Glacier melting promotes methane emission via increased methanogenic activity in the foreland alpine meadow.

Annual glacier melting alters hydrothermal conditions of the foreland alpine meadows, and causes significant fluctuations in methane (CH) flux. Previously we found that Tibetan glacier foreland alpine meadow shifts to CH source from sink during the melting season, but the potential mechanisms remain unclear. This study, via combination of in-situ measurement of seasonal CH flux and survey of microbial species that may involve in CH metabolism, explores the causes of glacier melting on CH flux in a glacier foreland alpine meadow on Tibetan Plateau.

Key microbial taxa play essential roles in maintaining soil muti-nutrient cycling following an extreme drought event in ecological buffer zones along the Yangtze River.

Climatic extremes, especially extreme droughts, are occurring more frequently and profoundly impacting biogeochemical processes. However, the relative importance of microbial communities on soil nutrient cycling and community maintenance under natural extreme drought events remains elusive. During a record-breaking drought in the Yangtze River Basin (YRB) in the summer of 2022, we collected ambient soils and drought-affected bare and vegetated soils in ecological buffer zones from two sites with similar soil and vegetation characteristics along the YRB, and examined the relative contribution of soil bacterial communities in supporting multi-nutrient cycling index (MNCI) involving carbon-, nitrate- and phosphorus-cycling and their associations with microbial network.

was the active and dominant methanotroph in Tibet lake sediments.

Methane (CH), an important greenhouse gas, significantly impacts the local and global climate. Our study focused on the composition and activity of methanotrophs residing in the lakes on the Tibetan Plateau, a hotspot for climate change research. Based on the field survey, the family had a much higher relative abundance in freshwater lakes than in brackish and saline lakes, accounting for ~92% of total aerobic methanotrophs.

Soil microbial subcommunity assembly mechanisms are highly variable and intimately linked to their ecological and functional traits.

Revealing the mechanisms underlying soil microbial community assembly is a fundamental objective in molecular ecology. However, despite increasing body of research on overall microbial community assembly mechanisms, our understanding of subcommunity assembly mechanisms for different prokaryotic and fungal taxa remains limited. Here, soils were collected from more than 100 sites across southwestern China.

Methylocystis dominates methane oxidation in glacier foreland soil at elevated temperature.

Methane-oxidizing bacteria (methanotrophs) play an important role in mitigating methane emissions in various ecological environments, including cold regions. However, the response of methanotrophs in these cold environments to extreme temperatures above the in-situ temperature has not been thoroughly explored. Therefore, this study collected soil samples from Longxiazailongba (LXZ) and Qiangyong (QY) glacier forelands and incubated them with 13CH4 at 35°C under different soil water conditions.

Vertical variations in microbial diversity, composition, and interactions in freshwater lake sediments on the Tibetan plateau.

Microbial communities in freshwater lake sediments exhibit a distinct depth-dependent variability. Further exploration is required to understand their biodiversity pattern and microbial interactions in vertical sediments. In this study, sediment cores from two freshwater lakes, Mugecuo (MGC) and Cuopu (CP), on the Tibetan plateau were sampled and subsequently sliced into layers at a depth of every centimeter or half a centimeter.

Distinct responses of soil methanotrophy in hummocks and hollows to simulated glacier meltwater and temperature rise in Tibetan glacier foreland.

Glacier foreland soils are known to be essential methane (CH) consumers. However, global warming and increased glacier meltwater have turned some foreland meadows into swamp meadows. The potential impact of this change on the function of foreland soils in methane consumption remains unclear.

Sink or Source: Alternative Roles of Glacier Foreland Meadow Soils in Methane Emission Is Regulated by Glacier Melting on the Tibetan Plateau.

Glacier foreland soils have long been considered as methane (CH) sinks. However, they are flooded by glacial meltwater annually during the glacier melting season, altering their redox potential. The impacts of this annual flooding on CH emission dynamics and methane-cycling microorganisms are not well understood.

Properties of sediment dissolved organic matter respond to eutrophication and interact with bacterial communities in a plateau lake.

Sediment dissolved organic matter (DOM) in inland waters is commonly affected by environmental changes. However, knowledge about how sediment DOM responds to eutrophication and the associations between sediment DOM and bacterial communities requires further investigation. We selected a sediment core from Dianchi Lake (China) that was dated from 1864 to 2019 by the activity of radionuclides (Pb and Cs).

Downward aeration promotes static composting by affecting mineralization and humification.

A composting experiment with sewage sludge and green waste was conducted to explore the effects of aeration directions (i.e., upward and downward) on static composting systems.

Bacterial community composition in soils covered by different vegetation types in the Yancheng tidal marsh.

Coastal wetland vegetation plays an important role in maintaining ecological function and is a key factor affecting the soil bacterial community. Spartina alterniflora was introduced to the Yancheng tidal marsh to stabilize the sediments and gradually replaced the native plants. However, the changes in the soil bacterial community profile caused by S.

Upland Soil Cluster Gamma dominates methanotrophic communities in upland grassland soils.

Aerobic methanotrophs in upland soils consume atmospheric methane, serving as a critical counterbalance to global warming; however, the biogeographic distribution patterns of their abundance and community composition are poorly understood, especial at a large scale. In this study, soils were sampled from 30 grasslands across >2000 km on the Qinghai-Tibetan Plateau to determine the distribution patterns of methanotrophs and their driving factors at a regional scale. Methanotroph abundance and community composition were analyzed using quantitative PCR and Illumina Miseq sequencing of pmoA genes, respectively.

