关键词: 沉积物-水界面, 内源磷释放, 湿地植被, 根际过程, 磷形态, 氧化还原条件, 生态修复

Abstract: The sediment-water interface is a key zone for the release, retention, and transformation of internal phosphorus (P) in wetlands. Wetland vegetation can alter the source-sink status of P at this interface by modifying hydrodynamic conditions, rhizosphere redox environments, plant uptake, and microbial processes. We synthesized the mechanisms by which wetland vegetation regulates P transport and transformation across the sediment-water interface, including physical sediment stabilization, radial oxygen loss, and iron-phosphorus coupling, plant-microbe interactions, and litter decomposition feedbacks. We further compared the regulatory effects of different plant life forms and community characteristics. Emergent plants generally exhibit strong rhizosphere oxygenation and sediment-stabilizing capacities, thereby favoring P retention at the interface. Submerged plants can reduce P release by increasing near-bottom dissolved oxygen, taking up P, and suppressing sediment resuspension. By contrast, the long-term effects of floating-leaved and free-floating plants depend more strongly on vegetation coverage, litter management, and bottom-water oxygen conditions. The effectiveness of vegetation-mediated P regulation is jointly constrained by hydrological fluctuations and wetting-drying cycles, temperature, dissolved oxygen, pH, sediment properties, initial P speciation, and external P loading. During the growing season, plant P uptake and interfacial P retention generally predominate, whereas senescence or disturbance may increase P release risks through litter return, oxygen depletion, and weakened sediment stabilization. Consequently, the long-term effect of wetland vegetation on P cycling is strongly context dependent. Future research should focus on identifying thresholds under multiple interacting factors, elucidating functional plant-microbe interactions, developing high-resolution in situ monitoring approaches, and evaluating the long-term stability of P source-sink dynamics, thereby providing a scientific basis for wetland vegetation restoration and precise management of internal P loading.

Key words: sediment-water interface, internal phosphorus release, wetland vegetation, rhizosphere process, phosphorus fraction, redox condition, ecological restoration