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Palviainen M, Pumpanen J, Mosquera V, Hasselquist EM, Laudon H, Ostonen I, Kull A, Wilson FR, Peltomaa E, Könönen M, Launiainen S, Peltola H, Ojala A, Laurén A. Extending the SUSI peatland simulator to include dissolved organic carbon formation, transport and biodegradation - Proper water management reduces lateral carbon fluxes and improves carbon balance. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 950:175173. [PMID: 39117189 DOI: 10.1016/j.scitotenv.2024.175173] [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: 03/13/2024] [Revised: 07/06/2024] [Accepted: 07/29/2024] [Indexed: 08/10/2024]
Abstract
Drainage intensity and forest management in peatlands affect carbon dioxide (CO2) emissions to the atmosphere and export of dissolved organic carbon (DOC) to water courses. The peatland carbon (C) balance results from a complex network of ecosystem processes from where lateral C fluxes have typically been ignored. Here, we present a new version of the SUSI Peatland simulator, the first advanced process-based ecosystem model that compiles a full C balance in drained forested peatland including DOC formation, transport and biodegradation. SUSI considers site, stand and terrain characteristics as well as the interactions and feedbacks between ecosystem processes and offers novel ways to evaluate and mitigate adverse environmental impacts with thorough management planning. Here, we extended SUSI by designing and parameterizing a mass-balance based decomposition module (ESOM) based on literature findings and tested the ESOM performance against an independent dataset measured in the laboratory using peat columns collected from Finland, Estonia, Sweden and Ireland. ESOM predicted the CO2 emissions and changes in DOC concentrations with a reasonable accuracy for the peat columns. We applied the new SUSI for drained peatland sites and found that reducing the depth to which ditches are cleaned by 0.3 m decreased the annual DOC export by 34 (17 %), 29 (19 %) and 7 (5 %) kg ha-1 in Finland, Estonia and Sweden, respectively, using typical ditch spacing for these countries. Correspondingly, site annual C sink increased by 305, 409 and 32 kg ha-1 in Finland, Estonia and Sweden, respectively. Our results also indicated that terrain slope can markedly alter the water residence time and consequently DOC biodegradation and export to ditches. We conclude that DOC export can be decreased and site C sink increased by reducing the depth to which ditches are cleaned or by increasing the ditch spacing.
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Affiliation(s)
- Marjo Palviainen
- Department of Forest Sciences, University of Helsinki, P.O. Box 27, 00014, Finland.
| | - Jukka Pumpanen
- Department of Environmental and Biological Sciences, Faculty of Science, Forestry and Technology, University of Eastern Finland, Kuopio, Finland
| | - Virginia Mosquera
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umeå, Sweden
| | - Eliza Maher Hasselquist
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umeå, Sweden
| | - Hjalmar Laudon
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umeå, Sweden
| | - Ivika Ostonen
- Institute of Ecology and Earth Sciences, University of Tartu, Estonia
| | - Ain Kull
- Institute of Ecology and Earth Sciences, University of Tartu, Estonia
| | - Florence Renou Wilson
- School of Biology and Environmental Science, University College Dublin, Dublin, Ireland
| | - Elina Peltomaa
- Department of Forest Sciences, University of Helsinki, P.O. Box 27, 00014, Finland
| | - Mari Könönen
- Natural Resources Institute Finland (Luke), Latokartanonkaari 9, 00790 Helsinki, Finland
| | - Samuli Launiainen
- Natural Resources Institute Finland (Luke), Latokartanonkaari 9, 00790 Helsinki, Finland
| | - Heli Peltola
- School of Forest Sciences, Faculty of Science, Forestry and Technology, University of Eastern Finland, P.O. Box 111, 80101 Joensuu, Finland
| | - Anne Ojala
- Natural Resources Institute Finland (Luke), Latokartanonkaari 9, 00790 Helsinki, Finland
| | - Annamari Laurén
- Department of Forest Sciences, University of Helsinki, P.O. Box 27, 00014, Finland; School of Forest Sciences, Faculty of Science, Forestry and Technology, University of Eastern Finland, P.O. Box 111, 80101 Joensuu, Finland
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Impact of Forest Harvesting Intensity and Water Table on Biodegradability of Dissolved Organic Carbon in Boreal Peat in an Incubation Experiment. FORESTS 2022. [DOI: 10.3390/f13040599] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Boreal peatlands are vast carbon (C) stores but also major sources of dissolved organic C (DOC) and nutrients to surface waters. Drainage and forest harvesting accelerates DOC leaching. Continuous cover forestry (CCF) is considered to cause fewer adverse environmental effects. Yet, the effects of CCF on DOC processes are unrecognised. We study DOC production and quality in unharvested, CCF, and clear-cut drained peatland forests and in a non-forested alluvial sedge fen. Parallel replicate peat columns with ground vegetation are collected from the uppermost 50 cm at each site, and the water table (WT) is set to −20 or −40 cm depths on the columns. During the eight-month ex situ incubation experiment, the soil water samples are extracted monthly or bi-monthly. The samples are incubated at 15 °C for multiple 72 h incubation cycles to study pore water quality and biodegradation of DOC. The CO2 production occurs during the first three days. The DOC concentrations and the CO2 release per volume of water are significantly lower in the sedge fen than in the drained peatland forests. The WT has a negligible effect on DOC concentrations and no effect on DOC quality, but the higher WT has generally higher CO2 production per DOC than the lower WT. The results suggest that peat in the drained peatlands is not vulnerable to changes per se but that forest management alters biotic and abiotic factors that control the production, transport, and biodegradation of DOC.
