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Huang Y, Yu L, Zhang B, Wu C, Niu Z, Sun Z. Unraveling the drivers for interannual variabilities of N 2O fluxes from forests soils across climatic zones. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 928:172322. [PMID: 38604370 DOI: 10.1016/j.scitotenv.2024.172322] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Revised: 04/05/2024] [Accepted: 04/06/2024] [Indexed: 04/13/2024]
Abstract
Forest soils are an important source of nitrous oxide (N2O), however, field observations of N2O emission have often exhibited large variabilities when compared with managed agricultural lands. In the last decade, the number of forest N2O studies has increased more than tenfold, but only a few of them have looked into the interannual flux variabilities from the regional scale. Here, we have collected 30 long-term N2O monitoring studies (≥ 2 years) based on a global database, and extracted variabilities (VARFlux) as well as relative variabilities (VAR%, in proportions) of annual N2O fluxes. The relationship of mean annual precipitation (MAP), mean annual temperature (MAT), and nitrogen (N) deposition with flux variabilities was examined to explore the underlying mechanisms for N2O emission on a long-term scale. Our results show that mean VARFlux is 0.43 kg N ha-1 yr-1 and VAR% is 28.68%. Across climatic zones, the subtropical forests have the largest annual N2O fluxes, as well as the largest fluctuations among annual budgets, while the tropics were the smallest. We found that the regulating factors for VARFlux and VAR% are fundamentally different, i.e., MAT and N input determine the annual fluxes as well as VARFlux while MAP and other limiting soil parameters determine VAR%. The relative contributions of different seasons to flux variabilities were also explored, indicating that N2O fluxes of warm and cool seasons are more responsible for the fluctuations in annual fluxes of the (sub)tropical and temperate forests, respectively. Overall, despite the limitation in interpretations due to few long-term studies from literature, this work highlights that significant interannual variabilities are common phenomena for N2O emission from different climatic zones forest soils; by unraveling the divergent drivers for VARFlux and VAR%, we have provided the possibility of improving N2O simulation models for constraining the heterogeneity of N2O emission processes from climatic zones forest soils.
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Affiliation(s)
- Yuanyuan Huang
- College of Life Science and Technology, Jinan University, Guangzhou 510632, China
| | - Longfei Yu
- Shenzhen Key Laboratory of Ecological Remediation and Carbon Sequestration, Institute of Environment and Ecology, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China..
| | - Bei Zhang
- Shenzhen Key Laboratory of Ecological Remediation and Carbon Sequestration, Institute of Environment and Ecology, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China
| | - Chuanhao Wu
- The National Key Laboratory of Water Disaster Prevention, Hohai University, Nanjing 210098, China; Yangtze Institute for Conservation and Development, Hohai University, Nanjing 210098, China
| | - Zetong Niu
- Shenzhen Key Laboratory of Ecological Remediation and Carbon Sequestration, Institute of Environment and Ecology, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China
| | - Zhongcong Sun
- Shenzhen Key Laboratory of Ecological Remediation and Carbon Sequestration, Institute of Environment and Ecology, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China
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Marcus MS, Hergoualc'h K, Honorio Coronado EN, Gutiérrez-Vélez VH. Spatial distribution of degradation and deforestation of palm swamp peatlands and associated carbon emissions in the Peruvian Amazon. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2024; 351:119665. [PMID: 38086114 DOI: 10.1016/j.jenvman.2023.119665] [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: 05/10/2023] [Revised: 10/13/2023] [Accepted: 11/19/2023] [Indexed: 01/14/2024]
Abstract
