tropical forest soil microbial community in China

Between 30% and 50% of the carbon (C) respired from tropical forests originates from soil, most of which is derived from the decomposition of organic matter. Subsoils contain more than half of the global soil organic C stocks, which have much slower turnover compared to the soil organic C in topsoil. Because of very slow process rates, the temperature sensitivity (Q₁₀) of subsoil organic C decomposition to rainfall changes is nearly unknown. Therefore, we investigated the responses of Q₁₀, soil organic acids, microbial communities and necromass of tropical forest soil to a delayed and wetter rain season in a 10-year manipulation experiment. Microbial respiration absence of differences in response to shifts in rainfall patterns. The delayed rain season did not affect Q₁₀, soil organic acids, bacterial and fungal communities and microbial necromass in 0–70 cm soil layers. Wetter rain season significantly increased the Q₁₀, which mainly due to wetter rain season increased C inputs and resulted in nitrogen limitation, and subsequently contribute to the decomposition of subsoil organic C. The concentrations of acetic acid and the relative abundance of Glomeromycota in 30-50 and 50–70 cm soil layers. Q₁₀ was positively associated with acetic acid and the relative abundance of Glomeromycota, and was negatively associated with bacterial necromass/soil organic C. Rare Glomeromycota taxa was the best microbial predictor in predicting the response of Q₁₀ to rainfall changes in tropical forests. Thus, our study suggested that rising temperature may trigger deep soil C loss from tropical forests under rainfall changes.