The Effects Of Nitrogen And Phosphorus Additions On Leaf Litter Decomposition Of Schima Superba In Tiantong

Leaf litter decomposition process is an important part of nutrient cycling between plant and soil. Increasing of nitrogen deposition may cause changes in soil nutrient availability and nutrient content of leaf litter, which directly or indirectly affect the process of decomposition of leaf litter. By conducting experimental studies about effects of nitrogen and phosphorus addition on leaf litter decomposition, we were trying to clarify the dynamic process of leaf litter dry matter loss and nutrient release or enrichment in response to nitrogen and phosphorus addition; Provide critical supporting data for further analysis about the effect of increasing nitrogen and phosphorus addition on the mechanisms of forest nutrient cycling and ecosystem stability.In this study, nitrogen and phosphorus fertilized plots of Schima superba forest in Tian tong choosed as experimental platform (control treatment,add nitrogen only,add phosphorus only, add nitrogen and phosphorus), we carried10.5months of Schima superba leaf litter decomposition experiment in situ and transposition; analyzed decomposition of leaf litter under separately and simultaneously adding different fertilizers; the impact of leaf litter initial characteristics on leaf litter decomposition and the combined effects of initial characteristics and fertilization. Obtain the following preliminary results:(1) Fertilization treatment changed partial chemical characteristics of Schima superba leaf litter, but there are differences between significant effects on chemical characteristics of leaf litter under different fertilization treatments.(2)After10.5months of decomposition, there is no significant difference among all different treatments when considering leaf litter mass remaining. The effects of adding N or P alone on leaf litter decomposition rate is not obvious, but applied N, P combined fertilizer could significantly inhibit leaf litter decomposition. (3) Initial characteristics of leaf litter effects leaf litter dry matter loss process. In N, P combined fertilization plots the decomposition rate of leaf litter was accelerated, and it was relevant to less initial C/N. But after increased application of N, P treatment, leaf litter decomposition was inhibited.(4)After fertilization treatment or after changing initial chemical characteristics, it has no obvious effect on N remaining. There’s no significant difference considering leaf litter P remaining Dynamic characteristics among different fertilized treatments, It changes because of different initial chemical characteristics. After four months of decomposition, P enrichment has significantly inhibited in leaf litter collected from fertilization plots, but increased after increasing fertilization, and the inhabitation was retarded.(5)After10.5months of decomposition, leaf litter N content of each treatment showed as net release, there’s no significant difference among treatments. In P fertilized treatment leaf litter P content changed into net enrichment, while all other treatment’s leaf litter P content showed as net release. After the decomposition of leaf litter collected from fertilized treatment placed on Control treated plot, P net release significantly higher than control, but simultaneously increasing fertilization reduced P net release level.