三江平原毛苔草沼泽和小叶章沼泽化草甸湿地水体中可溶性铁的分布特征  

Distribution of Water-soluble Ionic Iron of Deyeuxia angustifolia Marsh and Carex lasiocarpa Marsh in the Sanjiang Plain

作　　者：潘月鹏[1] 阎百兴[1] 张凤英[1] 徐治国[1] 

机构地区：[1]中国科学院东北地理与农业生态研究所

出　　处：《湿地科学》2007年第1期89-96,共8页Wetland Science

基　　金：国家重点基础研究发展计划(973)项目(2004CB418502);中日合作项目(三江平原铁的生物地球化学作用研究)资助

摘　　要：2006年5月至10月期间,对三江平原典型的毛苔草(Carex lasiocarpa)沼泽和小叶章(Calamagrostis angustifolia)沼泽化草甸湿地表层积水中可溶性铁(Fe2+,Fe3+)含量进行了现场采样和测试分析,同步测定了水体氧化还原电位(Eh)、电导率(EC)、pH值等指标。结果表明,除8月份的几次观测外,生长季内小叶章沼泽化草甸湿地水体中可溶性铁含量明显高于毛苔草沼泽湿地;两种湿地水体中可溶性铁存在的主要形态为Fe3+,且Fe2+与Fe3+含量之间呈显著正相关;受水温和降水的影响,湿地水体中可溶性铁含量具有明显的季节性差异,其中小叶章沼泽化草甸湿地水体中的可溶性铁含量呈单峰型季节变化,而其在毛苔草沼泽湿地水体中呈双峰型季节变化。统计分析表明,Fe2+含量与水体的Eh值具有负相关关系,Fe3+含量与水体的Eh值的相关性较小,而且其含量并未随着还原性Fe2+的增加而减少;pH值对沼泽湿地水体中铁的形态分布无显著影响;Fe2+含量与EC值相关性显著。The importance of iron as a limiting micronutrient for primary productivity in the world ocean, especially in the HNLC （ High Nitrate Low Chlorophyll） regions, has become increasing clear following large - scale in - situ iron enrichment experiments and also been proved by natural observation after the aerosol dust deposition on the ocean. In recent years, the shortage of dissolved iron was considered to be one of the main factors limiting the primary productivity in the Okhotsk Sea and the northern North Pacific, while the changes of land use patterns nearby affect the iron input of these waters. Marsh wetlands was one of the major possible sources of dissolved iron and played an important role in the dissolved iron output from terrestrial ecosystems to rivers, however, the mean annual decrement area of wetland in the Sanjiang Plain in Heilongjiang province of Northeast China were 86 × 10^3 hm^2 in the past 50 years, this maybe had been resulted in a marked decrease of dissolved iron output. In order to approach the dissolved iron species and their dynamics in the natural wetland, and estimate the contribution of wetland dissolved iron output to the nearby rivers, 2 typical natural fresh marsh wetlands without human activity disturbance were selected in the Sanjiang Experimental Station of Wetland Ecology, CAS. The concentration of ferrous iron（ Fe^2＋ ） and ferric iron（ Fe^3＋ ） ,as well as environmental factors such as redox potential （Eh） , electrical conductivity （ EC ） and water temperature （T） in the logging water of the above 2 typical fresh marshes were determined based on the in -situ sampling method and analyses technique from May to October in 2006, and the relationship of Eh, EC and Fe^2 ＋ , Fe^3＋ were also studied. Affected by the iron content both in the marsh soil and plants covered, the total concentration of water - soluble ionic iron in the gustifolia marsh waters ranged from 1.20 mg/L to 7.30 mg/L, which was higher than that in the Carex lasiocarpa （0.24 mg/L

关 键 词：可溶性铁 分布特征 淡水沼泽 三江平原 影响因素 

分 类 号：X144[环境科学与工程—环境科学]