The beneficial and pathogenic flora, environmental drivers, and community assembly mechanism of perennial poplar plantation

Soil microorganisms play a crucial role in promoting growth and development, nutrient absorption, and disease resistance in poplar plantations. Long-term planting decays soil nutrient contents and changes the microfloral structure, and pathogenic microorganisms accumulate. It is of great significance to clarify the distribution and synergistic relationships between beneficial and pathogenic microorganisms in plantation soil for solving the long-term planting obstacles of poplar plantation. High-throughput sequencing, culture, pure bacterial identification, functional verification, and bioinformatics methods were used to explore the population and functional characteristics of the soil microorganisms in the perennial poplar forest, identify the main pathogenic and beneficial microorganisms in the soil, and investigate the synergistic relationships among the microorganisms in the system. An evaluation of soil from a perennial poplar plantation revealed the presence of many beneficial microbes, such as Bacillus, Sphingomonas, Variovorax, and Streptomyces, as well as pathogenic microorganisms, including Fusarium and Alternaria. Most of these microorganisms were enriched in the rhizosphere soil. The study found that phosphorus was the driving factor affecting soil microorganisms, with available phosphorus (K = 0.189) and pH value (K = 0.113) significantly affecting fungal phylogeny. Bacterial community assembly processes were deterministic (βNTI < − 2), while those of fungi were stochastic (− 1 > βNTI > − 2). The microbial network in the rhizosphere was more stable than that in the bulk soil. This study expands our knowledge of the functional microbial germplasm resources of forest plantations and provides a theoretical basis for soil remediation in perennial poplar plantations.