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Slate ML, Antoninka A, Bailey L, Berdugo MB, Callaghan DA, Cárdenas M, Chmielewski MW, Fenton NJ, Holland-Moritz H, Hopkins S, Jean M, Kraichak BE, Lindo Z, Merced A, Oke T, Stanton D, Stuart J, Tucker D, Coe KK. Impact of changing climate on bryophyte contributions to terrestrial water, carbon, and nitrogen cycles. THE NEW PHYTOLOGIST 2024; 242:2411-2429. [PMID: 38659154 DOI: 10.1111/nph.19772] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Accepted: 03/22/2024] [Indexed: 04/26/2024]
Abstract
Bryophytes, including the lineages of mosses, liverworts, and hornworts, are the second-largest photoautotroph group on Earth. Recent work across terrestrial ecosystems has highlighted how bryophytes retain and control water, fix substantial amounts of carbon (C), and contribute to nitrogen (N) cycles in forests (boreal, temperate, and tropical), tundra, peatlands, grasslands, and deserts. Understanding how changing climate affects bryophyte contributions to global cycles in different ecosystems is of primary importance. However, because of their small physical size, bryophytes have been largely ignored in research on water, C, and N cycles at global scales. Here, we review the literature on how bryophytes influence global biogeochemical cycles, and we highlight that while some aspects of global change represent critical tipping points for survival, bryophytes may also buffer many ecosystems from change due to their capacity for water, C, and N uptake and storage. However, as the thresholds of resistance of bryophytes to temperature and precipitation regime changes are mostly unknown, it is challenging to predict how long this buffering capacity will remain functional. Furthermore, as ecosystems shift their global distribution in response to changing climate, the size of different bryophyte-influenced biomes will change, resulting in shifts in the magnitude of bryophyte impacts on global ecosystem functions.
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Affiliation(s)
- Mandy L Slate
- Department of Evolution, Ecology & Organismal Biology, The Ohio State University, Columbus, OH, 43210, USA
| | - Anita Antoninka
- School of Forestry, Northern Arizona University, Flagstaff, AZ, 86005, USA
| | - Lydia Bailey
- School of Forestry, Northern Arizona University, Flagstaff, AZ, 86005, USA
| | - Monica B Berdugo
- Plant Ecology and Geobotany, Department of Biology, University of Marburg, Karl-von-Frisch Str. 8, 35043, Marburg, Germany
| | - Des A Callaghan
- Bryophyte Surveys Ltd, Almondsbury, South Gloucestershire, BS32 4DU, UK
| | - Mariana Cárdenas
- Department of Ecology Evolution and Behavior, University of Minnesota, Saint Paul, MN, 55108, USA
| | | | - Nicole J Fenton
- Université du Québec en Abitibi-Témiscamingue, Rouyn-Noranda, QC, J9X 5E4, Canada
| | - Hannah Holland-Moritz
- Department of Natural Resources and the Environment, University of New Hampshire, Durham, NH, 03824, USA
| | - Samantha Hopkins
- Department of Biology, University of Western Ontario, London, ON, N6A 3K7, Canada
| | - Mélanie Jean
- Université de Moncton, Moncton, NB, E1A 3E9, Canada
| | - Bier Ekaphan Kraichak
- Department of Botany, Faculty of Science, Kasetsart University in Bangkok, Bangkok, 10900, Thailand
| | - Zoë Lindo
- Department of Biology, University of Western Ontario, London, ON, N6A 3K7, Canada
| | - Amelia Merced
- Department of Biology, University of Puerto Rico Río Piedras, San Juan, PR, 00925, USA
| | - Tobi Oke
- Wildlife Conservation Society & School of Environment & Sustainability, University of Saskatchewan, Saskatoon, SK, S7N 5C8, Canada
| | - Daniel Stanton
- Department of Ecology Evolution and Behavior, University of Minnesota, Saint Paul, MN, 55108, USA
| | - Julia Stuart
- College of Forest Resources and Environmental Science, Michigan Technological University, Houghton, MI, 49931, USA
- Mountain Planning Service Group, US Forest Service, Lakewood, CO, 80401, USA
| | - Daniel Tucker
- School of Environmental Studies, University of Victoria, Victoria, BC, V8P 5C2, Canada
| | - Kirsten K Coe
- Department of Biology, Middlebury College, Middlebury, VT, 05753, USA
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2
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Yu Z, Zhang C, Liu X, Lei J, Zhang Q, Yuan Z, Peng C, Koerner SE, Xu J, Guo L. Responses of C:N:P stoichiometric correlations among plants, soils and microorganisms to warming: A meta-analysis. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 912:168827. [PMID: 38030014 DOI: 10.1016/j.scitotenv.2023.168827] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Revised: 11/21/2023] [Accepted: 11/22/2023] [Indexed: 12/01/2023]
Abstract
Plants, soils and microorganisms play important roles in maintaining stable terrestrial stoichiometry. Studying how nutrient balances of these biotic and abiotic players vary across temperature gradients is important when predicting ecosystem changes on a warming planet. The respective responses of plant, soil and microbial stoichiometric ratios to warming have been observed, however, whether and how the stoichiometric correlations among the three components shift under warming has not been clearly understood and identified. In the present study, we have performed a meta-analysis based on 600 case studies from 74 sites or locations to clarify whether and how warming affects plant, soil and microbial stoichiometry, respectively, and their correlations. Our results indicated that: (1) globally, plants had higher C:N and C:P values compared to soil and microbial pools, but their N:P distributions were similar; (2) warming did not significantly alter plant, soil and microbial C:N and C:P values, but had a noticeable effect on plant N:P ratios. When ecosystem types, duration and magnitude of warming were taken into account, there was an inconsistent and even inverse warming response in terms of the direction and magnitude of changes in the C:N:P ratios occurring among plants, soils and microorganisms; (3) despite various warming responses of the stoichiometric ratios detected separately for plants, soils and microorganisms, the stoichiometric correlations among all three parts remained constant even under different warming scenarios. Our study highlighted the complexity of the effect of warming on the C:N:P stoichiometry, as well as the absence and importance of simultaneous measurements of stoichiometric ratios across different components of terrestrial ecosystems, which should be urgently strengthened in future studies.
