The Impact of Adjacent Road on Vascular Plant Species Composition in Herbaceous Layers of Peucedano-Pinetum and Tilio-Carpinetum Urban Forests in the City of Warsaw (Poland)

The research was conducted in two types of urban forests: Peucedano-Pinetum and Tilio-Carpinetum. The aim of the study was to determine the differences in plant species compositions in the herbaceous layer of urban forests with different habitat fertility adjacent to the road in the northern part of Warsaw (Poland). Seven transects were laid out in each type of forest, with 10 plots spread out from the edge zone (forest border) to the interior of the forests. The size of each plot was 100 m2. The other seven transects were located within the forest, 150 to 200 m away from the forest’s edge. The field research included phytosociological relevés carried out on the existing transects. The indoor studies included an analysis of forest community disturbance. Furthermore, an analysis of abiotic environmental conditions using ecological indicator numbers was carried out. Ecotones of Peucedano-Pinetum are more likely to be colonized by the species inconsistent with the habitat due to processes that increase habitat fertility. The Tilio-Carpinetum forest is more easily colonized by invasive plant species than the Peucedano-Pinetum. The range of road effects can be determined as an area located within 90 m inward of the forest in the case of the Peucedano-Pinetum community and 100 m in the case of the Tilio-Carpinetum community. The presented research is important for formulating directions about how to manage the forests and their surroundings in terms of shaping forests of more natural character, with species more consistent with a forest habitat.