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Exploring Soil Microbial Diversity in Volcanic Environments

Volcanic activity significantly transforms the Earth’s landscape and fosters the emergence of novel ecosystems, making them crucial for examining soil formation and the underlying processes such as microbial dynamics and the evolution of plant communities. Recent research increasingly indicates that soil microorganisms are integral to various ecological and biogeochemical functions, including carbon mineralization, the formation of humus, and nutrient cycling.

The complex interplay among soil features, plant life, and microbial populations necessitates an in-depth examination of microbial communities to enhance our understanding of ecosystem functionality. A new study conducted on the rhizosphere microbial communities associated with Boehmeria nivea L. in the volcanic region of Nvshan, Anhui Province, has revealed substantial spatial variations in microbial diversity, structural characteristics, and functional capabilities.

Research into volcanic soil illustrates its critical influence on the biodiversity of microbial communities, subsequently impacting the microorganisms present in the rhizosphere of B. nivea. The findings from this study were published on July 26, 2024, in Soil Ecology Letters and can be accessed here.

Li Xiaoyu’s team at Anhui Agricultural University undertook an extensive series of studies across multiple sites to investigate the rhizosphere microbial communities of volcanic B. nivea. Noteworthy observations from their research indicate that fungal communities are more susceptible to geographic and environmental changes. There were also notable differences in the diversity and functions of the rhizosphere microbial communities located in various geological formations such as volcanic pits and cones.

Professor Chen, leading the research, highlighted the unique characteristics of the Nvshan area, which is a well-preserved ancient crater recognized globally. It resides within a subtropical monsoon climate, characterized by an average annual precipitation of 939.9 mm and an average annual temperature of 15 °C. The volcanic landscape comprises distinctive geomorphological features, including craters, lava flows, and volcanic cones.

Throughout the geological history of Nvshan, multiple eruptions have shaped its unique landforms, thus providing an ideal natural laboratory to study the interactions of volcanic activity with environmental factors. B. nivea, recognized for its ecological and economic importance, is vital within this context, particularly influencing the rhizosphere microbial composition.

The research revealed a tendency for bacterial populations to thrive over fungal species across the rhizosphere soil of B. nivea. This could be linked to an increase in environmental disturbances, which may have resulted in the loss of less common fungal species and an overall decrease in biodiversity. Their findings illustrated this point with a Zi-Pi chart showcasing the significance of particular microbial species.

Data suggested that the proportion of bacterial generalist species exceeded that of fungi in both volcanic craters (15.5% vs. 11.7%) and cones (19.2% vs. 13.9%). Within the microbial community, Actinomycetes and Acidobacteria were predominant among bacteria, while Ascomycetes and Basidiomycetes prevailed within the fungi.

Actinomycetes are particularly important for humus degradation, possessing various enzyme-driven capabilities that allow them to thrive in nutrient-poor conditions. Fungi, however, exhibit greater proficiency in decomposing complex organic materials, such as polyphenols and cellulose substrates.

Building on this, Professor Chen mentioned the application of RMT random matrix theory to create networks analyzing the co-occurrence of bacterial and fungal communities present in volcanic environments. The results showed that compared to bacterial networks, fungal networks possessed a more intricate structure with greater modularity, indicating a complex microbial interdependence. Interestingly, in terms of average connectivity, the cone had a lower average clustering coefficient and higher average degree compared to the crater for bacterial networks, while the fungal networks showed inversely related values.

Moreover, structural equation modeling (SEM) indicated that the α diversity of these microorganisms had a more pronounced influence on their functional versatility than β diversity. Specifically, in craters, the increased α diversity of microorganisms correlated positively with their multifunctional abilities.

Through this research on the volcanic influences on the rhizosphere microbial community of B. nivea, insights into volcanic activity’s impact on soil ecosystems are being advanced. This knowledge not only informs conservation efforts aimed at protecting the ecological integrity around volcanoes but also aids in the responsible utilization of land resources. Furthermore, this study enhances our understanding of microbial interactions that promote plant growth and maintain soil health, providing essential knowledge for agricultural practices.

More information: Jin Chen et al, Characterization of microbial structure and function in the rhizosphere of Boehmeria nivea L.: A comparative study of volcanic cone and crater, Soil Ecology Letters (2024). DOI: 10.1007/s42832-024-0259-x

Citation: Study shows microbial diversity differences in volcanic cones and craters (2024, September 13) retrieved from Phys.org

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