Responses of soil bacterial compositions to concentrations of nitrogen forms in the process of Moso bamboo invasion

Abstract

We analyzed and compared the soil bacterial diversity and difference in community composition in a Moso bamboo forest, a mixed Moso bamboo–conifer (Pinus massoniana) forest, and a coniferous forest. The relative abundances of Acidobacteria and Planctomycetes were significantly lower in the Moso bamboo forest, while those of Actinobacteria, Bacteroidetes, TM‐7 and Chlamydiae were greatly increased. The α‐diversity in the Moso bamboo forest was different from that in the other two forest types but was not statistically distinguished. Principal coordinates analysis suggested that the invasion of Moso bamboo affected the community composition and diversity of soil bacteria. This impact was associated with the soil biochemical environment, as evidenced by increased mean values of soil organic carbon (C) and total nitrogen (N), significant increases in microbial biomass C and N, and a decrease in the NO3−–N content, which indicated that the nitrification rate was reduced in the mixed Moso bamboo–conifer forest. There were no overall correlations between the dominant bacterial phyla and soil biochemical gradients; however, individual dominant phyla correlated with the concentration of N forms, which indicated that the responses of bacteria were sensitive to, and varied depending on, the concentration of soil N forms. In addition, there were correlations between non‐dominant bacterial phyla with respect to operational taxonomic unit proportions <1.0%, and overall gradients of water‐soluble organic N and NO3−–N. The results of this study showed that the changes in soil bacterial flora are associated with the changes in concentration of N forms during the invasion of Moso bamboo.

Ecostoichiometry Reveals the Separation of Microbial Adaptation Strategies in a Bamboo Forest in an Urban Wetland under Simulated Nitrogen Deposition

“…In our experiment, ammonia N decreased, and nitrate N increased, which was similar to the research results of short-term N input by Hall and Matson [46], indicating that the net nitrification rate gradually increased with increasing N addition dose [47]. In general, the moso bamboo forest was short of N, especially with respect to the natural growth status, i.e., 20 years in our study, which is related to its preference for ammonium-N and strong clonal breeding habits [48]. Therefore, N deposition in moso bamboo forests can alleviate the degradation of ecosystems caused by N deficiency to a certain extent.…”

“…After SND, F:B decreased due to the decline in C:N, mainly because K-strategy fungi had higher biomass C:N than bacteria [3]. Li et al [48] suggested that N deposition can increase the soil MBC content, thus increasing MBC:MBN and reducing competition between plants and microorganisms [58]. Our results showed some differences from those conclusions, as they indicated that MBC decreased while MBC:MBN changed little.…”

Soil Nutrient, Salinity, and Alkalinity Responses of Dendrocalamopsis oldhami in High-Latitude Greenhouses Depending on Planting Year and Nitrogen Application

“…Bamboo is regarded as an invasive species because of its strong reproductive ability, rapid growth rate, and intertwined underground rhizome roots, which intertwine with each other. Following the introduction of bamboo, the soil ecology of mixed forests can easily change, including soil pH, biodiversity, enzyme activity, and nutrient composition [30][31][32][33][34][35]. Bamboo is not a halophyte; however, there are reports of its planting on saline-alkali land, and it is believed that bamboo plants have some saline-alkali tolerance.…”