Forest conversion strongly impacts soil microbial community (SMC) structure and microbial stoichiometry. Soil microbial stoichiometry plays an important role in the regulation of carbon (C) and nutrient (e.g., nitrogen (N) and phosphorus (P) ) cycling, and it is closely linked to SMC structure. However, how SMC structure and stoichiometry respond to long-term forest conversion is still unclear.  

By constructing a long-term (36 years) forest conversion scenario in subtropical region of China, researchers from the Wuhan Botanical Garden of the Chinese Academy of Sciences have examined dynamics of soil microbial C: N: P stoichiometry and SMC structure and their relationships at three soil depths (0-10, 10-30, and 30-60 cm).    

The researchers found that over more than three decades after forest conversion, soil microbial C: N: P stoichiometry was strongly or strictly homeostasis based on dissolved organic resources, regardless of soil depth. Soil microbial stoichiometry was decoupled from SMC Structure at each depth.    

Moreover, SMC structure could be jointly regulated by available resources (quality or quantity) and environment (i.e., microclimate in surface soils), showing few signs of nutrient limitation on the SMC structure.    

This research reveals that carbon dynamics in forests tend to reach resilience or re-equilibrium after the forest conversion, emphasizing the importance of reforested plantations of forest management for sustaining soil carbon over a long term. 

This work, supported by the Natural Science Foundation of China, has been published in Environmental Science and Pollution Research entitled "Soil microbial stoichiometry and community structure responses to long-term natural forest conversion to plantations in a subtropical region". 

   RDA of soil microbial groups and environmental factors across forests at (a) 0-10, (b) 10-30 and (c) 30-60 cm depths. (Image by WBG)