Litter Decomposition Of Typical Forest Ecosystems And Mutual Effects With Soil Biochemical Characteristics On The Upper Reach Of Minjiang River

Because of unreasonable forestation and management, the forest soil and fertility degraded and declined seriously. The decomposition and nutrient release of leaf litter can offer more nutrition for microorganism, increase the soil enzyme activity and improve the biological characteristic of the soil to maintain good land fertility. So accelerating the leaf litter decomposition is an important way to avoid the fertility recession and keep the soil fertility. In this paper, four kinds of artificial forests (C.japonicum, P. yunnanensis, B.utilis and P.asperata) on the upper reachers of Mingjiang River in Sichuan were studied. Through field plots experiments of external sources C (cane sugar) and N (NH4NO3) disturbances with different intensities to forests and decomposition of leaf litter, the decomposition rate , the C,N release rate and the effort on forest soil of different leaf litter was comprehensively appraised. The main conclusions are as follows:1 Study on decomposition of the different forest leaf litter in field.(1) It is obvious different on the decomposition rate and C, N releasing rate of four leaf litter. The decomposition rate and C, N releasing rate of B.utilis were maximum, the next were C.japonicum, P.asperata and P.yunnanensis in turn. In the course of decoposition, the C contents of leaf litter decreased gradually and the C, N releasing rate increased gradually. The N contents of C.japonicum, P. yunnanensis and P.asperata showed a tendency of increased first and decreased later. The N contents of B.utilis showed a tendency of decreased ~ increased ~ decreased.(2) The weight remaining rate of four different mixture leaf litter was B.utilis+P.asperata >B.utilis+P.yunnanensis>C.japonicum+P.asperata>C.japonicum+P.yunnanensis.The C and N releasing rate was B.utilis+P.yunnanensis> B.utilis+P.asperata> C.japonicum+ P.yunnanensis >C.japonicum+P.asperata. The C contents of mixture leaf litter decreased gradually and the N contents increased first and decreased later. It was found that mixture leaf litter of P.asperata and B.utilis, P.yunnanensis and B.utilis, C.japonicum and P.yunnanensis showed obvious positive interaction to decomposition, but mixture foliar litters of P.asperata and C. japonicum...