Cultivating an Understanding of Microbial Diversity

October 9, 2019

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Model of the combination of factors that increase microbial diversity. Green arrows indicate higher diversity and red arrows indicate lower diversity with arrow thickness representing the strength of the effect.
Model of the combination of factors that increase microbial diversity. Green arrows indicate higher diversity and red arrows indicate lower diversity with arrow thickness representing the strength of the effect.
Image courtesy of PNNL (https://doi.org/10.1016/j.soilbio.2019.01.016 for citation)

The Science

Biodiversity protects ecosystems from stressors, increases ecosystem services, and promotes sustainability by enhancing resilience. Researchers studied how plant growth, agricultural management, and season influence the diversity of microbial communities. Within soil clumps called aggregates, scientists saw that smaller soil aggregates had more bacterial and fungal diversity than larger ones.They also found that microbial diversity increases with plant diversity and changes seasonally. Larger soil aggregates were less diverse. But they had communities of microbes, known as microbiomes, that are more sensitive to environmental changes over the course of seasons.

The Impact

Understanding what controls the diversity and function of soil microbes can help researchers better predict how productive and healthy soil will be. This information can also help scientists predict how climate and environmental changes will influence the soil. Land management services might use this knowledge to enhance biodiversity and the benefits soil provides to society.

Summary

Within soil systems, microbes maintain nutrient cycling, influence plant productivity, enhance drought tolerance, and impact soil health and fertility. However, the ecological rules that reinforce soil biodiversity and microbial activities are not clearly defined at a microbial scale. This study helps close an important knowledge gap by investigating how the spatial structure of soil is vital to understanding the impact of microbiomes on ecosystem and biogeochemical services. Historically, researchers have examined microbial diversity in soils at ecosystem or landscape scales. In this study, researchers chose different size soil aggregates as a way to represent microbially relevant scales. Over years and seasons, soil aggregate turnover is dynamic and thereby structures soil microbial habitats. Temporal data from different size soil aggregates and three different bioenergy management systems revealed discrete microbial communities. This research is pertinent to evaluating how different management practices impact spatially discrete microbial communities in the soil. Management practices that increase plant diversity across growing seasons, the authors demonstrate, influence soil aggregate habitats and therefore increase microbial diversity. The study underscores the importance of including both spatial and temporal dynamics in investigations in order to fully understand microbial community assembly and persistence in soil.

Contact

(BER PM)
Dawn Adin
Office of Biological and Environmental Research, Office of Science, U.S. Department of Energy
dawn.adin@science.doe.gov

(PI Contact)
Kirsten Hofmockel
Pacific Northwest National Laboratory
Kirsten.Hofmockel@pnnl.gov

Funding

This research was supported by the the Biological and Environmental Research program within the Office of Science at the U.S. Department of Energy, under the award DE-SC0010775.

Publications

R.N. Upton, E.M. Bach, K.S. Hofmockel. “Spatio-temporal microbial community dynamics within soil aggregates.Soil Biology and Biochemistry 132 (2019) 58-68. DOI: [10.1016/j.soilbio.2019.01.016]