三江平原湿地小叶章各器官主要营养元素特征

Characteristics of Concentrations of Main Nutrient Elements of Calamagrostis angustifolia in Wetlands in Sanjiang Plain

选择生长在三江平原湿草甸和沼泽化草甸上的小叶章(Calamagrostis angustifolia)为研究对象,在2004～2008年小叶章生长季,测定了其根、茎、叶和叶鞘内的有机碳含量、全氮含量、全磷含量和全硫含量,研究了小叶章体内营养元素含量特征及其生长限制元素。结果表明,在两种类型湿地上生长的小叶章,其体内各器官的有机碳含量、全氮含量、全磷含量和全硫含量都存在差异;两种类型湿地的小叶章地上部分各器官中,全氮含量、全磷含量和全硫含量都是在叶中最大,其次为叶鞘、茎;湿草甸小叶章根营养元素含量明显低于其地上部分各器官,而沼泽化草甸小叶章则相反;两种类型湿地上的小叶章地上部分器官中的各营养元素含量之间多存在显著相关关系,而根中各元素含量之间几乎不相关;氮是限制小叶章生长发育的最主要的营养元素;湿草甸小叶章相对更易受到硫元素的限制。

Calamagrostis angustifolia was the dominant species in the wet meadow and marshy meadow in the Sanjiang Plain.In this paper,the concentrations of organic carbon,total nitrogen,total phosphorus and total sulphur in tissues of the plant were measured during the growing season from 2004 to 2008 for understanding of the limiting factor for the growth of the plant in two types of wetlands.The results showed that for the above ground tissues of Calamagrostis angustifolia,the maximum concentrations of total nitrogen,total phosphorus and total sulphur both occurred in leaf,the next was in vagina,and the minimum in stem.The concentrations of organic carbon,total nitrogen,total phosphorus and total sulphur in root of the plant in the wet meadow were lower than those of above ground tissues,In contrast,their concentrations in root in marshy meadow were higher than those of above ground tissues because the marshy meadow is seasonal water-logging, while the wet meadow is relatively dry.There were significant correlations between concentrations of nutrient elements in the tissues,especially in the vagina,the correlations were significant at the 0.05 level or even at the 0.01 level.The N：P in root,stem,leaf and vagina of the plant in the wet meadow were 5.9,3.0, 11.7 and 5.6,respectively,and the N：P for tissues of the plant in marsh meadow were 5.5,3.1,13.3 and 6.1, respectively.Nitrogen was the most limiting element for the growth of Calamagrostis angustifolia in two types of wetlands.