Soil fungal communities varied across aspects of restored grassland in former mining areas of the Qinghai-Tibet Plateau.

To determine whether different aspects lead to a heterogeneous distribution of soil fungi, we investigated artificially established alpine grasslands in the Muli mining area in the Qinghai-Tibet Plateau. Employing high-throughput sequencing techniques, we analyzed the composition, diversity, and function of soil fungal communities across various aspects (flat, East-facing, South-facing, West-facing, North-facing). We also examined their relationships with environmental factors. Soil fungal communities of restored alpine grasslands differed significantly across aspects in terms of the dominant phyla, classes and species level. Compared with No aspect, the Shannon index of fungi respectively decreased by 2.99%, 19.32%, 19.37% and 10.56% for East aspect, South aspect, West aspect and North aspect, respectively, and the Chao1 index of fungi respectively decreased by-2.44%, 35.50%, 42.15% and 3.21%, respectively. A total of 22 different types of fungi were identified in the study area. Predictive analysis, based on PICRUSt2, indicated that the primary functions of the fungal communities across different aspects were aerobic respiration I (cytochrome c) and aerobic respiration II (cytochrome c). Among the environmental variables, total phosphorus (P) and total nitrogen (N) were the principal factors influencing the fungal community composition.In conclusion, aspect plays a significant role in shaping the composition of fungal communities and also affects their overall diversity.

Distribution of rhizosphere fungi of Kobresia humilis on the Qinghai-Tibet Plateau.

Kobresia humilis is a major species in the alpine meadow communities of the Qinghai-Tibet Plateau (QTP); it plays a crucial role in maintaining the ecological balance of these meadows. Nevertheless, little is known about the rhizosphere fungi associated with K. humilis on the Qinghai Tibet Plateau. In this study, we used Illumina Miseq to investigate the fungal diversity, community structure, and ecological types in the root and rhizosphere soil of K. humilis across eight areas on the QTP and analyzed the correlation between rhizosphere fungi of K. humilis and environmental factors. A total of 19,423 and 25,101 operational taxonomic units (OTUs) were obtained from the roots and rhizosphere soil of K. humilis. These were classified into seven phyla, 25 classes, 68 orders, 138 families, and 316 genera in the roots, and nine phyla, 31 classes, 76 orders, 152 families, and 407 genera in the rhizosphere soil. There were 435 and 415 core OTUs identified in root and rhizosphere soil, respectively, which were categorized into 68 and 59 genera, respectively, with 25 shared genera. Among them, the genera with a relative abundance >1% included Mortierella, Microscypha, Floccularia, Cistella, Gibberella, and Pilidium. Compared with the rhizosphere soil, the roots showed five differing fungal community characteristics, as well as differences in ecological type, and in the main influencing environmental factors. First, the diversity, abundance, and total number of OTUs in the rhizosphere soil of K. humilis were higher than for the endophytic fungi in the roots by 11.85%, 9.85%, and 22.62%, respectively. The composition and diversity of fungal communities also differed between the eight areas. Second, although saprotroph-symbiotrophs were the main ecological types in both roots and rhizosphere soil; there were 62.62% fewer pathotrophs in roots compared to the rhizosphere soil. Thirdly, at the higher altitude sites (3,900-4,410 m), the proportion of pathotroph fungi in K. humilis was found to be lower than at the lower altitude sites (3,200-3,690 m). Fourthly, metacommunity-scale network analysis showed that during the long-term evolutionary process, ZK (EICZK = 1) and HY (EICHY = 1) were critical sites for development of the fungal community structure in the roots and rhizosphere soil of K. humilis, respectively. Fifthly, canonical correspondence analysis (CCA) showed that key driving factors in relation to the fungal community were longitude (R2 = 0.5410) for the root community and pH (R2 = 0.5226) for the rhizosphere soil community. In summary, these results show that K. humilis fungal communities are significantly different in the root and rhizosphere soil and at the eight areas investigated, indicating that roots select for specific microorganisms in the soil. This is the first time that the fungal distribution of K. humilis on the QTP in relation to long-term evolutionary processes has been investigated. These findings are critical for determining the effects of environmental variables on K. humilis fungal communities and could be valuable when developing guidance for ecological restoration and sustainable utilization of the biological resources of the QTP.