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Cui Y, Peng S, Delgado-Baquerizo M, Rillig MC, Terrer C, Zhu B, Jing X, Chen J, Li J, Feng J, He Y, Fang L, Moorhead DL, Sinsabaugh RL, Peñuelas J. Microbial communities in terrestrial surface soils are not widely limited by carbon. GLOBAL CHANGE BIOLOGY 2023; 29:4412-4429. [PMID: 37277945 DOI: 10.1111/gcb.16765] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Revised: 04/03/2023] [Accepted: 04/04/2023] [Indexed: 06/07/2023]
Abstract
Microbial communities in soils are generally considered to be limited by carbon (C), which could be a crucial control for basic soil functions and responses of microbial heterotrophic metabolism to climate change. However, global soil microbial C limitation (MCL) has rarely been estimated and is poorly understood. Here, we predicted MCL, defined as limited availability of substrate C relative to nitrogen and/or phosphorus to meet microbial metabolic requirements, based on the thresholds of extracellular enzyme activity across 847 sites (2476 observations) representing global natural ecosystems. Results showed that only about 22% of global sites in terrestrial surface soils show relative C limitation in microbial community. This finding challenges the conventional hypothesis of ubiquitous C limitation for soil microbial metabolism. The limited geographic extent of C limitation in our study was mainly attributed to plant litter, rather than soil organic matter that has been processed by microbes, serving as the dominant C source for microbial acquisition. We also identified a significant latitudinal pattern of predicted MCL with larger C limitation at mid- to high latitudes, whereas this limitation was generally absent in the tropics. Moreover, MCL significantly constrained the rates of soil heterotrophic respiration, suggesting a potentially larger relative increase in respiration at mid- to high latitudes than low latitudes, if climate change increases primary productivity that alleviates MCL at higher latitudes. Our study provides the first global estimates of MCL, advancing our understanding of terrestrial C cycling and microbial metabolic feedback under global climate change.
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Affiliation(s)
- Yongxing Cui
- Sino-French Institute for Earth System Science, College of Urban and Environmental Sciences, Peking University, Beijing, China
| | - Shushi Peng
- Sino-French Institute for Earth System Science, College of Urban and Environmental Sciences, Peking University, Beijing, China
| | - Manuel Delgado-Baquerizo
- Laboratorio de Biodiversidad y Funcionamiento Ecosistémico, Instituto de Recursos Naturales y Agrobiología de Sevilla (IRNAS), CSIC, Sevilla, Spain
- Unidad Asociada CSIC-UPO (BioFun). Universidad Pablo de Olavide, Sevilla, Spain
| | | | - César Terrer
- Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Boston, Massachusetts, USA
| | - Biao Zhu
- Institute of Ecology, College of Urban and Environmental Sciences, and Key Laboratory for Earth Surface Processes of the Ministry of Education, Peking University, Beijing, China
| | - Xin Jing
- State Key Laboratory of Grassland Agro-Ecosystems, and College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou, Gansu, China
| | - Ji Chen
- Department of Agroecology, Aarhus University, Tjele, Denmark
| | - Jinquan Li
- Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, National Observations and Research Station for Wetland Ecosystems of the Yangtze Estuary, Institute of Biodiversity Science and Institute of Eco-Chongming, School of Life Sciences, Fudan University, Shanghai, China
| | - Jiao Feng
- College of Resources and Environment, Huazhong Agricultural University, Wuhan, China
| | - Yue He
- Sino-French Institute for Earth System Science, College of Urban and Environmental Sciences, Peking University, Beijing, China
| | - Linchuan Fang
- School of Resource and Environmental Engineering, Wuhan University of Technology, Wuhan, China
| | - Daryl L Moorhead
- Department of Environmental Sciences, University of Toledo, Toledo, Ohio, USA
| | - Robert L Sinsabaugh
- Department of Biology, University of New Mexico, Albuquerque, New Mexico, USA
| | - Josep Peñuelas
- CSIC, Global Ecology Unit CREAF-CSIC-UAB, Bellaterra, Catalonia, Spain
- CREAF, Cerdanyola del Vallès, Catalonia, Spain
