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Johansson G, Fedje KK, Modin O, Haeger-Eugensson M, Uhl W, Andersson-Sköld Y, Strömvall AM. Removal and release of microplastics and other environmental pollutants during the start-up of bioretention filters treating stormwater. JOURNAL OF HAZARDOUS MATERIALS 2024; 468:133532. [PMID: 38387172 DOI: 10.1016/j.jhazmat.2024.133532] [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: 11/03/2023] [Revised: 01/10/2024] [Accepted: 01/12/2024] [Indexed: 02/24/2024]
Abstract
Untreated stormwater is a major source of microplastics, organic pollutants, metals, and nutrients in urban water courses. The aim of this study was to improve the knowledge about the start-up periods of bioretention filters. A rain garden pilot facility with 13 bioretention filters was constructed and stormwater from a highway and adjacent impervious surfaces was used for irrigation for ∼12 weeks. Selected plants (Armeria maritima, Hippophae rhamnoides, Juncus effusus, and Festuca rubra) was planted in ten filters. Stormwater percolated through the filters containing waste-to-energy bottom ash, biochar, or Sphagnum peat, mixed with sandy loam. Influent and effluent samples were taken to evaluate removal of the above-mentioned pollutants. All filters efficiently removed microplastics >10 µm, organic pollutants, and most metals. Copper leached from all filters initially but was significantly reduced in the biochar filters at the end of the period, while the other filters showed a declining trend. All filters leached nutrients initially, but concentrations decreased over time, and the biochar filters had efficiently reduced nitrogen after a few weeks. To conclude, all the filters effectively removed pollutants during the start-up period. Before being recommended for full-scale applications, the functionality of the filters after a longer period of operation should be evaluated.
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Affiliation(s)
- Glenn Johansson
- Water Environment Technology, Department of Architecture and Civil Engineering, Chalmers University of Technology, SE-41296 Gothenburg, Sweden.
| | - Karin Karlfeldt Fedje
- Water Environment Technology, Department of Architecture and Civil Engineering, Chalmers University of Technology, SE-41296 Gothenburg, Sweden; Recycling and Waste Management, Renova AB, Box 156, Gothenburg SE-40122, Sweden
| | - Oskar Modin
- Water Environment Technology, Department of Architecture and Civil Engineering, Chalmers University of Technology, SE-41296 Gothenburg, Sweden
| | | | - Wolfgang Uhl
- Aquateam COWI AS, Karvesvingen 2, 0579 Oslo, Norway
| | - Yvonne Andersson-Sköld
- Water Environment Technology, Department of Architecture and Civil Engineering, Chalmers University of Technology, SE-41296 Gothenburg, Sweden; Swedish National Road and Transport Research Institute Linköping (VTI), Box 8072, SE-40278 Gothenburg, Sweden
| | - Ann-Margret Strömvall
- Water Environment Technology, Department of Architecture and Civil Engineering, Chalmers University of Technology, SE-41296 Gothenburg, Sweden
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2
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Herndon E, Richardson J, Carrell AA, Pierce E, Weston D. Sulfur speciation in Sphagnum peat moss modified by mutualistic interactions with cyanobacteria. THE NEW PHYTOLOGIST 2024; 241:1998-2008. [PMID: 38135655 DOI: 10.1111/nph.19476] [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: 05/05/2023] [Accepted: 11/21/2023] [Indexed: 12/24/2023]
Abstract
Peat moss (Sphagnum spp.) develops mutualistic interactions with cyanobacteria by providing carbohydrates and S compounds in exchange for N-rich compounds, potentially facilitating N inputs into peatlands. Here, we evaluate how colonization of Sphagnum angustifolium hyaline cells by Nostoc muscorum modifies S abundance and speciation at the scales of individual cells and across whole leaves. For the first time, S K-edge X-ray Absorption Spectroscopy was used to identify bulk and micron-scale S speciation across isolated cyanobacteria colonies, and in colonized and uncolonized leaves. Uncolonized leaves contained primarily reduced organic S and oxidized sulfonate- and sulfate-containing compounds. Increasing Nostoc colonization resulted in an enrichment of S and changes in speciation, with increases in sulfate relative to reduced S and sulfonate. At the scale of individual hyaline cells, colonized cells exhibited localized enrichment of reduced S surrounded by diffuse sulfonate, similar to observations of cyanobacteria colonies cultured in the absence of leaves. We infer that colonization stimulates plant S uptake and the production of sulfate-containing metabolites that are concentrated in stem tissues. Sulfate compounds that are produced in response to colonization become depleted in colonized cells where they may be converted into reduced S metabolites by cyanobacteria.
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Affiliation(s)
- Elizabeth Herndon
- Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37830, USA
| | | | - Alyssa A Carrell
- Biological Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37830, USA
| | - Eric Pierce
- Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37830, USA
| | - David Weston
- Biological Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37830, USA
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3
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Yang Q, Liu Z, Bai E. Comparison of carbon and nitrogen accumulation rate between bog and fen phases in a pristine peatland with the fen-bog transition. GLOBAL CHANGE BIOLOGY 2023; 29:6350-6366. [PMID: 37602716 DOI: 10.1111/gcb.16915] [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: 01/01/2023] [Accepted: 07/17/2023] [Indexed: 08/22/2023]
Abstract
Long-term carbon and nitrogen dynamics in peatlands are affected by both vegetation production and decomposition processes. Here, we examined the carbon accumulation rate (CAR), nitrogen accumulation rate (NAR) and δ13 C, δ15 N of plant residuals in a peat core dated back to ~8500 cal year BP in a temperate peatland in Northeast China. Impacted by the tephra during 1160 and 789 cal year BP and climate change, the peatland changed from a fen dominated by vascular plants to a bog dominated by Sphagnum mosses. We used the Clymo model to quantify peat addition rate and decay constant for acrotelm and catotelm layers during both bog and fen phases. Our studied peatland was dominated by Sphagnum fuscum during the bog phase (789 to -59 cal year BP) and lower accumulation rates in the acrotelm layer was found during this phase, suggesting the dominant role of volcanic eruption in the CAR of the peat core. Both mean CAR and NAR were higher during the bog phase than during the fen phase in our study, consistent with the results of the only one similar study in the literature. Because the input rate of organic matter was considered to be lower during the bog phase, the decomposition process must have been much lower during the bog phase than during the fen phase and potentially controlled CAR and NAR. During the fen phase, CAR was also lower under higher temperature and summer insolation, conditions beneficial for decomposition. δ15 N of Sphagnum hinted that nitrogen fixation had a positive effect on nitrogen accumulation, particular in recent decades. Our study suggested that decomposition is more important for carbon and nitrogen sequestration than production in peatlands in most conditions and if future climate changes or human disturbance increase decomposition rate, carbon sequestration in peatlands will be jeopardized.
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Affiliation(s)
- Qiannan Yang
- Key Laboratory of Geographical Processes and Ecological Security of Changbai Mountains, Ministry of Education, School of Geographical Sciences, Northeast Normal University, Changchun, China
| | - Ziping Liu
- Key Laboratory of Geographical Processes and Ecological Security of Changbai Mountains, Ministry of Education, School of Geographical Sciences, Northeast Normal University, Changchun, China
- Key Laboratory of Vegetation Ecology, Ministry of Education, Northeast Normal University, Changchun, China
| | - Edith Bai
- Key Laboratory of Geographical Processes and Ecological Security of Changbai Mountains, Ministry of Education, School of Geographical Sciences, Northeast Normal University, Changchun, China
- Key Laboratory of Vegetation Ecology, Ministry of Education, Northeast Normal University, Changchun, China
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4
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Käärmelahti SA, Temmink RJM, van Dijk G, Prager A, Kohl M, Gaudig G, Koks AHW, Liu W, Vroom RJE, Gerwing K, Peters CJH, Krebs M, Fritz C. Nutrient dynamics of 12 Sphagnum species during establishment on a rewetted bog. PLANT BIOLOGY (STUTTGART, GERMANY) 2023. [PMID: 37186018 DOI: 10.1111/plb.13534] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Accepted: 04/11/2023] [Indexed: 05/17/2023]
Abstract
Peatland degradation through drainage and peat extraction have detrimental environmental and societal consequences. Rewetting is a mitigation option to restore lost ecosystem functions, such as carbon uptake, water retention, biodiversity and nutrient sequestration. Peat mosses (Sphagnum) are the most important peat-forming species in bogs. Most Sphagnum species occur in nutrient-poor habitats, however, high growth rates have been reported in artificial nutrient-rich conditions with optimal water supply. Here, we demonstrate the differences in nutrient dynamics of 12 Sphagnum species during their establishment in a one-year field experiment at a Sphagnum paludiculture area in NW Germany. The 12 species are categorized in three groups (slower, medium and fast-growing). Rapid establishment of the peat mosses is facilitated by constant and sufficient supply of nutrient-rich, low pH, and low alkalinity surface water. Our study shows that slower-growing species (S. papillosum, S. magellancium, S. fuscum, S. rubellum, S. austinii; often forming hummocks) displayed signs of nutrient imbalance. These species accumulated higher amounts of nitrogen, phosphorus, magnesium and calcium in their capitula, and had an elevated stem N:K quotient (> 3). Additionally, this group sequestered less carbon and potassium per m2 than the fast and medium growing species (S. denticulatum, S. fallax, S. riparium, S. fimbriatum, S. squarrosum, S. palustre, S. centrale). Lower lawn thickness may have amplified negative effects of flooding in slower-growing species. We conclude that nutrient dynamics and carbon/nutrient sequestration rates are species-specific. For optimal outcomes of bog restoration, generating ecosystem services or choosing suitable donor material for Sphagnum paludiculture, it is crucial to consider their compatibility with existing environmental conditions.
