黄河口潮滩盐沼沉积强度对碱蓬残体分解及氮动态的影响  

Effects of Sedimentation Intensity on Decomposition and Nitrogen Dynamics of Suaeda salsa Litters in Salt Marshes in Tidal Bank of the Yellow River Estuary

作　　者：孙志高[1,2] 牟晓杰[3] 王玲玲[2] 孙万龙[2] 孙文广[2,4] 

机构地区：[1]福建师范大学亚热带湿地研究中心、湿润亚热带生态一地理过程教育部重点实验室、福建师范大学地理科学学院,福建福州350007 [2]中国科学院海岸带烟台海岸带研究所,山东烟台264003 [3]中国科学院湿地生态与环境重点实验室、中国科学院东北地理与农业生态研究所,吉林长春130102 [4]中国科学院大学,北京100049

出　　处：《湿地科学》2015年第2期135-144,共10页Wetland Science

基　　金：国家自然科学基金项目(41371104,41171424)资助

摘　　要：2008年4月至2009年11月,基于野外原位分解实验,模拟研究了黄河口潮滩盐沼沉积强度对中潮滩碱蓬（Suaeda salsa）和低潮滩碱蓬残体分解及氮动态的可能影响。沿水盐梯度,设中潮滩和低潮滩2个分解小区,每个分解小区分别设无沉积（0 mm/a）、当前沉积增加（100 mm/a）和未来沉积增加（200 mm/a）3种固定沉积处理。结果表明,沉积强度对中潮滩和低潮滩碱蓬残体的分解具有一定影响,强沉积下残体的失重率和分解速率一般较高。当前或未来沉积增强后,二者残体的分解速率分别将增加138.10%~235.56%和8.89%~10.20%,95%分解时间分别将减少58.01%~70.24%和7.94%~9.13%。未来沉积增加处理下,中潮滩碱蓬残体的氮含量最大,其次为当前沉积增加处理下的氮含量,无沉积处理下的氮含量最小,3种处理下的氮含量无显著差异（p〉0.5）;低潮滩碱蓬残体在未来和当前沉积增加处理下的氮含量相当,无沉积处理下的氮含量最小,3种处理下的氮含量无显著差异（p〉0.5）。当前或未来沉积增强后,中潮滩碱蓬残体在分解阶段将大多表现为氮累积特征,而低潮滩碱蓬残体将一直表现为较强氮释放特征,C/N对二者残体分解过程中氮养分的调控作用更为重要。研究发现,当不同沉积强度下潮滩环境养分状况不发生较大变化时,中潮滩和低潮滩碱蓬残体的相对分解速率可能取决于其基质质量;当养分状况发生较大改变时,其相对分解速率可能取决于分解环境的养分供给状况。The potential effects of sedimentation intensity on decomposition and nitrogen dynamics of the Suaeda salsa litters in salt marshes in middle and low tidal banks in the Yellow River estuary were investigated by in situ experiment from April 2008 to November 2009. Two decomposition sub-zones were laid in intertidal zone along the water and salinity gradients. Three one-off sedimentation treatments（no sedimentation（0 mm/a）, current sedimentation（100 mm/a） and strong sedimentation（200 mm/a）） were designed in each decomposition sub-zone.The results showed that sedimentation intensity had great influences on the decomposition of the litters. High mass loss and decomposition rate were generally observed in the strong sedimentation treatment. If the sedimentation was enhanced, the decomposition rates of the litters in salt marshes in middle and low tidal banks would increase 138.10%-235.56% and 8.89%-10.20%, and the 95% decomposition time would decrease58.01%-70.24% and 7.94%-9.13%, respectively. Higher nitrogen contents of the litters in middle tidal bank were observed in strong sedimentation treatment compared to no sedimentation and current sedimentation treatments（p〉0.5）. Comparatively, the nitrogen contents of the litters in the low tidal bank with current and strong sedimentation treatments were approximate and higher than those in no sedimentation treatment（p〉0.5）. As the sedimentation was enhanced, the litters in the middle tidal bank would immobilize nitrogen from decomposition environment in most periods while the litters in low tidal bank would release more nitrogen to environment, which might be regulated by C/N ratios during decomposition. This study found that the relative decomposition rates, to a great extent, might depend on the substrate quality of the litters in the middle and low tidal banks if the nutrient status of decomposition environment did not change greatly. In reverse, if the nutrient status of environment varied significantly, the relative decomposition rates, to

关 键 词：残体分解 沉积 碱蓬盐沼 氮 黄河口 

分 类 号：X142[环境科学与工程—环境科学]