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Affiliation(s)
- Zongkai Yu
- College of Grassland Agriculture, Northwest A&F University, Yangling 712100, China
| | - Chao Zhang
- State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Northwest A&F University, Yangling 712100, China
| | - Xiaowei Liu
- College of Grassland Agriculture, Northwest A&F University, Yangling 712100, China
| | - Jichu Lei
- The Research Center of Soil and Water Conservation and Ecological Environment, Chinese Academy of Sciences and Ministry of Education, Yangling 712100, China; Institute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of Water Resources, Yangling 712100, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Qiang Zhang
- College of Grassland Agriculture, Northwest A&F University, Yangling 712100, China
| | - Zhiyou Yuan
- State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Northwest A&F University, Yangling 712100, China
| | - Changhui Peng
- School of Geographic Sciences, Hunan Normal University, Changsha 410081, China; Department of Biology Science, Institute of Environment Sciences, University of Quebec at Montreal, H3C 3P8, Canada
| | - Sally E Koerner
- Department of Biology, University of North Carolina at Greensboro, Greensboro 27402, USA
| | - Jianchu Xu
- Center for Mountain Ecosystem Studies, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China; World Agroforestry Center, Nairobi 00100, Kenya
| | - Liang Guo
- State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Northwest A&F University, Yangling 712100, China; Institute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of Water Resources, Yangling 712100, China.
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3
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Purcell AM, Dijkstra P, Hungate BA, McMillen K, Schwartz E, van Gestel N. Rapid growth rate responses of terrestrial bacteria to field warming on the Antarctic Peninsula. THE ISME JOURNAL 2023; 17:2290-2302. [PMID: 37872274 PMCID: PMC10689830 DOI: 10.1038/s41396-023-01536-4] [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: 11/16/2022] [Revised: 10/05/2023] [Accepted: 10/09/2023] [Indexed: 10/25/2023]
Abstract
Ice-free terrestrial environments of the western Antarctic Peninsula are expanding and subject to colonization by new microorganisms and plants, which control biogeochemical cycling. Measuring growth rates of microbial populations and ecosystem carbon flux is critical for understanding how terrestrial ecosystems in Antarctica will respond to future warming. We implemented a field warming experiment in early (bare soil; +2 °C) and late (peat moss-dominated; +1.2 °C) successional glacier forefield sites on the western Antarctica Peninsula. We used quantitative stable isotope probing with H218O using intact cores in situ to determine growth rate responses of bacterial taxa to short-term (1 month) warming. Warming increased the growth rates of bacterial communities at both sites, even doubling the number of taxa exhibiting significant growth at the early site. Growth responses varied among taxa. Despite that warming induced a similar response for bacterial relative growth rates overall, the warming effect on ecosystem carbon fluxes was stronger at the early successional site-likely driven by increased activity of autotrophs which switched the ecosystem from a carbon source to a carbon sink. At the late-successional site, warming caused a significant increase in growth rate of many Alphaproteobacteria, but a weaker and opposite gross ecosystem productivity response that decreased the carbon sink-indicating that the carbon flux rates were driven more strongly by the plant communities. Such changes to bacterial growth and ecosystem carbon cycling suggest that the terrestrial Antarctic Peninsula can respond fast to increases in temperature, which can have repercussions for long-term elemental cycling and carbon storage.
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Affiliation(s)
- Alicia M Purcell
- Department of Biological Sciences, Texas Tech University, Lubbock, TX, USA.
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, USA.
- Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ, USA.
| | - Paul Dijkstra
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, USA
- Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ, USA
| | - Bruce A Hungate
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, USA
- Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ, USA
| | - Kelly McMillen
- Department of Biological Sciences, Texas Tech University, Lubbock, TX, USA
| | - Egbert Schwartz
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, USA
- Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ, USA
| | - Natasja van Gestel
- Department of Biological Sciences, Texas Tech University, Lubbock, TX, USA
- TTU Climate Center, Texas Tech University, Lubbock, TX, USA
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Schuur EAG, Hicks Pries C, Mauritz M, Pegoraro E, Rodenhizer H, See C, Ebert C. Ecosystem and soil respiration radiocarbon detects old carbon release as a fingerprint of warming and permafrost destabilization with climate change. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2023; 381:20220201. [PMID: 37807688 PMCID: PMC10642809 DOI: 10.1098/rsta.2022.0201] [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: 01/06/2023] [Accepted: 05/09/2023] [Indexed: 10/10/2023]
Abstract
The permafrost region has accumulated organic carbon in cold and waterlogged soils over thousands of years and now contains three times as much carbon as the atmosphere. Global warming is degrading permafrost with the potential to accelerate climate change as increased microbial decomposition releases soil carbon as greenhouse gases. A 19-year time series of soil and ecosystem respiration radiocarbon from Alaska provides long-term insight into changing permafrost soil carbon dynamics in a warmer world. Nine per cent of ecosystem respiration and 23% of soil respiration observations had radiocarbon values more than 50‰ lower than the atmospheric value. Furthermore, the overall trend of ecosystem and soil respiration radiocarbon values through time decreased more than atmospheric radiocarbon values did, indicating that old carbon degradation was enhanced. Boosted regression tree analyses showed that temperature and moisture environmental variables had the largest relative influence on lower radiocarbon values. This suggested that old carbon degradation was controlled by warming/permafrost thaw and soil drying together, as waterlogged soil conditions could protect soil carbon from microbial decomposition even when thawed. Overall, changing conditions increasingly favoured the release of old carbon, which is a definitive fingerprint of an accelerating feedback to climate change as a consequence of warming and permafrost destabilization. This article is part of the Theo Murphy meeting issue 'Radiocarbon in the Anthropocene'.
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Affiliation(s)
- Edward A. G. Schuur
- Center for Ecosystem Science and Society, and Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ 86011, USA
| | - Caitlin Hicks Pries
- Department of Biological Sciences, Dartmouth College, Hanover, NH 03755, USA
| | - Marguerite Mauritz
- Biological Sciences, University of Texas at El Paso, 500 West University Avenue, El Paso, TX 79902, USA
| | - Elaine Pegoraro
- Climate and Ecosystem Sciences Division, Lawrence Berkeley National Lab, Berkeley, CA, USA
| | | | - Craig See
- Center for Ecosystem Science and Society, and Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ 86011, USA
| | - Chris Ebert
- Center for Ecosystem Science and Society, and Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ 86011, USA
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5
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Porada P, Bader MY, Berdugo MB, Colesie C, Ellis CJ, Giordani P, Herzschuh U, Ma Y, Launiainen S, Nascimbene J, Petersen I, Raggio Quílez J, Rodríguez-Caballero E, Rousk K, Sancho LG, Scheidegger C, Seitz S, Van Stan JT, Veste M, Weber B, Weston DJ. A research agenda for nonvascular photoautotrophs under climate change. THE NEW PHYTOLOGIST 2023; 237:1495-1504. [PMID: 36511294 DOI: 10.1111/nph.18631] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Accepted: 11/17/2022] [Indexed: 06/17/2023]
Abstract
Nonvascular photoautotrophs (NVP), including bryophytes, lichens, terrestrial algae, and cyanobacteria, are increasingly recognized as being essential to ecosystem functioning in many regions of the world. Current research suggests that climate change may pose a substantial threat to NVP, but the extent to which this will affect the associated ecosystem functions and services is highly uncertain. Here, we propose a research agenda to address this urgent question, focusing on physiological and ecological processes that link NVP to ecosystem functions while also taking into account the substantial taxonomic diversity across multiple ecosystem types. Accordingly, we developed a new categorization scheme, based on microclimatic gradients, which simplifies the high physiological and morphological diversity of NVP and world-wide distribution with respect to several broad habitat types. We found that habitat-specific ecosystem functions of NVP will likely be substantially affected by climate change, and more quantitative process understanding is required on: (1) potential for acclimation; (2) response to elevated CO2 ; (3) role of the microbiome; and (4) feedback to (micro)climate. We suggest an integrative approach of innovative, multimethod laboratory and field experiments and ecophysiological modelling, for which sustained scientific collaboration on NVP research will be essential.