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Affiliation(s)
- S A Käärmelahti
- Aquatic Ecology and Environmental Biology, Radboud Institute for Biological and Environmental Sciences, Radboud University, Heyendaalseweg 135, 6525, AJ, Nijmegen, the Netherlands
| | - R J M Temmink
- Aquatic Ecology and Environmental Biology, Radboud Institute for Biological and Environmental Sciences, Radboud University, Heyendaalseweg 135, 6525, AJ, Nijmegen, the Netherlands
- Environmental Sciences, Copernicus Institute of Sustainable Development, Utrecht University, Princetonlaan 8a, 3584, CB, Utrecht, the Netherlands
| | - G van Dijk
- Aquatic Ecology and Environmental Biology, Radboud Institute for Biological and Environmental Sciences, Radboud University, Heyendaalseweg 135, 6525, AJ, Nijmegen, the Netherlands
- B-WARE Research Centre, Toernooiveld 1, Nijmegen, 6525, ED, the Netherlands
| | - A Prager
- Institute of Botany and Landscape Ecology, University of Greifswald, partner in the Greifswald Mire Centre, Soldmannstr. 15, 17487, Greifswald, Germany
| | - M Kohl
- Institute of Botany and Landscape Ecology, University of Greifswald, partner in the Greifswald Mire Centre, Soldmannstr. 15, 17487, Greifswald, Germany
| | - G Gaudig
- Institute of Botany and Landscape Ecology, University of Greifswald, partner in the Greifswald Mire Centre, Soldmannstr. 15, 17487, Greifswald, Germany
| | - A H W Koks
- Aquatic Ecology and Environmental Biology, Radboud Institute for Biological and Environmental Sciences, Radboud University, Heyendaalseweg 135, 6525, AJ, Nijmegen, the Netherlands
- B-WARE Research Centre, Toernooiveld 1, Nijmegen, 6525, ED, the Netherlands
| | - W Liu
- Integrated Research on Energy, Environment and Society, University of Groningen, Nijenborgh 6, 9747, AG, Groningen, the Netherlands
| | - R J E Vroom
- Aquatic Ecology and Environmental Biology, Radboud Institute for Biological and Environmental Sciences, Radboud University, Heyendaalseweg 135, 6525, AJ, Nijmegen, the Netherlands
| | - K Gerwing
- Biology and Environmental Sciences, Carl von Ossietzky University of Oldenburg, Ammerländer Heerstraße 114-118, 26129, Oldenburg, Germany
| | - C J H Peters
- Aquatic Ecology and Environmental Biology, Radboud Institute for Biological and Environmental Sciences, Radboud University, Heyendaalseweg 135, 6525, AJ, Nijmegen, the Netherlands
| | - M Krebs
- Institute of Botany and Landscape Ecology, University of Greifswald, partner in the Greifswald Mire Centre, Soldmannstr. 15, 17487, Greifswald, Germany
| | - C Fritz
- Aquatic Ecology and Environmental Biology, Radboud Institute for Biological and Environmental Sciences, Radboud University, Heyendaalseweg 135, 6525, AJ, Nijmegen, the Netherlands
- Integrated Research on Energy, Environment and Society, University of Groningen, Nijenborgh 6, 9747, AG, Groningen, the Netherlands
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5
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Yang Q, Liu Z, Houlton BZ, Gao D, Chang Q, Li H, Fan X, Liu B, Bai E. Isotopic evidence for increased carbon and nitrogen exchanges between peatland plants and their symbiotic microbes with rising atmospheric CO 2 concentrations since 15,000 cal. year BP. GLOBAL CHANGE BIOLOGY 2023; 29:1939-1950. [PMID: 36585918 DOI: 10.1111/gcb.16578] [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: 09/20/2022] [Revised: 11/29/2022] [Accepted: 12/16/2022] [Indexed: 05/28/2023]
Abstract
Whether nitrogen (N) availability will limit plant growth and removal of atmospheric CO2 by the terrestrial biosphere this century is controversial. Studies have suggested that N could progressively limit plant growth, as trees and soils accumulate N in slowly cycling biomass pools in response to increases in carbon sequestration. However, a question remains over whether longer-term (decadal to century) feedbacks between climate, CO2 and plant N uptake could emerge to reduce ecosystem-level N limitations. The symbioses between plants and microbes can help plants to acquire N from the soil or from the atmosphere via biological N2 fixation-the pathway through which N can be rapidly brought into ecosystems and thereby partially or completely alleviate N limitation on plant productivity. Here we present measurements of plant N isotope composition (δ15 N) in a peat core that dates to 15,000 cal. year BP to ascertain ecosystem-level N cycling responses to rising atmospheric CO2 concentrations. We find that pre-industrial increases in global atmospheric CO2 concentrations corresponded with a decrease in the δ15 N of both Sphagnum moss and Ericaceae when constrained for climatic factors. A modern experiment demonstrates that the δ15 N of Sphagnum decreases with increasing N2 -fixation rates. These findings suggest that plant-microbe symbioses that facilitate N acquisition are, over the long term, enhanced under rising atmospheric CO2 concentrations, highlighting an ecosystem-level feedback mechanism whereby N constraints on terrestrial carbon storage can be overcome.
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Affiliation(s)
- Qiannan Yang
- Key Laboratory of Geographical Processes and Ecological Security of Changbai Mountains, Ministry of Education; School of Geographical Sciences, Northeast Normal University, Changchun, China
| | - Ziping Liu
- Key Laboratory of Geographical Processes and Ecological Security of Changbai Mountains, Ministry of Education; School of Geographical Sciences, Northeast Normal University, Changchun, China
- Key Laboratory of Vegetation Ecology, Ministry of Education, Northeast Normal University, Changchun, China
| | - Benjamin Z Houlton
- Department of Ecology and Evolutionary Biology and Department of Global Development, Cornell University, Ithaca, New York, USA
| | - Decai Gao
- Key Laboratory of Geographical Processes and Ecological Security of Changbai Mountains, Ministry of Education; School of Geographical Sciences, Northeast Normal University, Changchun, China
- Key Laboratory of Vegetation Ecology, Ministry of Education, Northeast Normal University, Changchun, China
| | - Qing Chang
- Key Laboratory of Geographical Processes and Ecological Security of Changbai Mountains, Ministry of Education; School of Geographical Sciences, Northeast Normal University, Changchun, China
- Key Laboratory of Vegetation Ecology, Ministry of Education, Northeast Normal University, Changchun, China
| | - Hongkai Li
- Key Laboratory of Geographical Processes and Ecological Security of Changbai Mountains, Ministry of Education; School of Geographical Sciences, Northeast Normal University, Changchun, China
- Key Laboratory of Vegetation Ecology, Ministry of Education, Northeast Normal University, Changchun, China
| | - Xianlei Fan
- Key Laboratory of Geographical Processes and Ecological Security of Changbai Mountains, Ministry of Education; School of Geographical Sciences, Northeast Normal University, Changchun, China
| | - Bai Liu
- Key Laboratory of Geographical Processes and Ecological Security of Changbai Mountains, Ministry of Education; School of Geographical Sciences, Northeast Normal University, Changchun, China
| | - Edith Bai
- Key Laboratory of Geographical Processes and Ecological Security of Changbai Mountains, Ministry of Education; School of Geographical Sciences, Northeast Normal University, Changchun, China
- Key Laboratory of Vegetation Ecology, Ministry of Education, Northeast Normal University, Changchun, China
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6
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Printarakul N, Adulkittichai K, Meeinkuirt W. Effects of copper accumulation on growth and development of Scopelophila cataractae grown in vitro. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2022; 245:114127. [PMID: 36179447 DOI: 10.1016/j.ecoenv.2022.114127] [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: 01/17/2022] [Revised: 09/14/2022] [Accepted: 09/26/2022] [Indexed: 06/16/2023]
Abstract
Scopelophila cataractae was cultured in vitro for 16 weeks to assess the contrasting effects of Cu on growth and reproduction, as well as gametophore stage. To induce buds and gametophores of S. cataractae, ten treatments (tr 1 to tr 10) of culture media were prepared using a combination of mineral salts, sugar, vitamin B complex, CuSO4, and exogenous hormones. Highest numbers of gametophores and buds were formed in media containing 500 µM CuSO4 in co-application with auxin and cytokinin, as shown in the modest Cu treatments (tr 6 and tr 7, 26 per cushion and 255 per 25 mm2, respectively). A 5000 µM CuSO4 concentration inhibited development of protonema, possibly due to Cu toxicity, resulting in chloronema forming contorted filaments or short cells containing lipid bodies, and brood body diaspores but no gametophore or bud formation. In this study, S. cataractae Cu accumulation in tissue was substantial (up to 2843.1 mg kg-1; tr 6) with no or minimal adverse effects, reflecting its potential for phytoremediation of Cu in terrestrial and aquatic ecosystems. The highest atomic percentages of Cu and Zn were detected in the stem surfaces of gametophores treated with 500 µM CuSO4 (11% atomic Cu and 7% atomic Zn), which served as a primary heavy metal storage site, ultimately protecting cells from metal toxicity. The success of this in vitro study on S. cataractae should also aid ex situ conservation efforts for a variety of rare moss taxa in the wild.
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Affiliation(s)
- Narin Printarakul
- Department of Biology, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand; Research Center in Bioresources for Agriculture, Industry and Medicine, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand
| | - Kanonrat Adulkittichai
- Research and Development Department, Chiang Mai Vanusnun Co., Ltd., Muang, Chiang Mai 50000, Thailand
| | - Weeradej Meeinkuirt
- Water and Soil Environmental Research Unit, Nakhonsawan Campus, Mahidol University, Nakhonsawan 60130, Thailand.
