TY - JOUR
T1 - Active populations and growth of soil microorganisms are framed by mean annual precipitation in three California annual grasslands
AU - Foley, Megan M.
AU - Blazewicz, Steven J.
AU - McFarlane, Karis J.
AU - Greenlon, Alex
AU - Hayer, Michaela
AU - Kimbrel, Jeffrey A.
AU - Koch, Benjamin J.
AU - Monsaint-Queeney, Victoria L.
AU - Morrison, Keith
AU - Morrissey, Ember
AU - Hungate, Bruce A.
AU - Pett-Ridge, Jennifer
N1 - Funding Information:
We thank Erin Nuccio, Amrita Bhattacharyya, Christina Ramon, and Aaron Chew for assistance with field sampling and lab analyses; John Bailey and Allison Smith at Hopland Research and Extension Center for help gathering meteorological data; and the Oregon State University Soil Lab for chemical and physical soil analyses. We would like to thank Thomas Bristow, at the NASA Ames Research Center, for allowing access to his lab space for qXRD analysis, and the Stable Isotope Laboratory at UC Berkeley for stable isotope analyses. MM Foley was supported by a National Science Foundation Graduate Research Fellowship while completing this work. This research was supported by the U.S. Department of Energy, Office of Biological and Environmental Research, Genomic Science Program ‘Microbes Persist’ Scientific Focus Area (# SCW1632 ) at Lawrence Livermore National Laboratory (LLNL) and a subcontract to Northern Arizona University. Work conducted at LLNL was conducted under the auspices of the US Department of Energy under Contract DE-AC52-07NA27344.
Funding Information:
We thank Erin Nuccio, Amrita Bhattacharyya, Christina Ramon, and Aaron Chew for assistance with field sampling and lab analyses; John Bailey and Allison Smith at Hopland Research and Extension Center for help gathering meteorological data; and the Oregon State University Soil Lab for chemical and physical soil analyses. We would like to thank Thomas Bristow, at the NASA Ames Research Center, for allowing access to his lab space for qXRD analysis, and the Stable Isotope Laboratory at UC Berkeley for stable isotope analyses. MM Foley was supported by a National Science Foundation Graduate Research Fellowship while completing this work. This research was supported by the U.S. Department of Energy, Office of Biological and Environmental Research, Genomic Science Program ‘Microbes Persist’ Scientific Focus Area (#SCW1632) at Lawrence Livermore National Laboratory (LLNL) and a subcontract to Northern Arizona University. Work conducted at LLNL was conducted under the auspices of the US Department of Energy under Contract DE-AC52-07NA27344.
Publisher Copyright:
© 2022
PY - 2023/2
Y1 - 2023/2
N2 - Climate influences soil microbial composition and function, but the relative importance of a site's historic climate versus its more immediate environmental conditions is unclear. Using quantitative stable isotope probing (qSIP), we characterized actively growing soil microbial communities and soil properties in three California annual grasslands that span a rainfall gradient and have developed on similar parent material. The soils were assayed in the wet winter season, when environmental conditions are most similar across sites. Since growing populations might be expected to be most responsive to contemporary environmental conditions, we hypothesized that the structure of growing microbial communities would be more similar across the gradient than that of total communities (i.e., including non-growing populations). In addition, we hypothesized that population growth rates would be slowest in the driest site, reflecting a legacy effect of low soil moisture on microbial growth. Soils along the rainfall gradient differed in pH, texture, and cation exchange capacity, but not in total C, C:N or dominant minerals. The radiocarbon (14C) age of soil C (reflecting turnover time) increased with mean annual precipitation but soil respiration was uniformly modern, reflecting microbial reliance on recent C inputs across the sites. The structure of both total and growing microbial communities differed across sites. Across major microbial phyla, including the Actinobacteria, Acidobacteria, Bacteroidetes, Gemmatimonadetes and Proteobacteria, bacterial growth rates were consistently lower in the site with the lowest mean annual precipitation. Taxa that were growing at the dry site alone grew more slowly than taxa that grew at multiple sites. These results reflect the influence of climate history and point to the role of environmental filtering at the driest site in shaping its slower growing microbial community, possibly reflecting adaptation to repeated exposure to water stress. Lastly, across taxa, the growth rate of a taxon at one site was correlated with its growth rate in the other sites. This growth rate coherence is likely a consequence of genetically determined physiological traits and is consistent with the idea that evolutionary history constrains growth rate.
AB - Climate influences soil microbial composition and function, but the relative importance of a site's historic climate versus its more immediate environmental conditions is unclear. Using quantitative stable isotope probing (qSIP), we characterized actively growing soil microbial communities and soil properties in three California annual grasslands that span a rainfall gradient and have developed on similar parent material. The soils were assayed in the wet winter season, when environmental conditions are most similar across sites. Since growing populations might be expected to be most responsive to contemporary environmental conditions, we hypothesized that the structure of growing microbial communities would be more similar across the gradient than that of total communities (i.e., including non-growing populations). In addition, we hypothesized that population growth rates would be slowest in the driest site, reflecting a legacy effect of low soil moisture on microbial growth. Soils along the rainfall gradient differed in pH, texture, and cation exchange capacity, but not in total C, C:N or dominant minerals. The radiocarbon (14C) age of soil C (reflecting turnover time) increased with mean annual precipitation but soil respiration was uniformly modern, reflecting microbial reliance on recent C inputs across the sites. The structure of both total and growing microbial communities differed across sites. Across major microbial phyla, including the Actinobacteria, Acidobacteria, Bacteroidetes, Gemmatimonadetes and Proteobacteria, bacterial growth rates were consistently lower in the site with the lowest mean annual precipitation. Taxa that were growing at the dry site alone grew more slowly than taxa that grew at multiple sites. These results reflect the influence of climate history and point to the role of environmental filtering at the driest site in shaping its slower growing microbial community, possibly reflecting adaptation to repeated exposure to water stress. Lastly, across taxa, the growth rate of a taxon at one site was correlated with its growth rate in the other sites. This growth rate coherence is likely a consequence of genetically determined physiological traits and is consistent with the idea that evolutionary history constrains growth rate.
KW - Environmental filtering
KW - Legacy effect
KW - Radiocarbon
KW - Soil carbon persistence
KW - Soil water
KW - Taxon-specific microbial growth
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UR - http://www.scopus.com/inward/citedby.url?scp=85143733238&partnerID=8YFLogxK
U2 - 10.1016/j.soilbio.2022.108886
DO - 10.1016/j.soilbio.2022.108886
M3 - Article
AN - SCOPUS:85143733238
SN - 0038-0717
VL - 177
JO - Soil Biology and Biochemistry
JF - Soil Biology and Biochemistry
M1 - 108886
ER -