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Genetic and environmental cues affecting seed microbial communities have been investigated to assess the ecological characteristics of seed microbial communities. However, little is known concerning seed-to-seed microbial variations and ecological drivers at the single-seed level. We report rare taxa-associated heterogeneity and robustness of seed bacterial and fungal communities in individual seeds using 63 pooled and 70 single-seed samples from a single field-grown rice plant. Ordination analyses showed that seed-to-seed variation patterns could be clustered according to the originating panicle branch. Bacterial–fungal associations and in silico extinction experiments demonstrated that rare taxa contribute to the connectivity and robustness of the associations. Null modeling-based statistical analysis revealed that the distribution of rare taxa is mainly governed by dispersal limitation, whereas the distribution of prevalent taxa is mainly governed by homogeneous selection and ecological drift. Our findings provide an ecological framework for understanding the heterogeneity of seed microbial communities in a single plant; they will facilitate the development and application of seed microbiota or single microbe-based engineering strategies.

Microbial diversity, together with carbon function, plays a key role in driving the wetland carbon cycle; however, the composition, driving factors of carbon-functional genes and the relationship with microbial community have not been well characterized in coastal wetlands. To understand these concerns, microbes, carbon-functional genes, and related environmental factors were investigated in twenty wetlands along China's coast. The results indicate that carbon-functional gene composition is dominated by archaeal rather than bacterial community and that Nanoarchaeaeota is the dominant archaeal phylum associated with carbon cycling in anoxic sediments. Compared with microbes, carbon-functional composition was more stable because they showed the highest Shannon diversity and archaeal functional redundancy. Deterministic processes dominated microbial community, and stochastic processes were more important for carbon-functional genes. Labile Fe governed archaeal and carbon-functional composition by coupling with nitrogen and carbon biogeochemical cycles, while bacterial community was affected by NH4-N and SOC/SON. This study highlights the predominant contributions of archaea to carbon-functional genes and to the stability of carbon-functional composition, thus providing new insights into the microbial dominance of the carbon cycle and the evaluation of carbon function in coastal wetlands. [ABSTRACT FROM AUTHOR]

Water shortage is one of the main hinder drivers of sustainable development in the Beijing–Tianjin–Hebei region, and ecological restoration is one of the main means to effectively curb ecological degradation. Addressing ecological degradation in the Beijing–Tianjin–Hebei region has been a major concern of the Chinese government, and this has led to a focus on intensified ecological restoration efforts in this area. However, the effect of these restoration actions is not clear. To understand how ecological restoration is impacting ecological quality in the Beijing–Tianjin–Hebei region, we used geographical information system technology, such as the vegetation index-biomass method and cumulative net primary production (NPP) method, to assess the change in ecosystem quality. We carried out the pixel binary model and Pearson's correlation coefficient analyses to understand the driving forces behind the change. Results showed that from 2000 to 2010, the quality of the Beijing–Tianjin–Hebei ecosystem has been improving, that natural vegetation is slowly re-establishing, and that there has been a slow increase toward climax communities. The change in ecosystem quality is positively correlated with the Sanbei shelterbelt and Beijing–Tianjin Sandstorm control project and negatively correlated with socioeconomic and agricultural factors. [ABSTRACT FROM AUTHOR]

• The spatial dynamic variations of mangrove MPs-associated bacteria are uncovered. • New framework based on niches is crucial for deciphering plastisphere variations. • Ecological drivers of plastispheres are firstly evaluated from the view of niches. • Rhodococcus erythropolis is speculated as MPs degradation species in mangrove forest. Myriad inherent and variable environmental features are controlling the assembly and succession of bacterial communities colonizing on mangrove microplastics (MPs). However, the mechanisms governing mangrove MPs-associated bacterial responses to environmental changes still remain unknown. Here, we assessed the dissimilarities of MPs-associated bacterial composition, diversity and functionality as well as quantified the niche variations of each taxon on plastispheres along river–mangrove–ocean and mangrove landward–to–seaward gradients in the Beibu Gulf, China, respectively. The bacterial richness and diversity as well as the niche breadth on mangrove sedimentary MPs dramatically decreased from landward to seaward regions. Characterizing the niche variations linked the difference of ecological drivers of MPs-associated bacterial populations and functions between river–mangrove–ocean (microplastic properties) and mangrove landward–to–seaward plastispheres (sediment physicochemical properties) to the trade-offs between selective stress exerted by inherent plastic substrates and microbial competitive stress imposed by environmental conditions. Notably, Rhodococcus erythropolis was predicted to be the generalist species and closely associated to biogeochemical cycles of mangrove plastispheres. Our work provides a reliable pathway for tackling the hidden mechanisms of environmental factors driving MPs-associated microbe from perspectives of niches and highlights the spatial dynamic variations of mangrove MPs-associated bacteria. [Display omitted] [ABSTRACT FROM AUTHOR]

