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Michaud TJ, Cline LC, Hobbie EA, Gutknecht JLM, Kennedy PG. Herbarium specimens reveal that mycorrhizal type does not mediate declining temperate tree nitrogen status over a century of environmental change. THE NEW PHYTOLOGIST 2024; 242:1717-1724. [PMID: 38073143 DOI: 10.1111/nph.19452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Accepted: 10/27/2023] [Indexed: 04/26/2024]
Abstract
Rising atmospheric carbon dioxide concentrations (CO2) and atmospheric nitrogen (N) deposition have contrasting effects on ectomycorrhizal (EM) and arbuscular mycorrhizal (AM) symbioses, potentially mediating forest responses to environmental change. In this study, we evaluated the cumulative effects of historical environmental change on N concentrations and δ15N values in AM plants, EM plants, EM fungi, and saprotrophic fungi using herbarium specimens collected in Minnesota, USA from 1871 to 2016. To better understand mycorrhizal mediation of foliar δ15N, we also analyzed a subset of previously published foliar δ15N values from across the United States to parse the effects of N deposition and CO2 rise. Over the last century in Minnesota, N concentrations declined among all groups except saprotrophic fungi. δ15N also declined among all groups of plants and fungi; however, foliar δ15N declined less in EM plants than in AM plants. In the analysis of previously published foliar δ15N values, this slope difference between EM and AM plants was better explained by nitrogen deposition than by CO2 rise. Mycorrhizal type did not explain trajectories of plant N concentrations. Instead, plants and EM fungi exhibited similar declines in N concentrations, consistent with declining forest N status despite moderate levels of N deposition.
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Affiliation(s)
- Talia J Michaud
- Department of Plant and Microbial Biology, University of Minnesota, St Paul, MN, 55108, USA
| | | | - Erik A Hobbie
- Earth Systems Research Center, University of New Hampshire, Durham, NH, 03824, USA
| | - Jessica L M Gutknecht
- Department of Soil, Water, and Climate, University of Minnesota, St Paul, MN, 55108, USA
| | - Peter G Kennedy
- Department of Plant and Microbial Biology, University of Minnesota, St Paul, MN, 55108, USA
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Netherway T, Bengtsson J, Buegger F, Fritscher J, Oja J, Pritsch K, Hildebrand F, Krab EJ, Bahram M. Pervasive associations between dark septate endophytic fungi with tree root and soil microbiomes across Europe. Nat Commun 2024; 15:159. [PMID: 38167673 PMCID: PMC10761831 DOI: 10.1038/s41467-023-44172-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Accepted: 12/04/2023] [Indexed: 01/05/2024] Open
Abstract
Trees interact with a multitude of microbes through their roots and root symbionts such as mycorrhizal fungi and root endophytes. Here, we explore the role of fungal root symbionts as predictors of the soil and root-associated microbiomes of widespread broad-leaved trees across a European latitudinal gradient. Our results suggest that, alongside factors such as climate, soil, and vegetation properties, root colonization by ectomycorrhizal, arbuscular mycorrhizal, and dark septate endophytic fungi also shapes tree-associated microbiomes. Notably, the structure of root and soil microbiomes across our sites is more strongly and consistently associated with dark septate endophyte colonization than with mycorrhizal colonization and many abiotic factors. Root colonization by dark septate endophytes also has a consistent negative association with the relative abundance and diversity of nutrient cycling genes. Our study not only indicates that root-symbiotic interactions are an important factor structuring soil communities and functions in forest ecosystems, but also that the hitherto less studied dark septate endophytes are likely to be central players in these interactions.
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Affiliation(s)
- Tarquin Netherway
- Department of Ecology, Swedish University of Agricultural Sciences, Ulls väg 16, 756 51, Uppsala, Sweden.
