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Sa'adi Z, Yaseen ZM, Muhammad MKI, Iqbal Z. On the prediction of methane fluxes from pristine tropical peatland in Sarawak: application of a denitrification-decomposition (DNDC) model. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:30724-30738. [PMID: 34993788 DOI: 10.1007/s11356-021-17917-1] [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: 07/12/2021] [Accepted: 11/30/2021] [Indexed: 06/14/2023]
Abstract
Tropical peatlands have high potential function as a major source of atmospheric methane (CH4) and can contribute to global warming due to their large soil carbon stock, high groundwater level (GWL), high humidity and high temperature. In this study, a process-based denitrification-decomposition (DNDC) model was used to simulate CH4 fluxes in a pristine tropical peatland in Sarawak. To test the accuracy of the model, eddy covariance tower datasets were compared. The model was validated for the year 2014, which showed the good performance of the model for simulating CH4 emissions. The monthly predictive ability of the model was better than the daily predictive ability, with a determination coefficient (R2) of 0.67, model error (ME) of 2.47, root mean square error (RMSE) of 3.33, mean absolute error (MAE) of 2.92 and mean square error (MSE) of 11.08. The simulated years of 2015 and 2016 showed the good performance of the DNDC model, although under- and overestimations were found during the drier and rainy months. Similarly, the monthly simulations for the year were better than the daily simulations for the year, showing good correlations at R2 at 0.84 (2015) and 0.87 (2016). Better statistical performance in terms of monthly ME, RMSE, MAE and MSE at - 0.11, 3.38, 3.05 and 11.45 for 2015 and - 1.14, 5.28, 4.93 and 27.83 for 2016, respectively, was also observed. Although the statistical performance of the model simulation for daily average CH4 fluxes was lower than that of the monthly average, we found that the results for total fluxes agreed well between the observed and the simulated values (E = 6.79% and difference = 3.3%). Principal component analysis (PCA) showed that CH4, GWL and rainfall were correlated with each other and explained 41.7% of the total variation. GWL was found to be relatively important in determining the CH4 fluxes in the naturally inundated pristine tropical peatland. These results suggest that GWL is an essential input variable for the DNDC model for predicting CH4 fluxes from the pristine tropical peatland in Sarawak on a monthly basis.
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Affiliation(s)
- Zulfaqar Sa'adi
- Centre for Environmental Sustainability and Water Security (IPASA), School of Civil Engineering, Faculty of Engineering, Universiti Teknologi Malaysia, 81310 UTM, Sekudai, Johor, Malaysia.
| | - Zaher Mundher Yaseen
- Department of Urban Planning, Engineering Networks and Systems, Institute of Architecture and Construction, South Ural State University, 76, Lenin Prospect, 454080, Chelyabinsk, Russia.
- New Era and Development in Civil Engineering Research Group, Scientific Research Center, Al-Ayen University, Thi-Qar, 64001, Iraq.
- College of Creative Design, Asia University, Taichung City, Taiwan.
