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Purpose: Soil microorganisms in grassland ecosystem exhibit varying spatial–temporal patterns. However, the underlying mechanisms shaping microbial community assembly during grassland restoration are largely unknown. Here, we assessed the relative importance of stochastic and deterministic processes in the assembly of soil fungal communities in a semiarid grassland during different grazing exclusion periods (i.e., 0, 20 and 40 years). Materials and methods: The patterns of soil fungal communities were assessed using high-throughput genomic tools and multivariate statistical analyses. Results and discussion: The mobility and alpha diversity of soil fungal communities peaked in grasslands where grazing had been excluded for 20 years, indicating that the soil fungal community had a higher dispersal ability and was more conducive to the increase of soil fungal community diversity. It was also noted that the soil fungal community compositions varied with grazing exclusion periods. However, Mantel tests, variance partitioning analysis (VPA), and hierarchical partitioning theory (HP) showed vegetation characteristics and soil properties had a small impact on soil fungal community compositions. The neutral community model (NCM), PER-SIMPER, and dispersal-niche continuum index (DNCI) highlighted that the formation of soil fungal community was primarily mediated by stochastic processes. Conclusions: Taken together, the results of this research provided a better understanding of the spatial and temporal patterns of soil fungal communities and the mechanisms underlying soil fungal community assembly during the restoration process. [ABSTRACT FROM AUTHOR]

Occurrences of Late Permian coiled nautiloids are widespread but they have never been analysed in terms of spatial and temporal disparity changes. Morphometric analyses using the cardinal Raupian conch parameters: conch width index, umbilical width index and whorl expansion rate with subsequent analysis by using principal components analysis and non‐metric multidimensional scaling, allow the construction of a nautiloid morphospace. The analyses show that there is a stable disparity in the coiled nautiloids from the Wuchiapingian to the Changhsingian. Differences between the three major Late Permian nautiloid occurrences (Salt Range, South China and Transcaucasus‐NW Iran) are considerably small; the South Chinese occurrences, however, are characterized by many endemic genera. The most important variation in morphospace occupation is caused by environmental differences such as water depth. [ABSTRACT FROM AUTHOR]

• Subshrub encroachment altered the composition of plant and bacterial communities. • Subshrub encroachment directly influenced vegetation and soil characteristics. • Subshrub encroachment indirectly influenced bacterial communities. Subshrub encroachment is a frequently occurring phenomenon in arid and semi-arid area, altering the plant community structure and function. However, the effects of the encroachment process on soil bacterial communities are poorly understood on the Loess Plateau, China. In this study, we assessed the changes in soil properties and vegetation characteristics, and their association with alterations in soil bacterial communities in grasslands subjected to different subshrub (Artemisia sacrorum Ledeb.) encroachment intensities (no subshrub encroachment, light subshrub encroachment, moderate subshrub encroachment, and heavy subshrub encroachment). Our results indicated that heavy subshrub encroachment significantly increased plant aboveground biomass and bacterial diversity, but adversely affected plant diversity. Heavy and moderate subshrub encroachment significantly increased soil organic carbon, total nitrogen and water content. Subshrub encroachment at all intensities increased community weighted mean trait values of leaf carbon content, leaf nitrogen content, leaf phosphorus content, specific leaf area, but decreased leaf dry matter content and community functional dispersion. In addition, subshrub encroachment altered the composition of plant and bacterial communities. The partial least squares structural equation model indicated that subshrub encroachment indirectly influenced bacterial communities by affecting vegetation characteristics and soil properties. The determinants of bacterial diversity were vegetation structures (community weighted mean trait values of specific leaf area and plant community composition) and soil properties (organic carbon content, alkaline hydrolysis nitrogen, total phosphorus, available phosphorus, and soil water content). The composition of bacterial community was primarily regulated by plant aboveground biomass and soil properties. Overall, the results of this study improved our understanding of the impact of subshrub encroachment on soil bacteria community on Loess Plateau, and the processes underlying the alterations in the soil bacterial community by subshrub encroachment. [ABSTRACT FROM AUTHOR]