Land use conversion increases the network complexity and stability of soil microbial communities in a temperate grassland

Authors: CORNELL, CAROLYN - University Of Oklahoma; ZHANG, YA - University Of Oklahoma; NING, DALIANG - University Of Oklahoma; XIAO, NAIJIA - University Of Oklahoma; Wagle, Pradeep; XIAO, XIANGMING - University Of Oklahoma; ZHOU, JIZHONG - University Of Oklahoma

Submitted to: Journal of the International Society for Microbial Ecology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/19/2023
Publication Date: 10/13/2023
Citation: Cornell, C.R., Zhang, Y., Ning, D., Xiao, N., Wagle, P., Xiao, X., Zhou, J. 2023. Land use conversion increases the network complexity and stability of soil microbial communities in a temperate grassland. Journal of the International Society for Microbial Ecology. 17(12):2210-2220 Available: https://doi.org/10.1038/s41396-023-01521-x.
DOI: https://doi.org/10.1038/s41396-023-01521-x

Interpretive Summary: Land use conversion, largely due to agricultural expansion, has considerably impacted ecosystem structure and function. Soil microorganisms are essential for providing many ecosystem services needed for agricultural production, but they are also very sensitive to land use changes and management disturbances. The responses and adaptations of microbial communities due to land use conversion have not yet been fully understood. This study examined the effects of land conversion for long-term cropland use on the network complexity and stability of soil microbial communities over 19 months. Despite reduced microbial biodiversity in comparison with native tallgrass prairie, conventional till (CT) wheat land use significantly increased network complexity such as connectivity, connectance, average clustering coefficient, relative modularity, and the number of species acting at network hubs and connectors as well as resulted in the greater temporal variation of complexity indices. Molecular ecological networks under CT wheat became significantly more robust and less vulnerable and increased network stability. The relationship between network complexity and stability was also substantially strengthened due to land use conversion. The results showed that cropland use increased the complexity and stability of networked microbial communities and strengthened relationships between complexity and stability despite frequent management disturbances. The results have important implications for improving the stability of cropland systems with biodiversity loss by preserving microbial relationships.

Technical Abstract: Soils harbor highly diverse microbial communities that are critical to soil health, but agriculture has caused extensive land use conversion resulting in negative effects on critical ecosystem processes. However, the responses and adaptations of microbial communities due to land use conversion have not yet been understood. Here, we examined the effects of land conversion for long-term cropland use on the network complexity and stability of soil microbial communities over 19 months. Despite reduced microbial biodiversity in comparison with native tallgrass prairie, conventionally tilled (CT) cropland use significantly increased network complexity such as connectivity, connectance, average clustering coefficient, relative modularity, and the number of species acting at network hubs and connectors as well as resulted in the greater temporal variation of complexity indices. Molecular ecological networks under CT cropland use became significantly more robust and less vulnerable, overall increasing network stability. The relationship between network complexity and stability was also substantially strengthened due to land use conversion. Lastly, CT cropland use decreased the number of relationships between network structure and environmental properties instead of being strongly correlated to management disturbances. These results indicate that agricultural disturbance generally increases the complexity and stability of species “interactions”, possibly as a trade-off for biodiversity loss to support ecosystem function when faced with frequent agricultural disturbance.