Drought increases microbial allocation to stress tolerance but with few tradeoffs among community-level traits

Journal Article · Sat Mar 15 00:00:00 EDT 2025 · Soil Biology and Biochemistry

DOI:https://doi.org/10.1016/j.soilbio.2025.109787· OSTI ID:2574295

Jones, Jennifer M. ^[1]; Benucci, Gian Maria Niccolò ^[2]; Evans, Sarah E. ^[1]

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1. Michigan State University, Hickory Corners, MI (United States)
2. Michigan State University, East Lansing, MI (United States); Great Lakes Bioenergy Research Center (GLBRC), East Lansing, MI (United States)

Climate change will increase soil drying, altering microbial communities via increasing water stress and decreasing resource availability. The responses of these microbial communities to changing environments could be governed by physiological tradeoffs between high yield, resource acquisition, and stress tolerance (YAS framework). We leveraged a unique field experiment that manipulates both drought and carbon availability across two years and three land uses, and we measured both physiological (with bioassays) and genetic (with metagenomics) microbial traits at the community level to test the following hypotheses: 1. Drought increases microbial allocation to stress tolerance functions, at both physiological and genetic levels. 2. Because microbes are resource-limited under drought, increased carbon will enable greater expression of stress tolerance. 3. All three key life history traits described in the YAS framework will trade off. Drought did increase microbial physiological investment in stress tolerance (measured via trehalose production), but we saw few other changes in microbial communities under drought. Adding carbon to plots increased resource acquisition (measured via enzyme activity and resource acquisition gene abundance) and stress tolerance (trehalose assay), but did so in both drought and average rainfall environments. Here, we found little evidence of trait tradeoffs, as a negative correlation between rRNA copy number and resource acquisition gene abundance was the only significant negative correlation between traits that we found that was consistent across years (for physiological or genetic traits). In summary, we found C addition, and to a lesser extent, drought, altered microbial community function and functional genes. However, resources did not alter drought response in a way that was consistent with theory of life history tradeoffs.

• Research Organization: University of Wisconsin, Madison, WI (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Biological and Environmental Research (BER)
• Grant/Contract Number: SC0018409
• OSTI ID: 2574295
• Journal Information: Soil Biology and Biochemistry, Journal Name: Soil Biology and Biochemistry Vol. 205; ISSN 0038-0717
• Publisher: Elsevier
• Country of Publication: United States
• Language: English