Effects of simulated acid rain on soil respiration and microbial community in a Moso bamboo forest in subtropical China

Abstract

Moso bamboo forest as one of the most important forest types in Southern part of China is always subject to the widespread acid rain. The objectives of this study are to evaluate the effects of acid rain on soil respiration and soil microbial community structure of Moso bamboo forest. Compared with simulated acid rain treatment at pH 6.4, Rs ratios of the treatments at pH 4, 3 and 2 were decreased by 11.4%, 17.5% and 21.1%, respectively, while Rh ratios of the treatments at pH 4, 3 and 2 were decreased by 15.6%, 9.5% and 8.4%, respectively. The results showed that acidic environment had great negative effects on Rs and Rh ratios. PCR-DGGE analysis showed that there were great shifts in bacterial community structure among the different simulated acid rain treatments, the absence of Caulobacter, Cystobacteraceae, Bradyrhizobium and Candida would inhibit the degradation of soil organic mattersand liberation of soil CO2, thereby aggravatingthe Rhrestriction. Additionally, simulated acid rain treatments at different pH had little effects on the types of fungal community. The existence of these fungus, such as Cephaliophora, Carnobacterium, Propionibacterium, Mortierella, Pseudallescheria and Zygorhynchus played a primary role in the decomposition of soil organic matters and Rs metabolism.