生态环境学报Issue(6)：924-930,7.
红树植物凋落叶分解对土壤可溶性有机质的影响
Effect of mangrove leaf litter decomposition on soil dissolved organic matter
摘要
Abstract
Understanding the sources, properties and fates of dissolved organic matter (DOM) in mangrove wetland soils is of signif-icance to reveal the role of DOM in biogeochemical cycles in mangrove wetlands. A 48-day soil incubation experiment was con-ducted with addition of nearly-senesced leaves of mangrove plants (Bruguiera gymnorrhiza, Kandelia candel and Aegiceras cornic-ulatum) to investigate soil DOM changes during mangrove leaf litter decomposition. Soil samples were collected after 6, 12, 18, 26, 36 and 48 days of incubation, and the concentrations of dissolved organic carbon (DOC) and total dissolved nitrogen (TDN), C:N ratio (DOC:TDN) and spectrophotometric absorbance (A280, A240/A420 and A250/A365 ratios) in soil solutions were analyzed. Results show that DOC concentrations in soil solutions were significantly increased by the addition of mangrove leaf litters, and reached the maximum after 6 days with an average increase of between 149%(K. candel) and 196%(A. corniculatum) compared with the control treatment without litter addition, followed by a decrease trend during later incubation periods, while those of control treatment re-mained fairly steady after a drop by day 6. Only slight change was observed for TDN content after input of leaf litter, while the C∶N ratios of soil solutions were significantly higher than those of control treatment (P<0.05) during the early decay of B. gymnorrhiza or A. corniculatum leaf litter. The spectrophotometric absorbances of soil solutions were also influenced by litter addition with an in-crease in A280 value and decrease in A240/A420 or A250/A365 ratio, noticeably for A. corniculatum leaf litter treatment but minimally for K. candel leaf litter treatment after 6-day incubation. These results suggested that litter input and decomposition strongly influenced contents and properties of DOM in soil, especially during the initial decomposition stage, resulting in enhancement of high-er-molecular components and aromatic compounds, and a decline in bioavailability of DOM. However, difference of DOM contents among litter treatments shrinked with further litter decay, and the properties of DOM became chemically similar to those of control treatment at the end of incubation.关键词
红树植物/凋落物/分解/可溶性有机质/土壤Key words
mangrove plant/litter/decomposition/dissolved organic matter/soil分类
农业科技引用本文复制引用
杨秀虹,彭琳婧,李适宇,王诗忠..红树植物凋落叶分解对土壤可溶性有机质的影响[J].生态环境学报,2013,(6):924-930,7.基金项目
国家高技术研究发展计划(863)海洋技术领域重点项目（2007AA091703）；国家自然科学基金项目（41001322）；中央高校基本科研业务费专项资金项目 （863）
