Litter Decomposition Characteristics Of Different Components Of Spartina Alterniflora In The Wetland Of Minjiang River Estuary

In this paper, decomposition characteristics and element changes during the decomposition processes of different components of Spartina alterniflora in the Shanyutan tidal marsh in the Minjiang River estuary were studied using mesh bags method. We explored the factors impacting litter composition. The research result indicted that:(1)Decomposition pattern of the litter of stem,leave,inflorescence and sheath was all "slow- quick-slow". Namely that at the standing decomposition stage, the litter decomposed slowly, at initial stage of lodging decomposition, they decomposed quickly; at the last stage, they decomposed slower again.(2)The decreasing order of litter decomposition rate was leave,inflorescence,sheath and stem. The decomposition rates ranged from 0.008210 d-1,0.006179 d-1,0.004289 d-1 and 0.003194 d-1. At the standing decomposition stage, decomposition rate of stem and sheath slowed down increasing altitude; at the lodging decomposition stage, decomposition rate was similer.(3)During the decomposition processes, the NAI of C and N of stem,leave,inflorescence and sheath of Spartina alterniflora were all less than 100%, namely that C,N released completely, the releasing order higher to slower was leave,inflorescence,sheath and stem. The NAI of P changed fluctuately. At the standing decomposition stage, complete accumulation of P appeared. At the lodging decomposition stage, the NAI of P changed as "V" tendency, and P released completely at this time.(4)Concentration of C and P impacted on the decomposition weakly; concentration of N becomed the major factor effecting decomposition. Decomposition rate of some component of litter significantly associated with C/N. Environmental factors effecting decomposition were mainly temperature, air humidity, wind speed, watersalinity and deposition, and the relevance of decomposition rate of different component of litter with different environmental factors was different. Under the treatment of N and P, the litter decomposed rapidly, and the input of high concentrations of N promoted decomposition more significantly.