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Wang S, Wang X, Sun X, Ma G, Du Y, Jiang J. Stoichiometry and stable isotopes of plants and their response to environmental factors in boreal peatland, Northeast China. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2022.1071947] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The alterations of plant composition and diversity pose a threat to the stability of the carbon pool in boreal peatland under climate change. We collected the samples of three plant functional types (deciduous shrubs, evergreen shrubs, and sedge) in seven permafrost peatlands of the Great Hing’an Mountains, China, and measured the properties of total carbon (TC), nitrogen (TN), and phosphorus (TP), their stoichiometric ratios (C:N, C:P, and N:P), and the stable isotope values (δ13C and δ15N) of six tissues (ranging from leaves to roots). For TC, TN, and TP, the contents had an average of 470.69 ± 1.56, 8.03 ± 0.23, and 1.71 ± 0.61 mg·g−1, respectively. TC contents of sedge were lower than those of shrubs for the whole plant. The allocations of N and P to shrub leaves were higher than to stems and roots. There was a similar trend of TN and TP contents, and stoichiometric ratios from leaves to roots between deciduous shrubs and evergreen shrubs. Shrubs and sedge have similar C: N in leaves and fine roots, while leaves of sedge C:P and N:P ratios were higher than shrubs, mainly showed that sedge is N and P co-limitation and shrubs are N limitation. The values of δ13C and δ15N were significantly higher in leaves and roots of sedge than those of shrubs, which means shrubs have higher nutrient acquisition strategies. These results support the shrubs are expanding in the boreal peatland under climate warming through nutrient competition. TC contents of all deciduous shrubs and sedge tissues were positively linear correlated to MAT and the values of δ13C and δ15N in sedge had significant relationships with MAT and MAP. Our results imply warming can increase plant photosynthesis in boreal peatland, and sedge was more sensitive to climate change. These findings would be helpful to understanding the responses of different plant tissues to climate changes in permafrost peatland.
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Zarzycki J, Zając E, Vončina G. Bryophytes and vascular plants on peat extraction sites - which factors influence their growth? J Nat Conserv 2022. [DOI: 10.1016/j.jnc.2022.126287] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Antala M, Juszczak R, van der Tol C, Rastogi A. Impact of climate change-induced alterations in peatland vegetation phenology and composition on carbon balance. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 827:154294. [PMID: 35247401 DOI: 10.1016/j.scitotenv.2022.154294] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Revised: 02/03/2022] [Accepted: 02/28/2022] [Indexed: 06/14/2023]
Abstract
Global climate is changing faster than humankind has ever experienced. Model-based predictions of future climate are becoming more complex and precise, but they still lack crucial information about the reaction of some important ecosystems, such as peatlands. Peatlands belong to one of the largest carbon stores on the Earth. They are mostly distributed in high latitudes, where the temperature rises faster than in the other parts of the planet. Warmer climate and changes in precipitation patterns cause changes in the composition and phenology of peatland vegetation. Peat mosses are becoming less abundant, vascular plants cover is increasing, and the vegetation season and phenophases of vascular plants start sooner. The alterations in vegetation cause changes in the carbon assimilation and release of greenhouse gases. Therefore, this article reviews the impact of climate change-induced alterations in peatland vegetation phenology and composition on future climate and the uncertainties that need to be addressed for more accurate climate prediction.
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Affiliation(s)
- Michal Antala
- Laboratory of Bioclimatology, Department of Ecology and Environmental Protection, Faculty of Environmental Engineering and Mechanical Engineering, Poznan University of Life Sciences, Piątkowska 94, 60-649 Poznań, Poland
| | - Radoslaw Juszczak
- Laboratory of Bioclimatology, Department of Ecology and Environmental Protection, Faculty of Environmental Engineering and Mechanical Engineering, Poznan University of Life Sciences, Piątkowska 94, 60-649 Poznań, Poland
| | - Christiaan van der Tol
- Faculty of Geo-Information Science and Earth Observation (ITC), University of Twente, 7500 AE Enschede, the Netherlands
| | - Anshu Rastogi
- Laboratory of Bioclimatology, Department of Ecology and Environmental Protection, Faculty of Environmental Engineering and Mechanical Engineering, Poznan University of Life Sciences, Piątkowska 94, 60-649 Poznań, Poland; Faculty of Geo-Information Science and Earth Observation (ITC), University of Twente, 7500 AE Enschede, the Netherlands.