The vast peat deposits in the Peruvian Amazon are crucial to the global climate. Palm swamp, the most extensive regional peatland ecosystem faces different threats, including deforestation and degradation due to felling of the dominant palm Mauritia flexuosa for fruit harvesting. While these activities convert this natural C sink into a source, the distribution of degradation and deforestation in this ecosystem and related C emissions remain unstudied. We used remote sensing data from Landsat, ALOS-PALSAR, and NASA's GEDI spaceborne LiDAR-derived products to map palm swamp degradation and deforestation within a 28 Mha area of the lowland Peruvian Amazon in 1990-2007 and 2007-2018. We combined this information with a regional peat map, C stock density data and peat emission factors to determine (1) peatland C stocks of peat-forming ecosystems (palm swamp, herbaceous swamp, pole forest), and (2) areas of palm swamp peatland degradation and deforestation and associated C emissions. In the 6.9 ± 0.1 Mha of predicted peat-forming ecosystems within the larger 28 Mha study area, 73% overlaid peat (5.1 ± 0.9 Mha) and stored 3.88 ± 0.12 Pg C. Degradation and deforestation in palm swamp peatlands totaled 535,423 ± 8,419 ha over 1990-2018, with a pronounced dominance for degradation (85%). The degradation rate increased 15% from 15,400 ha y-1 (1990-2007) to 17,650 ha y-1 (2007-2018) and the deforestation rate more than doubled from 1,900 ha y-1 to 4,200 ha y-1. Over 1990-2018, emissions from degradation amounted to 26.3 ± 3.5 Tg C and emissions from deforestation were 12.9 ± 0.5 Tg C. The 2007-2018 emission rate from both biomass and peat loss of 1.9 Tg C yr-1 is four times the average biomass loss rate due to gross deforestation in 2010-2019 reported for the hydromorphic Peruvian Amazon. The magnitude of emissions calls for the country to account for deforestation and degradation of peatlands in national reporting.
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Affiliation(s)
- Matthew S Marcus
- Temple University, Department of Geography and Urban Studies, Philadelphia, PA, USA; University of Arizona, School of Geography, Development and Environment, Tucson, AZ, USA.
| | - Kristell Hergoualc'h
- Center for International Forestry Research (CIFOR), Lima, Peru; Centre de coopération International en Recherche Agronomique pour le Développement (CIRAD), UMR Eco&Sols, Montpellier, France
| | - Eurídice N Honorio Coronado
- School of Geography and Sustainable Development, University of St Andrews, St Andrews, KY16 9AL, United Kingdom
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Jovani‐Sancho AJ, O'Reilly P, Anshari G, Chong XY, Crout N, Evans CD, Evers S, Gan JY, Gibbins CN, Gusmayanti E, Jamaludin J, Jaya A, Page S, Yosep Y, Upton C, Wilson P, Sjögersten S. CH 4 and N 2 O emissions from smallholder agricultural systems on tropical peatlands in Southeast Asia. GLOBAL CHANGE BIOLOGY 2023; 29:4279-4297. [PMID: 37100767 PMCID: PMC10946781 DOI: 10.1111/gcb.16747] [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: 03/01/2022] [Revised: 04/11/2023] [Accepted: 04/13/2023] [Indexed: 05/17/2023]
Abstract
There are limited data for greenhouse gas (GHG) emissions from smallholder agricultural systems in tropical peatlands, with data for non-CO2 emissions from human-influenced tropical peatlands particularly scarce. The aim of this study was to quantify soil CH4 and N2 O fluxes from smallholder agricultural systems on tropical peatlands in Southeast Asia and assess their environmental controls. The study was carried out in four regions in Malaysia and Indonesia. CH4 and N2 O fluxes and environmental parameters were measured in cropland, oil palm plantation, tree plantation and forest. Annual CH4 emissions (in kg CH4 ha-1 year-1 ) were: 70.7 ± 29.5, 2.1 ± 1.2, 2.1 ± 0.6 and 6.2 ± 1.9 at the forest, tree plantation, oil palm and cropland land-use classes, respectively. Annual N2 O emissions (in kg N2 O ha-1 year-1 ) were: 6.5 ± 2.8, 3.2 ± 1.2, 21.9 ± 11.4 and 33.6 ± 7.3 in the same order as above, respectively. Annual CH4 emissions were strongly determined by water table depth (WTD) and increased exponentially when annual WTD was above -25 cm. In contrast, annual N2 O emissions were strongly correlated with mean total dissolved nitrogen (TDN) in soil water, following a sigmoidal relationship, up to an apparent threshold of 10 mg N L-1 beyond which TDN seemingly ceased to be limiting for N2 O production. The new emissions data for CH4 and N2 O presented here should help to develop more robust country level 'emission factors' for the quantification of national GHG inventory reporting. The impact of TDN on N2 O emissions suggests that soil nutrient status strongly impacts emissions, and therefore, policies which reduce N-fertilisation inputs might contribute to emissions mitigation from agricultural peat landscapes. However, the most important policy intervention for reducing emissions is one that reduces the conversion of peat swamp forest to agriculture on peatlands in the first place.