| | - Mohd Khairul Idlan Muhammad
- Department of Water and Environmental Engineering, School of Civil Engineering, Faculty of Engineering, Universiti Teknologi Malaysia (UTM), 81310, Bahru Johor, Johor, Malaysia
| | - Zafar Iqbal
- Department of Water and Environmental Engineering, School of Civil Engineering, Faculty of Engineering, Universiti Teknologi Malaysia (UTM), 81310, Bahru Johor, Johor, Malaysia
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Wen Y, Zang H, Ma Q, Freeman B, Chadwick DR, Evans CD, Jones DL. Impact of water table levels and winter cover crops on greenhouse gas emissions from cultivated peat soils. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 719:135130. [PMID: 31837865 DOI: 10.1016/j.scitotenv.2019.135130] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Revised: 09/29/2019] [Accepted: 10/21/2019] [Indexed: 06/10/2023]
Abstract
Drainage and cultivation have turned peatlands from carbon (C) sinks into hotspots for greenhouse gas (GHG) emissions. Raising the water table and planting of winter cover crops are potential strategies to help reduce peat oxidation and re-initiate net C accumulation during the non-cropping period. However, the effects of these practices as well as their interactions on GHG emissions remain unclear. Here, we carried out an outdoor mesocosm experiment to elucidate the effect of water table levels (-30 cm and -50 cm) and winter cover crop cultivation (vetch, rye, no plant) on carbon dioxide (CO2), nitrous oxide (N2O) and methane (CH4) fluxes during the winter period (November-April). Soil-atmosphere GHG exchange, GHG concentrations within the peat profile and soil water solute concentrations were monitored. Our results showed that high water table significantly reduced ecosystem respiration, while it had no net effect on N2O and CH4 fluxes. Uptake of available N by the cover crop significantly reduced nitrate in soil solution, thereby lowering the potential for leaching and both direct and indirect N2O emissions. No interactive effects between water table levels and cover crops were detected for any of the measured GHG fluxes. Seasonal variations of GHG fluxes were positively correlated with soil air concentrations at -15 cm and -40 cm depths, which were further regulated by dissolved organic C, nitrate concentration, and anaerobic conditions in the soil. This study suggests that there is great potential to raise water table levels and introduce green cover crops to reduce GHG emissions. Further studies are needed to achieve a complete evaluation of these strategies outside of the growing season, which may provide a significant mitigation benefit in C-rich cultivated peatlands.
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Affiliation(s)
- Yuan Wen
- College of Agronomy and Biotechnology, China Agricultural University, Beijing, 100193, China; School of Natural Sciences, Bangor University, Bangor, LL57 2UW, UK.
| | - Huadong Zang
- College of Agronomy and Biotechnology, China Agricultural University, Beijing, 100193, China; School of Natural Sciences, Bangor University, Bangor, LL57 2UW, UK
| | - Qingxu Ma
- School of Natural Sciences, Bangor University, Bangor, LL57 2UW, UK
| | - Benjamin Freeman
- School of Natural Sciences, Bangor University, Bangor, LL57 2UW, UK
| | - David R Chadwick
- School of Natural Sciences, Bangor University, Bangor, LL57 2UW, UK
| | - Chris D Evans
- Centre for Ecology and Hydrology, Environment Centre Wales, Bangor, LL57 2UW, UK
| | - Davey L Jones
- School of Natural Sciences, Bangor University, Bangor, LL57 2UW, UK; SoilsWest, UWA School of Agriculture and Environment, The University of Western Australia, Perth, WA 6009, Australia
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Wu H, Yan L, Li Y, Zhang K, Hao Y, Wang J, Zhang X, Yan Z, Zhang Y, Kang X. Drought-induced reduction in methane fluxes and its hydrothermal sensitivity in alpine peatland. PeerJ 2020; 8:e8874. [PMID: 32274271 PMCID: PMC7130112 DOI: 10.7717/peerj.8874] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Accepted: 03/09/2020] [Indexed: 11/20/2022] Open
Abstract
Accurate estimation of CH4 fluxes in alpine peatland of the Qinghai-Tibetan Plateau under extreme drought is vital for understanding the global carbon cycle and predicting future climate change. However, studies on the impacts of extreme drought on peatland CH4 fluxes are limited. To study the effects of extreme drought on CH4 fluxes of the Zoige alpine peatland ecosystem, the CH4 fluxes during both extreme drought treatment (D) and control treatment (CK) were monitored using a static enclosed chamber in a control platform of extreme drought. The results showed that extreme drought significantly decreased CH4 fluxes in the Zoige alpine peatland by 31.54% (P < 0.05). Extreme drought significantly reduced the soil water content (SWC) (P < 0.05), but had no significant effect on soil temperature (Ts). Under extreme drought and control treatments, there was a significant negative correlation between CH4 fluxes and environmental factors (Ts and SWC), except Ts, at a depth of 5cm (P < 0.05). Extreme drought reduced the correlation between CH4 fluxes and environmental factors and significantly weakened the sensitivity of CH4 fluxes to SWC (P < 0.01). Moreover, it was found that the correlation between subsoil (20 cm) environmental factors and CH4 fluxes was higher than with the topsoil (5, 10 cm) environmental factors under the control and extreme drought treatments. These results provide a better understanding of the extreme drought effects on CH4 fluxes of alpine peatland, and their hydrothermal impact factors, which provides a reliable reference for peatland protection and management.