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Affiliation(s)
- Philipp Porada
- Ecological Modelling, Universität Hamburg, Ohnhorststr. 18, 22609, Hamburg, Germany
| | - Maaike Y Bader
- Ecological Plant Geography, University of Marburg, Deutschhausstr. 10, 35032, Marburg, Germany
| | - Monica B Berdugo
- Ecological Plant Geography, University of Marburg, Deutschhausstr. 10, 35032, Marburg, Germany
| | - Claudia Colesie
- School of Geosciences, University of Edinburgh, Edinburgh, EH9 3JW, UK
| | | | | | - Ulrike Herzschuh
- Polar Terrestrial Environmental Systems, Alfred Wegener Institute, Telegrafenberg A45, 14473, Potsdam, Germany
| | - Yunyao Ma
- Ecological Modelling, Universität Hamburg, Ohnhorststr. 18, 22609, Hamburg, Germany
| | - Samuli Launiainen
- Ecosystems and Modeling, Natural Resources Institute Finland (Luke), Latokartanonkaari 9, 00790, Helsinki, Finland
| | - Juri Nascimbene
- BIOME Lab, Department of Biological, Geological and Environmental Sciences, Alma Mater Studiorum University of Bologna, 40126, Bologna, Italy
| | - Imke Petersen
- Ecological Modelling, Universität Hamburg, Ohnhorststr. 18, 22609, Hamburg, Germany
| | - José Raggio Quílez
- Department of Pharmacology, Pharmacognosy and Botany, Universidad Complutense de Madrid, E-28040, Madrid, Spain
| | | | - Kathrin Rousk
- Department of Biology, University of Copenhagen, Universitetsparken 15, 2100, København, Denmark
| | - Leopoldo G Sancho
- Department of Pharmacology, Pharmacognosy and Botany, Universidad Complutense de Madrid, E-28040, Madrid, Spain
| | - Christoph Scheidegger
- Biodiversity and Conservation Biology, Eidg. Forschungsanstalt WSL, Zürcherstr. 111, 8903, Birmensdorf, Switzerland
| | - Steffen Seitz
- Soil Science and Geomorphology, University of Tübingen, Rümelinstr. 19-23, 72070, Tübingen, Germany
| | - John T Van Stan
- Department of Biological, Geological, and Environmental Sciences, Cleveland State University, 2121 Euclid Ave., Cleveland, OH, 44115, USA
| | - Maik Veste
- Institute of Environmental Sciences, Brandenburgische Technische Universität Cottbus-Senftenberg, Konrad-Wachsmann-Allee 6, 03046, Cottbus, Germany
| | - Bettina Weber
- Division of Plant Sciences, Institute for Biology, University of Graz, Holteigasse 6, A-8010, Graz, Austria
- Multiphase Chemistry Department, Max Planck Institute for Chemistry, Hahn-Meitner-Weg 1, 55128, Mainz, Germany
| | - David J Weston
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
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Mallen‐Cooper M, Cornwell WK. Tissue chemistry of biocrust species along an aridity gradient and comparison to vascular plant leaves. Funct Ecol 2021. [DOI: 10.1111/1365-2435.13903] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Max Mallen‐Cooper
- Ecology and Evolution Research Centre School of Biological, Earth and Environmental Sciences University of New South Wales Sydney New South Wales Australia
- Centre for Ecosystem Science School of Biological, Earth and Environmental Sciences University of New South Wales Sydney New South Wales Australia
| | - William K. Cornwell
- Ecology and Evolution Research Centre School of Biological, Earth and Environmental Sciences University of New South Wales Sydney New South Wales Australia
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Petit Bon M, Böhner H, BrÅthen KA, Ravolainen VT, Jónsdóttir IS. Variable responses of carbon and nitrogen contents in vegetation and soil to herbivory and warming in high‐Arctic tundra. Ecosphere 2021. [DOI: 10.1002/ecs2.3746] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Affiliation(s)
- Matteo Petit Bon
- Department of Arctic Biology University Centre in Svalbard (UNIS) PO Box 156 N‐9171 Longyearbyen Norway
- Department of Arctic and Marine Biology Faculty of Biosciences, Fisheries, and Economics Arctic University of Norway (UiT) N‐9037 Tromsø Norway
| | - Hanna Böhner
- Department of Arctic Biology University Centre in Svalbard (UNIS) PO Box 156 N‐9171 Longyearbyen Norway
- Department of Arctic and Marine Biology Faculty of Biosciences, Fisheries, and Economics Arctic University of Norway (UiT) N‐9037 Tromsø Norway
| | - Kari Anne BrÅthen
- Department of Arctic and Marine Biology Faculty of Biosciences, Fisheries, and Economics Arctic University of Norway (UiT) N‐9037 Tromsø Norway
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The relationship of C and N stable isotopes to high-latitude moss-associated N 2 fixation. Oecologia 2021; 197:283-295. [PMID: 34319437 DOI: 10.1007/s00442-021-05005-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Accepted: 07/23/2021] [Indexed: 10/20/2022]
Abstract
Moss-associated N2 fixation by epiphytic microbes is a key biogeochemical process in nutrient-limited high-latitude ecosystems. Abiotic drivers, such as temperature and moisture, and the identity of host mosses are critical sources of variation in N2 fixation rates. An understanding of the potential interaction between these factors is essential for predicting N inputs as moss communities change with the climate. To further understand the drivers and results of N2 fixation rate variation, we obtained natural abundance values of C and N isotopes and an associated rate of N2 fixation with 15N2 gas incubations in 34 moss species collected in three regions across Alaska, USA. We hypothesized that δ15N values would increase toward 0‰ with higher N2 fixation to reflect the increasing contribution of fixed N2 in moss biomass. Second, we hypothesized that δ13C and N2 fixation would be positively related, as enriched δ13C signatures reflect abiotic conditions favorable to N2 fixation. We expected that the magnitude of these relationships would vary among types of host mosses, reflecting differences in anatomy and habitat. We found little support for our first hypothesis, with only a modest positive relationship between N2 fixation rates and δ15N in a structural equation model. We found a significant positive relationship between δ13C and N2 fixation only in Hypnales, where the probability of N2 fixation activity reached 95% when δ13C values exceeded - 30.4‰. We conclude that moisture and temperature interact strongly with host moss identity in determining the extent to which abiotic conditions impact associated N2 fixation rates.
