Wpływ efektu brzegowego drogi na cechy drzewostanów sosnowych Puszczy Noteckiej

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 road No. 150 on inventory characteristics of neighboring Scots pine stands in the Notecka Forest (western Poland) – one of the larger forest complexes in Europe. Twelve rectangular experimental sites were established perpendicular to the road axis, called belt transects. Each transect consisted of 3−4 plots located at different distances from the pavement edge (fig.). Measurements and estimations were recorded for the plots. Values from all belt transects were approximated within plots at the same distance from the road and then compared using statistical methods. Observations were conducted in Scots pine stands growing on fresh coniferous forest (Bśw) and fresh mixed coniferous forest (BMśw) sites. Reduced stand density that resulted in decreased basal area, volume and growth rates were observed in the immediate vicinity of the road compared to the forest interior. Individual trees were thicker, but more often burdened with defects decreasing timber value. Any considerable effect of the road on tree height wasn't observed. The above mentioned changes were more evident in poorer habitat conditions, while the location in relation to the road had no significant effect. Modified lighting conditions are probably the main cause of these changes. At the edge of Scots pine stands in the Notecka Forest, a unique ecotone has formed under the influence of the provincial road.