1
|
Parker D, Tosiani A, Yazid M, Sari IL, Kartika T, Kustiyo, Firmansyah R, Said Z, Wijaya A, Potapov P, Tyukavina A, Stehman SV, Zalles V, Pickens A, Pickering J, Turubanova S, Hansen MC. Land in limbo: Nearly one third of Indonesia's cleared old-growth forests left idle. Proc Natl Acad Sci U S A 2024; 121:e2318029121. [PMID: 38950360 PMCID: PMC11252779 DOI: 10.1073/pnas.2318029121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2023] [Accepted: 05/10/2024] [Indexed: 07/03/2024] Open
Abstract
Indonesia has experienced rapid primary forest loss, second only to Brazil in modern history. We examined the fates of Indonesian deforested areas, immediately after clearing and over time, to quantify deforestation drivers in Indonesia. Using time-series satellite data, we tracked degradation and clearing events in intact and degraded natural forests from 1991 to 2020, as well as land use trajectories after forest loss. While an estimated 7.8 Mha (SE = 0.4) of forest cleared during this period had been planted with oil palms by 2020, another 8.8 Mha (SE = 0.4) remained unused. Of the 28.4 Mha (SE = 0.7) deforested, over half were either initially left idle or experienced crop failure before a land use could be detected, and 44% remained unused for 5 y or more. A majority (54%) of these areas were cleared mechanically (not by escaped fires), and in cases where idle lands were eventually converted to productive uses, oil palm plantations were by far the most common outcome. The apparent deliberate creation of idle deforested land in Indonesia and subsequent conversion of idle areas to oil palm plantations indicates that speculation and land banking for palm oil substantially contribute to forest loss, although failed plantations could also contribute to this dynamic. We also found that in Sumatra, few lowland forests remained, suggesting that a lack of remaining forest appropriate for palm oil production, together with an extensive area of banked deforested land, may partially explain slowing forest loss in Indonesia in recent years.
Collapse
Affiliation(s)
- Diana Parker
- Department of Geographical Sciences, University of Maryland, College Park, MD20742
| | - Anna Tosiani
- Ministry of Environment and Forestry of Indonesia, Jakarta10270, Indonesia
| | - Muhammad Yazid
- Ministry of Environment and Forestry of Indonesia, Jakarta10270, Indonesia
| | - Inggit L. Sari
- National Research and Innovation Agency of Indonesia, Jakarta10340, Indonesia
| | - Tatik Kartika
- National Research and Innovation Agency of Indonesia, Jakarta10340, Indonesia
| | - Kustiyo
- National Research and Innovation Agency of Indonesia, Jakarta10340, Indonesia
| | | | - Zuraidah Said
- World Resources Institute of Indonesia, Jakarta12170, Indonesia
- United Nations Development Programme Indonesia, Jakarta10250, Indonesia
| | - Arief Wijaya
- World Resources Institute of Indonesia, Jakarta12170, Indonesia
| | - Peter Potapov
- Department of Geographical Sciences, University of Maryland, College Park, MD20742
| | - Alexandra Tyukavina
- Department of Geographical Sciences, University of Maryland, College Park, MD20742
| | - Stephen V. Stehman
- Department of Sustainable Resources Management, College of Environmental Science and Forestry, State University of New York, Syracuse, NY13210
| | - Viviana Zalles
- Department of Geographical Sciences, University of Maryland, College Park, MD20742
| | - Amy Pickens
- Department of Geographical Sciences, University of Maryland, College Park, MD20742
| | - Jeffrey Pickering
- Department of Geographical Sciences, University of Maryland, College Park, MD20742
| | - Svetlana Turubanova
- Department of Geographical Sciences, University of Maryland, College Park, MD20742
| | - Matthew C. Hansen
- Department of Geographical Sciences, University of Maryland, College Park, MD20742
| |
Collapse
|
2
|
