Nitrogen and phosphorus dynamics and nutrient resorption of Rhizophora mangle leaves in south Florida, USA
Sternberg, Leonel da Silveira Lobo（Univ Miami, Dept Biol, Coral Gables, FL 33124 USA）
- 生命科学－已发表论文 
Nitrogen and phosphorus dynamics during leaf development, senescence, and decomposition of tall and dwarf forms of the red mangrove, Rhizophora mangle L., were studied in south Florida. Mature leaves of tall mangroves had significantly higher nitrogen (N) and phosphorus (P) concentrations than those of dwarf mangroves, which suggests that N and P are important factors associated with mangrove growth. Based on N:P ratios, both mangrove growth forms were P-limited, but dwarf mangroves were more so than tall mangroves. N and P were resorbed before leaf abscission as evidenced by the decrease in leaf N and P concentrations during leaf senescence. Mangroves showing indications of greater P-limitation had significantly higher phosphorus resorption efficiencies and proficiencies (PRE and PRP, respectively). PRP, however, was more sensitive to the molar N:P ratio and the phosphorus concentration of mature leaves than PRE. N and P immobilization was indicated by the gradual increase in leaf N and P concentrations during leaf decomposition. This immobilization could delay N and P leaching and loss from the detritus matrix and provide plants with available N and P over a prolonged period of time.