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Domeignoz-Horta LA, Pold G, Erb H, Sebag D, Verrecchia E, Northen T, Louie K, Eloe-Fadrosh E, Pennacchio C, Knorr MA, Frey SD, Melillo JM, DeAngelis KM. Substrate availability and not thermal acclimation controls microbial temperature sensitivity response to long-term warming. Glob Chang Biol 2023; 29:1574-1590. [PMID: 36448874 DOI: 10.1111/gcb.16544] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Accepted: 11/18/2022] [Indexed: 05/28/2023]
Abstract
Microbes are responsible for cycling carbon (C) through soils, and predicted changes in soil C stocks under climate change are highly sensitive to shifts in the mechanisms assumed to control the microbial physiological response to warming. Two mechanisms have been suggested to explain the long-term warming impact on microbial physiology: microbial thermal acclimation and changes in the quantity and quality of substrates available for microbial metabolism. Yet studies disentangling these two mechanisms are lacking. To resolve the drivers of changes in microbial physiology in response to long-term warming, we sampled soils from 13- and 28-year-old soil warming experiments in different seasons. We performed short-term laboratory incubations across a range of temperatures to measure the relationships between temperature sensitivity of physiology (growth, respiration, carbon use efficiency, and extracellular enzyme activity) and the chemical composition of soil organic matter. We observed apparent thermal acclimation of microbial respiration, but only in summer, when warming had exacerbated the seasonally-induced, already small dissolved organic matter pools. Irrespective of warming, greater quantity and quality of soil carbon increased the extracellular enzymatic pool and its temperature sensitivity. We propose that fresh litter input into the system seasonally cancels apparent thermal acclimation of C-cycling processes to decadal warming. Our findings reveal that long-term warming has indirectly affected microbial physiology via reduced C availability in this system, implying that earth system models including these negative feedbacks may be best suited to describe long-term warming effects on these soils.
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Affiliation(s)
- Luiz A Domeignoz-Horta
- Department of Microbiology, University of Massachusetts, Amherst, Massachusetts, USA
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland
| | - Grace Pold
- Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Hailey Erb
- Department of Microbiology, University of Massachusetts, Amherst, Massachusetts, USA
| | - David Sebag
- IFP Energies Nouvelles, Rueil-Malmaison, France
- Faculty of Geosciences and the Environment, Institute of Earth Surface Dynamics, University of Lausanne, Lausanne, Switzerland
| | - Eric Verrecchia
- Faculty of Geosciences and the Environment, Institute of Earth Surface Dynamics, University of Lausanne, Lausanne, Switzerland
| | - Trent Northen
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, California, USA
- The DOE Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, California, USA
| | - Katherine Louie
- The DOE Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, California, USA
| | - Emiley Eloe-Fadrosh
- The DOE Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, California, USA
| | - Christa Pennacchio
- The DOE Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, California, USA
| | - Melissa A Knorr
- School of Natural Resources and the Environment, University of New Hampshire, Durham, New Hampshire, USA
| | - Serita D Frey
- School of Natural Resources and the Environment, University of New Hampshire, Durham, New Hampshire, USA
| | - Jerry M Melillo
- The Ecosystems Center, Marine Biological Laboratories, Woods Hole, Massachusetts, USA
| | - Kristen M DeAngelis
- Department of Microbiology, University of Massachusetts, Amherst, Massachusetts, USA
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Dacal M, García-Palacios P, Asensio S, Cano-Díaz C, Gozalo B, Ochoa V, Maestre FT. Contrasting mechanisms underlie short- and longer-term soil respiration responses to experimental warming in a dryland ecosystem. Glob Chang Biol 2020; 26:5254-5266. [PMID: 32510698 DOI: 10.1111/gcb.15209] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Revised: 04/17/2020] [Accepted: 05/26/2020] [Indexed: 06/11/2023]
Abstract
Soil carbon losses to the atmosphere through soil respiration are expected to rise with ongoing temperature increases, but available evidence from mesic biomes suggests that such response disappears after a few years of experimental warming. However, there is lack of empirical basis for these temporal dynamics in soil respiration responses, and for the mechanisms underlying them, in drylands, which collectively form the largest biome on Earth and store 32% of the global soil organic carbon pool. We coupled data from a 10 year warming experiment in a biocrust-dominated dryland ecosystem with laboratory incubations to confront 0-2 years (short-term hereafter) versus 8-10 years (longer-term hereafter) soil respiration responses to warming. Our results showed that increased soil respiration rates with short-term warming observed in areas with high biocrust cover returned to control levels in the longer-term. Warming-induced increases in soil temperature were the main drivers of the short-term soil respiration responses, whereas longer-term soil respiration responses to warming were primarily driven by thermal acclimation and warming-induced reductions in biocrust cover. Our results highlight the importance of evaluating short- and longer-term soil respiration responses to warming as a mean to reduce the uncertainty in predicting the soil carbon-climate feedback in drylands.