Young DM, Baird AJ, Morris PJ, Dargie GC, Mampouya Wenina YE, Mbemba M, Boom A, Cook P, Betts R, Burke E, Bocko YE, Chadburn S, Crabtree DE, Crezee B, Ewango CEN, Garcin Y, Georgiou S, Girkin NT, Gulliver P, Hawthorne D, Ifo SA, Lawson IT, Page SE, Jovani-Sancho AJ, Schefuß E, Sciumbata M, Sjögersten S, Lewis SL. Simulating carbon accumulation and loss in the central Congo peatlands. GLOBAL CHANGE BIOLOGY 2023; 29:6812-6827. [PMID: 37815703 DOI: 10.1111/gcb.16966] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2023] [Revised: 08/25/2023] [Accepted: 09/10/2023] [Indexed: 10/11/2023]
Abstract
Peatlands of the central Congo Basin have accumulated carbon over millennia. They currently store some 29 billion tonnes of carbon in peat. However, our understanding of the controls on peat carbon accumulation and loss and the vulnerability of this stored carbon to climate change is in its infancy. Here we present a new model of tropical peatland development, DigiBog_Congo, that we use to simulate peat carbon accumulation and loss in a rain-fed interfluvial peatland that began forming ~20,000 calendar years Before Present (cal. yr BP, where 'present' is 1950 CE). Overall, the simulated age-depth curve is in good agreement with palaeoenvironmental reconstructions derived from a peat core at the same location as our model simulation. We find two key controls on long-term peat accumulation: water at the peat surface (surface wetness) and the very slow anoxic decay of recalcitrant material. Our main simulation shows that between the Late Glacial and early Holocene there were several multidecadal periods where net peat and carbon gain alternated with net loss. Later, a climatic dry phase beginning ~5200 cal. yr BP caused the peatland to become a long-term carbon source from ~3975 to 900 cal. yr BP. Peat as old as ~7000 cal. yr BP was decomposed before the peatland's surface became wetter again, suggesting that changes in rainfall alone were sufficient to cause a catastrophic loss of peat carbon lasting thousands of years. During this time, 6.4 m of the column of peat was lost, resulting in 57% of the simulated carbon stock being released. Our study provides an approach to understanding the future impact of climate change and potential land-use change on this vulnerable store of carbon.
Collapse
Affiliation(s)
| | - Andy J Baird
- School of Geography, University of Leeds, Leeds, UK
| | | | | | - Y Emmanuel Mampouya Wenina
- École Normale Supérieure, Departement des sciences et vie de la terre, Université Marien Ngouabi, Brazzaville, Republic of the Congo
| | - Mackline Mbemba
- École Normale Supérieure, Departement des sciences et vie de la terre, Université Marien Ngouabi, Brazzaville, Republic of the Congo
| | - Arnoud Boom
- School of Geography, Geology and the Environment, University of Leicester, Leicester, UK
| | - Peter Cook
- Global Systems Institute, University of Exeter, Exeter, UK
| | - Richard Betts
- Global Systems Institute, University of Exeter, Exeter, UK
- Met Office Hadley Centre, Exeter, UK
| | | | - Yannick E Bocko
- Faculté des Sciences et Techniques, Université Marien Ngouabi, Brazzaville, Republic of the Congo
| | - Sarah Chadburn
- College of Engineering, Mathematics, and Physical Sciences, University of Exeter, Exeter, UK
| | | | - Bart Crezee
- School of Geography, University of Leeds, Leeds, UK
| | - Corneille E N Ewango
- Faculté de Gestion des Ressources Naturelles Renouvelables, Université de Kisangani, Kisangani, Democratic Republic of the Congo
- Faculté des Sciences, Université de Kisangani, Kisangani, Democratic Republic of the Congo
| | - Yannick Garcin
- CNRS, IRD, INRAE, CEREGE, Aix Marseille University, Aix-en-Provence, France
| | - Selena Georgiou
- School of GeoSciences, University of Edinburgh, Edinburgh, UK
| | - Nicholas T Girkin
- School of Water, Energy and Environment, Cranfield University, Cranfield, UK
| | - Pauline Gulliver
- NEIF Radiocarbon Laboratory, Scottish Universities Environmental Research Centre, University of Glasgow, Glasgow, UK
| | - Donna Hawthorne
- School of Geography and Sustainable Development, University of St Andrews, St Andrews, UK
| | - Suspense A Ifo
- École Normale Supérieure, Departement des sciences et vie de la terre, Université Marien Ngouabi, Brazzaville, Republic of the Congo