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Pegoraro EF, Mauritz ME, Ogle K, Ebert CH, Schuur EAG. Lower soil moisture and deep soil temperatures in thermokarst features increase old soil carbon loss after 10 years of experimental permafrost warming. GLOBAL CHANGE BIOLOGY 2021; 27:1293-1308. [PMID: 33305441 DOI: 10.1111/gcb.15481] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Revised: 09/05/2020] [Accepted: 10/20/2020] [Indexed: 06/12/2023]
Abstract
Almost half of the global terrestrial soil carbon (C) is stored in the northern circumpolar permafrost region, where air temperatures are increasing two times faster than the global average. As climate warms, permafrost thaws and soil organic matter becomes vulnerable to greater microbial decomposition. Long-term soil warming of ice-rich permafrost can result in thermokarst formation that creates variability in environmental conditions. Consequently, plant and microbial proportional contributions to ecosystem respiration may change in response to long-term soil warming. Natural abundance δ13 C and Δ14 C of aboveground and belowground plant material, and of young and old soil respiration were used to inform a mixing model to partition the contribution of each source to ecosystem respiration fluxes. We employed a hierarchical Bayesian approach that incorporated gross primary productivity and environmental drivers to constrain source contributions. We found that long-term experimental permafrost warming introduced a soil hydrology component that interacted with temperature to affect old soil C respiration. Old soil C loss was suppressed in plots with warmer deep soil temperatures because they tended to be wetter. When soil volumetric water content significantly decreased in 2018 relative to 2016 and 2017, the dominant respiration sources shifted from plant aboveground and young soil respiration to old soil respiration. The proportion of ecosystem respiration from old soil C accounted for up to 39% of ecosystem respiration and represented a 30-fold increase compared to the wet-year average. Our findings show that thermokarst formation may act to moderate microbial decomposition of old soil C when soil is highly saturated. However, when soil moisture decreases, a higher proportion of old soil C is vulnerable to decomposition and can become a large flux to the atmosphere. As permafrost systems continue to change with climate, we must understand the thresholds that may propel these systems from a C sink to a source.
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Affiliation(s)
- Elaine F Pegoraro
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, USA
- Biological Sciences, Northern Arizona University, Flagstaff, AZ, USA
| | - Marguerite E Mauritz
- Ecology and Evolutionary Biology, The University of Texas at El Paso, El Paso, TX, USA
| | - Kiona Ogle
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, USA
- School of Informatics, Computing, and Cyber Systems, Northern Arizona University, Flagstaff, AZ, USA
| | - Christopher H Ebert
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, USA
| | - Edward A G Schuur
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, USA
- Biological Sciences, Northern Arizona University, Flagstaff, AZ, USA
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10
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Bouskill NJ, Riley WJ, Zhu Q, Mekonnen ZA, Grant RF. Alaskan carbon-climate feedbacks will be weaker than inferred from short-term experiments. Nat Commun 2020; 11:5798. [PMID: 33199687 PMCID: PMC7670472 DOI: 10.1038/s41467-020-19574-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Accepted: 10/22/2020] [Indexed: 11/08/2022] Open
Abstract
Climate warming is occurring fastest at high latitudes. Based on short-term field experiments, this warming is projected to stimulate soil organic matter decomposition, and promote a positive feedback to climate change. We show here that the tightly coupled, nonlinear nature of high-latitude ecosystems implies that short-term (<10 year) warming experiments produce emergent ecosystem carbon stock temperature sensitivities inconsistent with emergent multi-decadal responses. We first demonstrate that a well-tested mechanistic ecosystem model accurately represents observed carbon cycle and active layer depth responses to short-term summer warming in four diverse Alaskan sites. We then show that short-term warming manipulations do not capture the non-linear, long-term dynamics of vegetation, and thereby soil organic matter, that occur in response to thermal, hydrological, and nutrient transformations belowground. Our results demonstrate significant spatial heterogeneity in multi-decadal Arctic carbon cycle trajectories and argue for more mechanistic models to improve predictive capabilities.
