九段沙中沙湿地植物磷元素的分布积累与动态

Distribution,Accumulation and Development of Element P in Middle Shoal Plants of Jiuduansha Wetlands

对九段沙中沙湿地海三棱草、互花米草和芦苇3种典型湿地植物群落的植物各构件中磷(P)的分布、积累与动态进行研究.结果表明,3种湿地植物中磷含量存在很大差异,其大小排序为:海三棱草>芦苇>互花米草.磷在不同植物相同构件中的含量分布亦不同.3种湿地植物磷含量的季节动态规律有相似性,即随植物生长发育进程磷含量呈现逐渐降低的趋势,其中,茎秆中磷含量下降幅度最大,根中磷含量下降幅度最小.3种湿地植物磷含量的动态变化也存在差异,海三棱草各构件磷含量波动次数较少,互花米草和芦苇各构件磷含量波动次数则较多.植物中磷含量变化与土壤和地表水中相应元素含量变化密切相关.3种湿地植物均显示生长初期植物与土壤和地表水中磷含量的关联较小,3种植物最大关联出现的时间存在差异,这表明不同植物吸收土壤与地表水中磷元素的最佳时期存在差别.

This paper presents a reach on the distribution, accumulation and development of P in all components of three kinds of wetland plants, scirpus mariqueter, spartina alterniflora and phragmites australis in the middle shoal of the Yangtse River. The results show that P contents are different in three kinds of plants, and their content order from high to low is as follows： scirpus mariqueter 〉 phragmites australis〉spartina alterniflora. P contents are different even in the same components. However, the three kinds of plants share a similar seasonal development trend of P content： P content decreases gradually with the growing of plants, and the loss of P is the greatest in the stalk, but the least in the root. P contents change slightly in the components of scirpus mariqueter, but change a lot in spartina alterniflora and phragmites australis. The change of P content in the plant is closely related with the variation of different element content in the soil and water, and in the early growing stage related little with P content of soil and water. The closest correlation appears at different time for thesethree different plants, which indicates the plants absorb element P at different optimum time.