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Affiliation(s)
- Haidong Wu
- Institute of Wetland Research, Chinese Academy of Forestry, Beijing, China.,Beijing Key Laboratory of Wetland Services and Restoration, Beijing, China.,Sichuan Zoige Wetland Ecosystem Research Station, Tibetan Autonomous Prefecture of Aba, China
| | - Liang Yan
- Institute of Wetland Research, Chinese Academy of Forestry, Beijing, China.,Beijing Key Laboratory of Wetland Services and Restoration, Beijing, China.,Sichuan Zoige Wetland Ecosystem Research Station, Tibetan Autonomous Prefecture of Aba, China
| | - Yong Li
- Institute of Wetland Research, Chinese Academy of Forestry, Beijing, China.,Beijing Key Laboratory of Wetland Services and Restoration, Beijing, China.,Sichuan Zoige Wetland Ecosystem Research Station, Tibetan Autonomous Prefecture of Aba, China
| | - Kerou Zhang
- Institute of Wetland Research, Chinese Academy of Forestry, Beijing, China.,Beijing Key Laboratory of Wetland Services and Restoration, Beijing, China.,Sichuan Zoige Wetland Ecosystem Research Station, Tibetan Autonomous Prefecture of Aba, China
| | - Yanbin Hao
- University of Chinese Academy of Science, Beijing, China
| | - Jinzhi Wang
- Institute of Wetland Research, Chinese Academy of Forestry, Beijing, China.,Beijing Key Laboratory of Wetland Services and Restoration, Beijing, China.,Sichuan Zoige Wetland Ecosystem Research Station, Tibetan Autonomous Prefecture of Aba, China
| | - Xiaodong Zhang
- Institute of Wetland Research, Chinese Academy of Forestry, Beijing, China.,Beijing Key Laboratory of Wetland Services and Restoration, Beijing, China.,Sichuan Zoige Wetland Ecosystem Research Station, Tibetan Autonomous Prefecture of Aba, China
| | - Zhongqing Yan
- Institute of Wetland Research, Chinese Academy of Forestry, Beijing, China.,Beijing Key Laboratory of Wetland Services and Restoration, Beijing, China.,Sichuan Zoige Wetland Ecosystem Research Station, Tibetan Autonomous Prefecture of Aba, China
| | - Yuan Zhang
- University of Chinese Academy of Science, Beijing, China
| | - Xiaoming Kang
- Institute of Wetland Research, Chinese Academy of Forestry, Beijing, China.,Beijing Key Laboratory of Wetland Services and Restoration, Beijing, China.,Sichuan Zoige Wetland Ecosystem Research Station, Tibetan Autonomous Prefecture of Aba, China
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Wilson BJ, Servais S, Charles SP, Mazzei V, Gaiser EE, Kominoski JS, Richards JH, Troxler TG. Phosphorus alleviation of salinity stress: effects of saltwater intrusion on an Everglades freshwater peat marsh. Ecology 2019; 100:e02672. [PMID: 30942486 DOI: 10.1002/ecy.2672] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Revised: 01/07/2019] [Accepted: 02/04/2019] [Indexed: 11/09/2022]
Abstract
Saltwater intrusion and salinization of coastal wetlands around the world are becoming a pressing issue due to sea level rise. Here, we assessed how a freshwater coastal wetland ecosystem responds to saltwater intrusion. In wetland mesocosms, we continuously exposed Cladium jamaicense Crantz (sawgrass) plants and their peat soil collected from a freshwater marsh to two factors associated with saltwater intrusion in karstic ecosystems: elevated loading of salinity and phosphorus (P) inputs. We took repeated measures using a 2 × 2 factorial experimental design (n = 6) with treatments composed of elevated salinity (~9 ppt), P loading (14.66 μmol P/d), or a combination of both. We measured changes in water physicochemistry, ecosystem productivity, and plant biomass change over two years to assess monthly and two-year responses to saltwater intrusion. In the short-term, plants exhibited positive growth responses with simulated saltwater intrusion (salinity + P), driven by increased P availability. Despite relatively high salinity levels for a freshwater marsh (~9 ppt), gross ecosystem productivity (GEP), net ecosystem productivity (NEP), and aboveground biomass were significantly higher in the elevated salinity + P treated monoliths compared to the freshwater controls. Salinity stress became evident after extended exposure. Although still higher than freshwater controls, GEP and NEP were significantly lower in the elevated salinity + P treatment than the +P treatment after two years. However, elevated salinity decreased live root biomass regardless of whether P was added. Our results suggest that saltwater intrusion into karstic freshwater wetlands may initially act as a subsidy by stimulating aboveground primary productivity of marsh plants. However, chronic exposure to elevated salinity results in plant stress, negatively impacting belowground peat soil structure and stability through a reduction in plant roots.