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Affiliation(s)
- Nicholas J Bouskill
- Climate and Ecosystem Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.
| | - William J Riley
- Climate and Ecosystem Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Qing Zhu
- Climate and Ecosystem Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Zelalem A Mekonnen
- Climate and Ecosystem Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Robert F Grant
- Department of Renewable Resources, University of Alberta, Edmonton, Canada
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11
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Stuart JEM, Holland-Moritz H, Lewis LR, Jean M, Miller SN, McDaniel SF, Fierer N, Ponciano JM, Mack MC. Host Identity as a Driver of Moss-Associated N2 Fixation Rates in Alaska. Ecosystems 2020. [DOI: 10.1007/s10021-020-00534-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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12
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Luo Y, Schuur EAG. Model parameterization to represent processes at unresolved scales and changing properties of evolving systems. GLOBAL CHANGE BIOLOGY 2020; 26:1109-1117. [PMID: 31782216 DOI: 10.1111/gcb.14939] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Revised: 11/21/2019] [Accepted: 11/22/2019] [Indexed: 06/10/2023]
Abstract
Modeling has become an indispensable tool for scientific research. However, models generate great uncertainty when they are used to predict or forecast ecosystem responses to global change. This uncertainty is partly due to parameterization, which is an essential procedure for model specification via defining parameter values for a model. The classic doctrine of parameterization is that a parameter is constant. However, it is commonly known from modeling practice that a model that is well calibrated for its parameters at one site may not simulate well at another site unless its parameters are tuned again. This common practice implies that parameter values have to vary with sites. Indeed, parameter values that are estimated using a statistically rigorous approach, that is, data assimilation, vary with time, space, and treatments in global change experiments. This paper illustrates that varying parameters is to account for both processes at unresolved scales and changing properties of evolving systems. A model, no matter how complex it is, could not represent all the processes of one system at resolved scales. Interactions of processes at unresolved scales with those at resolved scales should be reflected in model parameters. Meanwhile, it is pervasively observed that properties of ecosystems change over time, space, and environmental conditions. Parameters, which represent properties of a system under study, should change as well. Tuning has been practiced for many decades to change parameter values. Yet this activity, unfortunately, did not contribute to our knowledge on model parameterization at all. Data assimilation makes it possible to rigorously estimate parameter values and, consequently, offers an approach to understand which, how, how much, and why parameters vary. To fully understand those issues, extensive research is required. Nonetheless, it is clear that changes in parameter values lead to different model predictions even if the model structure is the same.
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Affiliation(s)
- Yiqi Luo
- Department of Biological Sciences, Center for Ecosystem Sciences and Society, Northern Arizona University, Flagstaff, AZ, USA
| | - Edward A G Schuur
- Department of Biological Sciences, Center for Ecosystem Sciences and Society, Northern Arizona University, Flagstaff, AZ, USA
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Feng J, Wang C, Lei J, Yang Y, Yan Q, Zhou X, Tao X, Ning D, Yuan MM, Qin Y, Shi ZJ, Guo X, He Z, Van Nostrand JD, Wu L, Bracho-Garillo RG, Penton CR, Cole JR, Konstantinidis KT, Luo Y, Schuur EAG, Tiedje JM, Zhou J. Warming-induced permafrost thaw exacerbates tundra soil carbon decomposition mediated by microbial community. MICROBIOME 2020; 8:3. [PMID: 31952472 PMCID: PMC6969446 DOI: 10.1186/s40168-019-0778-3] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Accepted: 12/23/2019] [Indexed: 05/27/2023]
Abstract
BACKGROUND It is well-known that global warming has effects on high-latitude tundra underlain with permafrost. This leads to a severe concern that decomposition of soil organic carbon (SOC) previously stored in this region, which accounts for about 50% of the world's SOC storage, will cause positive feedback that accelerates climate warming. We have previously shown that short-term warming (1.5 years) stimulates rapid, microbe-mediated decomposition of tundra soil carbon without affecting the composition of the soil microbial community (based on the depth of 42684 sequence reads of 16S rRNA gene amplicons per 3 g of soil sample). RESULTS We show that longer-term (5 years) experimental winter warming at the same site altered microbial communities (p < 0.040). Thaw depth correlated the strongest with community assembly and interaction networks, implying that warming-accelerated tundra thaw fundamentally restructured the microbial communities. Both carbon decomposition and methanogenesis genes increased in relative abundance under warming, and their functional structures strongly correlated (R2 > 0.725, p < 0.001) with ecosystem respiration or CH4 flux. CONCLUSIONS Our results demonstrate that microbial responses associated with carbon cycling could lead to positive feedbacks that accelerate SOC decomposition in tundra regions, which is alarming because SOC loss is unlikely to subside owing to changes in microbial community composition. Video Abstract.