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7
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Defining the
Sphagnum
Core Microbiome across the North American Continent Reveals a Central Role for Diazotrophic Methanotrophs in the Nitrogen and Carbon Cycles of Boreal Peatland Ecosystems. mBio 2022. [PMCID: PMC8863050 DOI: 10.1128/mbio.03714-21] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Peat mosses of the genus Sphagnum are ecosystem engineers that frequently predominate over photosynthetic production in boreal peatlands. Sphagnum spp. host diverse microbial communities capable of nitrogen fixation (diazotrophy) and methane oxidation (methanotrophy), thereby potentially supporting plant growth under severely nutrient-limited conditions. Moreover, diazotrophic methanotrophs represent a possible “missing link” between the carbon and nitrogen cycles, but the functional contributions of the Sphagnum-associated microbiome remain in question. A combination of metagenomics, metatranscriptomics, and dual-isotope incorporation assays was applied to investigate Sphagnum microbiome community composition across the North American continent and provide empirical evidence for diazotrophic methanotrophy in Sphagnum-dominated ecosystems. Remarkably consistent prokaryotic communities were detected in over 250 Sphagnum SSU rRNA libraries from peatlands across the United States (5 states, 17 bog/fen sites, 18 Sphagnum species), with 12 genera of the core microbiome comprising 60% of the relative microbial abundance. Additionally, nitrogenase (nifH) and SSU rRNA gene amplicon analysis revealed that nitrogen-fixing populations made up nearly 15% of the prokaryotic communities, predominated by Nostocales cyanobacteria and Rhizobiales methanotrophs. While cyanobacteria comprised the vast majority (>95%) of diazotrophs detected in amplicon and metagenome analyses, obligate methanotrophs of the genus Methyloferula (order Rhizobiales) accounted for one-quarter of transcribed nifH genes. Furthermore, in dual-isotope tracer experiments, members of the Rhizobiales showed substantial incorporation of 13CH4 and 15N2 isotopes into their rRNA. Our study characterizes the core Sphagnum microbiome across large spatial scales and indicates that diazotrophic methanotrophs, here defined as obligate methanotrophs of the rare biosphere (Methyloferula spp. of the Rhizobiales) that also carry out diazotrophy, play a keystone role in coupling of the carbon and nitrogen cycles in nutrient-poor peatlands.
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Vesala R, Kiheri H, Hobbie EA, van Dijk N, Dise N, Larmola T. Atmospheric nitrogen enrichment changes nutrient stoichiometry and reduces fungal N supply to peatland ericoid mycorrhizal shrubs. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 794:148737. [PMID: 34323746 DOI: 10.1016/j.scitotenv.2021.148737] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Revised: 05/30/2021] [Accepted: 06/25/2021] [Indexed: 06/13/2023]
Abstract
Peatlands store one third of global soil carbon (C) and up to 15% of global soil nitrogen (N) but often have low plant nutrient availability owing to slow organic matter decomposition under acidic and waterlogged conditions. In rainwater-fed ombrotrophic peatlands, elevated atmospheric N deposition has increased N availability with potential consequences to ecosystem nutrient cycling. Here, we studied how 14 years of continuous N addition with either nitrate or ammonium had affected ericoid mycorrhizal (ERM) shrubs at Whim Bog, Scotland. We examined whether enrichment has influenced foliar nutrient stoichiometry and assessed using N stable isotopes whether potential changes in plant nutrient constraints are linked with plant N uptake through ERM fungi versus direct plant uptake. High doses of ammonium alleviated N deficiency in Calluna vulgaris and Erica tetralix, whereas low doses of ammonium and nitrate improved plant phosphorus (P) nutrition, indicated by the lowered foliar N:P ratios. Root acid phosphatase activities correlated positively with foliar N:P ratios, suggesting enhanced P uptake as a result of improved N nutrition. Elevated foliar δ15N of fertilized shrubs suggested that ERM fungi were less important for N supply with N fertilization. Increases in N availability in peat porewater and in direct nonmycorrhizal N uptake likely have reduced plant nitrogen uptake via mycorrhizal pathways. As the mycorrhizal N uptake correlates with the reciprocal C supply from host plants to the soil, such reduction in ERM activity may affect peat microbial communities and even accelerate C loss via decreased ERM activity and enhanced saprotrophic activity. Our results thus introduce a previously unrecognized mechanism for how anthropogenic N pollution may affect nutrient and carbon cycling within peatland ecosystems.
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Affiliation(s)
- Risto Vesala
- Natural Resources Institute Finland (Luke), Finland.
| | - Heikki Kiheri
- Natural Resources Institute Finland (Luke), Finland; Department of Microbiology, Faculty of Agriculture and Forestry, University of Helsinki, Finland
| | - Erik A Hobbie
- Earth Systems Research Center, University of New Hampshire, United States
| | - Netty van Dijk
- UK Centre for Ecology & Hydrology (UKCEH), Edinburgh, UK
| | - Nancy Dise
- UK Centre for Ecology & Hydrology (UKCEH), Edinburgh, UK
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9
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Zhou Y, Huang Y, Peng X, Xu J, Hu Y. Sphagnum response to nitrogen deposition and nitrogen critical load: A meta-analysis. Glob Ecol Conserv 2021. [DOI: 10.1016/j.gecco.2021.e01791] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
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10
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Sgouridis F, Yates CA, Lloyd CEM, Saiz E, Schillereff DN, Tomlinson S, Williamson J, Ullah S. Chronic atmospheric reactive N deposition has breached the N sink capacity of a northern ombrotrophic peatbog increasing the gaseous and fluvial N losses. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 787:147552. [PMID: 34004537 DOI: 10.1016/j.scitotenv.2021.147552] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Revised: 04/23/2021] [Accepted: 04/30/2021] [Indexed: 06/12/2023]
Abstract
Peatlands play an important role in modulating the climate, mainly through sequestration of carbon dioxide into peat carbon, which depends on the availability of reactive nitrogen (Nr) to mosses. Atmospheric Nr deposition in the UK has been above the critical load for functional and structural changes to peatland mosses, thus threatening to accelerate their succession by vascular plants and increasing the possibility of Nr export to downstream ecosystems. The N balance of peatlands has received comparatively little attention, mainly due to the difficulty in measuring gaseous N losses as well as the Nr inputs due to biological nitrogen fixation (BNF). In this study we have estimated the mean annual N balance of an ombrotrophic bog (Migneint, North Wales) by measuring in situ N2 + N2O gaseous fluxes and also BNF in peat and mosses. Fluvial N export was monitored through a continuous record of DON flux, while atmospheric N deposition was modelled on a 5 × 5 km grid. The mean annual N mass balance was slightly positive (0.7 ± 4.1 kg N ha-1 y-1) and varied interannually indicating the fragile status of this bog ecosystem that has reached N saturation and is prone to becoming a net N source. Gaseous N losses were a major N output term accounting for 70% of the N inputs, mainly in the form of the inert N2 gas, thus providing partial mitigation to the adverse effects of chronic Nr enrichment. BNF was suppressed by 69%, compared to rates in pristine bogs, but was still active, contributing ~2% of the N inputs. The long-term peat N storage rate (8.4 ± 0.8 kg N ha-1 y-1) cannot be met by the measured N mass balance, showing that the bog catchment is losing more N than it can store due its saturated status.
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Affiliation(s)
| | | | | | - Ernesto Saiz
- Lennard-Jones Laboratories, Birchall Centre, Keele University, UK
| | | | - Sam Tomlinson
- UK Centre for Ecology & Hydrology (UKCEH), Lancaster, UK
| | | | - Sami Ullah
- Department of Geography, Earth and Environmental Science, University of Birmingham, UK
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11
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Zhang H, Tuittila ES, Korrensalo A, Laine AM, Uljas S, Welti N, Kerttula J, Maljanen M, Elliott D, Vesala T, Lohila A. Methane production and oxidation potentials along a fen-bog gradient from southern boreal to subarctic peatlands in Finland. GLOBAL CHANGE BIOLOGY 2021; 27:4449-4464. [PMID: 34091981 DOI: 10.1111/gcb.15740] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Accepted: 04/30/2021] [Indexed: 06/12/2023]
Abstract
Methane (CH4 ) emissions from northern peatlands are projected to increase due to climate change, primarily because of projected increases in soil temperature. Yet, the rates and temperature responses of the two CH4 emission-related microbial processes (CH4 production by methanogens and oxidation by methanotrophs) are poorly known. Further, peatland sites within a fen-bog gradient are known to differ in the variables that regulate these two mechanisms, yet the interaction between peatland type and temperature lacks quantitative understanding. Here, we investigated potential CH4 production and oxidation rates for 14 peatlands in Finland located between c. 60 and 70°N latitude, representing bogs, poor fens, and rich fens. Potentials were measured at three different temperatures (5, 17.5, and 30℃) using the laboratory incubation method. We linked CH4 production and oxidation patterns to their methanogen and methanotroph abundance, peat properties, and plant functional types. We found that the rich fen-bog gradient-related nutrient availability and methanogen abundance increased the temperature response of CH4 production, with rich fens exhibiting the greatest production potentials. Oxidation potential showed a steeper temperature response than production, which was explained by aerenchymous plant cover, peat water holding capacity, peat nitrogen, and sulfate content. The steeper temperature response of oxidation suggests that, at higher temperatures, CH4 oxidation might balance increased CH4 production. Predicting net CH4 fluxes as an outcome of the two mechanisms is complicated due to their different controls and temperature responses. The lack of correlation between field CH4 fluxes and production/oxidation potentials, and the positive correlation with aerenchymous plants points toward the essential role of CH4 transport for emissions. The scenario of drying peatlands under climate change, which is likely to promote Sphagnum establishment over brown mosses in many places, will potentially reduce the predicted warming-related increase in CH4 emissions by shifting rich fens to Sphagnum-dominated systems.