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Affiliation(s)
- Benjamin J Wilson
- Department of Biological Sciences and Southeast Environmental Research Center, Florida International University, Miami, Florida, 33199, USA
| | - Shelby Servais
- Department of Biological Sciences and Southeast Environmental Research Center, Florida International University, Miami, Florida, 33199, USA
| | - Sean P Charles
- Department of Biological Sciences and Southeast Environmental Research Center, Florida International University, Miami, Florida, 33199, USA
| | - Viviana Mazzei
- Department of Biological Sciences and Southeast Environmental Research Center, Florida International University, Miami, Florida, 33199, USA
| | - Evelyn E Gaiser
- Department of Biological Sciences and Southeast Environmental Research Center, Florida International University, Miami, Florida, 33199, USA
| | - John S Kominoski
- Department of Biological Sciences and Southeast Environmental Research Center, Florida International University, Miami, Florida, 33199, USA
| | - Jennifer H Richards
- Department of Biological Sciences and Southeast Environmental Research Center, Florida International University, Miami, Florida, 33199, USA
| | - Tiffany G Troxler
- Department of Biological Sciences and Southeast Environmental Research Center, Florida International University, Miami, Florida, 33199, USA.,Sea Level Solutions Center, Florida International University, Miami, Florida, 33199, USA
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Taft HE, Cross PA, Hastings A, Yeluripati J, Jones DL. Estimating greenhouse gases emissions from horticultural peat soils using a DNDC modelling approach. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2019; 233:681-694. [PMID: 30634114 DOI: 10.1016/j.jenvman.2018.11.113] [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: 11/23/2018] [Accepted: 11/23/2018] [Indexed: 06/09/2023]
Abstract
Peat soils represent an important global carbon (C) sink, but can also provide a highly fertile medium for growing horticultural crops. Sustainable crop production on peat soils involves a trade-off between ensuring food security and mitigating typically high greenhouse gas (GHG) emissions and rates of soil C loss. An alternative approach to resource intensive field-based monitoring of GHG fluxes for all potential management scenarios is to use a process-based model driven by existing field data to estimate emissions. The aim of this study was to evaluate the suitability of the Denitrification-Decomposition (DNDC) model for estimating emissions of CO2, N2O and CH4 from horticultural peat soils. The model was parameterised using climatic, soil, and crop management data from two intensively cultivated sites on soils of contrasting soil organic matter (SOM) contents (∼35% and ∼70% SOM content). Simulated emissions of CO2, N2O and CH4, and simulated soil physical and crop output values, were compared to actual GHG, soil and crop measurements. Model performance was assessed using baseline parameterisation (i.e. model defaults), then calibrated using pre-simulation and sensitivity analysis processes. Under baseline parameterisation conditions, DNDC proved poor at predicting GHG emissions and soil/crop variables. Calibration and validation improved DNDC performance in estimating the annual magnitude of emissions, but model refinement is still required for reproducing seasonal GHG patterns in particular. Key constraints on model functioning appear to be its ability to reliably model soil moisture and some aspects of C and nitrogen dynamics, as well as the quality of input data relating to water table dynamics. In conclusion, our results suggest that the DNDC (v. 9.5) model cannot accurately reproduce or be used to replace actual field measurements for estimation of GHG emission factors under different management scenarios for horticultural peat soils, but may be able to do so with further modification.
