Inland dunes geosystem in the agricultural landscape on the example of the Bzura and Ner basins

Abstract

Inland dunes are a common form of land relief in the Polish lowlands; the distinctive feature of the underlying geosystem is the dryness of the base. High thickness of quartz sands, low-lying ground water, and soil of poor quality are qualities that support the development of pine forests. These sandy areas are particularly susceptible to human activity. Removal of forests and ploughing of the uncovered surface often resulted in stimulating aeolian processes in the past. Even in the mid20th century some dunes were blown away by wind. This process in agricultural areas should be considered as a threat and, therefore, it is important to utilise dunes properly, in a manner appropriate for the existing abiotic conditions. In the basins of the rivers Bzura and Ner (central Poland) there are located rich soils intensely used for agriculture; forests occupy 0–5% of the surface area in various communes. This area has also generated inland dunes, some of which reach the height of 20 m. In the article the author analyses the forms of use and utilisation of inland dunes and evaluates the susceptibility of this ecosystem to various forms of anthropogenic impact. Modern use of dune surface within the studied area is mostly matched with the features of the natural environment. Most forms are overgrown with pine forests. However, forests occupy a small area in total and are scattered throughout agricultural land as they only occupy dunes. These forests are of a multifunctional nature – they serve the ecological, economic, and cultural functions. They fulfil the important functions of pedogensis and they protect the area from aeolian and water erosion. Finally, within the homogeneous agricultural landscape, pine forests in dunes also carry huge scenic benefit as they offer contrast to the monotony of farmlands. Soils in aeolian sands feature low productivity, they are prone to aeolian erosion, and their cultivation is uneconomic which is why today farmlands can only be found in the lower sections of dunes. Before the mid-20th century there were more cultivated lands on dunes but they were forested.
Dry base has long supported settlement efforts which is why dense rural development exists in the immediate vicinity of dune forms while on dunes developments are scattered. Since the mid-20th century some dunes and their surrounding areas have featured vacation developments. Plain agricultural areas do not feature many natural assets that would support recreation and their main asset are the forests overgrowing dunes, yet in some cases developmental pressure exceeds the potential ofthe small stock of forests.