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Affiliation(s)
| | - Patrick O'Reilly
- School of Geography, Geology & the EnvironmentUniversity of LeicesterLeicesterUK
- School of Biological and Environmental SciencesLiverpool John Mores UniversityLiverpoolUK
| | - Gusti Anshari
- Magister of Environmental ScienceUniversitas TanjungpuraPontianakIndonesia
- Soil Science DepartmentUniversitas TanjungpuraPontianakIndonesia
| | - Xin Yi Chong
- School of Environmental and Geographical SciencesUniversity of Nottingham MalaysiaSemenyihMalaysia
| | - Neil Crout
- School of BiosciencesUniversity of NottinghamLoughboroughUK
| | | | - Stephanie Evers
- School of Biological and Environmental SciencesLiverpool John Mores UniversityLiverpoolUK
- School of Environmental and Geographical SciencesUniversity of Nottingham MalaysiaSemenyihMalaysia
| | - Jing Ye Gan
- School of Environmental and Geographical SciencesUniversity of Nottingham MalaysiaSemenyihMalaysia
| | - Christopher N. Gibbins
- School of Environmental and Geographical SciencesUniversity of Nottingham MalaysiaSemenyihMalaysia
| | - Evi Gusmayanti
- Magister of Environmental ScienceUniversitas TanjungpuraPontianakIndonesia
- Agrotechnology DepartmentUniversitas TanjungpuraPontianakIndonesia
| | | | - Adi Jaya
- Faculty of AgricultureUniversity of Palangka RayaPalangka RayaIndonesia
| | - Susan Page
- School of Geography, Geology & the EnvironmentUniversity of LeicesterLeicesterUK
| | - Yosep Yosep
- Faculty of AgricultureUniversity of Palangka RayaPalangka RayaIndonesia
| | - Caroline Upton
- School of Geography, Geology & the EnvironmentUniversity of LeicesterLeicesterUK
| | - Paul Wilson
- School of BiosciencesUniversity of NottinghamLoughboroughUK
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Deshmukh CS, Susanto AP, Nardi N, Nurholis N, Kurnianto S, Suardiwerianto Y, Hendrizal M, Rhinaldy A, Mahfiz RE, Desai AR, Page SE, Cobb AR, Hirano T, Guérin F, Serça D, Prairie YT, Agus F, Astiani D, Sabiham S, Evans CD. Net greenhouse gas balance of fibre wood plantation on peat in Indonesia. Nature 2023; 616:740-746. [PMID: 37020018 PMCID: PMC10132972 DOI: 10.1038/s41586-023-05860-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Accepted: 02/16/2023] [Indexed: 04/07/2023]
Abstract
Tropical peatlands cycle and store large amounts of carbon in their soil and biomass1-5. Climate and land-use change alters greenhouse gas (GHG) fluxes of tropical peatlands, but the magnitude of these changes remains highly uncertain6-19. Here we measure net ecosystem exchanges of carbon dioxide, methane and soil nitrous oxide fluxes between October 2016 and May 2022 from Acacia crassicarpa plantation, degraded forest and intact forest within the same peat landscape, representing land-cover-change trajectories in Sumatra, Indonesia. This allows us to present a full plantation rotation GHG flux balance in a fibre wood plantation on peatland. We find that the Acacia plantation has lower GHG emissions than the degraded site with a similar average groundwater level (GWL), despite more intensive land use. The GHG emissions from the Acacia plantation over a full plantation rotation (35.2 ± 4.7 tCO2-eq ha-1 year-1, average ± standard deviation) were around two times higher than those from the intact forest (20.3 ± 3.7 tCO2-eq ha-1 year-1), but only half of the current Intergovernmental Panel on Climate Change (IPCC) Tier 1 emission factor (EF)20 for this land use. Our results can help to reduce the uncertainty in GHG emissions estimates, provide an estimate of the impact of land-use change on tropical peat and develop science-based peatland management practices as nature-based climate solutions.
