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.

Effects of community structure of sprouting forests with different densities on ecosystem carbon density at the early stage of succession.

To explore potential responses of ecosystem carbon density to changes of community structure during natural regeneration of woody plants, we analyzed the relationships between ecosystem carbon density and its components, tree species diversity, structural diversity (CV) and spatial structure parameters (mingling, aggregation, dominance, crowding) of forests with different sprouting densities (1154, 847 and 465 individuals·hm) at the early stage of succession in Baishanzu National Park. The results showed that tree species diversity (species richness index and Shannon diversity index) increased with the decrease of sprouting density of . Among the stand structural parameters, CV, stand density, and mingling increased with the decrease of sprouting density of .