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5
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Trifiró G, York R, Bell NGA. High-Resolution Molecular-Level Characterization of a Blanket Bog Peat Profile. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:660-671. [PMID: 34932324 DOI: 10.1021/acs.est.1c05837] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
To understand peatland carbon-cycling processes ultimately requires the ability to track changes occurring on the molecular-level. In this study, we profile a peat core taken from the world's largest blanket bog, Flow Country, Scotland, using physicochemical properties, ATR-FTIR, solid/liquid-state NMR, and solid/liquid-state FT-ICR-MS. Air-dried peat and labile and recalcitrant peat extracts, including pore water dissolved organic matter (PW-DOM), are analyzed and the merits of each technique are discussed. Solid-state NMR demonstrated changing distribution of compound classes with core depth and water table, the latter not picked up by IR. Liquid-state NMR and MS both demonstrated variations in molecular composition along the core depth in all phases and extracts. Contrary to previous reports, the composition of PW-DOM varied with depth. Major compounds, some previously unreported, identified by 1D/2D NMR occurred throughout the core, suggesting the existence of hot spots of microbial activity/compound accumulation. Offering complementary views, the techniques provided evidence of gradual molecular level changes with age, zonation due to the water table, and hot spots due to microbial activity. This study provides new insights into the molecular signatures of peat layers and establishes the foundation for examining peat function and health at the molecular-level.
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Affiliation(s)
- Gianluca Trifiró
- University of Edinburgh, Joseph Black Building, David Brewster Road, Edinburgh EH9 3FJ, United Kingdom
| | - Richard York
- University of Edinburgh, Joseph Black Building, David Brewster Road, Edinburgh EH9 3FJ, United Kingdom
| | - Nicholle G A Bell
- University of Edinburgh, Joseph Black Building, David Brewster Road, Edinburgh EH9 3FJ, United Kingdom
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Heffernan L, Jassey VEJ, Frederickson M, MacKenzie MD, Olefeldt D. Constraints on potential enzyme activities in thermokarst bogs: Implications for the carbon balance of peatlands following thaw. GLOBAL CHANGE BIOLOGY 2021; 27:4711-4726. [PMID: 34164885 DOI: 10.1111/gcb.15758] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Revised: 05/04/2021] [Accepted: 06/15/2021] [Indexed: 06/13/2023]
Abstract
Northern peatlands store a globally significant amount of soil organic carbon, much of it found in rapidly thawing permafrost. Permafrost thaw in peatlands often leads to the development and expansion of thermokarst bogs, where microbial activity will determine the stability of the carbon storage and the release of greenhouse gases. In this study, we compared potential enzyme activities between young (thawed ~30 years ago) and mature (~200 years) thermokarst bogs, for both shallow and deep peat layers. We found very low potential enzyme activities in deep peat layers, with no differences between the young and mature bogs. Peat quality at depth was found to be highly humified (FTIR analysis) in both the young and mature bogs. This suggests that deep, old peat was largely stable following permafrost thaw, without a rapid pulse of decomposition during the young bog stage. For near-surface peat, we found significantly higher potential enzyme activities in the young bog than in the mature-associated with differences in peat quality derived from different Sphagnum species. A laboratory incubation of near-surface peat showed that differences in potential enzyme activity were primarily influenced by peat type rather than oxygen availability. This suggested that the young bog can have higher rates of near-surface decomposition despite being substantially wetter than the mature bog. Overall, our study shows that peat properties are the dominant constraint on potential enzyme activity and that peatland site development (successional pathways and permafrost history) through its influence on peat type and chemistry is likely to determine peat decomposition following permafrost thaw.
