Litters Decomposition And Soil N Translation Cryptomeria Fortunei And Castanopsis Platyacantha-Schima Sinensis Forests

A better understanding of the effect of different litters on soil nitrogen mineralization is urgently required for developing effective site management to enhance sustainable forest production and environmental benefits. We conducted a controlling experiment in the lab to study the N mineralization and element content of soils , the mass loss and variaty of elements of litters, and the effects of Castanopsis platyacantha-Schima sinensis forest and Cryptomeria fortunei forest litters on the N mineralization of soils. The main results are as follows:1. the order of the decomposition rates of three litters done was degressively ranked as broad-leaf forest litter, conifer forest litter and mixed litter in the coniferious soil, but in the broadleaf forest soil the order is broad-leaf forest litter, mixed litter and conifer forest litter. The variational rule is the same with the mass loss of litters in forest soils.2. Litter decomposition rates were negatively correlated with litter total N(r=-0.878, P<0.05) and positively with total C(r=0.829, P<0.05, N=12), while weakly positively correlated with litter C/N ratios (r=0.486,.P>0.05, N=12) .3. Varieties of C, N, P content of the treatments litters in the two forests. C content is not changed with time, N content decreases first then increases, and P content shows no regular pattern with time.4. Tht mixed litters influence on the N content and N transformation rate of soils in two forests more strongly than litters of other treatments(P<0.05, N=12). In the boroad-leaf forest, NO₃^--N content of soil treated by MLD is the highest, being 286.81 mg·kg^-1. Additionally, the rates of N transformation were the highest in the soil with mixed litters too, i.e. nitrification rate was 1.74 mg · kg^-1· d^-1; ammonification rate was 0.36 mg · kg^-1·d^-1; N mineralization rate was 1.90mg·kg^-1·d^-1.5. Soil C affects N mineralization rate strongly in two forest soils, while the affecting factors are different. For example, in the coniferous soils, soil N mineralization rate is positively correlated with soil C(r=0.536, P<0.05, N=12) and inatial N content of litter(r=0.510, P<0.05,N=12), and negatively with mass loss of litter(r=-0.551, P<0.05, N=12). Soil C influences on N mineralization rate of broad-leaf forest soil.