Litterfall,Litter Decomposition,and Nutrient Dynamics in Two Subtropical Bamboo Plantations of China

Bamboos are one of the fast-growing and multiple use species in the world,and thus bamboo forests/plantations play an important role in C sequestration at regional and global levels.We studied aboveground litterfall,litter decomposition and nutrient dynamics for two years in two subtropical bamboo ecosystems in Southwest China so as to test the hypothesis that litter quality determine the rate and nutrient dynamics during decomposition of different litter fractions.Mean annual total aboveground litter production ranged from 494 to 434 g m-2in two bamboo stands(P stand,dominated by Pleioblastus amarus and H stand,hybrid bamboo dominated by Bambusa pervariabilis x Dendrocalamopsis daii).Bulk(80%)of litter production was contributed by leaf litter in two stands followed by twigs and sheathes.Different litter fractions represented considerable variations in the rates of mass loss and nutrient release.Variation of the mass remaining after 2 years of decomposition was significantly explained by initial C/N ratio and initial P concentration.Initial concentrations of N,P,Ca,and Mg explained 57.9%,95.0%,99.8%and 98.1%,respectively,of the variations of these elements mass remaining after 2 years of decomposition.The patterns of nutrient dynamics and the final amount remaining were mainly determined by their initial litter substrate quality in these two subtropical bamboo plantations.