scholarly journals Diversity and Variation of Asymbiotic Nitrogen-Fixing Microorganisms in Alpine Grasslands on the Tibetan Plateau

2021 ◽  
Vol 9 ◽  
Author(s):  
Wenyan Li ◽  
Fei Li ◽  
Haijun Zeng ◽  
Lin Ma ◽  
Lingyan Qi ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
High Throughput Sequencing ◽  
Alpine Grassland ◽  
The Tibetan Plateau ◽  
Grassland Degradation ◽  
Nitrogen Fixing ◽  
Sequencing Technology ◽  
Degraded Grassland ◽  
Natural Grassland ◽  
Grassland Types

Asymbiotic nitrogen-fixing (ANF) bacteria contribute a substantial amount of nitrogen in ecosystems, especially in those with low symbiotic nitrogen fixation (SNF) capability. Degradation of alpine grassland is widespread on the Tibetan Plateau and sown grassland has become one of the main strategies for grassland restoration. However, the diversity and community structure of ANF bacteria in different grassland types remain unknown. The aim of this study was to fill this gap. Soil samples were obtained from 39 grassland plots selected from three counties in the eastern Tibetan Plateau. The plots were classified as natural grassland (NG), sown grassland (SG), lightly degraded grassland (LDG), and severely degraded grassland (SDG). ANF microbial communities of the four grassland types were compared at the level of community and species diversity by 16S rRNA high-throughput sequencing technology. The phylum Proteobacteria accounted for >72% of the ANF bacteria. The community structures of soil ANF bacteria differed significantly (p < 0.01) among grassland types. We concluded that: (1) planting gramineous forage could possibly mitigate the decrease in diversity of soil ANF bacteria caused by grassland degradation; and (2) the diversity of soil ANF bacteria in alpine grassland of the Tibetan Plateau is closely related to grassland degradation and restoration.

Carbon fluxes and environmental controls across different alpine grassland types on the Tibetan Plateau

2021 ◽  
Vol 311 ◽  
pp. 108694
Author(s):  
Yuyang Wang ◽  
Jingfeng Xiao ◽  
Yaoming Ma ◽  
Yiqi Luo ◽  
Zeyong Hu ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Carbon Fluxes ◽  
Alpine Grassland ◽  
The Tibetan Plateau ◽  
Environmental Controls ◽  
Grassland Types

scholarly journals Soil Bacterial Communities and Diversity in Alpine Grasslands on the Tibetan Plateau Based on 16S rRNA Gene Sequencing

2021 ◽  
Vol 9 ◽  
Author(s):  
Hongmao Jiang ◽  
Youchao Chen ◽  
Yang Hu ◽  
Ziwei Wang ◽  
Xuyang Lu
Keyword(s):  
Tibetan Plateau ◽  
Bacterial Communities ◽  
Soil Bacteria ◽  
Alpine Grassland ◽  
Rrna Gene ◽  
The Tibetan Plateau ◽  
Alpine Grasslands ◽  
Soil Bacterial Communities ◽  
Soil Bacterial ◽  
Grassland Types

The Tibetan Plateau, widely known as the world’s “Third Pole,” has gained extensive attention due to its susceptibility to climate change. Alpine grasslands are the dominant ecosystem on the Tibetan Plateau, albeit little is known about the microbial community and diversity among different alpine grassland types. Here, soil bacterial composition and diversity in the upper soils of five alpine grassland ecosystems, alpine meadow (AM), alpine steppe (AS), alpine meadow steppe (AMS), alpine desert (AD), and alpine desert steppe (ADS), were investigated based on the 16S rRNA gene sequencing technology. Actinobacteria (46.12%) and Proteobacteria (29.67%) were the two dominant soil bacteria at the phylum level in alpine grasslands. There were significant differences in the relative abundance at the genus level among the five different grassland types, especially for the Rubrobacter, Solirubrobacter, Pseudonocardia, Gaiella, Haliangium, and Geodermatophilus. Six alpha diversity indices were calculated based on the operational taxonomic units (OTUs), including Good’s coverage index, phylogenetic diversity (PD) whole tree index, Chao1 index, observed species index, Shannon index, and Simpson index. The Good’s coverage index value was around 0.97 for all the grassland types in the study area, meaning the soil bacteria samplings sequenced sufficiently. No statistically significant difference was shown in other diversity indices’ value, indicating the similar richness and evenness of soil bacteria in these alpine grasslands. The beta diversity, represented by Bray–Curtis dissimilarity and the non-metric multidimensional scaling (NMDS), showed that OTUs were clustered within alpine grasslands, indicating a clear separation of soil bacterial communities. In addition, soil organic matter (SOM), total nitrogen (TN), total phosphorus (TP), pH, and soil water content (SWC) were closely related to the variations in soil bacterial compositions. These results indicated that soil bacterial taxonomic compositions were similar, while soil bacterial community structures were different among the five alpine grassland types. The environmental conditions, including SOM, TN, TP, pH, and SWC, might influence the soil bacterial communities on the Tibetan Plateau.

scholarly journals Plants and Microbes Mediate the Shift in Ecosystem Multifunctionality From Low to High Patterns Across Alpine Grasslands on the Tibetan Plateau

2021 ◽  
Vol 12 ◽  
Author(s):  
Yi Wang ◽  
Miao Liu ◽  
Youchao Chen ◽  
Tao Zeng ◽  
Xuyang Lu ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Correlation Coefficients ◽  
Terrestrial Ecosystems ◽  
Alpine Grassland ◽  
Future Climate Change ◽  
The Tibetan Plateau ◽  
Grassland Ecosystem ◽  
The Impact ◽  
Ecosystem Multifunctionality ◽  
Alpine Grassland Ecosystem

Both plant communities and soil microbes have been reported to be correlated with ecosystem multifunctionality (EMF) in terrestrial ecosystems. However, the process and mechanism of aboveground and belowground communities on different EMF patterns are not clear. In order to explore different response patterns and mechanisms of EMF, we divided EMF into low (<0) and high patterns (>0). We found that there were contrasting patterns of low and high EMF in the alpine grassland ecosystem on the Tibetan Plateau. Specifically, compared with low EMF, environmental factors showed higher sensitivity to high EMF. Soil properties are critical factors that mediate the impact of community functions on low EMF based on the change of partial correlation coefficients from 0 to 0.24. In addition, plant community functions and microbial biomass may mediate the shift of EMF from low to high patterns through the driving role of climate across the alpine grassland ecosystem. Our findings will be vital to clarify the mechanism for the stability properties of grassland communities and ecosystems under ongoing and future climate change.

scholarly journals Current challenges in distinguishing climatic and anthropogenic contributions to alpine grassland variation on the Tibetan Plateau

2018 ◽  
Vol 8 (11) ◽  
pp. 5949-5963 ◽  
Author(s):  
Lanhui Li ◽  
Yili Zhang ◽  
Linshan Liu ◽  
Jianshuang Wu ◽  
Shicheng Li ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Alpine Grassland ◽  
The Tibetan Plateau ◽  
Anthropogenic Contributions

CO2 processes in an alpine grassland ecosystem on the Tibetan Plateau

2003 ◽  
Vol 13 (4) ◽  
pp. 429-437 ◽  
Author(s):  
Pei Zhiyong ◽  
Ouyang Hua ◽  
Zhou Caiping ◽  
Xu Xingliang
Keyword(s):  
Tibetan Plateau ◽  
Alpine Grassland ◽  
The Tibetan Plateau ◽  
Grassland Ecosystem ◽  
Alpine Grassland Ecosystem
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