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Affiliation(s)
- Helen E Taft
- School of Natural Sciences, Bangor University, Deiniol Road, Bangor, Gwynedd, LL57 2UW, UK.
| | - Paul A Cross
- School of Natural Sciences, Bangor University, Deiniol Road, Bangor, Gwynedd, LL57 2UW, UK
| | - Astley Hastings
- Institute of Biological and Environmental Sciences, University of Aberdeen, 23 St. Machar Drive, Aberdeen, AB24 3UU, UK
| | | | - Davey L Jones
- School of Natural Sciences, Bangor University, Deiniol Road, Bangor, Gwynedd, LL57 2UW, UK; UWA School of Agriculture and Environment, University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia
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6
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Wilson BJ, Servais S, Mazzei V, Kominoski JS, Hu M, Davis SE, Gaiser E, Sklar F, Bauman L, Kelly S, Madden C, Richards J, Rudnick D, Stachelek J, Troxler TG. Salinity pulses interact with seasonal dry-down to increase ecosystem carbon loss in marshes of the Florida Everglades. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2018; 28:2092-2108. [PMID: 30376192 DOI: 10.1002/eap.1798] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Revised: 07/10/2018] [Accepted: 08/02/2018] [Indexed: 06/08/2023]
Abstract
Coastal wetlands are globally important sinks of organic carbon (C). However, to what extent wetland C cycling will be affected by accelerated sea-level rise (SLR) and saltwater intrusion is unknown, especially in coastal peat marshes where water flow is highly managed. Our objective was to determine how the ecosystem C balance in coastal peat marshes is influenced by elevated salinity. For two years, we made monthly in situ manipulations of elevated salinity in freshwater (FW) and brackish water (BW) sites within Everglades National Park, Florida, USA. Salinity pulses interacted with marsh-specific variability in seasonal hydroperiods whereby effects of elevated pulsed salinity on gross ecosystem productivity (GEP), ecosystem respiration (ER), and net ecosystem productivity (NEP) were dependent on marsh inundation level. We found little effect of elevated salinity on C cycling when both marsh sites were inundated, but when water levels receded below the soil surface, the BW marsh shifted from a C sink to a C source. During these exposed periods, we observed an approximately threefold increase in CO2 efflux from the marsh as a result of elevated salinity. Initially, elevated salinity pulses did not affect Cladium jamaicense biomass, but aboveground biomass began to be significantly decreased in the saltwater amended plots after two years of exposure at the BW site. We found a 65% (FW) and 72% (BW) reduction in live root biomass in the soil after two years of exposure to elevated salinity pulses. Regardless of salinity treatment, the FW site was C neutral while the BW site was a strong C source (-334 to -454 g C·m-2 ·yr-1 ), particularly during dry-down events. A loss of live roots coupled with annual net CO2 losses as marshes transition from FW to BW likely contributes to the collapse of peat soils observed in the coastal Everglades. As SLR increases the rate of saltwater intrusion into coastal wetlands globally, understanding how water management influences C gains and losses from these systems is crucial. Under current Everglades' water management, drought lengthens marsh dry-down periods, which, coupled with saltwater intrusion, accelerates CO2 loss from the marsh.