Mounting evidence suggests that Archaea are widespread and abundant in aquatic and terrestrial habitats and play fundamental roles in global biogeochemical cycles, yet the pattern and its ecological drivers of biogeographic distribution of archaeal community in estuarine ecosystem are still not well understood. Here, we investigated planktonic and benthic archaeal communities in the human-impacted Jiulong River estuary (JRE), southern China by using real-time PCR (RT-PCR) and Illumina 16S ribosomal RNA (rRNA) amplicon sequencing. RT-PCR analysis indicated that Archaea accounted for an average of 0.79 and 5.31 % of prokaryotic biomass in water and sediment samples of the JRE, respectively. The diversity of planktonic archaeal community decreased gradually from the river runoff to seawater, whereas that of benthic community did not show the similar pattern. The results of taxonomic assignments indicated that Thaumarchaeota ( Nitrosopumilus and Cenarchaeum), Methanocorpusculum, and Methanospirillum were significantly more abundant in planktonic than benthic communities, whereas the relative abundances of Miscellaneous Crenarchaeotic Group, Marine Benthic Group-B/-D, anaerobic methane-oxidizing Archaea -1/-2D, and South Africa Gold Mine Euryarchaeotic Group 1 were higher in sediments than in surface waters. Moreover, planktonic archaeal community composition varied significantly at broad and finer-scale taxonomic levels along the salinity gradient. Multivariate statistical analyses revealed that salinity is the main factor structuring the JRE planktonic but not benthic archaeal community at both total community and population level. SourceTrakcer analysis indicated that river might be a major source of archaea in the freshwater zone of the JRE. Overall, this study advances our understanding of the biogeographic patterns and its ecological drivers of estuarine archaeal communities. [ABSTRACT FROM AUTHOR]

Microbial diversity, together with carbon function, plays a key role in driving the wetland carbon cycle; however, the composition, driving factors of carbon-functional genes and the relationship with microbial community have not been well characterized in coastal wetlands. To understand these concerns, microbes, carbon-functional genes, and related environmental factors were investigated in twenty wetlands along China's coast. The results indicate that carbon-functional gene composition is dominated by archaeal rather than bacterial community and that Nanoarchaeaeota is the dominant archaeal phylum associated with carbon cycling in anoxic sediments. Compared with microbes, carbon-functional composition was more stable because they showed the highest Shannon diversity and archaeal functional redundancy. Deterministic processes dominated microbial community, and stochastic processes were more important for carbon-functional genes. Labile Fe governed archaeal and carbon-functional composition by coupling with nitrogen and carbon biogeochemical cycles, while bacterial community was affected by NH 4 -N and SOC/SON. This study highlights the predominant contributions of archaea to carbon-functional genes and to the stability of carbon-functional composition, thus providing new insights into the microbial dominance of the carbon cycle and the evaluation of carbon function in coastal wetlands., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Yang, Liu, Wang, Li, Li and Liu.)

Abstract: Dicranopteris is a common fern distributed throughout tropical and subtropical regions of the world. It often forms a mat-like understory, especially in open areas. A forest floor dominated by Dicranopteris plays an important role in ecosystem dynamics, but is often overlooked in ecological research. We conducted an experiment by removing overstory or understory Dicranopteris to compare their effects on soil microclimate, litter decomposition, soil decomposer food web and ecosystem nutrient cycling. Results of our field study showed that removal of a Dicranopteris-dominated understory leads to increased soil temperature and reduced soil moisture, subsequently, altering the components of the soil food web (microbial community, nematode and microarthropod densities) and reducing ecosystem processes of litter decomposition. When present, Dicranopteris forms a dense understory layer in subtropical and tropical regions, which is favorable for sustaining soil microclimates and acts as the major driver of soil biota and ecological processes in intensive forest ecosystems. [Copyright &y& Elsevier]