[Seasonal dynamics of soil mineral nitrogen pools and nitrogen mineralization rate in different forests in subtropical China].

-N and mineral N pool varied seasonally in all forests, and were higher in dormant season (October to February) than in growing season (March to September). Soil nitrification rate was very low in the whole year in all three forests and soil net ammonification was the major process of soil net mineralization. Tree species significantly affected soil net ammonification rate, and the value under Chinese fir was significantly lower than the other two fore-sts. The seasonal patterns of the soil net ammonification rate were not similar in all the three forests, but with the lowest value occurring in November and February in the following year. Analysis using variance of repeated measures indicated that soil mineral N concentrations and soil N mineralization rates were significantly affected by forest type and season, and correlation analysis showed that soil mineral N and soil N mineralization rate were significantly affected by water moisture and temperature, and the effects of litter on soil N mineralization rate were mainly through quality control, ra-ther than the quantity control.