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Affiliation(s)
- Chandra S Deshmukh
- Asia Pacific Resources International Ltd., Pelalawan Regency, Indonesia.
| | - Ari P Susanto
- Asia Pacific Resources International Ltd., Pelalawan Regency, Indonesia
| | - Nardi Nardi
- Asia Pacific Resources International Ltd., Pelalawan Regency, Indonesia
| | - Nurholis Nurholis
- Asia Pacific Resources International Ltd., Pelalawan Regency, Indonesia
| | - Sofyan Kurnianto
- Asia Pacific Resources International Ltd., Pelalawan Regency, Indonesia
| | | | - M Hendrizal
- Asia Pacific Resources International Ltd., Pelalawan Regency, Indonesia
| | - Ade Rhinaldy
- Asia Pacific Resources International Ltd., Pelalawan Regency, Indonesia
| | - Reyzaldi E Mahfiz
- Asia Pacific Resources International Ltd., Pelalawan Regency, Indonesia
| | - Ankur R Desai
- Department of Atmospheric and Oceanic Sciences, University of Wisconsin-Madison, Madison, WI, USA
| | - Susan E Page
- School of Geography, Geology and the Environment, University of Leicester, Leicester, UK
| | - Alexander R Cobb
- Singapore-MIT Alliance for Research and Technology, Singapore, Singapore
| | - Takashi Hirano
- Research Faculty of Agriculture, Hokkaido University, Sapporo, Japan
| | - Frédéric Guérin
- Géosciences Environnement Toulouse, CNRS, IRD, Université Paul-Sabatier, Toulouse, France
| | - Dominique Serça
- LAERO, Université de Toulouse, CNRS, IRD, UT3, Toulouse, France
| | - Yves T Prairie
- UNESCO Chair in Global Environmental Change, Université du Québec à Montréal, Montréal, Québec, Canada
| | - Fahmuddin Agus
- National Research and Innovation Agency (BRIN), Cibinong, Indonesia
| | - Dwi Astiani
- Faculty of Forestry, Tanjungpura University, Pontianak, Indonesia
| | - Supiandi Sabiham
- Department of Soil Science and Land Resources, IPB University, Bogor, Indonesia
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Busman NA, Melling L, Goh KJ, Imran Y, Sangok FE, Watanabe A. Soil CO 2 and CH 4 fluxes from different forest types in tropical peat swamp forest. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 858:159973. [PMID: 36347298 DOI: 10.1016/j.scitotenv.2022.159973] [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: 05/06/2022] [Revised: 10/22/2022] [Accepted: 11/01/2022] [Indexed: 06/16/2023]
Abstract
Information on temporal and spatial variations in soil greenhouse gas (GHG) fluxes from tropical peat forests is essential to predict the influence of climate change and estimate the effects of land use on global warming and the carbon (C) cycle. To obtain such basic information, soil carbon dioxide (CO2) and methane (CH4) fluxes, together with soil physicochemical properties and environmental variables, were measured at three major forest types in the Maludam National Park, Sarawak, Malaysia, for eight years, and their relationships were analyzed. Annual soil CO2 fluxes ranged from 860 to 1450 g C m⁻2 yr⁻1 without overall significant differences between the three forest sites, while soil CH4 fluxes, 1.2-10.8 g C m⁻2 yr⁻1, differed. Differences in GHG fluxes between dry and rainy seasons were not necessarily significant, corresponding to the extent of seasonal variation in groundwater level (GWL). The lack of significant differences in soil CO2 fluxes between the three sites could be attributed to set-off between the negative and positive effects of the decomposability of soil organic matter as estimated by pyrophosphate solubility index (PSI) and GWL. The impact of El-Niño on annual CO2 flux also varied between the sites. The variation in soil CH4 fluxes from the three sites was enhanced by variations in temperature, GWL, PSI, and soil iron (Fe) content. A positive correlation was observed between the annual CH4 flux and GWL at only one site, and the influence of soil properties was more pronounced at the site with the lowest GWL and the highest PSI. Variation in annual CH4 fluxes was controlled more strongly by temperature where GWL was the highest and GWL and plant growth fluctuations were the least. Inter-annual variations in soil CO2 and CH4 fluxes confirmed the importance of long-term monitoring of these at multiple sites supporting different forest types.