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Affiliation(s)
- Hui Zhang
- Institute for Atmospheric and Earth System Research (INAR), Department of Physics, University of Helsinki, Helsinki, Finland
- Helsinki Institute of Sustainability Science (HELSUS), Helsinki, Finland
| | | | - Aino Korrensalo
- Department of Forest Sciences, University of Eastern Finland, Joensuu, Finland
| | - Anna M Laine
- Department of Forest Sciences, University of Eastern Finland, Joensuu, Finland
- Department of Ecology and Genetics, University of Oulu, Oulu, Finland
- Geological Survey of Finland, Kuopio, Finland
| | - Salli Uljas
- Department of Forest Sciences, University of Eastern Finland, Joensuu, Finland
| | - Nina Welti
- Department of Environmental and Biological Sciences, University of Eastern Finland, Kuopio, Finland
| | - Johanna Kerttula
- Department of Environmental and Biological Sciences, University of Eastern Finland, Kuopio, Finland
| | - Marja Maljanen
- Department of Environmental and Biological Sciences, University of Eastern Finland, Kuopio, Finland
| | - David Elliott
- Environmental Sustainability Research Centre, University of Derby, Derby, UK
| | - Timo Vesala
- Institute for Atmospheric and Earth System Research (INAR), Department of Physics, University of Helsinki, Helsinki, Finland
- Institute for Atmospheric and Earth System Research (INAR), Department of Forest Sciences, University of Helsinki, Helsinki, Finland
- Yugra State University, Khanty-Mansiysk, Russia
| | - Annalea Lohila
- Institute for Atmospheric and Earth System Research (INAR), Department of Physics, University of Helsinki, Helsinki, Finland
- Climate System Research, Finnish Meteorological Institute, Helsinki, Finland
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12
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Wicaksono WA, Cernava T, Berg C, Berg G. Bog ecosystems as a playground for plant-microbe coevolution: bryophytes and vascular plants harbour functionally adapted bacteria. MICROBIOME 2021; 9:170. [PMID: 34380552 PMCID: PMC8359052 DOI: 10.1186/s40168-021-01117-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Accepted: 06/21/2021] [Indexed: 05/05/2023]
Abstract
BACKGROUND Bogs are unique ecosystems inhabited by distinctive, coevolved assemblages of organisms, which play a global role for carbon storage, climate stability, water quality and biodiversity. To understand ecology and plant-microbe co-occurrence in bogs, we selected 12 representative species of bryophytes and vascular plants and subjected them to a shotgun metagenomic sequencing approach. We explored specific plant-microbe associations as well as functional implications of the respective communities on their host plants and the bog ecosystem. RESULTS Microbial communities were shown to be functionally adapted to their plant hosts; a higher colonization specificity was found for vascular plants. Bryophytes that commonly constitute the predominant Sphagnum layer in bogs were characterized by a higher bacterial richness and diversity. Each plant group showed an enrichment of distinct phylogenetic and functional bacterial lineages. Detailed analyses of the metabolic potential of 28 metagenome-assembled genomes (MAGs) supported the observed functional specification of prevalent bacteria. We found that novel lineages of Betaproteobacteria and Actinobacteria in the bog environment harboured genes required for carbon fixation via RuBisCo. Interestingly, several of the highly abundant bacteria in both plant types harboured pathogenicity potential and carried similar virulence factors as found with corresponding human pathogens. CONCLUSIONS The unexpectedly high specificity of the plant microbiota reflects intimate plant-microbe interactions and coevolution in bog environments. We assume that the detected pathogenicity factors might be involved in coevolution processes, but the finding also reinforces the role of the natural plant microbiota as a potential reservoir for human pathogens. Overall, the study demonstrates how plant-microbe assemblages can ensure stability, functioning and ecosystem health in bogs. It also highlights the role of bog ecosystems as a playground for plant-microbe coevolution. Video abstract.
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Affiliation(s)
- Wisnu Adi Wicaksono
- Institute of Environmental Biotechnology, Graz University of Technology, Graz, Austria
| | - Tomislav Cernava
- Institute of Environmental Biotechnology, Graz University of Technology, Graz, Austria
| | - Christian Berg
- Institute of Plant Sciences, University of Graz, Graz, Austria
| | - Gabriele Berg
- Institute of Environmental Biotechnology, Graz University of Technology, Graz, Austria
- Leibniz Institute for Agricultural Engineering and Bioeconomy (ATB), Potsdam, Germany
- Institute for Biochemistry and Biology, University of Postdam, Postdam, Germany
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13
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Saiz E, Sgouridis F, Drijfhout FP, Peichl M, Nilsson MB, Ullah S. Chronic Atmospheric Reactive Nitrogen Deposition Suppresses Biological Nitrogen Fixation in Peatlands. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:1310-1318. [PMID: 33389989 DOI: 10.1021/acs.est.0c04882] [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] [Indexed: 06/12/2023]
Abstract
Biological nitrogen fixation (BNF) represents the natural pathway by which mosses meet their demands for bioavailable/reactive nitrogen (Nr) in peatlands. However, following intensification of nitrogen fertilizer and fossil fuel use, atmospheric Nr deposition has increased exposing peatlands to Nr loading often above the ecological threshold. As BNF is energy intensive, therefore, it is unclear whether BNF shuts down when Nr availability is no longer a rarity. We studied the response of BNF under a gradient of Nr deposition extending over decades in three peatlands in the U.K., and at a background deposition peatland in Sweden. Experimental nitrogen fertilization plots in the Swedish site were also evaluated for BNF activity. In situ BNF activity of peatlands receiving Nr deposition of 6, 17, and 27 kg N ha-1 yr-1 was not shut down but rather suppressed by 54, 69, and 74%, respectively, compared to the rates under background Nr deposition of ∼2 kg N ha-1 yr-1. These findings were corroborated by similar BNF suppression at the fertilization plots in Sweden. Therefore, contribution of BNF in peatlands exposed to chronic Nr deposition needs accounting when modeling peatland's nitrogen pools, given that nitrogen availability exerts a key control on the carbon capture of peatlands, globally.
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Affiliation(s)
- Ernesto Saiz
- School of Geography, Geology, and the Environment, Keele University, Staffordshire ST5 5BG, United Kingdom
| | - Fotis Sgouridis
- School of Geographical Sciences, University of Bristol, Bristol BS8 1SS, United Kingdom
| | - Falko P Drijfhout
- Chemical Ecology Group, School of Physical and Chemical Sciences, Keele University, Staffordshire ST5 5BG, United Kingdom
| | - Matthias Peichl
- Department of Forest Ecology & Management, Swedish University of Agricultural Sciences, Umeå 750 07, Sweden
| | - Mats B Nilsson
- Department of Forest Ecology & Management, Swedish University of Agricultural Sciences, Umeå 750 07, Sweden
| | - Sami Ullah
- School of Geography, Earth, and Environmental Sciences, and Birmingham Institute of Forest Research, University of Birmingham, Birmingham B15 2TT, United Kingdom
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14
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Graminoid Removal Reduces the Increase in N2O Fluxes Due to Nitrogen Fertilization in a Boreal Peatland. Ecosystems 2020. [DOI: 10.1007/s10021-020-00516-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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15
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Oke TA, Turetsky MR. Evaluating
Sphagnum
traits in the context of resource economics and optimal partitioning theories. OIKOS 2020. [DOI: 10.1111/oik.07195] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Tobi A. Oke
- Marine Science Inst., The Univ. of Texas Austin 750 Channel View Drive Port Aransas TX 78373 USA
| | - Merritt R. Turetsky
- Inst. of Arctic and Alpine Research, Univ. of Colorado Boulder, Boulder, CO, USA, and: Dept of Integrative Biology, Univ. of Guelph Guelph ON Canada
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16
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Gaudig G, Krebs M, Joosten H. Sphagnum growth under N saturation: interactive effects of water level and P or K fertilization. PLANT BIOLOGY (STUTTGART, GERMANY) 2020; 22:394-403. [PMID: 31999043 DOI: 10.1111/plb.13092] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Accepted: 01/13/2020] [Indexed: 06/10/2023]
Abstract
Sphagnum biomass is a promising material that could be used as a substitute for peat in growing media and can be sustainably produced by converting existing drainage-based peatland agriculture into wet, climate-friendly agriculture (paludiculture). Our study focuses on yield maximization of Sphagnum as a crop. We tested the effects of three water level regimes and of phosphorus or potassium fertilization on the growth of four Sphagnum species (S. papillosum, S. palustre, S. fimbriatum, S. fallax). To simulate field conditions in Central and Western Europe we carried out a glasshouse experiment under nitrogen-saturated conditions. A constant high water table (remaining at 2 cm below capitulum during growth) led to highest productivity for all tested species. Water table fluctuations between 2 and 9 cm below capitulum during growth and a water level 2 cm below capitulum at the start but falling relatively during plant growth led to significantly lower productivity. Fertilization had no effect on Sphagnum growth under conditions with high atmospheric deposition such as in NW Germany (38 kg N, 0.3 kg P, 7.6 kg K·ha-1 ·year-1 ). Large-scale maximization of Sphagnum yields requires precise water management, with water tables just below the capitula and rising with Sphagnum growth. The nutrient load in large areas of Central and Western Europe from atmospheric deposition and irrigation water is high but, with an optimal water supply, does not hamper Sphagnum growth, at least not of regional provenances of Sphagnum.
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Affiliation(s)
- G Gaudig
- Institute of Botany and Landscape Ecology, University of Greifswald, partner in the Greifswald Mire Centre, Greifswald, Germany
| | - M Krebs
- Institute of Botany and Landscape Ecology, University of Greifswald, partner in the Greifswald Mire Centre, Greifswald, Germany
| | - H Joosten
- Institute of Botany and Landscape Ecology, University of Greifswald, partner in the Greifswald Mire Centre, Greifswald, Germany
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17
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Kox MAR, van den Elzen E, Lamers LPM, Jetten MSM, van Kessel MAHJ. Microbial nitrogen fixation and methane oxidation are strongly enhanced by light in Sphagnum mosses. AMB Express 2020; 10:61. [PMID: 32236738 PMCID: PMC7109220 DOI: 10.1186/s13568-020-00994-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Accepted: 03/16/2020] [Indexed: 12/25/2022] Open
Abstract
Peatlands have acted as C-sinks for millennia, storing large amounts of carbon, of which a significant amount is yearly released as methane (CH4). Sphagnum mosses are a key genus in many peat ecosystems and these mosses live in close association with methane-oxidizing and nitrogen-fixing microorganisms. To disentangle mechanisms which may control Sphagnum-associated methane-oxidation and nitrogen-fixation, we applied four treatments to Sphagnum mosses from a pristine peatland in Finland: nitrogen fertilization, phosphorus fertilization, CH4 addition and light. N and P fertilization resulted in nutrient accumulation in the moss tissue, but did not increase Sphagnum growth. While net CO2 fixation rates remained unaffected in the N and P treatment, net CH4 emissions decreased because of enhanced CH4 oxidation. CH4 addition did not affect Sphagnum performance in the present set-up. Light, however, clearly stimulated the activity of associated nitrogen-fixing and methane-oxidizing microorganisms, increasing N2 fixation rates threefold and CH4 oxidation rates fivefold. This underlines the strong connection between Sphagnum and associated N2 fixation and CH4 oxidation. It furthermore indicates that phototrophy is a strong control of microbial activity, which can be directly or indirectly.
