Background: Accompanying its rapid economic development and population growth, China is the world's third
largest acid rain region, following Europe and North America. The effects of acid rain on forest ecosystem were
widely researched, including the growth, the nutrient of the leaf and soil, and so on. However, there are few
reports about the effects of acid rain on the soil microbial diversity. This study investigated the effects of acid
rain on soil microbial community function under potted Masson pine seedlings (
Pinus massoniana
Lamb).
Results: After 7 months of treatment with simulated acid rain, the low acid load treatment (pH 5.5) stimulated
soil microbial activity, and increased soil microbial diversity and richness, while the higher levels of acid
application (pH 4.5, pH 3.5) resulted in lower soil microbial activity and had no significant effects on soil
microbial diversity and richness. Principal component analysis showed that there was clear discrimination in
themetabolic capability of the soilmicrobial community among the simulated acid rain and control treatments.
Conclusion: The results obtained indicated that the higher acid load decreased the soil microbial activity and no
effects on soil microbial diversity assessed by Biolog of potted Masson pine seedlings. Simulated acid rain also
changed the metabolic capability of the soil microbial community.
