鹭鸟栖息对杭州湾湿地土壤磷累积及形态分布的影响

Impact of egrets habitation on accumulation and distribution of various forms of phosphorus in soils of Hangzhou Bay wetland

土壤中磷含量对维持生态系统平衡起着重要作用。为研究杭州湾湿地迁徙候鸟栖息以及鸟粪的输入对栖息地土壤生态环境的影响,开展了鹭鸟筑巢树林下(影响区)和无鹭鸟筑巢树林下(对照区)土壤磷累积、土壤及鸟粪磷形态分布研究。结果表明:鹭鸟影响区土壤有机碳(Soil Organic Carbon, SOC)、全氮(Total Nitrogen, TN)、全磷(Total Phosphorus, TP)、有效磷(Available Phosphorus, AP)含量显著高于对照区(P<0.05);对照区土壤TP含量为718.33 mg/kg,影响区土壤TP平均含量最高可达2040 mg/kg,其中钙结合态磷(Ca-bound P, Ca-P)含量最高,约占55.22%-62.96%,其次是残渣态磷(Residual Phosphorus, RP)、有机磷(Organic Phosphorus, OP)、铁铝结合态磷(Fe/Al-bound P,(Al+Fe)-P)、交换态磷(Exchangeable P,Exch-P)。鸟粪中有机碳(Organic Carbon, OC)、TN、TP含量分别是表层土壤的11.18-40.90倍,94.22-148.11倍,15.41-43.22倍,差异极显著(P<0.01)。TP含量与Exch-P、(Fe+Al)-P、Ca-P、AP极显著正相关,与RP显著正相关,与pH显著负相关。结果表明鸟粪输入使杭州湾湿地土壤TP含量显著提高,Exch-P、(Fe+Al)-P、Ca-P、AP含量均有提高,且占TP百分比增大,鸟粪输入造成了该地土壤磷素累积的同时增加了土壤磷素的流失风险。

The content of phosphorus in soil plays an important role in maintaining the balance of the ecosystem. In order to study the impact of migratory birds inhabiting and dropping guano on the soil ecological environment in Hangzhou Bay wetland, the research of phosphorus accumulation and distribution of various forms of phosphorus in soil and guano was carried out in the area with or without egrets inhabiting(affected area and controlled area). The results showed that the content of Soil Organic Carbon(SOC), Total Nitrogen(TN), Total Phosphorus(TP) and Available Phosphorus(AP) in the egrets effecting area was significantly higher than that in the controlled area(P<0.05). The soil TP content in the controlled area was 718.33 mg/kg, which was up to 2040 mg/kg in the affected area. The content of Ca-bound P(Ca-P) rank first among all these forms of phosphorus, accounting for about 55.22%-62.96%, followed by Residual Phosphorus(RP), Organic Phosphorus(OP), Fe/Al-bound P((Fe+Al)-P) and Exchangeable P(Exch-P). The contents of Organic Carbon(OC), TN, and TP in guano were 11.18-40.90 times, 94.22-148.11 times and 15.41-43.22 times of the soil, showing significant difference(P<0.01). TP content showed extremely significantly positive correlations with Exch-P,(Fe+Al)-P, Ca-P, AP, significantly positively correlated with RP, while significantly negatively correlated with pH. Generally, the content of TP in soil of Hangzhou Bay wetland was significantly increased due to guano input. The content of Exch-P,(Fe+Al)-P, Ca-P and AP were all increased, so as the percentages of them did in TP. Input of guano caused the accumulation of phosphorus in the soil which increased the risk of phosphorus loss from the soil, as well.