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Affiliation(s)
- Martine A R Kox
- Department of Microbiology, Radboud University, Heijendaalseweg 135, 6525 AJ, Nijmegen, The Netherlands
| | - Eva van den Elzen
- Department of Aquatic Ecology and Environmental Biology, Radboud University, Heijendaalseweg 135, 6525 AJ, Nijmegen, The Netherlands
| | - Leon P M Lamers
- Department of Aquatic Ecology and Environmental Biology, Radboud University, Heijendaalseweg 135, 6525 AJ, Nijmegen, The Netherlands
| | - Mike S M Jetten
- Department of Microbiology, Radboud University, Heijendaalseweg 135, 6525 AJ, Nijmegen, The Netherlands
| | - Maartje A H J van Kessel
- Department of Microbiology, Radboud University, Heijendaalseweg 135, 6525 AJ, Nijmegen, The Netherlands.
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18
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van den Elzen E, Bengtsson F, Fritz C, Rydin H, Lamers LPM. Variation in symbiotic N2 fixation rates among Sphagnum mosses. PLoS One 2020; 15:e0228383. [PMID: 32017783 PMCID: PMC7001857 DOI: 10.1371/journal.pone.0228383] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Accepted: 01/14/2020] [Indexed: 11/18/2022] Open
Abstract
Biological nitrogen (N) fixation is an important process supporting primary production in ecosystems, especially in those where N availability is limiting growth, such as peatlands and boreal forests. In many peatlands, peat mosses (genus Sphagnum) are the prime ecosystem engineers, and like feather mosses in boreal forests, they are associated with a diverse community of diazotrophs (N2-fixing microorganisms) that live in and on their tissue. The large variation in N2 fixation rates reported in literature remains, however, to be explained. To assess the potential roles of habitat (including nutrient concentration) and species traits (in particular litter decomposability and photosynthetic capacity) on the variability in N2 fixation rates, we compared rates associated with various Sphagnum moss species in a bog, the surrounding forest and a fen in Sweden. We found appreciable variation in N2 fixation rates among moss species and habitats, and showed that both species and habitat conditions strongly influenced N2 fixation. We here show that higher decomposition rates, as explained by lower levels of decomposition-inhibiting compounds, and higher phosphorous (P) levels, are related with higher diazotrophic activity. Combining our findings with those of other studies, we propose a conceptual model in which both species-specific traits of mosses (as related to the trade-off between rapid photosynthesis and resistance to decomposition) and P availability, explain N2 fixation rates. This is expected to result in a tight coupling between P and N cycling in peatlands.
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Affiliation(s)
- Eva van den Elzen
- Department of Aquatic Ecology and Environmental Biology, Institute for
Water and Wetland Research, Radboud University, AJ Nijmegen, the
Netherlands
| | - Fia Bengtsson
- Department of Plant Ecology and Evolution, Evolutionary Biology Centre,
Uppsala University, Uppsala, Sweden
| | - Christian Fritz
- Department of Aquatic Ecology and Environmental Biology, Institute for
Water and Wetland Research, Radboud University, AJ Nijmegen, the
Netherlands
| | - Håkan Rydin
- Department of Plant Ecology and Evolution, Evolutionary Biology Centre,
Uppsala University, Uppsala, Sweden
| | - Leon P. M. Lamers
- Department of Aquatic Ecology and Environmental Biology, Institute for
Water and Wetland Research, Radboud University, AJ Nijmegen, the
Netherlands
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19
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Bagnoud A, Guye-Humbert S, Schloter-Hai B, Schloter M, Zopfi J. Environmental factors determining distribution and activity of anammox bacteria in minerotrophic fen soils. FEMS Microbiol Ecol 2020; 96:5647352. [PMID: 31782780 DOI: 10.1093/femsec/fiz191] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Accepted: 11/26/2019] [Indexed: 11/13/2022] Open
Abstract
In contrast to the pervasive occurrence of denitrification in soils, anammox (anaerobic ammonium oxidation) is a spatially restricted process that depends on specific ecological conditions. To identify the factors that constrain the distribution and activity of anammox bacteria in terrestrial environments, we investigated four different soil types along a catena with opposing ecological gradients of nitrogen and water content, from an amended pasture to an ombrotrophic bog. Anammox was detected by polymerase chain reaction (PCR) and quantitative PCR (qPCR) only in the nitrophilic wet meadow and the minerotrophic fen, in soil sections remaining water-saturated for most of the year and whose interstitial water contained inorganic nitrogen. Contrastingly, aerobic ammonia oxidizing microorganisms were present in all examined samples and outnumbered anammox bacteria usually by at least one order of magnitude. 16S rRNA gene sequencing revealed a relatively high diversity of anammox bacteria with one Ca. Brocadia cluster. Three additional clusters could not be affiliated to known anammox genera, but have been previously detected in other soil systems. Soil incubations using 15N-labeled substrates revealed that anammox processes contributed about <2% to total N2 formation, leaving nitrification and denitrification as the dominant N-removal mechanism in these soils that represent important buffer zones between agricultural land and ombrotrophic peat bogs.
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Affiliation(s)
- Alexandre Bagnoud
- Laboratory of Microbiology, University of Neuchâtel, Rue Emile-Argand 11, CH-2009 Neuchâtel, Switzerland.,Institut de Génie Thermique, Haute École d'Ingénierie et de Gestion du Canton de Vaud, Avenue des Sports 20, CH-1400 Yverdon-les-Bains, Switzerland
| | - Sylvia Guye-Humbert
- Laboratory of Microbiology, University of Neuchâtel, Rue Emile-Argand 11, CH-2009 Neuchâtel, Switzerland
| | - Brigitte Schloter-Hai
- Research Unit for Comparative Microbiome Analysis; Helmholtz Zentrum München, Ingolstädter Landstraße 1, D-85764 Neuherberg, Germany
| | - Michael Schloter
- Research Unit for Comparative Microbiome Analysis; Helmholtz Zentrum München, Ingolstädter Landstraße 1, D-85764 Neuherberg, Germany
| | - Jakob Zopfi
- Laboratory of Microbiology, University of Neuchâtel, Rue Emile-Argand 11, CH-2009 Neuchâtel, Switzerland.,Aquatic and Stable Isotope Biogeochemistry, University of Basel, Bernoullistrasse 30, CH-4056 Basel, Switzerland
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20
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Desie E, Vancampenhout K, Nyssen B, van den Berg L, Weijters M, van Duinen GJ, den Ouden J, Van Meerbeek K, Muys B. Litter quality and the law of the most limiting: Opportunities for restoring nutrient cycles in acidified forest soils. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 699:134383. [PMID: 31525545 DOI: 10.1016/j.scitotenv.2019.134383] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Revised: 09/07/2019] [Accepted: 09/08/2019] [Indexed: 06/10/2023]
Abstract
The adverse effects of soil acidification are extensive and may result in hampered ecosystem functioning. Admixture of tree species with nutrient rich litter has been proposed to restore acidified forest soils and improve forest vitality, productivity and resilience. However, it is common belief that litter effects are insufficiently functional for restoration of poorly buffered sandy soils. Therefore we examined the effect of leaf litter on the forest floor, soil chemistry and soil biota in temperate forest stands along a range of sandy soil types in Belgium, the Netherlands and Germany. Specifically, we address: i) Which tree litter properties contribute most to the mitigation of soil acidification effects and ii) Do rich litter species have the potential to improve the belowground nutrient status of poorly buffered, sandy soils? Our analysis using structural equation modelling shows that litter base cation concentration is the decisive trait for the dominating soil buffering mechanism in forests that are heavily influenced by atmospheric nitrogen (N) deposition. This is in contrast with studies in which leaf litter quality is summarized by C/N ratio. We suggest that the concept of rich litter is context dependent and should consider Liebig's law of the most limiting: if N is not limiting in the ecosystem, litter C/N becomes of low importance, while base cations (calcium, magnesium, potassium) become determining. We further find that on poorly buffered soils, tree species with rich litter induce fast nutrient cycling, sustain higher earthworm biomass and keep topsoil base saturation above a threshold of 30%. Hence, rich litter can trigger a regime shift to the exchange buffer domain in sandy soils. This highlights that admixing tree species with litter rich in base cations is a promising measure to remediate soil properties on acidified sandy soils that receive, or have received, high inputs of N via deposition.
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Affiliation(s)
- Ellen Desie
- Division Forest, Nature and Landscape, KU Leuven, Celestijnenlaan 200E, Box 2411, B-3001 Leuven, Belgium.
| | - Karen Vancampenhout
- Department of Earth and Environmental Sciences, KU Leuven Campus Geel, Kleinhoefstraat 4, B-2240 Geel, Belgium
| | - Bart Nyssen
- Division Forest, Nature and Landscape, KU Leuven, Celestijnenlaan 200E, Box 2411, B-3001 Leuven, Belgium; Bosgroep Zuid-Nederland, Huisvenseweg 14, 5591 VD Heeze, the Netherlands
| | - Leon van den Berg
- Bosgroep Zuid-Nederland, Huisvenseweg 14, 5591 VD Heeze, the Netherlands; Aquatic Ecology & Environmental Biology, Radboud University Nijmegen, Heyendaalseweg 135, 6525 AJ Nijmegen, the Netherlands
| | - Maaike Weijters
- B-WARE Research Centre, Radboud University Nijmegen, Toernooiveld 1, 6525 ED Nijmegen, the Netherlands
| | | | - Jan den Ouden
- Forest Ecology and Management Group, Wageningen University, P.O. box 47, Wageningen, the Netherlands
| | - Koenraad Van Meerbeek
- Division Forest, Nature and Landscape, KU Leuven, Celestijnenlaan 200E, Box 2411, B-3001 Leuven, Belgium
| | - Bart Muys
- Division Forest, Nature and Landscape, KU Leuven, Celestijnenlaan 200E, Box 2411, B-3001 Leuven, Belgium.
