Alkaline phosphatase activity in ornithogenic soils in polar tundra

摘要

Phosphatase plays an important role in the microbial liberation of phosphorus in soil systems.In this study,alkaline phosphatase activity (APA) was investigated from tundra ornithogenic soil profiles in Antarctica and Arctic.The organic carbon (TOC),total nitrogen (TN),and phosphorus fractions and pH were also analyzed in these soils.The correlation between APA and soil chemical properties is discussed.In almost all the soil profiles,APA showed the same variation patterns.The maximum APA appeared in the surface layers,and decreased with soil depth.The APA ranged from 1.00 ppm to 1 403.5 ppm with an average of approximately 408.3 ppm.The APA showed a significant positive correlation with TOC (r =0.70,p <0.001),TN (r =0.43,p =0.002),total phosphorus (r =0.39,p <0.05)and inorganic phosphorus (r =0.40,p =0.037),indicating that they were predominant factors affecting APA in the polar tundra soils.In addition,APA showed a significant negative correlation with Cu and Zn concentrations in the soils,indicating that Cu and Zn may inhibit APA.Our results showed that APA could be used as an important indicator for soil fertility in polar tundra ecosystems.