Litter Decomposition And Nutrient Dynamics In The Minjiang River Estuarine Wetland

The process of litter decomposition and nutrient release plays an important role in maintaining higher primary productivity of the plant and the sustainability of structure and function in wetland ecosystem. However, fewer studies focus on home-field advantage and the mixed litter decomposition of estuarine tidal wetland, specially, the variation of litter decomposition in aboveground and belowground. In order to clarify the characteristics of litter decomposition and the effects of inundation frequency, home-field advantage and litter mixture on litter decomposition were studied via field sampling and laboratory experiment from March2012to March2013in the Min River estuarine wetland which locates in the southeast of China. The results showed that:(1) During the observation period, inundation frequency showed significantly effect on the litter decomposition and nutrient release rate of Cyperus malaccensis, but there was not significantly impact on the litter decomposition and nutrient release rate of Phragmites australis and Spartina alterniflora. The order of the litter decomposition rates were C. malaccensis> S. alterniflora> P. australis except in neap tide flooded habitat. In continuously flooded habitat, middle tide flooded and spring tide flooded habitats, the litter decomposition rates of C. malaccensis were0.0028d-1,0.0045d-1and0.0057d-1, respectively. The litter decomposition rates of S. alterniflora were0.0025d-1,0.0029d-1and0.0033d-1, respectively. And the litter decomposition rates of P. australis were0.0024d-1,0.0026d-1and0.0031d"1, respectively. The order of nutrient release was different for the three plant litters in the different flooded habitats.(2) During the observation period, home-field advantage showed significantly effect on the litter decomposition and nutrient release rate of C.malaccensis, but there were not significantly impact on the litter decomposition and nutrient release rate of P. australis and S. alterniflora. The litter decomposition rates of C. malaccensis in home field habitat and visiting field habitat were0.0045d-1(home field habitat),0.0029d-1and0.0026d-1(visiting field habitat), respectively. The litter decomposition rates of S. alterniflora were0.0029d-1(home field habitat) and0.0047d-1(visiting field habitat), respectively. And the litter decomposition rates of P. australis were0.0026d-1(home field habitat) and0.0047 d"1(visiting field habitat), respectively. The significance of home-field advantage was determined by the nutrient provision by the visiting filed.(3) For the litter of same species, the decomposition and nutrient release rates of different plant organs litter mixture varied with the change of plant species. The decomposition and nutrient release rates of mixed plant species litters were influenced by the mixed litter types and the ratios of mixture. The aboveground litter decomposition and nutrient release rates were higher than those of belowground.