Analysis of spatiotemporal variations in the characteristics of soil microbial communities in Castanopsis fargesii forests

Abstract

Castanopsis fargesii is a good afforestation plants and various microorganisms play important roles in mediating the growth and ecological functions of this species. In this study, we evaluated changes in microbial communities in soil samples from C. fargesii forests. The phospholipid fatty acid (PLFA) biomarker method was used to obtain bacteria, fungi, actinomycetes, gram-positive bacteria (G+), gram-negative bacteria (G−), aerobic bacteria, and anaerobic bacteria to investigate spatiotemporal changes in microbial communities during the growing season. The results show that soil microorganisms were mainly concentrated in the upper 20-cm layer, demonstrating an obvious surface aggregation ( P \u2009<\u20090.05). Large amounts of litter and heavy rainfall during the early growing season resulted in the highest PLFA contents for various microorganisms, whereas relatively low and stable levels were observed during other times. The dominant species during each period were bacteria. G+ or aerobic bacteria were the main bacterial populations, providing insights into the overall trends of soil bacterial PLFA contents. Due to the relative accumulation of refractory substances during the later stages of litter decomposition, the effects of fungi increased significantly. Overall, our findings demonstrate that the main factors influencing microbial communities were litter, rainfall, and soil field capacity.