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Affiliation(s)
- Nur Azima Busman
- Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan; Sarawak Tropical Peat Research Institute, Lot 6035, Kuching-Kota Samarahan Expressway, 94300 Kota Samarahan, Sarawak, Malaysia.
| | - Lulie Melling
- Sarawak Tropical Peat Research Institute, Lot 6035, Kuching-Kota Samarahan Expressway, 94300 Kota Samarahan, Sarawak, Malaysia
| | - Kah Joo Goh
- Advanced Agriecological Research Sdn Bhd, Kota Damansara, Petaling Jaya 47810, Malaysia
| | - Yazid Imran
- Sarawak Tropical Peat Research Institute, Lot 6035, Kuching-Kota Samarahan Expressway, 94300 Kota Samarahan, Sarawak, Malaysia
| | - Faustina E Sangok
- Sarawak Tropical Peat Research Institute, Lot 6035, Kuching-Kota Samarahan Expressway, 94300 Kota Samarahan, Sarawak, Malaysia
| | - Akira Watanabe
- Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan
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Swails E, Hergoualc'h K, Deng J, Frolking S, Novita N. How can process-based modeling improve peat CO 2 and N 2O emission factors for oil palm plantations? THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 839:156153. [PMID: 35609697 DOI: 10.1016/j.scitotenv.2022.156153] [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: 01/25/2022] [Revised: 05/15/2022] [Accepted: 05/18/2022] [Indexed: 06/15/2023]
Abstract
Oil palm plantations on peat and associated drainage generate sizeable GHG emissions. Current IPCC default emission factors (EF) for oil palm on organic soil are based on a very limited number of observations from young plantations, thereby resulting in large uncertainties in emissions estimates. To explore the potential of process-based modeling to refine oil palm peat CO2 and N2O EFs, we simulated peat GHG emissions and biogeophysical variables over 30 years in plantations of Central Kalimantan, Indonesia. The DNDC model simulated well the magnitude of C inputs (litterfall and root mortality) and dynamics of annual heterotrophic respiration and peat decomposition N2O fluxes. The modeled peat onsite CO2-C EF was lower than the IPCC default (11 Mg C ha-1 yr-1) and decreased from 7.7 ± 0.4 Mg C ha-1 yr-1 in the first decade to 3.0 ± 0.2 and 1.8 ± 0.3 Mg C ha-1 yr-1 in the second and third decades of the rotation. The modeled N2O-N EF from peat decomposition was higher than the IPCC default (1.2 kg N ha-1 yr-1) and increased from 3.5 ± 0.3 kg N ha-1 yr-1 in the first decade to 4.7-4.6 ± 0.5 kg N ha-1 yr-1 in the following ones. Modeled fertilizer-induced N2O emissions were minimal and much less than 1.6% of N inputs recommended by the IPCC in wet climates regardless of soil type. Temporal variations in EFs were strongly linked to soil C:N ratio and soil mineral N content for CO2 and fertilizer-induced N2O emissions, and to precipitation, water table level and soil NH4+ content for peat decomposition N2O emissions. These results suggest that current IPCC EFs for oil palm on organic soil could over-estimate peat onsite CO2 emissions and underestimate peat decomposition N2O emissions and that temporal variation in emissions should be considered for further improvement of EFs.
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Affiliation(s)
- Erin Swails
- Center for International Forestry Research, Jalan CIFOR, Situ Gede, Sindang Barang, Bogor 16115, Indonesia.