| | - Jan Bengtsson
- Department of Ecology, Swedish University of Agricultural Sciences, Ulls väg 16, 756 51, Uppsala, Sweden
| | - Franz Buegger
- Research Unit for Environmental Simulation (EUS), German Research Center for Environmental Health, Helmholtz Zentrum München, Ingolstaedter Landstr. 1, 85764, Neuherberg, Germany
| | - Joachim Fritscher
- Quadram Institute Bioscience, Norwich Research Park, Norwich, Norfolk, NR4 7UQ, UK
- Digital Biology, Earlham Institute, Norwich Research Park, Norwich, Norfolk, NR4 7UQ, UK
| | - Jane Oja
- Department of Botany, Institute of Ecology and Earth Sciences, University of Tartu, 40 Lai St, Tartu, Estonia
| | - Karin Pritsch
- Research Unit for Environmental Simulation (EUS), German Research Center for Environmental Health, Helmholtz Zentrum München, Ingolstaedter Landstr. 1, 85764, Neuherberg, Germany
| | - Falk Hildebrand
- Quadram Institute Bioscience, Norwich Research Park, Norwich, Norfolk, NR4 7UQ, UK
- Digital Biology, Earlham Institute, Norwich Research Park, Norwich, Norfolk, NR4 7UQ, UK
| | - Eveline J Krab
- Department of Soil and Environment, Swedish University of Agricultural Sciences, Lennart Hjelms väg 9, 750 07, Uppsala, Sweden
| | - Mohammad Bahram
- Department of Ecology, Swedish University of Agricultural Sciences, Ulls väg 16, 756 51, Uppsala, Sweden
- Department of Botany, Institute of Ecology and Earth Sciences, University of Tartu, 40 Lai St, Tartu, Estonia
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Hawkins HJ, Cargill RIM, Van Nuland ME, Hagen SC, Field KJ, Sheldrake M, Soudzilovskaia NA, Kiers ET. Mycorrhizal mycelium as a global carbon pool. Curr Biol 2023; 33:R560-R573. [PMID: 37279689 DOI: 10.1016/j.cub.2023.02.027] [Citation(s) in RCA: 25] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
For more than 400 million years, mycorrhizal fungi and plants have formed partnerships that are crucial to the emergence and functioning of global ecosystems. The importance of these symbiotic fungi for plant nutrition is well established. However, the role of mycorrhizal fungi in transporting carbon into soil systems on a global scale remains under-explored. This is surprising given that ∼75% of terrestrial carbon is stored belowground and mycorrhizal fungi are stationed at a key entry point of carbon into soil food webs. Here, we analyze nearly 200 datasets to provide the first global quantitative estimates of carbon allocation from plants to the mycelium of mycorrhizal fungi. We estimate that global plant communities allocate 3.93 Gt CO2e per year to arbuscular mycorrhizal fungi, 9.07 Gt CO2e per year to ectomycorrhizal fungi, and 0.12 Gt CO2e per year to ericoid mycorrhizal fungi. Based on this estimate, 13.12 Gt of CO2e fixed by terrestrial plants is, at least temporarily, allocated to the underground mycelium of mycorrhizal fungi per year, equating to ∼36% of current annual CO2 emissions from fossil fuels. We explore the mechanisms by which mycorrhizal fungi affect soil carbon pools and identify approaches to increase our understanding of global carbon fluxes via plant-fungal pathways. Our estimates, although based on the best available evidence, are imperfect and should be interpreted with caution. Nonetheless, our estimations are conservative, and we argue that this work confirms the significant contribution made by mycorrhizal associations to global carbon dynamics. Our findings should motivate their inclusion both within global climate and carbon cycling models, and within conservation policy and practice.
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Affiliation(s)
- Heidi-Jayne Hawkins
- Department of Biological Sciences, University of Cape Town, Cape Town 7701, South Africa; Conservation International, Forrest House, Belmont Park, Cape Town 7700, South Africa.
| | - Rachael I M Cargill
- Amsterdam Institute for Life and Environment, Vrije Universiteit, De Boelelaan 1085, NL-1081 HV Amsterdam, The Netherlands; AMOLF, Science Park 102, Amsterdam, The Netherlands
| | - Michael E Van Nuland
- Amsterdam Institute for Life and Environment, Vrije Universiteit, De Boelelaan 1085, NL-1081 HV Amsterdam, The Netherlands; Society for the Protection of Underground Networks, SPUN, 3500 South DuPont Highway, Dover, DE 19901, USA
| | | | - Katie J Field
- Plants, Photosynthesis and Soil, School of Biosciences, The University of Sheffield, Western Bank, Sheffield S10 2TN, UK
| | - Merlin Sheldrake
- Amsterdam Institute for Life and Environment, Vrije Universiteit, De Boelelaan 1085, NL-1081 HV Amsterdam, The Netherlands; Society for the Protection of Underground Networks, SPUN, 3500 South DuPont Highway, Dover, DE 19901, USA
| | | | - E Toby Kiers
- Amsterdam Institute for Life and Environment, Vrije Universiteit, De Boelelaan 1085, NL-1081 HV Amsterdam, The Netherlands; Society for the Protection of Underground Networks, SPUN, 3500 South DuPont Highway, Dover, DE 19901, USA
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