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Affiliation(s)
- Liam Heffernan
- Department of Renewable Resources, University of Alberta, Edmonton, AB, Canada
| | - Vincent E J Jassey
- Laboratorie d'Ecologie Fonctionelle et Envrionnement, Université de Toulouse, CNRS, Toulouse, France
| | - Maya Frederickson
- Department of Renewable Resources, University of Alberta, Edmonton, AB, Canada
| | - M Derek MacKenzie
- Department of Renewable Resources, University of Alberta, Edmonton, AB, Canada
| | - David Olefeldt
- Department of Renewable Resources, University of Alberta, Edmonton, AB, Canada
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Decomposition of peatland DOC affected by root exudates is driven by specific r and K strategic bacterial taxa. Sci Rep 2021; 11:18677. [PMID: 34548501 PMCID: PMC8455546 DOI: 10.1038/s41598-021-97698-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Accepted: 08/26/2021] [Indexed: 02/08/2023] Open
Abstract
In peatlands, decomposition of organic matter is limited by harsh environmental conditions and low decomposability of the plant material. Shifting vegetation composition from Sphagnum towards vascular plants is expected in response to climate change, which will lead to increased root exudate flux to the soil and stimulation of microbial growth and activity. We aimed to evaluate the effect of root exudates on the decomposition of recalcitrant dissolved organic carbon (DOC) and to identify microorganisms involved in this process. The exudation was mimicked by an addition of a mixture of 13C labelled compounds into the recalcitrant DOC in two realistic levels; 2% and 5% of total DOC and peatland porewater with added root exudates was incubated under controlled conditions in the lab. The early stage of incubation was characterized by a relative increase of r-strategic bacteria mainly from Gammaproteobacteria and Bacteriodetes phyla within the microbial community and their preferential use of the added compounds. At the later stage, Alphaproteobacteria and Acidobacteria members were the dominating phyla, which metabolized both the transformed 13C compounds and the recalcitrant DOC. Only higher exudate input (5% of total DOC) stimulated decomposition of recalcitrant DOC compared to non-amended control. The most important taxa with a potential to decompose complex DOC compounds were identified as: Mucilaginibacter (Bacteriodetes), Burkholderia and Pseudomonas (Gammaproteobacteria) among r-strategists and Bryocella and Candidatus Solibacter (Acidobacteria) among K-strategists. We conclude that increased root exudate inputs and their increasing C/N ratio stimulate growth and degradation potential of both r-strategic and K-strategic bacteria, which make the system more dynamic and may accelerate decomposition of peatland recalcitrant DOC.
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Purre A, Ilomets M, Truus L, Pajula R, Sepp K. The effect of different treatments of moss layer transfer technique on plant functional types' biomass in revegetated milled peatlands. Restor Ecol 2020. [DOI: 10.1111/rec.13246] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Anna‐Helena Purre
- School of Natural Science and Health Tallinn University Narva Road 29 Tallinn 10120 Estonia
| | - Mati Ilomets
- Institute of Ecology Tallinn University Uus‐Sadama 5 Tallinn 10120 Estonia
| | - Laimdota Truus
- Institute of Ecology Tallinn University Uus‐Sadama 5 Tallinn 10120 Estonia
| | - Raimo Pajula
- Institute of Ecology Tallinn University Uus‐Sadama 5 Tallinn 10120 Estonia
| | - Kairi Sepp
- School of Natural Science and Health Tallinn University Narva Road 29 Tallinn 10120 Estonia
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Chroňáková A, Bárta J, Kaštovská E, Urbanová Z, Picek T. Spatial heterogeneity of belowground microbial communities linked to peatland microhabitats with different plant dominants. FEMS Microbiol Ecol 2020; 95:5551480. [PMID: 31425589 DOI: 10.1093/femsec/fiz130] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Accepted: 08/16/2019] [Indexed: 11/13/2022] Open
Abstract
Peatland vegetation is composed mostly of mosses, graminoids and ericoid shrubs, and these have a distinct impact on peat biogeochemistry. We studied variation in soil microbial communities related to natural peatland microhabitats dominated by Sphagnum, cotton-grass and blueberry. We hypothesized that such microhabitats will be occupied by structurally and functionally different microbial communities, which will vary further during the vegetation season due to changes in temperature and photosynthetic activity of plant dominants. This was addressed using amplicon-based sequencing of prokaryotic and fungal rDNA and qPCR with respect to methane-cycling communities. Fungal communities were highly microhabitat-specific, while prokaryotic communities were additionally directed by soil pH and total N content. Seasonal alternations in microbial community composition were less important; however, they influenced the abundance of methane-cycling communities. Cotton-grass and blueberry bacterial communities contained relatively more α-Proteobacteria but less Chloroflexi, Fibrobacteres, Firmicutes, NC10, OD1 and Spirochaetes than in Sphagnum. Methanogens, syntrophic and anaerobic bacteria (i.e. Clostridiales, Bacteroidales, Opitutae, Chloroflexi and Syntrophorhabdaceae) were suppressed in blueberry indicating greater aeration that enhanced abundance of fungi (mainly Archaeorhizomycetes) and resulted in the highest fungi-to-bacteria ratio. Thus, microhabitats dominated by different vascular plants are inhabited by unique microbial communities, contributing greatly to spatial functional diversity within peatlands.
