芦苇与土壤间氮磷化学计量的灰色关联分析

多数水生植物对于湿地土壤中氮磷元素的固持起着至关重要的作用。为了明晰芦苇与土壤间氮磷元素的关系,笔者利用灰色关联分析方法,对溱湖湿地芦苇各器官氮磷含量、季节动态及其与各土层氮磷含量之间的关联度进行了研究。结果表明:①芦苇各器官氮磷元素含量规律基本相同,即总氮含量叶>穗>根>茎,总磷含量叶>根>穗>茎; ②由于芦苇根系的垂直分布特征,溱湖湿地芦苇与土壤氮磷元素交互关联主要集中在0～30 cm土层,说明土壤-植被系统固持水体营养元素过程主要集中在表层土壤中; ③植物生长相对旺盛的春、夏季,土壤-植被系统氮磷元素交互作用主要出现在土壤表层,同时由于地下水位上升,≥45～60 cm土层也会对芦苇氮磷含量产生重要影响。
Many aquatic plants play an important role in the immobilization of nitrogen and phosphorus in the wetland soil. Gray correlation analysis was conducted in this study to clarify the relationship of nitrogen and phosphorus contents between the organs of Phragmites australis(common reed)and soil in different depth in Qinhu Lake wetland. The results show that: ①The distribution pattern of nitrogen and phosphorus in the organs of common reed were the same: the total nitrogen contents were with the order of leaf >spike>root > stem and the total phosphorus contents were with the order of leaf > root >spike> stem. ②The interaction of nitrogen and phosphorus between common reed and soil mainly concentrated in the 0-30 cm soil layer due to the vertical distribution of reed roots. It indicated that the fixation of nitrogen and phosphorus in the soil-vegetation system concentrated in the surface of soil. ③In the growth period(spring and summer), the interaction of nitrogen and phosphorus in soil-vegetation system primarily occurred in the soil surface. At the same time, a close association of nitrogen and phosphorus contents between ≥45-60 cm depth of soil and the common reed was observed in this study which may be caused by the rising of underground water level