Determination of nitrogen mineralization potential in black pine stands subjected to fire

The aim of this study is to determine the nitrogen mineralization change in burned and adjacent unburned soils of Black pine stands. For this purpose medium and low intensity fires were conducted in flat (10%) and sloped (60%) areas of Black pine forests in Osmancık Forest Sub-District Directorate (Samsun/TURKEY). Prescribed burning was done at two level of fire intensity (low and medium) in each slope group. Control plots also were determined adjacent these sites. After the fire soil sampling was done at 4 different terms to determine the nitrogen mineralization. Soil samples were taken with the help of steel bars (15×15×15 cm) and by thrice repetitive sampling in three sample plots chosen from each group, totally 9 samples were taken. Soil samples were passed from steel mesh (4 mm standard) and so soils separated from plant parts and stones as well as soil particles became standard. Soil samples was brought to the laboratory within polyethylene bags by taking about 1200-1800 grams of each sieved soils. Received soil samples were air-dried and stored in the paper bags at room conditions. Variance, correlation and regression analysis were performed on the obtained data using SPSS.11.0 ™ program. Soil samples taken from burned and unburned areas were analyzed and nitrogen mineralization potentials' were compared. According to result of analysis, fire had an increasing effect on nitrogen mineralization. This positive effect was found maximum at surface soil layer of medium intensity fire site in flat area and minimum at sub-surface soil layer of low intensity fire site in sloped area.