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Palviainen M, Peltomaa E, Laurén A, Kinnunen N, Ojala A, Berninger F, Zhu X, Pumpanen J. Water quality and the biodegradability of dissolved organic carbon in drained boreal peatland under different forest harvesting intensities. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 806:150919. [PMID: 34653471 DOI: 10.1016/j.scitotenv.2021.150919] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Revised: 10/07/2021] [Accepted: 10/07/2021] [Indexed: 06/13/2023]
Abstract
Boreal peatlands are major sources of nitrogen (N), phosphorus (P) and dissolved organic carbon (DOC) to downstream aquatic ecosystems, and forest harvesting generally further increases the loading of DOC and nutrients. Continuous cover forestry (CCF) is proposed to be an environmentally more sustainable management option for peatland forests than conventional even-aged clear-cutting. However, the impacts of CCF on water quality, the biodegradability of DOC and consequent CO2 emissions from inland waters are poorly known. We studied the concentrations of N, P and DOC, the quality of DOC, and the mineralization of DOC to CO2 in ground water and ditch water in clear-cut, partially harvested, i.e. CCF, and uncut drained forests in Finland. Groundwater total N, NH4-N and PO4-P concentrations were significantly lower in CCF and uncut forest than in the clear-cut forest. Groundwater DOC concentrations were often highest in the clear-cut forest, where the water table was closer to the soil surface. Ditch water DOC and N concentrations were lowest next to the clear-cut area. DOC aromaticity in ground water was higher in the uncut forest than in the clear-cut and CCF, whereas ditch water aromaticity did not differ between the treatments. The biodegradation of DOC was studied by incubating water (at 15 °C for 24 h) 1, 3, 7 and 21 days after sampling. The results indicated that the majority of the CO2 production took place during the first three days, and CO2 fluxes were considerably higher from the ditch water than from the groundwater. The CO2 emissions were lower in summer than in the other seasons. Ditch water and groundwater CO2 production were generally significantly higher in the clear-cut than in the uncut forest. The results suggest that CCF can decrease the nutrient concentrations as well as CO2 emissions from inland waters compared to conventional clear-cutting.
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Affiliation(s)
| | - Elina Peltomaa
- Department of Forest Sciences, University of Helsinki, Finland
| | - Ari Laurén
- Faculty of Science and Forestry, University of Eastern Finland, Joensuu, Finland
| | - Niko Kinnunen
- Department of Environmental and Biological Sciences, University of Eastern Finland, Kuopio, Finland
| | - Anne Ojala
- Natural Resources Institute Finland, Finland
| | - Frank Berninger
- Department of Environmental and Biological Sciences, University of Eastern Finland, Joensuu, Finland
| | - Xudan Zhu
- Department of Environmental and Biological Sciences, University of Eastern Finland, Joensuu, Finland
| | - Jukka Pumpanen
- Department of Environmental and Biological Sciences, University of Eastern Finland, Kuopio, Finland
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Taylor AE, Ottoman C, Chaplen F. Implications of the Thermodynamic Response of Soil Mineralization, Respiration, and Nitrification on Soil Organic Matter Retention. Front Microbiol 2021; 12:651210. [PMID: 34093466 PMCID: PMC8170049 DOI: 10.3389/fmicb.2021.651210] [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: 01/08/2021] [Accepted: 04/21/2021] [Indexed: 11/24/2022] Open
Abstract
Considerable research has shown that modifications in global temperature regimes can lead to changes in the interactions between soil respiration and the sequestration of C and N into soil organic matter (SOM). We hypothesized that despite the interconnected nature of respiration, net N mineralization, and nitrification processes, there would be differences in their thermodynamic responses that would affect the composition of inorganic soil N and the potential for retention of N in SOM. To test this hypothesis, soil respiration, N mineralization and nitrification responses were evaluated during constant temperature incubations at seven temperatures (4–42°C) in tilled and no-till soils from two major agroecological zones in Oregon; Willamette Valley, and Pendleton located in the Columbia River Basin. We observed (1) significant thermodynamic differences between the three processes in all soils, (2) a distinctly different thermodynamic profile in Willamette vs. Pendleton, and (3) a dynamic response of Topt (optimal temperature for activity), and Tsmax (temperature of greatest rate response to temperature), and temperature sensitivity (ΔCp‡) over the incubation time course, resulting in shifts in the thermodynamic profiles that could not be adequately explained by changes in process rates. We found that differences in contributions of ammonia oxidizing archaea and bacteria to nitrification activity across temperature helped to explain the thermodynamic differences of this process between Willamette and Pendleton soils. A two-pool model of SOM utilization demonstrated that the dynamic thermodynamic response of respiration in the soils was due to shifts in utilization of labile and less-labile pools of C; and that the respiration response by Pendleton soils was more dependent upon contributions from the less-labile C pool resulting in higher Topt and Tsmax than Willamette soils. Interestingly, modeling of N mineralization using the two-pool model suggested that only the less-labile pool of SOM was contributing to N mineralization at most temperatures in all soils. The difference in labile and less-labile SOM pool utilization between respiration and N mineralization may suggest that these processes may not be as interconnected as previously thought.
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Affiliation(s)
- Anne E Taylor
- Department of Crop and Soil Science, Oregon State University, Corvallis, OR, United States
| | - Camille Ottoman
- Department of Crop and Soil Science, Oregon State University, Corvallis, OR, United States
| | - Frank Chaplen
- Department of Biological and Ecological Engineering, Oregon State University, Corvallis, OR, United States
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