Complementary Utilization of Nutrients between Phragmites Australis and Phalaris Arundinacea Based on Accumulative Dynamics of Soil Nutrient during Litter Decomposition

The objective of this study was to explore the maintenance mechanism for the coexistence of Phragmites australis and Phalaris arundinacea by studying the accumulation dynamics of soil nutrients during the whole decomposition of the two species of litter. To do this, the complementary utilization of nutrients between the two species in the Phragmites–Phalaris community was studied. Results showed that the composition and quality of plant litter determined its level of contribution to soil nutrient. Different proportions of nitrogen and phosphorus, which were released to the soil from P. arundinacea, were preferentially utilized by Phalaris arundinacea and Phragmites australis, respectively; while different proportions of nitrogen and phosphorus, which were released to the soil from Phragmites australis, were preferentially utilized by Phalaris arundinacea and Phragmites australis, respectively. These results showed that the complementary utilization of nutrients is one of the maintenance mechanisms of coexistence of Phragmites and Phalaris in the community.