Summary:

The development of the transportation network brings both benefits and threats. Much attention is paid to soil contamination with trace elements, difficulties in animal migration, noise propagation or synanthropisation of the vegetation cover. This paper deals with the effect of provincial very low-volume road No. 150 on the herbaceous vegetation cover, especially on the occurrence of 3 species of the heather family: Calluna vulgaris, Vaccinium myrtillus and V. vitis-idaea. Observations were conducted in pine stands in fresh coniferous forest and fresh mixed coniferous forest sites in the Puszcza Notecka Forest, Poland - one of the larger forest complexes in Europe. Twelve rectangular experimental sites were established perpendicular to the road axis, called belt transects. Each of them consisted of 3-4 plots located at different distances from the pavement edge. Measurements and estimations of herbaceous vegetation cover and pH soils were recorded for the each plots. Values from all belt transects were approximated within plots at the same distance from the road and then compared using statistical methods. By the road humus was a less acidic than in the depth of the tree stand, there was more abundant herbaceous vegetation, including Calluna vulgaris, but rarely appeared Vaccinium myrtillus and V. vitis-idaea whose incidence is increased with increasing distance from the road edge.