| | - Kristell Hergoualc'h
- Center for International Forestry Research, Jalan CIFOR, Situ Gede, Sindang Barang, Bogor 16115, Indonesia
| | - Jia Deng
- Earth Systems Research Center, Institute for the Study of Earth, Oceans and Space, University of New Hampshire, 8 College Road, Durham, NH 03824, USA
| | - Steve Frolking
- Earth Systems Research Center, Institute for the Study of Earth, Oceans and Space, University of New Hampshire, 8 College Road, Durham, NH 03824, USA
| | - Nisa Novita
- Yayasan Konservasi Alam Nusantara, Graha Iskandarsyah 3(rd) floor, Jalan Iskandarsyah Raya 66 C, 12160 Jakarta, Indonesia
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Rewetting Tropical Peatlands Reduced Net Greenhouse Gas Emissions in Riau Province, Indonesia. FORESTS 2022. [DOI: 10.3390/f13040505] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Draining deforested tropical peat swamp forests (PSFs) converts greenhouse gas (GHG) sinks to sources and increases the likelihood of fire hazards. Rewetting deforested and drained PSFs before revegetation is expected to reverse this outcome. This study aims to quantify the GHG emissions of deforested PSFs that have been (a) reforested, (b) converted into oil palm, or (c) replanted with rubber. Before rewetting, heterotrophic soil respiration in reforested, oil palm, and rubber plantation areas were 48.91 ± 4.75 Mg CO2 ha−1 yr−1, 54.98 ± 1.53 Mg CO2 ha−1 yr−1, and 67.67 ± 2.13 Mg CO2 ha−1 yr−1, respectively. After rewetting, this decreased substantially by 21%, 36%, and 39%. Conversely, rewetting drained landscapes that used to be methane (CH4) sinks converted them into CH4 sources; almost twice as much methane was emitted after rewetting. Nitrous oxide (N2O) emissions tended to decrease; in nitrogen-rich rubber plantations, N2O emissions halved; in nitrogen-poor reforested areas, emissions reduced by up to a quarter after rewetting. Overall, rewetting reduced the net emissions up to 15.41 Mg CO2-eq ha−1 yr−1 (25%) in reforested, 18.36 Mg CO2-eq ha−1 yr−1 (18%) in oil palm, and 28.87 Mg CO2-eq ha−1 yr−1 (17%) in rubber plantation areas.
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Chen Q, Long C, Chen J, Cheng X. Differential response of soil CO 2 , CH 4 , and N 2 O emissions to edaphic properties and microbial attributes following afforestation in central China. GLOBAL CHANGE BIOLOGY 2021; 27:5657-5669. [PMID: 34363712 DOI: 10.1111/gcb.15826] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Accepted: 07/19/2021] [Indexed: 06/13/2023]
Abstract
Land use change specially affects greenhouse gas (GHG) emissions, and it can act as a sink/source of GHGs. Alterations in edaphic properties and microbial attributes induced by land use change can individually/interactively contribute to GHG emissions, but how they predictably affect soil CO2 , CH4 , and N2 O emissions remain unclear. Here, we investigated the direct and indirect controls of edaphic properties (i.e., dissolved organic carbon [DOC], soil organic C, total nitrogen, C:N ratio, NH4+ -N, NO3- -N, soil temperature [ST], soil moisture [SM], pH, and bulk density [BD]) and microbial attributes (i.e., total phospholipid fatty acids [PLFAs], 18:1ω7c, nitrifying genes [ammonia-oxidizing archaea, ammonia-oxidizing bacteria], and denitrifying genes [nirS, nirK, and nosZ]) over the annual soil CO2 , CH4 , and N2 O emissions from the woodland, shrubland, and abandoned land in subtropical China. Soil CO2 and N2 O emissions were higher in the afforested lands (woodland and shrubland) than in the abandoned land, but the annual cumulative CH4 uptake did not significantly differ among all land use types. The CO2 emission was positively associated with microbial activities (e.g., total PLFAs), while the CH4 uptake was tightly correlated with soil environments (i.e., ST and SM) and chemical properties (i.e., DOC, C:N ratio, and NH4+ -N concentration), but not significantly related to the methanotrophic bacteria (i.e., 18:1ω7c). Whereas, soil N2 O emission was positively associated with nitrifying genes, but negatively correlated with denitrifying genes especially nosZ. Overall, our results suggested that soil CO2 and N2 O emissions were directly dependent on microbial attributes, and soil CH4 uptake was more directly related to edaphic properties rather than microbial attributes. Thus, different patterns of soil CO2 , CH4 , and N2 O emissions and associated controls following land use change provided novel insights into predicting the effects of afforestation on climate change mitigation outcomes.
