The Effect of Fire on Vegetation and Some Physical and Chemical Properties of Soil (Case study: Varcheshmeh Tusmal Rangeland, Mazandaran)

Fire is one of the most important ecological factors that can change the function of natural ecosystems. Plant growth depends on the soil, and fire can cause various changes in it. In order to investigate the effect of fire on soil and vegetation, two sites were selected including control and firefighting, each of them with an area of 37 ha, in Varcheshmeh Tusmal Rangeland of Kiasar in Mazandaran province. And in each site was done sampling of vegetation and soil by random – systematic sampling. In each site, 10 drilling and sampling profiles were performed from a depth of 0-15 and 0-30 cm. 30 square plots (1m2) were used to collect vegetation data. Plant characteristics including life form, biodiversity and soil characteristics including moisture, texture, electrical conductivity, acidity carbon, organic matter, lime, nitrogen, phosphorus, potassium were determined. The results of life forms in control and burnt rangelands showed that due to the fire of perennial species, the burned areas decreased by 33.15% compared to control. While it did not have a significant effect on annual and biennial species. The results of the effect of fire on the diversity of the whole species showed that the characteristics of the number of species, Simpson, Shannon, Margalf and Mannhinik richness were decreased 66.66, 45.6, 57.92, 67.74 and 129.49% respectively. While fire had no significant effect on the uniformity index. The results of soil experiments showed that the percentage of sand and silt, soil absorbable potassium, adsorbent phosphorus, soil nitrogen, lime, carbon, organic matter, soil acidity and electrical conductivity in burned treatment increased significantly. However, the percentage of clay and the percentage of soil moisture in the burned areas compared to the control showed a decreasing trend.