ObjectiveThis paper aims to study the relationship between the endangered plant Syringa pinnatifolia var. alanshanica and soil nutrients, soil enzyme and soil microorganisms, and provide evidence for understanding its impact mechanism.

MethodFive-point sampling method was employed to collect three soil samples (treatment group) under the S. pinnatifolia var. alanshanica shrub and three control samples (control group) from the naked land near the plant. After the physicochemical properties and enzyme activities determination, the microbial community structure was further analyzed via high-throughput sequencing technique.

ResultThe soil pH value remained unchanged, while the contents of water, organic matter, total nitrogen, available potassium and nitrogen was increased significantly (P < 0.05), and the available phosphorus content was decreased significantly (P < 0.05) by S. pinnatifolia var. alanshanica. At the same time, the activities of sucrase, urease, and laccase were increased significantly (P < 0.05). Under the S. pinnatifolia var. alanshanica shrub, the diversity of soil bacteria was decreased with the richness of bacteria being almost unchanged, but both the diversity and abundance of fungi were increased significantly. The numbers of Bacillus in bacteria and Saccharomycopsis, Clonostachys, Trichoderma, Paranamyces in fungi were increased by S. pinnatifolia var. alanshanica. However, the numbers of Sphingomonas and Flavobacterium in bacteria, Lentinula, Fusarium, Gibberella, Lycogalopsis, Ilyonectria, Aspergillus, Synchytrium, and Acremonium in fungi were decreased significantly. All the alterations of microorganisms were closely associated with the changes of nutrients and enzymes.

ConclusionS. pinnatifolia var. alanshanica increased the activities of soil enzymes by altering the community structure of soil fungi, and enhanced the contents of soil nutrients and water, and promoted the cycling of carbon, nitrogen, phosphorus and potassium by increasing the richness of functional bacteria.