洱海缓冲带典型入湖溪流沉积物磷形态的分布特征

Distribution Characteristics of Phosphorus Forms in Typical Inflow Rivers in Buffer Zones of Erhai Lake

[目的]了解洱海缓冲带典型入湖河流沉积物磷形态分布特征,为洱海生态系统修复提供科学依据。[方法]对洱海缓冲带3条典型入湖溪流茫涌溪、莫残溪、中和溪进行了沉积物的采集,并对其中总磷(TP)、无机磷(IP)、铁铝磷(Fe/Al-P)、钙磷(Ca-P)4种磷形态的含量进行测定。[结果]3条溪流沉积物磷形态沿程变化趋势大不相同;洱海的缓冲带结构缺乏合理性,有待改进;土地的利用类型不同对洱海缓冲带入湖河流沉积物磷形态贡献率也就不同;入湖口沉积物磷形态含量从大到小均依次为:中和溪>莫残溪>茫涌溪;从磷形态组成来看,茫涌溪沉积物中的磷主要为Ca-P,莫残溪、中和溪则均以Fe/Al-P为主;磷形态的相关性分析表明,3条溪沉积物中TP含量的变化与Fe/Al-P,及有机磷(OP)呈极显著正相关。[结论]沉积物中OP的变化对Ca-P,Fe/Al-P的含量有一定影响。Fe/Al-P含量对IP含量有较高的贡献率。Fe/Al-P与Ca-P之间相关性较弱。

[Objective]Analyzing the distribution characteristics of phosphorus forms in typical inflow rivers in buffer zones of Erhai lake in order to provide the basis for ecosystem restoration in Erhai lake.[Methods]The sediment samples were collected in Zhonghe river,Mocan river and Mangyong river in the buffer zone of Erhai lake.Four different phosphorus forms,including total phosphorus（TP）,inorganic phosphorus（IP）,Fe/Al-P and Ca-P in the sediments were measured.[Results]The contribution rate of different land-use types was different with the various phosphorous forms.The variation trend of the phosphorous forms in three rivers was different along the way.The structure of the buffer zone in Erhai lake was not reasonable,and need to be improved.The content of phosphorus forms in estuary sediment was as follows（in a descending order）：Zhonghe riverMocan riverMangyong river.The phosphorus in Zhonghe and Mocan rivers was mainly Fe/Al-P,while it was mainly Ca-P in Mangyong river.There was a significant positive correlation between the change of TP in sediments and the Fe/Al-P,OP（organic phosphorous）.[Conclusion]The change of OP in sediments influenced the content of Ca-P,Fe/Al-P.The content of Fe/Al-P had a great contribution to the content of IP.The correlation between Fe/Al-P and Ca-P was not significant.