Effects Of Cutting On Soil Carbon And Nitrogen Transformation Rates In Planted Pinus Tabulaeformis Forest

In order to reveal the law of carbon and nitrogen conversion rates inside the surface soil in the planted Pinus tabulaeformis forest, and to study the nitrogen and carbon transformation rates with different logging intensities during the growing season. In this paper, the Barometric Process Separation technology is used to determine the rates of soil gross nitrification, denitrification and respiration from June to September. The results show that the transformation rates of nitrogen and carbon are different in four months and values in August and September are maximum separately. Simultaneously, the soil temperature and moisture are the main factors affect the transformation rates. The average value during growing season of gross nitrification rate decreases in the plots haver been selective cutted. Besides, the denitrification is strongest in August, but the value of its rates is zero in the other three months. In addition, the respiration rates increase with logging intensities, but it suddenly decrease to the minimum value in the plot with the maximum logging intensity. It is found that the different rates of nitrogen and carbon transformation due to logging intensities are mainly affected by soil moisture, organic carbon content and total nitrogen content. In the above study, it is also found that a strong consistency exists between the rates of gross nitrification and denitrification, but they are weakly correlated with the rates of respiration.