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21
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Alleviation of Plant Stress Precedes Termination of Rich Fen Stages in Peat Profiles of Lowland Mires. Ecosystems 2019. [DOI: 10.1007/s10021-019-00437-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Abstract
Mesotrophic rich fens, that is, groundwater-fed mires, may be long-lasting, as well as transient ecosystems, displaced in time by poor fens, bogs, forests or eutrophic reeds. We hypothesized that fen stability is controlled by plant stress caused by waterlogging with calcium-rich and nutrient-poor groundwater, which limits expansion of hummock mosses, tussock sedges and trees. We analysed 32 European Holocene macrofossil profiles of rich fens using plant functional traits (PFTs) which indicate the level of plant stress in the environment: canopy height, clonal spread, diaspore mass, specific leaf area, leaf dry matter content, Ellenberg moisture value, hummock-forming ability, mycorrhizal status and plant functional groups. Six PFTs, which formed long-term significant trends during mire development, were compiled as rich fen stress indicator (RFSI). We found that RFSI values at the start of fen development were correlated with the thickness of subsequently accumulated rich fen peat. RFSI declined in fens approaching change into another mire type, regardless whether it was shifting into bog, forest or eutrophic reeds. RFSI remained comparatively high and stable in three rich fens, which have not terminated naturally until present times. By applying PFT analysis to macrofossil data, we demonstrated that fens may undergo a gradual autogenic process, which lowers the ecosystem’s resistance and enhances shifts to other mire types. Long-lasting rich fens, documented by deep peat deposits, are rare. Because autogenic processes tend to alleviate stress in fens, high levels of stress are needed at initial stages of rich fen development to enable its long persistence and continuous peat accumulation.
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22
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Xu Y, Xiao H, Wu D. Traffic-related dustfall and NO x, but not NH 3, seriously affect nitrogen isotopic compositions in soil and plant tissues near the roadside. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2019; 249:655-665. [PMID: 30933763 DOI: 10.1016/j.envpol.2019.03.074] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Accepted: 03/18/2019] [Indexed: 06/09/2023]
Abstract
Ammonia (NH3) emissions from traffic have received particular attention in recent years because of their important contributions to the growth of secondary aerosols and the negative effects on urban air quality. However, few studies have been performed on the impacts of traffic NH3 emissions on adjacent soil and plants. Moreover, doubt remains over whether dry nitrogen (N) deposition still contributes a minor proportion of plant N nutrition compared with wet N deposition in urban road environments. This study investigated the δ15N values of road dustfall, soil, moss, camphor leaf and camphor bark samples collected along a distance gradient from the road, suggesting that samples collected near the road have significantly more positive δ15N values than those of remote sites. According to the SIAR model (Stable Isotope Analysis in R) applied to dustfall and moss samples from the roadside, it was found that NH3 from traffic exhaust (8.8 ± 7.1%) contributed much less than traffic-derived NO2 (52.2 ± 10.0%) and soil N (39.0 ± 13.8%) to dustfall bulk N; additionally, 68.6% and 31.4% of N in mosses near the roadside could be explained by dry N deposition (only 20.4 ± 12.5% for traffic-derived NH3) and wet N deposition, respectively. A two-member mixing model was used to analyse the δ15N in continuously collected mature camphor leaf and camphor bark samples, which revealed a similarity of the δ15N values of plant-available deposited N to 15N-enriched traffic-derived NOx-N. We concluded that a relatively high proportion of N inputs in urban road environments was contributed by traffic-related dustfall and NOx rather than NH3. These information provide useful insights into reducing the impacts of traffic exhaust on adjacent ecosystems and can assist policy makers in determining the reconstruction of a monitoring network for N deposition that reaches the road level.
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Affiliation(s)
- Yu Xu
- Key Laboratory of Poyang Lake Environment and Resource Utilization of Ministry of Education, School of Resource, Environmental and Chemical Engineering, Nanchang University, Nanchang, Jiangxi 330031, China
| | - Huayun Xiao
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, No. 99, Linchengxi Road, Guiyang 550081, China.
| | - Daishe Wu
- Key Laboratory of Poyang Lake Environment and Resource Utilization of Ministry of Education, School of Resource, Environmental and Chemical Engineering, Nanchang University, Nanchang, Jiangxi 330031, China.
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Novak M, Pacherova P, Elliott EM, Jackova I, Stepanova M, Curik J, Cejkova B, Buzek F, Prechova E, Valkova I. δ15N systematics in two minerotrophic peatlands in the eastern U.S.: Insights into nitrogen cycling under moderate pollution. Glob Ecol Conserv 2019. [DOI: 10.1016/j.gecco.2019.e00571] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
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24
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Kox MAR, Aalto SL, Penttilä T, Ettwig KF, Jetten MSM, van Kessel MAHJ. The influence of oxygen and methane on nitrogen fixation in subarctic Sphagnum mosses. AMB Express 2018; 8:76. [PMID: 29730829 PMCID: PMC5936483 DOI: 10.1186/s13568-018-0607-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2018] [Accepted: 04/28/2018] [Indexed: 11/10/2022] Open
Abstract
Biological nitrogen fixation is an important source of bioavailable nitrogen in Sphagnum dominated peatlands. Sphagnum mosses harbor a diverse microbiome including nitrogen-fixing and methane (CH4) oxidizing bacteria. The inhibitory effect of oxygen on microbial nitrogen fixation is documented for many bacteria. However, the role of nitrogen-fixing methanotrophs in nitrogen supply to Sphagnum peat mosses is not well explored. Here, we investigated the role of both oxygen and methane on nitrogen fixation in subarctic Sphagnum peat mosses. Five species of Sphagnum mosses were sampled from two mesotrophic and three oligotrophic sites within the Lakkasuo peatland in Orivesi, central Finland. Mosses were incubated under either ambient or low oxygen conditions in the presence or absence of methane. Stable isotope activity assays revealed considerable nitrogen-fixing and methane-assimilating rates at all sites (1.4 ± 0.2 µmol 15N-N2 g-1 DW day-1 and 12.0 ± 1.1 µmol 13C-CH4 g-1 DW day-1, respectively). Addition of methane did not stimulate incorporation of 15N-nitrogen into biomass, whereas oxygen depletion increased the activity of the nitrogen-fixing community. Analysis of the 16S rRNA genes at the bacterial community level showed a very diverse microbiome that was dominated by Alphaproteobacteria in all sites. Bona fide methane-oxidizing taxa were not very abundant (relative abundance less than 0.1%). Based on our results we conclude that methanotrophs did not contribute significantly to nitrogen fixation in the investigated peatlands.
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Affiliation(s)
- Martine A. R. Kox
- Department of Microbiology, Radboud University, Nijmegen, The Netherlands
| | - Sanni L. Aalto
- Department of Biological and Environmental Science, University of Jyväskylä, PO Box 35, 40014 Jyväskylä, Finland
- Department of Environmental and Biological Sciences, University of Eastern Finland, PO Box 1627, 70211 Kuopio, Finland
| | - Timo Penttilä
- Natural Resources Institute Finland, PO Box 2, 00791 Helsinki, Finland
| | | | - Mike S. M. Jetten
- Department of Microbiology, Radboud University, Nijmegen, The Netherlands
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van den Elzen E, van den Berg LJL, van der Weijden B, Fritz C, Sheppard LJ, Lamers LPM. Effects of airborne ammonium and nitrate pollution strongly differ in peat bogs, but symbiotic nitrogen fixation remains unaffected. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 610-611:732-740. [PMID: 28822940 DOI: 10.1016/j.scitotenv.2017.08.102] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Revised: 08/09/2017] [Accepted: 08/10/2017] [Indexed: 06/07/2023]
Abstract
Pristine bogs, peatlands in which vegetation is exclusively fed by rainwater (ombrotrophic), typically have a low atmospheric deposition of reactive nitrogen (N) (<0.5kgha-1y-1). An important additional N source is N2 fixation by symbiotic microorganisms (diazotrophs) in peat and mosses. Although the effects of increased total airborne N by anthropogenic emissions on bog vegetation are well documented, the important question remains how different N forms (ammonium, NH4+, versus nitrate, NO3-) affect N cycling, as their relative contribution to the total load strongly varies among regions globally. Here, we studied the effects of 11years of experimentally increased deposition (32 versus 8kgNha-1y-1) of either NH4+ or NO3- on N accumulation in three moss and one lichen species (Sphagnum capillifolium, S. papillosum, Pleurozium schreberi and Cladonia portentosa), N2 fixation rates of their symbionts, and potential N losses to peat soil and atmosphere, in a bog in Scotland. Increased input of both N forms led to 15-90% increase in N content for all moss species, without affecting their cover. The keystone species S. capillifolium showed 4 times higher N allocation into free amino acids, indicating N stress, but only in response to increased NH4+. In contrast, NO3- addition resulted in enhanced peat N mineralization linked to microbial NO3- reduction, increasing soil pH, N concentrations and N losses via denitrification. Unexpectedly, increased deposition from 8 to 32kgha-1y-1 in both N forms did not affect N2 fixation rates for any of the moss species and corresponded to an additional input of 5kgNha-1y-1 with a 100% S. capillifolium cover. Since both N forms clearly show differential effects on living Sphagnum and biogeochemical processes in the underlying peat, N form should be included in the assessment of the effects of N pollution on peatlands.
