Analysis of plant residue decomposition dynamics in alpine swamp meadow

The plant residue decomposition in alpine swamp soil was studied by using a mesh-bag method at the Haibei Research Station from September 2000 to August 2002. The standing dead matter and root decomposition rates showed clear seasonal change. The most mass loss occurred in the initial stage after sample burial and during the plant-growing season. There was almost no decomposition during the winter freezing season and in the late stage after sample burial. The decomposition rates of plant residue in different months showed significant differences. In the first month after samples of standing dead matter were buried, the decomposition rates of plant residue in swamp meadow were higher than in Kobresia humilis meadow, but afterwards the rates were similar. The decomposition rate of K. humilis roots buried in swamp meadow soil was significantly higher than when buried in K. humilis meadow soil (P0.01). The correlation analysis showed that the decomposition rates of plant residue correlated with soil microorganism communities, soil temperature and soil water content. The chemical character of the plant residue is also a key factor influencing the decomposition rate.