| | - Ian T Lawson
- School of Geography and Sustainable Development, University of St Andrews, St Andrews, UK
| | - Susan E Page
- School of Geography, Geology and the Environment, University of Leicester, Leicester, UK
| | - A Jonay Jovani-Sancho
- UK Center of Ecology & Hydrology, Bangor, UK
- School of Biosciences, University of Nottingham, Nottingham, UK
| | - Enno Schefuß
- MARUM-Center for Marine Environmental Sciences, University of Bremen, Bremen, Germany
| | - Matteo Sciumbata
- Amsterdam Institute for Life and Environment, Section Systems Ecology, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | | | - Simon L Lewis
- School of Geography, University of Leeds, Leeds, UK
- Department of Geography, University College London, London, UK
| |
Collapse
|
3
|
Mozafari B, Bruen M, Donohue S, Renou-Wilson F, O'Loughlin F. Peatland dynamics: A review of process-based models and approaches. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 877:162890. [PMID: 36933711 DOI: 10.1016/j.scitotenv.2023.162890] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Revised: 03/09/2023] [Accepted: 03/12/2023] [Indexed: 05/06/2023]
Abstract
Despite peatlands' important feedbacks on the climate and global biogeochemical cycles, predicting their dynamics involves many uncertainties and an overwhelming variety of available models. This paper reviews the most widely used process-based models for simulating peatlands' dynamics, i.e., the exchanges of energy and mass (water, carbon, and nitrogen). 'Peatlands' here refers to mires, fens, bogs, and peat swamps both intact and degraded. Using a systematic search (involving 4900 articles), 45 models were selected that appeared at least twice in the literature. The models were classified into four categories: terrestrial ecosystem models (biogeochemical and global dynamic vegetation models, n = 21), hydrological models (n = 14), land surface models (n = 7), and eco-hydrological models (n = 3), 18 of which featured "peatland-specific" modules. By analysing their corresponding publications (n = 231), we identified their proven applicability domains (hydrology and carbon cycles dominated) for different peatland types and climate zones (northern bogs and fens dominated). The studies range in scale from small plots to global, and from single events to millennia. Following a FOSS (Free Open-Source Software) and FAIR (Findable, Accessible, Interoperable, Reusable) assessment, the number of models was reduced to 12. Then, we conducted a technical review of the approaches and associated challenges, as well as the basic aspects of each model, e.g., spatiotemporal resolution, input/output data format and modularity. Our review streamlines the process of model selection and highlights: (i) standardization and coordination are required for both data exchange and model calibration/validation to facilitate intercomparison studies; and (ii) there are overlaps in the models' scopes and approaches, making it imperative to fully optimize the strengths of existing models rather than creating redundant ones. In this regard, we provide a futuristic outlook for a 'peatland community modelling platform' and suggest an international peatland modelling intercomparison project.
Collapse
Affiliation(s)
- Behzad Mozafari
- School of Civil Engineering, UCD Earth Institute and UCD Dooge Centre for Water Resources Research, University College Dublin, Dublin 4, Ireland.
| | - Michael Bruen
- School of Civil Engineering, UCD Earth Institute and UCD Dooge Centre for Water Resources Research, University College Dublin, Dublin 4, Ireland
| | - Shane Donohue
- School of Civil Engineering and UCD Earth Institute, University College Dublin, Dublin 4, Ireland
| | - Florence Renou-Wilson
- School of Biology and Environmental Science, Science Centre-West, University College Dublin, Dublin 4, Ireland
| | - Fiachra O'Loughlin
- School of Civil Engineering, UCD Earth Institute and UCD Dooge Centre for Water Resources Research, University College Dublin, Dublin 4, Ireland
| |
Collapse
|
4
|
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.