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Affiliation(s)
- Benjamin J Wilson
- Department of Biological Sciences and Southeast Environmental Research Center, Florida International University, Miami, Florida, 33199, USA
| | - Shelby Servais
- Department of Biological Sciences and Southeast Environmental Research Center, Florida International University, Miami, Florida, 33199, USA
| | - Viviana Mazzei
- Department of Biological Sciences and Southeast Environmental Research Center, Florida International University, Miami, Florida, 33199, USA
| | - John S Kominoski
- Department of Biological Sciences and Southeast Environmental Research Center, Florida International University, Miami, Florida, 33199, USA
| | - Minjie Hu
- College of the Environment and Ecology, Xiamen University, Xiamen, 361102, China
| | | | - Evelyn Gaiser
- Department of Biological Sciences and Southeast Environmental Research Center, Florida International University, Miami, Florida, 33199, USA
| | - Fred Sklar
- South Florida Water Management District, West Palm Beach, Florida, 33406, USA
| | - Laura Bauman
- Department of Biological Sciences and Southeast Environmental Research Center, Florida International University, Miami, Florida, 33199, USA
| | - Stephen Kelly
- South Florida Water Management District, West Palm Beach, Florida, 33406, USA
| | - Christopher Madden
- South Florida Water Management District, West Palm Beach, Florida, 33406, USA
| | - Jennifer Richards
- Department of Biological Sciences and Southeast Environmental Research Center, Florida International University, Miami, Florida, 33199, USA
| | - David Rudnick
- Everglades National Park, Homestead, Florida, 33034, USA
| | - Joseph Stachelek
- South Florida Water Management District, West Palm Beach, Florida, 33406, USA
- Michigan State University, East Lansing, Michigan, 48824, USA
| | - Tiffany G Troxler
- Department of Biological Sciences and Southeast Environmental Research Center, Florida International University, Miami, Florida, 33199, USA
- Sea Level Solutions Center, Florida International University, Miami, Florida, 33199, USA
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Wang W, Roulet NT, Kim Y, Strachan IB, Del Giorgio P, Prairie YT, Tremblay A. Modelling CO 2 emissions from water surface of a boreal hydroelectric reservoir. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 612:392-404. [PMID: 28863371 DOI: 10.1016/j.scitotenv.2017.08.203] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2017] [Revised: 08/18/2017] [Accepted: 08/19/2017] [Indexed: 06/07/2023]
Abstract
To quantify CO2 emissions from water surface of a reservoir that was shaped by flooding the boreal landscape, we developed a daily time-step reservoir biogeochemistry model. We calibrated the model using the measured concentrations of dissolved organic and inorganic carbon (C) in a young boreal hydroelectric reservoir, Eastmain-1 (EM-1), in northern Quebec, Canada. We validated the model against observed CO2 fluxes from an eddy covariance tower in the middle of EM-1. The model predicted the variability of CO2 emissions reasonably well compared to the observations (root mean square error: 0.4-1.3gCm-2day-1, revised Willmott index: 0.16-0.55). In particular, we demonstrated that the annual reservoir surface effluxes were initially high, steeply declined in the first three years, and then steadily decreased to ~115gCm-2yr-1 with increasing reservoir age over the estimated "engineering" reservoir lifetime (i.e., 100years). Sensitivity analyses revealed that increasing air temperature stimulated CO2 emissions by enhancing CO2 production in the water column and sediment, and extending the duration of open water period over which emissions occur. Increasing the amount of terrestrial organic C flooded can enhance benthic CO2 fluxes and CO2 emissions from the reservoir water surface, but the effects were not significant over the simulation period. The model is useful for the understanding of the mechanism of C dynamics in reservoirs and could be used to assist the hydro-power industry and others interested in the role of boreal hydroelectric reservoirs as sources of greenhouse gas emissions.
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Affiliation(s)
- Weifeng Wang
- College of Biology and the Environment, Nanjing Forestry University, Nanjing, Jiangsu 210037, China.
| | - Nigel T Roulet
- Department of Geography, McGill University, Montréal, QC H3A 0B9, Canada; Centre d'Études Nordiques, Université Laval, Québec, QC G1V 0A6, Canada.
| | - Youngil Kim
- Department of Forest Ecosystems and Society, Oregon State University, Corvallis, OR 97330, USA.
| | - Ian B Strachan
- Department of Natural Resource Sciences, McGill University, Ste Anne de Bellevue, Montréal, QC H9X 3V9, Canada.
| | - Paul Del Giorgio
- Département des Sciences Biologiques, Université du Québec à Montréal, Case Postale 8888, Succ Centre-Ville, Montréal, QC H3C 3P8, Canada.
| | - Yves T Prairie
- Département des Sciences Biologiques, Université du Québec à Montréal, Case Postale 8888, Succ Centre-Ville, Montréal, QC H3C 3P8, Canada.
| | - Alain Tremblay
- Environment Production, Hydro-Québec, Montreal, QC H2Z 1A4, Canada.