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Affiliation(s)
- Marina Dacal
- Departamento de Biología y Geología, Física y Química Inorgánica, Universidad Rey Juan Carlos, Móstoles, Spain
- Instituto Multidisciplinar para el Estudio del Medio "Ramon Margalef", Universidad de Alicante, Alicante, Spain
| | - Pablo García-Palacios
- Instituto de Ciencias Agrarias, Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - Sergio Asensio
- Instituto Multidisciplinar para el Estudio del Medio "Ramon Margalef", Universidad de Alicante, Alicante, Spain
| | - Concha Cano-Díaz
- Departamento de Biología y Geología, Física y Química Inorgánica, Universidad Rey Juan Carlos, Móstoles, Spain
| | - Beatriz Gozalo
- Instituto Multidisciplinar para el Estudio del Medio "Ramon Margalef", Universidad de Alicante, Alicante, Spain
| | - Victoria Ochoa
- Instituto Multidisciplinar para el Estudio del Medio "Ramon Margalef", Universidad de Alicante, Alicante, Spain
| | - Fernando T Maestre
- Instituto Multidisciplinar para el Estudio del Medio "Ramon Margalef", Universidad de Alicante, Alicante, Spain
- Departamento de Ecología, Universidad de Alicante, Alicante, Spain
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García-Palacios P, Escolar C, Dacal M, Delgado-Baquerizo M, Gozalo B, Ochoa V, Maestre FT. Pathways regulating decreased soil respiration with warming in a biocrust-dominated dryland. Glob Chang Biol 2018; 24:4645-4656. [PMID: 30007104 DOI: 10.1111/gcb.14399] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Revised: 05/17/2018] [Accepted: 05/31/2018] [Indexed: 06/08/2023]
Abstract
A positive soil carbon (C)-climate feedback is embedded into the climatic models of the IPCC. However, recent global syntheses indicate that the temperature sensitivity of soil respiration (RS ) in drylands, the largest biome on Earth, is actually lower in warmed than in control plots. Consequently, soil C losses with future warming are expected to be low compared with other biomes. Nevertheless, the empirical basis for these global extrapolations is still poor in drylands, due to the low number of field experiments testing the pathways behind the long-term responses of soil respiration (RS ) to warming. Importantly, global drylands are covered with biocrusts (communities formed by bryophytes, lichens, cyanobacteria, fungi, and bacteria), and thus, RS responses to warming may be driven by both autotrophic and heterotrophic pathways. Here, we evaluated the effects of 8-year experimental warming on RS , and the different pathways involved, in a biocrust-dominated dryland in southern Spain. We also assessed the overall impacts on soil organic C (SOC) accumulation over time. Across the years and biocrust cover levels, warming reduced RS by 0.30 μmol CO2 m-2 s-1 (95% CI = -0.24 to 0.84), although the negative warming effects were only significant after 3 years of elevated temperatures in areas with low initial biocrust cover. We found support for different pathways regulating the warming-induced reduction in RS at areas with low (microbial thermal acclimation via reduced soil mass-specific respiration and β-glucosidase enzymatic activity) vs. high (microbial thermal acclimation jointly with a reduction in autotrophic respiration from decreased lichen cover) initial biocrust cover. Our 8-year experimental study shows a reduction in soil respiration with warming and highlights that biocrusts should be explicitly included in modeling efforts aimed to quantify the soil C-climate feedback in drylands.
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Affiliation(s)
- Pablo García-Palacios
- Departamento de Biología y Geología, Física y Química Inorgánica y Analítica, Escuela Superior de Ciencias Experimentales y Tecnología, Universidad Rey Juan Carlos, Móstoles, Spain
| | - Cristina Escolar
- Departamento de Biología y Geología, Física y Química Inorgánica y Analítica, Escuela Superior de Ciencias Experimentales y Tecnología, Universidad Rey Juan Carlos, Móstoles, Spain
| | - Marina Dacal
- Departamento de Biología y Geología, Física y Química Inorgánica y Analítica, Escuela Superior de Ciencias Experimentales y Tecnología, Universidad Rey Juan Carlos, Móstoles, Spain
| | - Manuel Delgado-Baquerizo
- Departamento de Biología y Geología, Física y Química Inorgánica y Analítica, Escuela Superior de Ciencias Experimentales y Tecnología, Universidad Rey Juan Carlos, Móstoles, Spain
- Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, Colorado
| | - Beatriz Gozalo
- Departamento de Biología y Geología, Física y Química Inorgánica y Analítica, Escuela Superior de Ciencias Experimentales y Tecnología, Universidad Rey Juan Carlos, Móstoles, Spain
| | - Victoria Ochoa
- Departamento de Biología y Geología, Física y Química Inorgánica y Analítica, Escuela Superior de Ciencias Experimentales y Tecnología, Universidad Rey Juan Carlos, Móstoles, Spain
| | - Fernando T Maestre
- Departamento de Biología y Geología, Física y Química Inorgánica y Analítica, Escuela Superior de Ciencias Experimentales y Tecnología, Universidad Rey Juan Carlos, Móstoles, Spain
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