Collapse
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
| | | |
Collapse
|
5
|
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.
Collapse
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
| |
Collapse
|
6
|
Carbon Dynamics in Rewetted Tropical Peat Swamp Forests. CLIMATE 2022. [DOI: 10.3390/cli10030035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
Degraded and drained peat swamp forests (PSFs) are major sources of carbon emissions in the forestry sector. Rewetting interventions aim to reduce carbon loss and to enhance the carbon stock. However, studies of rewetting interventions in tropical PSFs are still limited. This study examined the effect of rewetting interventions on carbon dynamics at a rewetted site and an undrained site. We measured aboveground carbon (AGC), belowground carbon (BGC), litterfall, heterotrophic components of soil respiration (Rh), methane emissions (CH4), and dissolved organic carbon (DOC) concentration at both sites. We found that the total carbon stock at the rewetted site was slightly lower than at the undrained site (1886.73 ± 87.69 and 2106.23 ± 214.33 Mg C ha−1, respectively). The soil organic carbon (SOC) was 1685 ± 61 Mg C ha−1 and 1912 ± 190 Mg C ha−1 at the rewetted and undrained sites, respectively, and the carbon from litterfall was 4.68 ± 0.30 and 3.92 ± 0.34 Mg C ha−1 year−1, respectively. The annual average Rh was 4.06 ± 0.02 Mg C ha−1 year−1 at the rewetted site and was 3.96 ± 0.16 Mg C ha−1 year−1 at the undrained site. In contrast, the annual average CH4 emissions were −0.0015 ± 0.00 Mg C ha−1 year−1 at the rewetted site and 0.056 ± 0.000 Mg C ha−1 year−1 at the undrained site. In the rewetted condition, carbon from litter may become stable over a longer period. Consequently, carbon loss and gain mainly depend on the magnitude of peat decomposition (Rh) and CH4 emissions.
Collapse
|
7
|
Can We Simultaneously Restore Peatlands and Improve Livelihoods? Exploring Community Home Yard Innovations in Utilizing Degraded Peatland. LAND 2022. [DOI: 10.3390/land11020150] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Peatlands support the daily needs of people in many villages in Indonesia, including in Central Kalimantan Province. They provide the natural resources to enable fisheries, agriculture, plantations, and forestry. However, peatland utilization comes with various challenges, including fire, soil acidity, inundation, low fertility, and limited choice of suitable species. Many of the current uses of peatland can result in its degradation, oxidation, and increased risk of peat fire. Avoiding further environmental degradation will require the development of new technology that allows the community to both earn a livelihood and protect the peatland. In this study we assessed a range of technologies applied by 14 farmers at Tumbang Nusa village, Central Kalimantan province, in managing degraded peatlands in their home yard for agricultural business. The study shows that for endemic peatland species, good success can be achieved if they are planted directly. However, for species endemic to mineral land, there are four technologies applied by farmers in managing degraded peatland. The choice of technologies is influenced by their economic capacity/cash flow flexibility and their understanding of peatlands. Technologies intended to adapt to land inundation include the use of polybags, development of raised beds, and making peat mounds with mineral soil in the centre. Technologies to address the acidity and soil fertility include amelioration with dolomite lime and fertilizer. The use of polybags filled with peat soil is the easiest technology to adopt and can be conducted by all family members. However, a farmer’s choice of technology needs to always consider the potential environmental impacts in addition to increasing soil fertility so that peat conservation is maintained.