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Affiliation(s)
- Eva van den Elzen
- Department of Aquatic Ecology & Environmental Biology, Institute for Water and Wetland Research, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands.
| | | | - Bas van der Weijden
- Department of Aquatic Ecology & Environmental Biology, Institute for Water and Wetland Research, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
| | - Christian Fritz
- Department of Aquatic Ecology & Environmental Biology, Institute for Water and Wetland Research, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands; Centre for Energy and Environmental Studies, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Lucy J Sheppard
- Centre for Ecology & Hydrology Edinburgh, Bush Estate, Penicuik EH26 0QB, UK
| | - Leon P M Lamers
- Department of Aquatic Ecology & Environmental Biology, Institute for Water and Wetland Research, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
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26
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Dong YP, Liu XY, Sun XC, Song W, Zheng XD, Li R, Liu CQ. Inter-species and intra-annual variations of moss nitrogen utilization: Implications for nitrogen deposition assessment. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2017; 230:506-515. [PMID: 28692942 DOI: 10.1016/j.envpol.2017.06.058] [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: 02/28/2017] [Revised: 06/16/2017] [Accepted: 06/17/2017] [Indexed: 06/07/2023]
Abstract
Moss nitrogen (N) concentrations and natural 15N abundance (δ15N values) have been widely employed to evaluate annual levels and major sources of atmospheric N deposition. However, different moss species and one-off sampling were often used among extant studies, it remains unclear whether moss N parameters differ with species and different samplings, which prevented more accurate assessment of N deposition via moss survey. Here concentrations, isotopic ratios of bulk carbon (C) and bulk N in natural epilithic mosses (Bryum argenteum, Eurohypnum leptothallum, Haplocladium microphyllum and Hypnum plumaeforme) were measured monthly from August 2006 to August 2007 at Guiyang, SW China. The H. plumaeforme had significantly (P < 0.05) lower bulk N concentrations and higher δ13C values than other species. Moss N concentrations were significantly (P < 0.05) lower in warmer months than in cooler months, while moss δ13C values exhibited an opposite pattern. The variance component analyses showed that different species contributed more variations of moss N concentrations and δ13C values than different samplings. Differently, δ15N values did not differ significantly between moss species, and its variance mainly reflected variations of assimilated N sources, with ammonium as the dominant contributor. These results unambiguously reveal the influence of inter-species and intra-annual variations of moss N utilization on N deposition assessment.
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Affiliation(s)
- Yu-Ping Dong
- Institute of Surface-Earth System Science, Tianjin University, Tianjin, 300072, China
| | - Xue-Yan Liu
- Institute of Surface-Earth System Science, Tianjin University, Tianjin, 300072, China; State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, 550002, China.
| | - Xin-Chao Sun
- Institute of Surface-Earth System Science, Tianjin University, Tianjin, 300072, China.
| | - Wei Song
- Institute of Surface-Earth System Science, Tianjin University, Tianjin, 300072, China
| | - Xu-Dong Zheng
- Institute of Surface-Earth System Science, Tianjin University, Tianjin, 300072, China
| | - Rui Li
- Institute of Surface-Earth System Science, Tianjin University, Tianjin, 300072, China
| | - Cong-Qiang Liu
- Institute of Surface-Earth System Science, Tianjin University, Tianjin, 300072, China; State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, 550002, China
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27
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Govers LL, van der Zee EM, Meffert JP, van Rijswick PCJ, Man in ‘t Veld WA, Heusinkveld JHT, van der Heide T. Copper treatment during storage reduces Phytophthora and Halophytophthora infection of Zostera marina seeds used for restoration. Sci Rep 2017; 7:43172. [PMID: 28225072 PMCID: PMC5320552 DOI: 10.1038/srep43172] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Accepted: 01/20/2017] [Indexed: 11/16/2022] Open
Abstract
Restoration is increasingly considered an essential tool to halt and reverse the rapid decline of vital coastal ecosystems dominated by habitat-forming foundation species such as seagrasses. However, two recently discovered pathogens of marine plants, Phytophthora gemini and Halophytophthora sp. Zostera, can seriously hamper restoration efforts by dramatically reducing seed germination. Here, we report on a novel method that strongly reduces Phytophthora and Halophytophthora infection of eelgrass (Zostera marina) seeds. Seeds were stored in seawater with three different copper sulphate concentrations (0.0, 0.2, 2.0 ppm) crossed with three salinities (0.5, 10.0, 25.0 ppt). Next to reducing seed germination, infection significantly affected cotyledon colour: 90% of the germinated infected seeds displayed a brown cotyledon upon germination that did not continue development into the seedling stage, in contrast to only 13% of the germinated non-infected seeds. Copper successfully reduced infection up to 86% and the 0.2 ppm copper sulphate treatment was just as successful as the 2.0 ppm treatment. Infection was completely eliminated at low salinities, but green seed germination was also dramatically lowered by 10 times. We conclude that copper sulphate treatment is a suitable treatment for disinfecting Phytophthora or Halophytophthora infected eelgrass seeds, thereby potentially enhancing seed-based restoration success.
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Affiliation(s)
- Laura L. Govers
- Department of Aquatic Ecology and Environmental Biology, Institute for Water and Wetland research (IWWR), Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
- Conservation Ecology Group, Groningen Institute for Evolutionary Life Sciences, University of Groningen (GELIFES), Post Office Box 11103, 9700 CC The Netherlands
| | - Els M. van der Zee
- Altenburg & Wymenga Ecological Consultants, Suderwei 2, 9269 TZ Veenwouden, The Netherlands
| | - Johan P. Meffert
- Department of Mycology, National Plant Protection Organisation (NPPO-NL), Post Office Box 9102, 6700 HC Wageningen, The Netherlands
| | - Patricia C. J. van Rijswick
- Department of Mycology, National Plant Protection Organisation (NPPO-NL), Post Office Box 9102, 6700 HC Wageningen, The Netherlands
| | - Willem A. Man in ‘t Veld
- Department of Mycology, National Plant Protection Organisation (NPPO-NL), Post Office Box 9102, 6700 HC Wageningen, The Netherlands
| | | | - Tjisse van der Heide
- Department of Aquatic Ecology and Environmental Biology, Institute for Water and Wetland research (IWWR), Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
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28
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Chiwa M, Sheppard LJ, Leith ID, Leeson SR, Tang YS, Cape JN. Sphagnum can 'filter' N deposition, but effects on the plant and pore water depend on the N form. THE SCIENCE OF THE TOTAL ENVIRONMENT 2016; 559:113-120. [PMID: 27058130 DOI: 10.1016/j.scitotenv.2016.03.130] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Revised: 03/18/2016] [Accepted: 03/18/2016] [Indexed: 06/05/2023]
Abstract
The ability of Sphagnum moss to efficiently intercept atmospheric nitrogen (N) has been assumed to be vulnerable to increased N deposition. However, the proposed critical load (20kgNha(-1)yr(-1)) to exceed the capacity of the Sphagnum N filter has not been confirmed. A long-term (11years) and realistic N manipulation on Whim bog was used to study the N filter function of Sphagnum (Sphagnum capillifolium) in response to increased wet N deposition. On this ombrotrophic peatland where ambient deposition was 8kgNha(-1)yr(-1), an additional 8, 24, and 56kgNha(-1)yr(-1) of either ammonium (NH4(+)) or nitrate (NO3(-)) has been applied for 11years. Nutrient status of Sphagnum and pore water quality from the Sphagnum layer were assessed. The N filter function of Sphagnum was still active up to 32kgNha(-1)yr(-1) even after 11years. N saturation of Sphagnum and subsequent increases in dissolved inorganic N (DIN) concentration in pore water occurred only for 56kgNha(-1)yr(-1) of NH4(+) addition. These results indicate that the Sphagnum N filter is more resilient to wet N deposition than previously inferred. However, functionality will be more compromised when NH4(+) dominates wet deposition for high inputs (56kgNha(-1)yr(-1)). The N filter function in response to NO3(-) uptake increased the concentration of dissolved organic N (DON) and associated organic anions in pore water. NH4(+) uptake increased the concentration of base cations and hydrogen ions in pore water though ion exchange. The resilience of the Sphagnum N filter can explain the reported small magnitude of species change in the Whim bog ecosystem exposed to wet N deposition. However, changes in the leaching substances, arising from the assimilation of NO3(-) and NH4(+), may lead to species change.
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Affiliation(s)
- Masaaki Chiwa
- Kyushu University Forest, Kyushu University, 394 Tsubakuro, Sasaguri, Fukuoka 811-2415, Japan.
| | - Lucy J Sheppard
- Centre for Ecology & Hydrology (CEH) Edinburgh, Bush Estate, Penicuik, Midlothian EH260QB, UK
| | - Ian D Leith
- Centre for Ecology & Hydrology (CEH) Edinburgh, Bush Estate, Penicuik, Midlothian EH260QB, UK
| | - Sarah R Leeson
- Centre for Ecology & Hydrology (CEH) Edinburgh, Bush Estate, Penicuik, Midlothian EH260QB, UK
| | - Y Sim Tang
- Centre for Ecology & Hydrology (CEH) Edinburgh, Bush Estate, Penicuik, Midlothian EH260QB, UK
| | - J Neil Cape
- Centre for Ecology & Hydrology (CEH) Edinburgh, Bush Estate, Penicuik, Midlothian EH260QB, UK
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29
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Contrasting δ15N Values of Atmospheric Deposition and Sphagnum Peat Bogs: N Fixation as a Possible Cause. Ecosystems 2016. [DOI: 10.1007/s10021-016-9985-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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30
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van Diggelen JMH, Smolders AJP, Visser EJW, Hicks S, Roelofs JGM, Lamers LPM. Differential responses of two wetland graminoids to high ammonium at different pH values. PLANT BIOLOGY (STUTTGART, GERMANY) 2016; 18:307-315. [PMID: 26404423 DOI: 10.1111/plb.12398] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2014] [Accepted: 09/17/2015] [Indexed: 06/05/2023]
Abstract
Enhanced soil ammonium (NH4+) concentrations in wetlands often lead to graminoid dominance, but species composition is highly variable. Although NH4+ is readily taken up as a nutrient, several wetland species are known to be sensitive to high NH4+ concentrations or even suffer toxicity, particularly at low soil pH. More knowledge about differential graminoid responses to high NH4+ availability in relation to soil pH can help to better understand vegetation changes. The responses of two wetland graminoids, Juncus acutiflorus and Carex disticha, to high (2 mmol·l(-1) ) versus control (20 μmol·l(-1) ) NH4+ concentrations were tested in a controlled hydroponic set up, at two pH values (4 and 6). A high NH4+ concentration did not change total biomass for these species at either pH, but increased C allocation to shoots and increased P uptake, leading to K and Ca limitation, depending on pH treatment. More than 50% of N taken up by C. disticha was invested in N-rich amino acids with decreasing C:N ratio, but only 10% for J. acutiflorus. Although both species appeared to be well adapted to high NH4+ loadings in the short term, C. disticha showed higher classic detoxifying responses that are early warning indicators for decreased tolerance in the long term. In general, the efficient aboveground biomass allocation, P uptake and N detoxification explain the competitive strength of wetland graminoids at the expense of overall biodiversity at high NH4+ loading. In addition, differential responses to enhanced NH4+ affect interspecific competition among graminoids and lead to a shift in vegetation composition.
