Effect of Forest Road on Herbaceous Diversity and Tree Regeneration

Road construction is one of the effective factors for ecological changes which affects diversity and species composition in forest roads edges. This research was performed in Kheirud forest to evaluate herbaceous diversity and tree regeneration establishment in different distances from road edge. For this purpose, we sampled herbaceous and tree species regeneration in 0,5,10,25, 50 and 100 m distances from road in down and up-hill sides. Biodiversity indices (Shannon and Simpson), richness index (species number )s)) and evenness index (Pielou) were calculated to determine the degree and magnitude of road effects on herbaceous and regeneration diversity. The results showed that, the species diversity, richness and evenness indices were not significantly related to down and up slope while these attributes were significant to distance from the road. Distance from road edge was a significant factor which affect composition and distribution of herbaceous plants and tree regenerations. In road edges, the first plots (0, 5, 10 m distance) had significantly greater number of light demanding species like Rubus hirtus, Carex remota ,Sumbucus ebulus , Acer velutinum and Alnus glutinosa than interior plots. Based on results, among the environmental factors, light condition was major determinant of species distribution and abundance of road to forest interior gradient. These results are expected to provide critical information for decision makers to design carefully and appropriate forest roads to minimum damages of habitats to establishment of regeneration and also help to select the proper species bioengineering