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Affiliation(s)
- Qiong Chen
- Key Laboratory of Soil Ecology and Health in Universities of Yunnan Province, School of Ecology and Environmental Sciences, Yunnan University, Kunming, P.R. China
| | - Chunyan Long
- Key Laboratory of Soil Ecology and Health in Universities of Yunnan Province, School of Ecology and Environmental Sciences, Yunnan University, Kunming, P.R. China
| | - Jingwen Chen
- South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Xiaoli Cheng
- Key Laboratory of Soil Ecology and Health in Universities of Yunnan Province, School of Ecology and Environmental Sciences, Yunnan University, Kunming, P.R. China
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Dezzeo N, Grandez-Rios J, Martius C, Hergoualc'h K. Degradation-driven changes in fine root carbon stocks, productivity, mortality, and decomposition rates in a palm swamp peat forest of the Peruvian Amazon. CARBON BALANCE AND MANAGEMENT 2021; 16:33. [PMID: 34714416 PMCID: PMC8555211 DOI: 10.1186/s13021-021-00197-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/22/2021] [Accepted: 10/21/2021] [Indexed: 06/13/2023]
Abstract
BACKGROUND Amazon palm swamp peatlands are major carbon (C) sinks and reservoirs. In Peru, this ecosystem is widely threatened owing to the recurrent practice of cutting Mauritia flexuosa palms for fruit harvesting. Such degradation could significantly damage peat deposits by altering C fluxes through fine root productivity, mortality, and decomposition rates which contribute to and regulate peat accumulation. Along a same peat formation, we studied an undegraded site (Intact), a moderately degraded site (mDeg) and a heavily degraded site (hDeg) over 11 months. Fine root C stocks and fluxes were monthly sampled by sequential coring. Concomitantly, fine root decomposition was investigated using litter bags. In the experimental design, fine root stocks and dynamics were assessed separately according to vegetation type (M. flexuosa palm and other tree species) and M. flexuosa age class. Furthermore, results obtained from individual palms and trees were site-scaled by using forest composition and structure. RESULTS At the scale of individuals, fine root C biomass in M. flexuosa adults was higher at the mDeg site than at the Intact and hDeg sites, while in trees it was lowest at the hDeg site. Site-scale fine root biomass (Mg C ha-1) was higher at the mDeg site (0.58 ± 0.05) than at the Intact (0.48 ± 0.05) and hDeg sites (0.32 ± 0.03). Site-scale annual fine root mortality rate was not significantly different between sites (3.4 ± 1.3, 2.0 ± 0.8, 1.5 ± 0.7 Mg C ha-1 yr-1 at the Intact, mDeg, and hDeg sites) while productivity (same unit) was lower at the hDeg site (1.5 ± 0.8) than at the Intact site (3.7 ± 1.2), the mDeg site being intermediate (2.3 ± 0.9). Decomposition was slow with 63.5-74.4% of mass remaining after 300 days and it was similar among sites and vegetation types. CONCLUSIONS The significant lower fine root C stock and annual productivity rate at the hDeg site than at the Intact site suggests a potential for strong degradation to disrupt peat accretion. These results stress the need for a sustainable management of these forests to maintain their C sink function.
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Affiliation(s)
- Nelda Dezzeo
- Center for International Forestry Research (CIFOR), c/o Centro Internacional de la Papa (CIP), Av. La Molina 1895, La Molina, Apdo Postal 1558, 15024, Lima, Peru
- Venezuelan Institute for Scientific Research (IVIC), Caracas, Venezuela
| | - Julio Grandez-Rios
- Center for International Forestry Research (CIFOR), c/o Centro Internacional de la Papa (CIP), Av. La Molina 1895, La Molina, Apdo Postal 1558, 15024, Lima, Peru
- Universidad Nacional de la Amazonia Peruana (UNAP), Loreto, Peru
| | | | - Kristell Hergoualc'h
- Center for International Forestry Research (CIFOR), c/o Centro Internacional de la Papa (CIP), Av. La Molina 1895, La Molina, Apdo Postal 1558, 15024, Lima, Peru.
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