Greater impacts of phosphorus fertilization on soil phosphatase activity in tropical forests than in non-tropical natural terrestrial ecosystems: A meta-analysis

Abstract

In phosphorus (P)-poor tropical forests, soil microorganisms are hypothesized to depend on organic P sources more intensively than in other natural terrestrial ecosystems. I tested this hypothesis by conducting a meta-analysis to compare soil phosphatase activity responses to experimental P fertilization between tropical forests and other natural terrestrial ecosystems. I found that P fertilization significantly reduced soil phosphatase activity in tropical forests, and to a significantly greater extent than in non-tropical natural terrestrial ecosystems including temperate forests, supporting the above hypothesis. I suggest three potential mechanisms for this result. First, inorganic P supply may be lower in tropical forests; however, this mechanism is less likely because inorganic P input into tropical forests soils via biological processes is not necessarily small. Second, the strong P adsorption capacity of tropical soils may substantially reduce inorganic P availability, thereby enhancing microbial organic P dependence. Third, higher P demand due to higher biological productivity in tropical forests may intensify microbial organic P dependence.