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Chen X, Wang F, Lu J, Li H, Zhu J, Lv X. Simulation of the Effect of Artificial Water Transfer on Carbon Stock of Phragmites australis in the Baiyangdian Wetland, China. SCIENTIFICA 2017; 2017:7905710. [PMID: 28348922 PMCID: PMC5350307 DOI: 10.1155/2017/7905710] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Accepted: 01/17/2017] [Indexed: 06/06/2023]
Abstract
How to explain the effect of seasonal water transfer on the carbon stocks of Baiyangdian wetland is studied. The ecological model of the relationship between the carbon stocks and water depth fluctuation of the reed was established by using STELLA software. For the first time the Michaelis-Menten equation (1) introduced the relation function between the water depth and reed environmental carrying capacity, (2) introduced the concept of suitable growth water depth, and (3) simulated the variation rules of water and reed carbon stocks of artificial adjustment. The model could be used to carry out the research on the optimization design of the ecological service function of the damaged wetland.
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Affiliation(s)
- Xinyong Chen
- Shanghai Key Laboratory for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200062, China
- Hebei Provincial Academy of Environmental Sciences, Shijiazhuang City, Hebei 050037, China
| | - Fengyi Wang
- State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai 200062, China
| | - Jianjian Lu
- Shanghai Key Laboratory for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200062, China
| | - Hongbo Li
- Hebei Provincial Academy of Environmental Sciences, Shijiazhuang City, Hebei 050037, China
| | - Jing Zhu
- Hebei Zhengrun Environmental Technology Co. Ltd., Shijiazhuang City, Hebei 050000, China
| | - Xiaotong Lv
- Shanghai Key Laboratory for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200062, China
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Wang H, Yu L, Zhang Z, Liu W, Chen L, Cao G, Yue H, Zhou J, Yang Y, Tang Y, He JS. Molecular mechanisms of water table lowering and nitrogen deposition in affecting greenhouse gas emissions from a Tibetan alpine wetland. GLOBAL CHANGE BIOLOGY 2017; 23:815-829. [PMID: 27536811 DOI: 10.1111/gcb.13467] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Revised: 07/11/2016] [Accepted: 08/03/2016] [Indexed: 06/06/2023]
Abstract
Rapid climate change and intensified human activities have resulted in water table lowering (WTL) and enhanced nitrogen (N) deposition in Tibetan alpine wetlands. These changes may alter the magnitude and direction of greenhouse gas (GHG) emissions, affecting the climate impact of these fragile ecosystems. We conducted a mesocosm experiment combined with a metagenomics approach (GeoChip 5.0) to elucidate the effects of WTL (-20 cm relative to control) and N deposition (30 kg N ha-1 yr-1 ) on carbon dioxide (CO2 ), methane (CH4 ) and nitrous oxide (N2 O) fluxes as well as the underlying mechanisms. Our results showed that WTL reduced CH4 emissions by 57.4% averaged over three growing seasons compared with no-WTL plots, but had no significant effect on net CO2 uptake or N2 O flux. N deposition increased net CO2 uptake by 25.2% in comparison with no-N deposition plots and turned the mesocosms from N2 O sinks to N2 O sources, but had little influence on CH4 emissions. The interactions between WTL and N deposition were not detected in all GHG emissions. As a result, WTL and N deposition both reduced the global warming potential (GWP) of growing season GHG budgets on a 100-year time horizon, but via different mechanisms. WTL reduced GWP from 337.3 to -480.1 g CO2 -eq m-2 mostly because of decreased CH4 emissions, while N deposition reduced GWP from 21.0 to -163.8 g CO2 -eq m-2 , mainly owing to increased net CO2 uptake. GeoChip analysis revealed that decreased CH4 production potential, rather than increased CH4 oxidation potential, may lead to the reduction in net CH4 emissions, and decreased nitrification potential and increased denitrification potential affected N2 O fluxes under WTL conditions. Our study highlights the importance of microbial mechanisms in regulating ecosystem-scale GHG responses to environmental changes.
