Aims The co-occurrence of soil microorganisms and plants is of great significance in revealing the material cycle. The study of the community structure and co-occurrence network relationship of rhizosphere soil fungi of the relict plant Alsophila spinulosa can reveal the mechanism of constructing soil fungal communities. Methods The community structure and co-occurrence network characteristics of soil fungi in the rhizosphere of A. spinulosa were analysed using Illumina Miseq sequencing technology and co-occurrence networks. Results The rhizosphere soil fungal communities of A. spinulosa are significantly different from those in the nonrhizosphere soil. The rhizosphere soil fungal phylogeny of A. spinulosa was concentrated in Ascomycota, Mortierellomycota, and Rozellomycota. Aggregation of Cutaneotrichosporon, the main differential species, significantly affected the construction of the rhizosphere fungal community of A. spinulosa. The indicator fungal groups of the rhizosphere soil fungal community of A. spinulosa were significantly influenced by habitat. Saprotrophs are the main fungi responsible for material exchange in A. spinulosa. Increase in the relative abundance of animal pathogens was the main factor affecting the percentage of pathotroph. The rhizosphere soil fungal co-occurrence networks of A. spinulosa had high synergism and network connectivity, and more intense interspecies competition at the order level. Conclusions Overall, the rhizosphere soil fungal community of A. spinulosa altered significantly, with a stable co-occurrence network. Continuous in-depth study on the growth of the key soil fungi can help understand the growth mechanism of A. spinulosa.

East Yunnan-Guizhou Plateau is rich in biodiversity in China. Complex geographical and climatic conditions, and rich bird resources made this area an ideal system for studying the spatial distribution mechanism and influencing factors of birds, which were still unknown. Bird community data from 37 sites in this region were collected, including 505 bird species and 164 species of resident passerine bird analyzed. The taxonomic diversity, phylogenetic diversity, functional diversity, and community structure index were calculated. Redundancy analysis (RDA), ordinary least square (OLS), and structural equation model (SEM), were used to explore the relationship between bird diversity index and 12 environmental factors used to describe the habitat conditions of birds. Results indicated that the vascular plant species richness, habitat area, and vertical altitude difference were the three most critical factors affecting bird diversity. The phylogenetic structure of bird community was dispersed in west and clustered in east, and significantly related to latitude, habitat area, and vertical altitude difference. The functional structure was dispersed in all sites, and significantly related to mean annual precipitation and longitude. This suggest that the distribution pattern of bird diversity was caused by the comprehensive action of various habitat factors which were mainly related to food availability and habitat heterogeneity. Considering the protection of birds in this area, it is necessary to continuously promote the construction of nature reserve system proposed by the Chinese government, and pay attention to the protection of urban green space such as campus and urban parks, to maintain the area and integrity of bird habitat, while only a high plant species and area is not enough, improving the habitat heterogeneity is of great significance.

The relationships among species diversity, functional diversity, functional redundancy, and community stability are central to community and ecosystem ecology. This paper examines plant communities at different stages of vegetation restoration in the Guizhou karst plateau to study the relationship among functional diversity, functional redundancy, and stability of plant communities. The most important results include the following. (1) Species diversity (SD), functional redundancy (FR), and stability (STB) gradually increased with restoration, and there were significant differences among the different stages; functional diversity (FD) increased at first and then decreased, and reached the highest level at the tree irrigation stage. (2) Plant height (PLH) and specific leaf area (SLA) were functional traits that affected the diversity and stability of the plant community, and PLH was positively correlated with plant community diversity and stability, while SLA was negatively correlated with plant community diversity and stability. (3) During the community recovery, FD and FR interacted to maintain stability. In the early and late stages of recovery, the effect of functional redundancy on stability was greater than that of functional diversity, but it was the opposite in the middle stages. (4) The tree irrigation stage is the likely point at which the species diversity of plant communities in karst areas reached saturation, and the growth rate of functional redundancy after species diversity saturation was greater than that before saturation.