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Affiliation(s)
- Jiajie Feng
- Institute for Environmental Genomics, Department of Microbiology and Plant Biology, University of Oklahoma, Norman, OK, 73019, USA
| | - Cong Wang
- Institute for Environmental Genomics, Department of Microbiology and Plant Biology, University of Oklahoma, Norman, OK, 73019, USA
| | - Jiesi Lei
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing, 100084, China
| | - Yunfeng Yang
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing, 100084, China.
| | - Qingyun Yan
- Institute for Environmental Genomics, Department of Microbiology and Plant Biology, University of Oklahoma, Norman, OK, 73019, USA
- Environmental Microbiomics Research Center, School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou, 510006, China
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou, 510006, China
| | - Xishu Zhou
- Institute for Environmental Genomics, Department of Microbiology and Plant Biology, University of Oklahoma, Norman, OK, 73019, USA
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing, 100084, China
- School of Minerals Processing and Bioengineering, Central South University, Changsha, 410083, China
| | - Xuanyu Tao
- Institute for Environmental Genomics, Department of Microbiology and Plant Biology, University of Oklahoma, Norman, OK, 73019, USA
| | - Daliang Ning
- Institute for Environmental Genomics, Department of Microbiology and Plant Biology, University of Oklahoma, Norman, OK, 73019, USA
| | - Mengting M Yuan
- Institute for Environmental Genomics, Department of Microbiology and Plant Biology, University of Oklahoma, Norman, OK, 73019, USA
| | - Yujia Qin
- Institute for Environmental Genomics, Department of Microbiology and Plant Biology, University of Oklahoma, Norman, OK, 73019, USA
| | - Zhou J Shi
- Institute for Environmental Genomics, Department of Microbiology and Plant Biology, University of Oklahoma, Norman, OK, 73019, USA
| | - Xue Guo
- Institute for Environmental Genomics, Department of Microbiology and Plant Biology, University of Oklahoma, Norman, OK, 73019, USA
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing, 100084, China
| | - Zhili He
- Institute for Environmental Genomics, Department of Microbiology and Plant Biology, University of Oklahoma, Norman, OK, 73019, USA
- Environmental Microbiomics Research Center, School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou, 510006, China
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou, 510006, China
| | - Joy D Van Nostrand
- Institute for Environmental Genomics, Department of Microbiology and Plant Biology, University of Oklahoma, Norman, OK, 73019, USA
| | - Liyou Wu
- Institute for Environmental Genomics, Department of Microbiology and Plant Biology, University of Oklahoma, Norman, OK, 73019, USA
| | - Rosvel G Bracho-Garillo
- School of Forest Resources and Conservation, University of Florida, Gainesville, FL, 32611, USA
| | - C Ryan Penton
- Center for Fundamental and Applied Microbiomics, Arizona State University, Mesa, AZ, 85212, USA
- College of Integrative Sciences and Arts, Faculty of Science and Mathematics, Arizona State University, Mesa, Arizona, 85212, USA
| | - James R Cole
- Center for Microbial Ecology, Michigan State University, East Lansing, MI, 48824, USA
| | - Konstantinos T Konstantinidis
- School of Civil and Environmental Engineering, School of Biology, and Center for Bioinformatics and Computational Genomics, Georgia Institute of Technology, Atlanta, GA, 30332, USA
| | - Yiqi Luo
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, 86011, USA
| | - Edward A G Schuur
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, 86011, USA
| | - James M Tiedje
- Center for Microbial Ecology, Michigan State University, East Lansing, MI, 48824, USA
- DOE Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, MI, 48824, USA
| | - Jizhong Zhou
- Institute for Environmental Genomics, Department of Microbiology and Plant Biology, University of Oklahoma, Norman, OK, 73019, USA.
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing, 100084, China.
- Earth and Environmental Sciences, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.
