of transformations related to anthropogenic denudation. Based on obtained results and colour diversity of surface horizons, the spatial range of individual soil types was specified. It also enabled determination of anthropogenic denudation impact on formation of the soil cover. Totally eroded soils, classified as pelosols, located on hills' summits, are characterized by very bright colours of surface horizons, resulting from content of calcium carbonate in glacial tills. The range of soil lessivés, prevailing within the slopes boundaries, where the erosion resulted in exposure of argic horizons rich in iron compounds and clay fraction, coincided with occurrence of brown colours. Bright grey surface horizons are characteristic of deluvial soils. This colour arises from sandy texture of deluvial material (low content of iron) in combination with humus nature. The soils located in relatively vast field depressions were covered with small thickness of diluvium, which was reflected in dark grey colours of surface horizons. These horizons are relatively rich in soil humus. Significant amounts of humus are related with mix of deluvial material with material formed in humus horizons, originally occurring on surfaces of soils rich in organic matter -black earths and organic soils.

The term deluvial is applied to a deposit formed as a result of geodynamic processes in hilly and undulating landscapes by natural and technogenic movement of topsoil or products of weathering down the slope and its accumulation. The properties and distribution of deluvial soils are important for agriculture history, soil erosion and water protection.

The objective of this publication is presentation of taxonomy position of vertical texture-contrast soils developed from bottom moraine material covered by fluvioglacial or ablation sandy layers in young glacial landscapes. Studied soils were classified as 5 different Reference Soil Groups according to WRB system: Luvisols, Albeluvisols, Alisols, Umbrisols and Arenosols. Several proposals for modifications in the WRB classification have been suggested for a more complete description of investigated soils properties.