滇东南典型岩溶湿地沉积物不同形态磷分布特征

以滇东南普者黑岩溶湿地为研究对象,设置典型样地,采用典型样带布点方式,探索稻田湿地、草甸湿地和湖滨湿地区域中沉积物总磷(TP)和各形态磷(磷酸二钙,Ca₂-P;磷酸八钙,Ca₈-P;磷酸十钙,Ca₁₀-P;铝磷,Al-P;闭蓄态磷,O-P)含量分布特征,并分析各形态磷间的相关性。结果表明,稻田湿地、草甸湿地、湖滨湿地区域中沉积物总磷含量变化幅度较大,依次为稻田湿地>湖滨湿地>草甸湿地。沉积物各形态磷组分中,以Ca-P为主,且Ca-P中的Ca₁₀-P所占比例最高,对沉积物TP贡献最大。Ca₂-P、Ca₈-P、O-P、Ca₁₀-P的空间分布特征与TP一致。湖滨湿地区沉积物各形态磷含量垂直方向总体均以表层(0—5 cm)最高,并依次向下层递减。沉积物中各形态磷与TP含量均呈正相关,其中,Ca₂-P、Al-P与TP显著相关,对沉积物TP的影响较大。

Distribution characteristic of different phosphorus speciation in sediment of typical karst wetland located in southeast of Yunnan

In the present study, Puzhehei karst wetland, located in the southeast of Yunnan, was selected as the research area, and typical sample plots were also set to determine the contents of different speciation of phosphorus and the distribution characteristics of total phosphorus (TP) and different phosphorus speciation (Ca₂-P, Ca₈-P, Ca₁₀-P, Al-P and O-P) in the area of paddy wetland, meadow wetland and lakeside wetland, as well as the correlation analysis among phosphorus speciation. It was shown that the contents of total phosphorus exhibited large variations in the sediment of paddy wetland,meadow wetland and lakeside wetland, which followed the sequence of paddy wetland>lakeside wetland>meadow wetland. Ca-P was the main form of phosphorus speciation in sediments, and the Ca₁₀-P showed the highest proportion in Ca-P. The spatial distribution characteristics of Ca₂-P, Ca₈-P, O-P, Ca₁₀-P were consistent with that of TP. In the vertical direction, the distribution of each phosphorus speciation showed the highest concentrations in the surface layer (0-5 cm) of the sediments in lakeside wetland and decreased with the increasing depth. Each of the phosphorus speciation was positively correlated to TP in sediment, and Ca₂-P and Al-P were significantly correlated to TP.