The impact of fire on the forest and plants diversity in Iranian Oak forest

Fire, as a natural ecological disturbance factor in forest, this study located in the Marivan region, Northern Zagros forest, and western Iranian state of Kurdistan. In each burned and unburned area 30 circle sample plot (1000 m²) were collected by randomized–systematic method in the 100×200 m net (in total 60 plots). In every sample plot the kind of species, number of tree, the height of coppice shoot, the diameter of coppice shoot at breast height, tree crown diameter, shrub and regeneration information (i.e. coppice and seed provenance) were recorded. In the sample plots the micro plots of 2 m by 2 m (i.e. area of 4 m²) were designed and herb information was recorded then. Species diversity indexes including Shannon Wiener (H ׳), Simpson (1-D) and Margaleff (R1) were used to evaluate plant diversity in each sample plot. Data analyzing was done by SPSS16 and Ecological Methodological software’s. In this forest have 79 plant species, which consist of 6 trees, 4 shrubs and 69 herbaceous species. Results indicated that Compositae families have the highest number of species. Herbaceous layer in burned area has higher the unburned area, but shrub layers in the unburned area higher the burned area. T-test analysis indicated the differences between diversity indexes in the shrub and Herbaceous in the two areas were statistically significant, but differences between diversity indexes in the tree layer in the two areas not statistically significant. Herbaceous layer had the highest richness, evenness and diversity in the vegetation layer.