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Affiliation(s)
- Alica Chroňáková
- Biology Centre, CAS, Institute of Soil Biology and SoWa RI, Na Sádkách 7, České Budějovice 370 05, Czech Republic
| | - Jiří Bárta
- Department of Ecosystem Biology, University of South Bohemia in České Budějovice, Branišovská 1760, České Budějovice 370 05, Czech Republic
| | - Eva Kaštovská
- Department of Ecosystem Biology, University of South Bohemia in České Budějovice, Branišovská 1760, České Budějovice 370 05, Czech Republic
| | - Zuzana Urbanová
- Department of Ecosystem Biology, University of South Bohemia in České Budějovice, Branišovská 1760, České Budějovice 370 05, Czech Republic
| | - Tomáš Picek
- Department of Ecosystem Biology, University of South Bohemia in České Budějovice, Branišovská 1760, České Budějovice 370 05, Czech Republic
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Straková P, Larmola T, Andrés J, Ilola N, Launiainen P, Edwards K, Minkkinen K, Laiho R. Quantification of Plant Root Species Composition in Peatlands Using FTIR Spectroscopy. FRONTIERS IN PLANT SCIENCE 2020; 11:597. [PMID: 32508861 PMCID: PMC7250167 DOI: 10.3389/fpls.2020.00597] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Accepted: 04/20/2020] [Indexed: 05/27/2023]
Abstract
Evidence of plant root biomass and production in peatlands at the level of species or plant functional type (PFT) is needed for defining ecosystem functioning and predicting its future development. However, such data are limited due to methodological difficulties and the toilsomeness of separating roots from peat. We developed Fourier transform infrared (FTIR) spectroscopy based calibration models for quantifying the mass proportions of several common peatland species, and alternatively, the PFTs that these species represented, in composite root samples. We further tested whether woody roots could be classified into diameter classes, and whether dead and living roots could be separated. We aimed to solve whether general models applicable in different studies can be developed, and what would be the best way to build such models. FTIR spectra were measured from dried and powdered roots: both "pure roots", original samples of 25 species collected in the field, and "root mixtures", artificial composite samples prepared by mixing known amounts of pure roots of different species. Partial least squares regression was used to build the calibration models. The general applicability of the models was tested using roots collected in different sites or times. Our main finding is that pure roots can replace complex mixtures as calibration data. Using pure roots, we constructed generally applicable models for quantification of roots of the main PFTs of northern peatlands. The models provided accurate estimates even for far distant sites, with root mean square error (RMSE) 1.4-6.6% for graminoids, forbs and ferns. For shrubs and trees the estimates were less accurate due to higher within-species heterogeneity, partly related to variation in root diameter. Still, we obtained RMSE 3.9-10.8% for total woody roots, but up to 20.1% for different woody-root types. Species-level and dead-root models performed well within the calibration dataset but provided unacceptable estimates for independent samples, limiting their routine application in field conditions. Our PFT-level models can be applied on roots separated from soil for biomass determination or from ingrowth cores for estimating root production. We present possibilities for further development of species-level or dead-root models using the pure-root approach.
