七星湿地土壤磷的时空分布特征研究

Temporal and Spatial Distribution Characteristics of Phosphorus in Soil of Qixing Wetland

目的研究七星湿地土壤磷的时空分布特征,掌握七星湿地土壤中磷质量分数的变化规律。方法在枯水期和丰水期分别对七星湿地的典型区域内进行取点采样,通过碱融钼锑抗比色法对土壤中的总磷进行测定,通过SMT分级分离方法对无机磷(IP)、有机磷(OP)、NaOH-P、HCl-P的质量分数进行分析,得到每份土壤样品中总磷的质量分数以及有机磷无机磷所占总磷的比例。结果湿地上游土壤中总磷的质量分数始终小于湿地下游。湿地土壤中总磷质量分数从湿地上游到下游逐渐减小。从土壤表层到深层总磷质量分数逐渐减小,随着土壤深度的增加总磷减小的速率会变慢。七星湿地土壤中以无机磷为主。在丰水期植物可以减少总磷的质量分数,而在枯水期植物的残体反倒会增加总磷的质量分数。结论湿地对土壤中的磷具有一定的净化作用,湿地中的植物对土壤中磷的时空分布具有比较明显的影响。

The temporal and spatial distribution characteristics of phosphorus in soil was studied to the variation law of phosphorus concentration in soil of Qixing Wetland.Soil samples were taken in the typical area of Qixing Wetland during the dry season and the wet season.The mass concentration of total phosphorus was determined by the alkali fusion molybdenum antimony colorimetric method.And the mass concentration of the inorganic phosphorus(IP),organic phosphorus(OP),NaOH-P,and HCl-P in the samples was analyzed by the SMT fractionation method.According the total mass concentration of phosphorus,the ratio of organic phosphorus and inorganic phosphorus to total phosphorus,the mass concentration of total phosphorus in the upper reaches of the wetland is always lower than that in the lower reaches of the wetland.The mass concentration of total phosphorus in wetland soil gradually decreases from the upstream to the downstream of the wetland and from the surface of the soil to the deep layer.And the decrease rate is slow down with the depth of the soil increase.The soil of Qixing Wetland is dominated by inorganic phosphorus.Plants can reduce the content of total phosphorus in the wet season,while plant residues in the dry season will increase the content of total phosphorus.Wetland has a certain purification effect on the phosphorus in the soil,and plants in the wetland have a relatively obvious impact on the temporal and spatial distribution of phosphorus in the soil.