中文摘要：

红树林输送的溶解态陆源有机质是海洋中陆源有机质的主要来源之一,对其光降解和生物降解过程的研究有助于进一步了解红树林生态系统输出的有机质在近岸的归宿以及对近岸水体生物地球化学过程的影响,因此于2010年4月在海南省清澜港红树林采集间隙水,并进行了光降解和生物降解培养实验。分析了光培养（光降解）和暗培养过程（生物降解）中溶解态有机碳（DOC）、细菌以及溶解态木质素等的变化。结果显示经历128d的暗培养后,DOC由初始的2 216μmol/L下降至718μmol/L,表明红树林间隙水的生物可利用性约为70%左右;经历11d的自然光照后,DOC下降至800μmol/L。木质素在光降解过程中的移除速率（-0.132d-1）远高于生物降解过程（-0.008d-1）。光培养中,木质素的下降速率高于总体DOC。不同系列溶解态木质素的下降速率不同,随着培养的进行,紫丁香基酚类（S）与香草基酚类（V）的比值（S/V）呈下降趋势,而V系列的酸醛比值（（Ad/Al）v）呈上升的趋势。对比光培养和暗培养过程中DOC和木质素的变化可以得出生物消耗是引起红树林间隙水DOC从水体中移除的主要因素;而光照则是陆源有机质从水体中移除的主要因素;光培养和暗培养过程中细菌变化的差异表明光照可以促进细菌对溶解态有机碳的利用。与其他地区比较发现,海南红树林间隙水的光降解速率与热带河流（刚果河）相近,高于温带密西西比河流,降解过程中各参数的变化[S/V和（Ad/Al）v]与其他区域接近。

英文摘要：

Terrestrial dissolved organic matter（DOM）exported from mangrove comprises an important fraction of terrestrial DOM in the ocean.The study of photo-and bio-degradation of mangrove DOM can help better understanding the fate of mangrove DOM and the role of mangrove DOM in the coastal biogeochemical cycle.Therefore,mangrove pore-water samples were collected in April 2010to perform the photo-and bio-degradation of mangrove DOM.Dissolved organic carbon（DOC）,density of bacteria and dissolved lignin phenols were measured in light（photo-degradation）and dark incubation（bio-degradation）,respectively.The results showed that after 128ddark incubation,DOC decreased from 2 216μmol/L to 718μmol/L,indicating that the bioavailability of mangrove pore-water DOC was approximately 70%;after 11days exposure to the natural sunlight,DOC decreased from 2216μmol/L to 800μmol/L.The degradation rates of lignin phenols were much higher in light incubation（0.132d-1）than dark incubation（-0.008d-1）.During the light incubation,the degradation rates of lignin phenols were higher than DOC.The rates of photo-degradation of lignin phenols were different among different lignin groups,with the increase of sunlight exposure,the ratio of syringyl（S）phenols to vanillyl（V）phenols decreased and the ratio of vanillic acid to vanillin（Ad/Al）v increased.The comparison of the variations of DOC and lignin phenols during photo-and bio-degradation suggested that microbial consumption was the major factor for the removal of mangrove DOC and photo-degradation was the major factor for the removal of terrestrial DOM in water column.The comparison of the variations of bacteria during photo-and bio-degradation implied that light can improve the utilization of DOC by bacteria.The degradation rate of lignin in mangrove forest was close to Congo River sample,but higher than that of Mississippi River samples.However,the trends of S/V and（Ad/Al）v were similar as other regions.