Tree species richness and soil organic carbon stock

Recently, the perspectives for the stronger persistence of soil organic
carbon (SOC) caused by the higher molecular diversity of organic compounds
were proposed. Therefore, the effects of tree species richness and
composition on the diversity of molecular components of SOC need to be
explored. In this study, we collected data on tree species diversity and
composition, SOC concentration, chemical composition, litter and fine root
properties, and examined the relationships between the richness,
composition and functional diversity of tree species, and the evenness of
SOC chemical compositions at a molecular level by 13C nuclear magnetic
resonance, across six natural forest types encompassing a diversity
gradient, ranging from cold temperate to tropical forests. Across the
range, tree species richness correlated to the evenness of SOC chemical
components through tree species composition. The negative correlation of
evenness of SOC chemical components with tree species composition and the
positive correlation of evenness of SOC chemical components with tree
functional diversity were found. The positive correlation of the evenness
of SOC chemical components with indicator tree species. These findings
suggest that the indicator tree species conservation might be preferable
to simply increasing tree species richness, for enhancing the potential
resistance of SOC to decomposition.