In this study, phylogenetic analyses of Phellodon from China were carried out based on sequences from the internal transcribed spacer (ITS) regions, the large subunit of nuclear ribosomal RNA gene (nLSU), the small subunit of nuclear ribosomal RNA gene (nSSU), the largest subunit of RNA polymerase II (RPB1), and the second largest subunit of RNA polymerase II (RPB2), combined with morphological characters of the collected specimens in China. The fruiting bodies of the specimens were used to observe their characteristics, and three new species of Phellodon are discovered. Phellodon crassipileatus is characterized by its pale brown to dark brown pileal surface, tomentose pileal margin, white spines, and the presence of clamp connections in generative hyphae of pileal surface, context, and stipe. Phellodon griseofuscus is characterized by its dark brown to black pileal surface, white to pale brown pileal margin, the presence of both simple septa and clamp connections in generative hyphae of spines, and moderately long basidia. Phellodon perchocolatus is characterized by its woody and broad pileus, brown to greyish brown pileal surface when fresh, tomentose pileal margin when young, which becomes glabrous with age, and the presence of both simple septa and clamp connections in the generative hyphae of the spines. This is the first time both single and multi-genes analysis is used in such a phylogenetic and taxonomic study on Phellodon, which can provide the basis for the phylogenetic study of the genus.

Phellodon is a genus of ectomycorrhizal fungi with important ecological roles and exploitable biological activities. In this study, four new species of Phellodon, P. caesius, P. henanensis, P. concentricus and P. subgriseofuscus, are described from China based on morphological characters and molecular evidence. The phylogenetic analyses of Phellodon were carried out based on the ITS + nLSU gene regions and the combined sequence dataset of ITS + nLSU + nSSU + RPB1 + RPB2 gene regions. Phellodon caesius is characterized by its dark bluish-grey, dark grey to black grey pileus, ash grey to dark bluish-grey spines, and the presence of both simple septa and clamp connections on generative hyphae of stipe. Phellodon concentricus is characterized by its zonate pileal surface, dark grey context in pileus, and spongy basidiomata. Phellodon henanensis is characterized by its ash grey, light vinaceous grey to light brown pileal surface, thin context in pileus, and the presence of both simple septa and clamp connections on generative hyphae of spines. Phellodon subgriseofuscus is characterized by its fuscous to black pileal surface, white to light brown spines, and vinaceous grey context. Illustrated descriptions and the ecological habits of the novel species are provided.

Afforestation plays a pivotal role in ecosystem restoration, exemplified by the Saihanba Mechanized Forest Farm, the world’s largest planted forest; however, the assembly mechanisms and interactions of soil microbial communities in such forests remain inadequately understood. This study aimed to elucidate the impact of different afforestation tree species, namely Larix gmelinii var. principis-rupprechtii, Picea asperata, and Pinus sylvestris var. mongolica, on soil bacterial diversity and community structure in comparison to grassland. Sixty soil samples were collected at a 20 cm depth, and high-throughput sequencing was employed to identify bacterial communities and assess their interactions with environmental factors. A total of 6528 operational taxonomic units (OTUs) were identified, with Solirubrobacter, Conexibacter, Bacillus, Massilia, Gaiella, Acidibacter, and Vicinamibacter being the dominant genera. Afforestation significantly impacted soil bacterial alpha diversity, with notable influence from key soil chemical properties, including available phosphorus (AP), cation exchange capacity (CEC), and the carbon-to-nitrogen ratio of soil organic matter (SOM-C/N). The Mantel test highlighted pH, the Normalized Difference Vegetation Index (NDVI), and spatial variable (dbMEM) as primary environmental factors influencing dominant bacterial genera. The bacterial community structure demonstrated deterministic homogeneous selection, wherein SOM-C/N emerged as a significant factor influencing the dissimilarity of soil bacterial communities. Furthermore, plantation soils exhibited a more complex network structure than grassland soil, highlighting the crucial role of bacterial communities in vegetation changes and providing valuable insights into their response to environmental factors during the reforestation process.

Phellodon is a genus of ectomycorrhizal fungi belonging to the group known as the stipitate hydnoids. It is associated with coniferous trees in forest ecosystems and is widely distributed in the northern hemisphere. Phellodon, together with Hydnellum, and Sarcodon, is classified in the Bankeraceae, members of which are generally considered as symbiotic fungi. Ectomycorrhizal fungi can help plant roots fix nitrogen and improve the absorption capacity of soil nutrients by trees, so they play an important role in ecosystem protection. Taxonomic and phylogenetic studies of Chinese Phellodon collections were carried out. Four new Phellodon species were discovered from southwestern China based on a combination of morphological characters and molecular data. Phellodon atroardesiacus is characterized by the blackish blue to dark grey pileus, dark grey to ash grey spines, and presence of clamp connections in spines. Phellodon cinereofuscus is distinguished by a cottony tomentose pileal margin, long spines which become clay-buff when dry, and echinulate basidiospores. Phellodon stramineus is characterized by a depressed and tomentose pileus, straw buff-colored pileal surface, and dark grey to ash grey spines. Phellodon yunnanensis is distinguished by a clay-pink to brown pileus, pale brown to white spines, and the presence of clamp connections in the outer layer of stipe. Detailed descriptions, illustrations, and ecological traits for the new taxa are provided. Phylogenetic analyses inferred from the internal transcribed spacer (ITS) regions confirmed that the four new species are distinct within Phellodon.