极区鸟粪土中磷酸酶活性变化特征及其影响因素

VARIATIONS OF PHOSPHATASE ACTIVITY IN THE SOILS IMPACTED BY SEABIRD GUANO AND ITS AFFECTING FACTORS

磷酸酶在土壤生物释磷过程中起着重要作用。本文以极地苔原鸟粪土为研究对象,测定了不同环境条件下土壤剖面中碱性磷酸酶(APA)的活力,研究了APA在土壤中随深度的变化规律,并同步测定了相应土壤中有机碳、总氮、各形态磷、pH,分析了酶活力与这些因子的相关性。结果表明:同一采样点土壤剖面中碱性磷酸酶活力大小呈现一定规律性,最大值出现在表层,且随采样深度的增加而递减,变化范围为1.00—1403.49ppm,平均约为408.31ppm。碱性磷酸酶活性与土壤中有机碳含量(r=0.70,p<0.01)、氮含量(r=0.43,p<0.01)呈显著正相关性,表明土壤中碳、氮等有机物含量是影响极地苔原土壤磷酸酶活力的主要因素。另外,碱性磷酸酶活性与总磷(r=0.39,p<0.05)、无机磷(r=0.40,p<0.05)和有机磷(r=0.11,p=0.67)含量也呈正相关性,表明各形态磷在一定程度上也影响着土壤中碱性磷酸酶活力;与土壤中铜含量(r=-0.38,p<0.05)和锌含量(r=-0.28,p=0.05)呈显著负相关,表明土壤中Cu、Zn等金属离子对极地苔原土壤磷酸酶活力具有抑制和破坏作用。结果证实土壤磷酸酶活性可作为指示极地土壤肥力的一个重要指标。

Phosphatase plays an important role in microbial liberation of phosphorus in the soil systems. In this paper,the tundra ornithogenic soils were used to study the variations of the alkaline phosphatase activity （ APA） with depths. Simultaneously,the organic carbon,total nitrogen,phosphorus,pH in the soils were also analyzed in these soils. The correlation between APA and soil chemical properties was discussed. In almost all soil profiles,the variations of APA showed the same patterns,the maximum appeared in the surface soils,and APA decreased with the soil depth. The APA ranged from 1. 00 ppm to 1403. 49 ppm with the average of about 408. 31 ppm. APA showed a significant positive correlation with soil organic carbon （ r = 0. 70,p 0. 01） and nitrogen content （ r = 0. 43,p 0. 01） ,indicating that soil carbon and nitrogen contents were predominant factors affecting APA in polar soils. In addition,APA also positively correlated with inorganic phosphorus （ r = 0. 40,p 0. 05） ,organic phosphorus and total phosphorus（ r = 0. 39,p 0. 05） ,suggesting that various forms of phosphorus,to some extent,affect APA in the soil systems. APA showed a significant negative correlation with Cu and Zn contents in the soils,indicating that Cu and Zn might inhibit APA in the polar soils. Our results showed that APA can be used as an important indicator of soil fertility in polar regions.