Tsinghua University School of Environment Dr. Guo Xue and his collaborator at the University of Oklahoma in the United States, "Climate warming restructurings seasonal dynamics of grassland soil microbial communities" was officially launched on mLife on September 15, 2022. The research team used field temperature increase experiments to study the seasonal dynamic changes of soil microbial communities in temperate grasslands in response to climate warming. It found that the difference between soil microbial communities and control groups in the warming environment increases nonlinearly with the season, and the increase in temperature increases simultaneously to enhance the complexity and stability of microbial networks in different seasons (especially cold seasons).
Background introduction
In the past 20 years, a large number of studies have been carried out around the mechanism of soil microorganisms to respond to climate warming, which has greatly enriched our understanding of soil microbial community changes and the function of regulating carbon and nitrogen circulation. Most areas of the Earth's terrestrial ecosystem are affected by seasonal changes, but few are still known about the seasonal evolution of soil microorganisms under warming conditions.
Scientific discovery
The team analyzed the soil microbial communities in temperate grassland ecosystems in a month-by-month period under long-term temperature conditions, and found that the temperature increase was significant (p=0.001) and changed the soil microbial community structure (Figure 1A), resulting in the difference between the soil microbial community and the control group under the temperature increase environment nonlinearly with the season (R2 =0.578, p=0.021). In summer, the difference between the soil microbial community in the warming environment and the control group was minimal, while in the lower temperatures, the difference between the microbial community from the control group increased (Fig. 1B). At the same time, the dispersion of the microbial community also increased significantly under the heating conditions (Fig. 1C).
Figure 1 Temperature increases change seasonal changes in soil microbial communities. The temperature increase changes the microbial community structure (A), causing the microbial community variation to increase with the season (B) and enhances the dispersion of the community (C)
Based on the method of random matrix theory, a microbial molecular ecological network was constructed in different seasons and throughout the year under the temperature increase and control conditions. All these microbial networks exhibit scale-free and small-world characteristics, and the distribution of network links is independent of network size. Molecular ecological network analysis shows that the complexity of the microbial network has increased to varying degrees in different seasons (Figure 2A), resulting in an increase in network topological parameters such as network node number, connectivity, connectivity, average aggregation coefficient, and relative modularity (Figure 2B). Although there are large differences in the size and complexity of microbial networks in different seasons, it was found that the impact of temperature increase in seasons with lower temperatures on the structure of microbial networks is significantly higher than that in warm summers.
Figure 2 Temperature increase affects the network structure of microbial communities. The temperature increase enhances the complexity of microbial networks in different seasons (A), resulting in an increase in network-related topology index (B)
Summary Outlook
This study results prove that climate warming reshapes the seasonal dynamic changes of soil microbial communities in temperate grasslands, resulting in greater responses to temperature increase in winter. Over time, this seasonal response may alter soil community phenology and related functions and have an impact on the terrestrial carbon cycle. Information on the seasonal dynamics of these soil microbial communities is of great guiding significance for predicting the global carbon cycle process.
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https://onlinelibrary.wiley.com/doi/full/10.1002/mlf2.12035
Citize this paper:
Guo X, Yuan M, Lei J, Shi Z, ZhouX, Li J, et al. Climate warming restructurings seasonal dynamics of grassland soil microbial communities. mLife. 2022.
https://doi.org/10.1002/mlf2.12035
