Effects of elevated atmospheric CO2 on rhizosphere microbial community of Pinus densiflora (Korean red pine)

Abstract The concentration of atmospheric CO2 is increasing largely owing to human activities. Although it is well established that elevated CO2 (eCO2) stimulates plant growth and primary productivity, the effect of eCO2 on soil microbial communities remains poorly understood. In this study, we aimed to examine the effects of eCO2 on the taxonomical diversity, composition, and structure of rhizosphere microbial communities of Korean red pine (Pinus densiflora) through next-generation sequencing (NGS) of 16S rRNA genes. Three bacterial phyla, Proteobacteria, Acidobacteria, and Actinobacteria, were found to be dominant in all samples. Species richness estimates (Chao1 and ACE) and diversity indices (Shannon and Simpson) for the three sampling chambers were the highest from the eCO2 (approximately 1.4× ambient, ≈ 560 ppm). These findings suggested that elevated atmospheric CO2 affected the bacterial community composition in the rhizosphere of Korean red pine (Pinus densiflora).