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Affiliation(s)
- J M H van Diggelen
- B-WARE Research Centre, Radboud University Nijmegen, Nijmegen, the Netherlands
- Institute for Water and Wetland Research, Department of Aquatic Ecology and Environmental Biology, Radboud University Nijmegen, Nijmegen, the Netherlands
| | - A J P Smolders
- B-WARE Research Centre, Radboud University Nijmegen, Nijmegen, the Netherlands
- Institute for Water and Wetland Research, Department of Aquatic Ecology and Environmental Biology, Radboud University Nijmegen, Nijmegen, the Netherlands
| | - E J W Visser
- Institute for Water and Wetland Research, Department of Experimental Plant Ecology, Radboud University Nijmegen, Nijmegen, the Netherlands
| | - S Hicks
- B-WARE Research Centre, Radboud University Nijmegen, Nijmegen, the Netherlands
| | - J G M Roelofs
- Institute for Water and Wetland Research, Department of Aquatic Ecology and Environmental Biology, Radboud University Nijmegen, Nijmegen, the Netherlands
| | - L P M Lamers
- Institute for Water and Wetland Research, Department of Aquatic Ecology and Environmental Biology, Radboud University Nijmegen, Nijmegen, the Netherlands
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31
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Skrzypek G, Wojtuń B, Richter D, Jakubas D, Wojczulanis-Jakubas K, Samecka-Cymerman A. Diversification of Nitrogen Sources in Various Tundra Vegetation Types in the High Arctic. PLoS One 2015; 10:e0136536. [PMID: 26376204 PMCID: PMC4574312 DOI: 10.1371/journal.pone.0136536] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Accepted: 08/05/2015] [Indexed: 11/19/2022] Open
Abstract
Low nitrogen availability in the high Arctic represents a major constraint for plant growth, which limits the tundra capacity for carbon retention and determines tundra vegetation types. The limited terrestrial nitrogen (N) pool in the tundra is augmented significantly by nesting seabirds, such as the planktivorous Little Auk (Alle alle). Therefore, N delivered by these birds may significantly influence the N cycling in the tundra locally and the carbon budget more globally. Moreover, should these birds experience substantial negative environmental pressure associated with climate change, this will adversely influence the tundra N-budget. Hence, assessment of bird-originated N-input to the tundra is important for understanding biological cycles in polar regions. This study analyzed the stable nitrogen composition of the three main N-sources in the High Arctic and in numerous plants that access different N-pools in ten tundra vegetation types in an experimental catchment in Hornsund (Svalbard). The percentage of the total tundra N-pool provided by birds, ranged from 0-21% in Patterned-ground tundra to 100% in Ornithocoprophilous tundra. The total N-pool utilized by tundra plants in the studied catchment was built in 36% by birds, 38% by atmospheric deposition, and 26% by atmospheric N2-fixation. The stable nitrogen isotope mixing mass balance, in contrast to direct methods that measure actual deposition, indicates the ratio between the actual N-loads acquired by plants from different N-sources. Our results enhance our understanding of the importance of different N-sources in the Arctic tundra and the used methodological approach can be applied elsewhere.
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Affiliation(s)
- Grzegorz Skrzypek
- West Australian Biogeochemistry Centre, School of Plant Biology, The University of Western Australia, Crawley, Western Australia, Australia
| | - Bronisław Wojtuń
- Department of Ecology, Biogeochemistry and Environmental Protection, The University of Wrocław, Wrocław, Poland
| | - Dorota Richter
- Department of Botany and Plant Ecology, The Wrocław University of Environmental and Life Sciences, Wrocław, Poland
| | - Dariusz Jakubas
- Department of Vertebrate Ecology and Zoology, The University of Gdańsk, Gdańsk, Poland
| | | | - Aleksandra Samecka-Cymerman
- Department of Ecology, Biogeochemistry and Environmental Protection, The University of Wrocław, Wrocław, Poland
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32
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Weston DJ, Timm CM, Walker AP, Gu L, Muchero W, Schmutz J, Shaw AJ, Tuskan GA, Warren JM, Wullschleger SD. Sphagnum physiology in the context of changing climate: emergent influences of genomics, modelling and host-microbiome interactions on understanding ecosystem function. PLANT, CELL & ENVIRONMENT 2015; 38:1737-1751. [PMID: 25266403 DOI: 10.1111/pce.12458] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2014] [Revised: 09/16/2014] [Accepted: 09/18/2014] [Indexed: 06/03/2023]
Abstract
Peatlands harbour more than one-third of terrestrial carbon leading to the argument that the bryophytes, as major components of peatland ecosystems, store more organic carbon in soils than any other collective plant taxa. Plants of the genus Sphagnum are important components of peatland ecosystems and are potentially vulnerable to changing climatic conditions. However, the response of Sphagnum to rising temperatures, elevated CO2 and shifts in local hydrology have yet to be fully characterized. In this review, we examine Sphagnum biology and ecology and explore the role of this group of keystone species and its associated microbiome in carbon and nitrogen cycling using literature review and model simulations. Several issues are highlighted including the consequences of a variable environment on plant-microbiome interactions, uncertainty associated with CO2 diffusion resistances and the relationship between fixed N and that partitioned to the photosynthetic apparatus. We note that the Sphagnum fallax genome is currently being sequenced and outline potential applications of population-level genomics and corresponding plant photosynthesis and microbial metabolic modelling techniques. We highlight Sphagnum as a model organism to explore ecosystem response to a changing climate and to define the role that Sphagnum can play at the intersection of physiology, genetics and functional genomics.
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Affiliation(s)
- David J Weston
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Collin M Timm
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Anthony P Walker
- Environmental Sciences Division and Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Lianhong Gu
- Environmental Sciences Division and Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Wellington Muchero
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Jeremy Schmutz
- Department of Energy Joint Genome Institute, Walnut Creek, CA, 94598, USA
- HudsonAlpha Institute of Biotechnology, Huntsville, AL, 35806, USA
| | - A Jonathan Shaw
- Department of Biology, Duke University, Durham, NC, 27708, USA
| | - Gerald A Tuskan
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Jeffrey M Warren
- Environmental Sciences Division and Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Stan D Wullschleger
- Environmental Sciences Division and Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
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33
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Knorr KH, Horn MA, Borken W. Significant nonsymbiotic nitrogen fixation in Patagonian ombrotrophic bogs. GLOBAL CHANGE BIOLOGY 2015; 21:2357-2365. [PMID: 25545459 DOI: 10.1111/gcb.12849] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2014] [Revised: 12/04/2014] [Accepted: 12/05/2014] [Indexed: 06/04/2023]
Abstract
Nitrogen (N) nutrition in pristine peatlands relies on the natural input of inorganic N through atmospheric deposition or biological dinitrogen (N2 ) fixation. However, N2 fixation and its significance for N cycling, plant productivity, and peat buildup are mostly associated with the presence of Sphagnum mosses. Here, we report high nonsymbiotic N2 -fixation rates in two pristine Patagonian bogs with diversified vegetation and natural N deposition. Nonsymbiotic N2 fixation was measured in samples from 0 to 10, 10 to 20, and 40 to 50 cm depth using the (15) N2 assay as well as the acetylene reduction assay (ARA). The ARA considerably underestimated N2 fixation and can thus not be recommended for peatland studies. Based on the (15) N2 assay, high nonsymbiotic N2 -fixation rates of 0.3-1.4 μmol N2 g(-1) day(-1) were found down to 50 cm under micro-oxic conditions (2 vol.%) in samples from plots covered by Sphagnum magellanicum or by vascular cushion plants, latter characterized by dense and deep aerenchyma roots. Peat N concentrations point to greater potential of nonsymbiotic N2 fixation under cushion plants, likely because of the availability of easily decomposable organic compounds and oxic conditions in the rhizosphere. In the Sphagnum plots, high N2 fixation below 10 cm depth rather reflects the potential during dry periods or low water level when oxygen penetrates the top peat layer and triggers peat mineralization. Natural abundance of the (15) N isotope of live Sphagnum (5.6 δ‰) from 0 to 10 cm points to solely N uptake from atmospheric deposition and nonsymbiotic N2 fixation. A mean (15) N signature of -0.7 δ‰ of peat from the cushion plant plots indicates additional N supply from N mineralization. Our findings suggest that nonsymbiotic N2 fixation overcomes N deficiency in different vegetation communities and has great significance for N cycling and peat accumulation in pristine peatlands.
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Affiliation(s)
- Klaus-Holger Knorr
- Institute for Landscape Ecology, Hydrology Group, University of Münster, Heisenbergstr. 2, 48149, Münster, Germany
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34
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Vegetation Composition in Bogs is Sensitive to Both Load and Concentration of Deposited Nitrogen: A Modeling Analysis. Ecosystems 2014. [DOI: 10.1007/s10021-014-9820-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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