Effects of forest roads on species composition of trees regeneration in selection cutting management of high forests

Forest road network is one of the most essential forest management infrastructures. nevertheless, roads can change the plant's biodiversity by changing the environmental conditions around them. the aim of the present study was to evaluate the road effect on density and species diversity of trees regeneration and to determine the road effect zone on species composition of trees regeneration in different altitudes of mixed broadleaves high forests in northern iran. for this reason, the density and composition of trees regeneration were analyzed in three altitude classes (<600, 600–1200, and 1200–1800 masl) and five distance classes (0–30, 30–60, 60–90, 90–120, and 120–150 m) from the road edge. results indicated that the roads had a significant impact on the density and species diversity of trees regeneration at a distance of 30 m from the road edge, although the impact distance on the presence or absence of a tree regeneration was >30 m, depending on the regeneration species and altitude. density (stem ha−1) and species diversity (shannon index) of trees regeneration around forest roads (30 m) were 35% and 33%, respectively, higher than those of forest interior zones. the range of road effect on the diversity, richness, and density of trees regeneration species was approximately 30 m. the impact of forest road on the trees regeneration population was mostly influenced by trees species of stand rather than the altitude.