The voltage signals of microbial fuel cell-based sensors positively correlated with methane emission flux in paddy fields of China.

Previous studies showed that exoelectrogenic bacteria in paddy soil could suppress methanogens and methanogenesis after they were enriched by application of Fe3+ or running microbial fuel cells (MFCs). However, the relationship between exoelectrogenic bacteria and methanogens without the enrichment process is unknown. Our study was conducted in three paddy fields in China and over three seasons.

Methylococcaceae are the dominant active aerobic methanotrophs in a Chinese tidal marsh.

Although coastal marshes are net carbon sinks, they are net methane sources. Aerobic methanotrophs in coastal marsh soils are important methane consumers, but their activity and populations are poorly characterized. DNA stable-isotope probing followed by sequencing was used to determine how active methanotrophic populations differed in the main habitats of a Chinese coastal marsh.

Autotrophic and symbiotic diazotrophs dominate nitrogen-fixing communities in Tibetan grassland soils.

Biological nitrogen fixation, conducted by soil diazotrophs, is the primary nitrogen source for natural grasslands. However, the diazotrophs in grassland soils are still far from fully investigated. Particularly, their regional-scale distribution patterns have never been systematically examined.

Anthropogenic protection alters the microbiome in intertidal mangrove wetlands in Hainan Island.

Intertidal mangrove wetlands are of great economic and ecological importance. The regular influence of tides has led to the microbial communities in these wetlands differing significantly from those in other habitats. In this study, we investigated the microbiomes of the two largest mangrove wetlands in Hainan Island, China, which have different levels of anthropogenic protection.

Mucilaginibacterpsychrotolerans sp. nov., isolated from peatlands.

A Gram-stain-negative, rod-shaped, non-flagellated, pink, cold-tolerant bacterial strain, NH7-4T, was isolated from the Riganqiao peatlands on the Tibetan Plateau. The 16S rRNA gene sequence of the novel isolate shared a pairwise similarity ranging from 96.84 to 93.

Salinity Affects the Composition of the Aerobic Methanotroph Community in Alkaline Lake Sediments from the Tibetan Plateau.

Lakes are widely distributed on the Tibetan Plateau, which plays an important role in natural methane emission. Aerobic methanotrophs in lake sediments reduce the amount of methane released into the atmosphere. However, no study to date has analyzed the methanotroph community composition and their driving factors in sediments of these high-altitude lakes (>4000 m).

Identification of active aerobic methanotrophs in plateau wetlands using DNA stable isotope probing.

Sedge-dominated wetlands on the Qinghai-Tibetan Plateau are methane emission centers. Methanotrophs at these sites play a role in reducing methane emissions, but relatively little is known about the composition of active methanotrophs in these wetlands. Here, we used DNA stable isotope probing to identify the key active aerobic methanotrophs in three sedge-dominated wetlands on the plateau.

Aerobic methanotroph diversity in Sanjiang wetland, Northeast China.

Aerobic methanotrophs present in wetlands can serve as a methane filter and thereby significantly reduce methane emissions. Sanjiang wetland is a major methane source and the second largest wetland in China, yet little is known about the characteristics of aerobic methanotrophs in this region. In the present study, we investigated the diversity and abundance of methanotrophs in marsh soils from Sanjiang wetland with three different types of vegetation by 16S ribosomal RNA (rRNA) and pmoA gene analysis.

Microbial diversity in hummock and hollow soils of three wetlands on the Qinghai-Tibetan Plateau revealed by 16S rRNA pyrosequencing.

The wetlands of the Qinghai-Tibetan Plateau are believed to play an important role in global nutrient cycling, but the composition and diversity of microorganisms in this ecosystem are poorly characterized. An understanding of the effects of geography and microtopography on microbial populations will provide clues to the underlying mechanisms that structure microbial communities. In this study, we used pyrosequencing-based analysis of 16S rRNA gene sequences to assess and compare the composition of soil microbial communities present in hummock and hollow soils from three wetlands (Dangxiong, Hongyuan and Maduo) on the Qinghai-Tibetan Plateau, the world's highest plateau.

Bacterial community structure in two permafrost wetlands on the Tibetan Plateau and Sanjiang Plain, China.

Permafrost wetlands are important methane emission sources and fragile ecosystems sensitive to climate change. Presently, there remains a lack of knowledge regarding bacterial communities, especially methanotrophs in vast areas of permafrost on the Tibetan Plateau in Northwest China and the Sanjiang Plain (SJ) in Northeast China. In this study, 16S rRNA-based quantitative PCR (qPCR) and 454 pyrosequencing were used to identify bacterial communities in soils sampled from a littoral wetland of Lake Namco on the Tibetan Plateau (NMC) and an alluvial wetland on the SJ.

Aerobic methanotroph diversity in Riganqiao peatlands on the Qinghai-Tibetan Plateau.

The Zoige Plateau is characterized by its high altitude, low latitude and low annual mean temperature of approximately 1°C and is a major source of atmospheric methane in the Qinghai-Tibetan Plateau. Methanotrophs play an important role in the global cycling of CH4, but the diversity, identity and activity of methanotrophs in this region are poorly characterized. Soils were collected from hummocks and hollows in the Riganqiao peatland and the methanotroph community was analysed by qPCR and sequencing methane monooxygenase (pmoA and mmoX) genes.