Characteristics of soil nitrogen and phosphorus fractions and microbial traits with increasing stand age in two-layered + plantations.

Soil nitrogen and phosphorus are two key elements limiting tree growth in subtropical areas. Understanding the regulation of soil microorganisms on nitrogen and phosphorus nutrition is beneficial to reveal maintenance mechanism of soil fertility in plantations. We analyzed the characteristics of soil nitrogen and phosphorus fractions, soil microbial community composition and function, and their relationship across three stands of two-layered + with different ages (4, 7 and 11 a) and the pure plantation.