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Affiliation(s)
- Hao Wang
- Department of Ecology, College of Urban and Environmental Sciences and Key Laboratory for Earth Surface Processes of the Ministry of Education, Peking University, 5 Yiheyuan Road, Beijing, 100871, China
- Key Laboratory of Adaptation and Evolution of Plateau Biota, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, 23 Xining Road, Xining, 810008, China
| | - Lingfei Yu
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, 20 Nanxincun, Beijing, 100093, China
| | - Zhenhua Zhang
- Key Laboratory of Adaptation and Evolution of Plateau Biota, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, 23 Xining Road, Xining, 810008, China
| | - Wei Liu
- Key Laboratory of Adaptation and Evolution of Plateau Biota, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, 23 Xining Road, Xining, 810008, China
| | - Litong Chen
- Key Laboratory of Adaptation and Evolution of Plateau Biota, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, 23 Xining Road, Xining, 810008, China
| | - Guangmin Cao
- Key Laboratory of Adaptation and Evolution of Plateau Biota, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, 23 Xining Road, Xining, 810008, China
| | - Haowei Yue
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, 1 Tsinghua Garden Road, Beijing, 100084, China
| | - Jizhong Zhou
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, 1 Tsinghua Garden Road, Beijing, 100084, China
- Department of Microbiology and Plant Biology, Institute for Environmental Genomics, University of Oklahoma, Norman, OK, 73019, USA
- Earth Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Yunfeng Yang
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, 1 Tsinghua Garden Road, Beijing, 100084, China
| | - Yanhong Tang
- Department of Ecology, College of Urban and Environmental Sciences and Key Laboratory for Earth Surface Processes of the Ministry of Education, Peking University, 5 Yiheyuan Road, Beijing, 100871, China
| | - Jin-Sheng He
- Department of Ecology, College of Urban and Environmental Sciences and Key Laboratory for Earth Surface Processes of the Ministry of Education, Peking University, 5 Yiheyuan Road, Beijing, 100871, China
- Key Laboratory of Adaptation and Evolution of Plateau Biota, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, 23 Xining Road, Xining, 810008, China
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Malone SL, Starr G, Staudhammer CL, Ryan MG. Effects of simulated drought on the carbon balance of Everglades short-hydroperiod marsh. GLOBAL CHANGE BIOLOGY 2013; 19:2511-2523. [PMID: 23554284 DOI: 10.1111/gcb.12211] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2013] [Accepted: 03/17/2013] [Indexed: 06/02/2023]
Abstract
Hydrology drives the carbon balance of wetlands by controlling the uptake and release of CO2 and CH4 . Longer dry periods in between heavier precipitation events predicted for the Everglades region, may alter the stability of large carbon pools in this wetland's ecosystems. To determine the effects of drought on CO2 fluxes and CH4 emissions, we simulated changes in hydroperiod with three scenarios that differed in the onset rate of drought (gradual, intermediate, and rapid transition into drought) on 18 freshwater wetland monoliths collected from an Everglades short-hydroperiod marsh. Simulated drought, regardless of the onset rate, resulted in higher net CO2 losses net ecosystem exchange (NEE) over the 22-week manipulation. Drought caused extensive vegetation dieback, increased ecosystem respiration (Reco ), and reduced carbon uptake gross ecosystem exchange (GEE). Photosynthetic potential measured by reflective indices (photochemical reflectance index, water index, normalized phaeophytinization index, and the normalized difference vegetation index) indicated that water stress limited GEE and inhibited Reco . As a result of drought-induced dieback, NEE did not offset methane production during periods of inundation. The average ratio of net CH4 to NEE over the study period was 0.06, surpassing the 100-year greenhouse warming compensation point for CH4 (0.04). Drought-induced diebacks of sawgrass (C3 ) led to the establishment of the invasive species torpedograss (C4 ) when water was resupplied. These changes in the structure and function indicate that freshwater marsh ecosystems can become a net source of CO2 and CH4 to the atmosphere, even following an extended drought. Future changes in precipitation patterns and drought occurrence/duration can change the carbon storage capacity of freshwater marshes from sinks to sources of carbon to the atmosphere. Therefore, climate change will impact the carbon storage capacity of freshwater marshes by influencing water availability and the potential for positive feedbacks on radiative forcing.
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Affiliation(s)
- Sparkle L Malone
- Department of Biological Sciences, University of Alabama, Tuscaloosa, AL 35401, USA.
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