Abstract: With litterbag method, this paper studied the mass loss of Deyeuxia angustifolia litter during 16 months of its decomposition in Sanjiang Plain, and the dynamics of the major elements in the litter. The results showed that the annual decomposition rate of D. angustifolia litter was 0.257, and the double exponential model W_t/W₀=0.0399e^-0.545t+0.9601e^0.018t (R²=0.945) could describe the mass loss more effectively. During decomposition, the element accumulation index (NAI)values of C, N, P and Ca were significantly less than 100% (P<0.05), indicating the net release of the four elements, while the NAI values of K and Na were significantly higher than 100% (P<0.05), indicating the net accumulation of these two elements. The NAI values of Mg, Mn and Fe were approached to 100%, which indicated that the release and accumulation of these three elements occurred simultaneously during the decomposition. After 16 months of decomposition, the release rate of the elements fromD. angustifolia litter was in the order of Fe>P>Ca>N>C>Mg>Mn>K>Na, and the corresponding released amount was 0.106, 0.147, 0.971, 0.568, 65.37, -0.017, -0.114, -0.209 and -0.125 g·m^-2, respectively.

Key words: Liposcelis bostrychophila, Life table, Population parameters