Changes of phenolic substances after fire in turkish red pine forest soils and their relationship with the seedling growth of Turkish red pine

In this study, it was aimed to investigate the effects of fires on allelopathic phenolic substances released by vegetation and accumulated in the soil, and the effects of potential changes in the amount of phenolic substances due to fire on Turkish red pine (Pinus brutia Ten.) seed germination and seedling growth, and physical and chemical parameters of the soil. In this context, soil samples taken from the areas destroyed by the surface and crown fires and unburned areas in Göcek region of Fethiye District of Muğla were compared in terms of phenolic substance amounts, physical and chemical soil properties, Turkish red pine seed germination and seedling development. According to the findings, the total phenolic substance amounts of the soil samples taken from the study areas were found to be low and close to each other. In terms of seed germination and seedling growth value, the highest total height, stem and root length values were determined in the soils of the surface fire area, the highest dry weight and crown length values were determined in the soils belonging to the unburned area. The highest germination rate was found in the soils of the crown fire area. As a result of the soil analysis, the saturation, organic matter, total organic carbon, nitrogen, potassium, magnesium and cation exchange capacity values are high in the soils of the surface fire area. Electrical conductivity, lime, phosphorus and calcium values were found to be highest in soils of the crown fire, and pH values were found to be highest in soils of the unburned area. The findings obtained as a result of the study show that the total phenolic substance accumulation in the study areas is not in amounts that can cause allelopathic effects, but fire can have significant effects on the physical and chemical parameters of the soil, and these changes may affect the seed germination and seedling growth of Turkish red pine.