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Mauritz M, Bracho R, Celis G, Hutchings J, Natali SM, Pegoraro E, Salmon VG, Schädel C, Webb EE, Schuur EAG. Nonlinear CO 2 flux response to 7 years of experimentally induced permafrost thaw. GLOBAL CHANGE BIOLOGY 2017; 23:3646-3666. [PMID: 28208232 DOI: 10.1111/gcb.13661] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2016] [Accepted: 01/19/2017] [Indexed: 06/06/2023]
Abstract
Rapid Arctic warming is expected to increase global greenhouse gas concentrations as permafrost thaw exposes immense stores of frozen carbon (C) to microbial decomposition. Permafrost thaw also stimulates plant growth, which could offset C loss. Using data from 7 years of experimental Air and Soil warming in moist acidic tundra, we show that Soil warming had a much stronger effect on CO2 flux than Air warming. Soil warming caused rapid permafrost thaw and increased ecosystem respiration (Reco ), gross primary productivity (GPP), and net summer CO2 storage (NEE). Over 7 years Reco , GPP, and NEE also increased in Control (i.e., ambient plots), but this change could be explained by slow thaw in Control areas. In the initial stages of thaw, Reco , GPP, and NEE increased linearly with thaw across all treatments, despite different rates of thaw. As thaw in Soil warming continued to increase linearly, ground surface subsidence created saturated microsites and suppressed Reco , GPP, and NEE. However Reco and GPP remained high in areas with large Eriophorum vaginatum biomass. In general NEE increased with thaw, but was more strongly correlated with plant biomass than thaw, indicating that higher Reco in deeply thawed areas during summer months was balanced by GPP. Summer CO2 flux across treatments fit a single quadratic relationship that captured the functional response of CO2 flux to thaw, water table depth, and plant biomass. These results demonstrate the importance of indirect thaw effects on CO2 flux: plant growth and water table dynamics. Nonsummer Reco models estimated that the area was an annual CO2 source during all years of observation. Nonsummer CO2 loss in warmer, more deeply thawed soils exceeded the increases in summer GPP, and thawed tundra was a net annual CO2 source.
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Affiliation(s)
- Marguerite Mauritz
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, USA
| | - Rosvel Bracho
- School of Forest Resources and Conservation, University of Florida, Gainesville, FL, USA
| | - Gerardo Celis
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, USA
| | - Jack Hutchings
- Department of Geological Sciences, University of Florida, Gainesville, FL, USA
| | | | - Elaine Pegoraro
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, USA
| | - Verity G Salmon
- Environmental Sciences Division and Climate Change Sciences Institute, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - Christina Schädel
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, USA
| | - Elizabeth E Webb
- Department of Biology, University of Florida, Gainesville, FL, USA
| | - Edward A G Schuur
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, USA
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15
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Salmon VG, Soucy P, Mauritz M, Celis G, Natali SM, Mack MC, Schuur EAG. Nitrogen availability increases in a tundra ecosystem during five years of experimental permafrost thaw. GLOBAL CHANGE BIOLOGY 2016; 22:1927-1941. [PMID: 26718892 DOI: 10.1111/gcb.13204] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Revised: 11/19/2015] [Accepted: 12/01/2015] [Indexed: 06/05/2023]
Abstract
Perennially frozen soil in high latitude ecosystems (permafrost) currently stores 1330-1580 Pg of carbon (C). As these ecosystems warm, the thaw and decomposition of permafrost is expected to release large amounts of C to the atmosphere. Fortunately, losses from the permafrost C pool will be partially offset by increased plant productivity. The degree to which plants are able to sequester C, however, will be determined by changing nitrogen (N) availability in these thawing soil profiles. N availability currently limits plant productivity in tundra ecosystems but plant access to N is expected improve as decomposition increases in speed and extends to deeper soil horizons. To evaluate the relationship between permafrost thaw and N availability, we monitored N cycling during 5 years of experimentally induced permafrost thaw at the Carbon in Permafrost Experimental Heating Research (CiPEHR) project. Inorganic N availability increased significantly in response to deeper thaw and greater soil moisture induced by Soil warming. This treatment also prompted a 23% increase in aboveground biomass and a 49% increase in foliar N pools. The sedge Eriophorum vaginatum responded most strongly to warming: this species explained 91% of the change in aboveground biomass during the 5 year period. Air warming had little impact when applied alone, but when applied in combination with Soil warming, growing season soil inorganic N availability was significantly reduced. These results demonstrate that there is a strong positive relationship between the depth of permafrost thaw and N availability in tundra ecosystems but that this relationship can be diminished by interactions between increased thaw, warmer air temperatures, and higher levels of soil moisture. Within 5 years of permafrost thaw, plants actively incorporate newly available N into biomass but C storage in live vascular plant biomass is unlikely to be greater than losses from deep soil C pools.
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Affiliation(s)
- Verity G Salmon
- Biology Department, University of Florida, Gainesville, FL, 32611, USA
| | - Patrick Soucy
- Biology Department, University of Florida, Gainesville, FL, 32611, USA
| | - Marguerite Mauritz
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, 86011, USA
| | - Gerardo Celis
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, 86011, USA
| | | | - Michelle C Mack
- Biology Department, University of Florida, Gainesville, FL, 32611, USA
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, 86011, USA
| | - Edward A G Schuur
- Biology Department, University of Florida, Gainesville, FL, 32611, USA
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, 86011, USA
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