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Affiliation(s)
- Petra Straková
- Natural Resources Institute Finland (LUKE), Helsinki, Finland
- Department of Forest Sciences, University of Helsinki, Helsinki, Finland
| | - Tuula Larmola
- Natural Resources Institute Finland (LUKE), Helsinki, Finland
| | - Javier Andrés
- Department of Agricultural Sciences, University of Helsinki, Helsinki, Finland
| | - Noora Ilola
- Financial and Administrative Services, Education Department, City of Vantaa, Vantaa, Finland
| | - Piia Launiainen
- Department of Forest Sciences, University of Helsinki, Helsinki, Finland
| | - Keith Edwards
- Department of Ecosystem Biology, University of South Bohemia, ČeskéBudějovice, Czechia
| | - Kari Minkkinen
- Department of Forest Sciences, University of Helsinki, Helsinki, Finland
| | - Raija Laiho
- Natural Resources Institute Finland (LUKE), Helsinki, Finland
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Zhang Y, Shi FX, Mao R. Alnus sibirica encroachment promotes dissolved organic carbon biodegradation in a boreal peatland. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 695:133882. [PMID: 31421329 DOI: 10.1016/j.scitotenv.2019.133882] [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: 05/13/2019] [Revised: 08/10/2019] [Accepted: 08/10/2019] [Indexed: 06/10/2023]
Abstract
Symbiotic dinitrogen (N2)-fixing trees have been expanding to boreal peatlands, yet its influence on dissolved organic carbon (DOC) biodegradation is unclear. Here, we measured DOC, ammonium‑nitrogen (NH4+-N), nitrate‑nitrogen (NO3--N), dissolved inorganic nitrogen (DIN), and dissolved total nitrogen (DTN) concentrations, specific ultraviolet absorbance at 254 nm (SUVA254), and humification index in the extracts obtained from peats in the 0-10 cm, 10-20 cm, and 20-40 cm depths in the open peatlands and Alnus sibirica islands in a boreal peatland, Northeast China. Afterwards, the peat extracts were used to assess the effect of N2-fixing woody plant expansion on DOC biodegradation with a 42-day incubation experiment. The expansion of A. sibirica significantly increased NH4+-N, NO3--N, DIN, and DTN concentrations, but did not produce a significant effect on SUVA254 and humification index in the extracts in each depth. Following A. sibirica expansion, DOC biodegradation was enhanced by 24.5%, 15.4%, and 38.3% at 0-10 cm, 10-20 cm, and 20-40 cm depths, respectively. Furthermore, DOC biodegradation was significantly and negatively correlated with DOC:DIN and DOC:DTN ratios, but exhibited no significant relationship with SUVA254 and humification index. This implied that improved N availability and associated shifts in C:N stoichiometry determined the increase in DOC biodegradation following A. sibirica expansion. Our findings suggest that N2-fixing tree encroachment promotes microbial decomposition of DOC through improved N availability in boreal peatlands, which may cause organic C loss from soils in these C-enriched ecosystems.
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Affiliation(s)
- Yang Zhang
- 2011 Collaborative Innovation Center of Jiangxi Typical Trees Cultivation and Utilization, College of Forestry, Jiangxi Agricultural University, Nanchang 330045, China
| | - Fu-Xi Shi
- 2011 Collaborative Innovation Center of Jiangxi Typical Trees Cultivation and Utilization, College of Forestry, Jiangxi Agricultural University, Nanchang 330045, China
| | - Rong Mao
- 2011 Collaborative Innovation Center of Jiangxi Typical Trees Cultivation and Utilization, College of Forestry, Jiangxi Agricultural University, Nanchang 330045, China; Key Laboratory of Wetland Ecology and Environment, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102, China.
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Arsenault J, Talbot J, Moore TR, Beauvais MP, Franssen J, Roulet NT. The Spatial Heterogeneity of Vegetation, Hydrology and Water Chemistry in a Peatland with Open-Water Pools. Ecosystems 2019. [DOI: 10.1007/s10021-019-00342-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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