Collapse
|
8
|
Comparing GHG Emissions from Drained Oil Palm and Recovering Tropical Peatland Forests in Malaysia. WATER 2021. [DOI: 10.3390/w13233372] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
For agricultural purposes, the drainage and deforestation of Southeast Asian peatland resulted in high greenhouse gases’ (GHGs, e.g., CO2, N2O and CH4) emission. A peatland regenerating initiative, by rewetting and vegetation restoration, reflects evidence of subsequent forest recovery. In this study, we compared GHG emissions from three Malaysian tropical peatland systems under the following different land-use conditions: (i) drained oil palm plantation (OP), (ii) rewetting-restored forest (RF) and (iii) undrained natural forest (NF). Biweekly temporal measurements of CO2, CH4 and N2O fluxes were conducted using a closed-chamber method from July 2017 to December 2018, along with the continuous measurement of environmental variables and a one-time measurement of the soil physicochemical properties. The biweekly emission data were integrated to provide cumulative fluxes using the trapezoidal rule. Our results indicated that the changes in environmental conditions resulting from draining (OP) or rewetting historically drained peatland (RF) affected CH4 and N2O emissions more than CO2 emissions. The cumulative CH4 emission was significantly higher in the forested sites (RF and NF), which was linked to their significantly higher water table (WT) level (p < 0.05). Similarly, the high cumulative CO2 emission trends at the RF and OP sites indicated that the RF rewetting-restored peatland system continued to have high decomposition rates despite having a significantly higher WT than the OP (p < 0.05). The highest cumulative N2O emission at the drained-fertilized OP and rewetting-restored RF sites was linked to the available substrates for high decomposition (low C/N ratio) together with soil organic matter mineralization that provided inorganic nitrogen (N), enabling ideal conditions for microbial mediated N2O emissions. Overall, the measured peat properties did not vary significantly among the different land uses. However, the lower C/N ratio at the OP and the RF sites indicated higher decomposition rates in the drained and historically drained peat than the undrained natural peat (NF), which was associated with high cumulative CO2 and N2O emissions in our study.
Collapse
|
9
|
Ribeiro K, Pacheco FS, Ferreira JW, de Sousa-Neto ER, Hastie A, Krieger Filho GC, Alvalá PC, Forti MC, Ometto JP. Tropical peatlands and their contribution to the global carbon cycle and climate change. GLOBAL CHANGE BIOLOGY 2021; 27:489-505. [PMID: 33070397 DOI: 10.1111/gcb.15408] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Revised: 08/06/2020] [Accepted: 09/11/2020] [Indexed: 06/11/2023]
Abstract
Peatlands are carbon-rich ecosystems that cover 185-423 million hectares (Mha) of the earth's surface. The majority of the world's peatlands are in temperate and boreal zones, whereas tropical ones cover only a total area of 90-170 Mha. However, there are still considerable uncertainties in C stock estimates as well as a lack of information about depth, bulk density and carbon accumulation rates. The incomplete data are notable especially in tropical peatlands located in South America, which are estimated to have the largest area of peatlands in the tropical zone. This paper displays the current state of knowledge surrounding tropical peatlands and their biophysical characteristics, distribution and carbon stock, role in the global climate, the impacts of direct human disturbances on carbon accumulation rates and greenhouse gas (GHG) emissions. Based on the new peat extension and depth data, we estimate that tropical peatlands store 152-288 Gt C, or about half of the global peatland emitted carbon. We discuss the knowledge gaps in research on distribution, depth, C stock and fluxes in these ecosystems which play an important role in the global carbon cycle and risk releasing large quantities of GHGs into the atmosphere (CO2 and CH4 ) when subjected to anthropogenic interferences (e.g., drainage and deforestation). Recent studies show that although climate change has an impact on the carbon fluxes of these ecosystems, the direct anthropogenic disturbance may play a greater role. The future of these systems as carbon sinks will depend on advancing current scientific knowledge and incorporating local understanding to support policies geared toward managing and conserving peatlands in vulnerable regions, such as the Amazon where recent records show increased forest fires and deforestation.
Collapse
Affiliation(s)
- Kelly Ribeiro
- Earth System Science Center (CCST), National Institute for Space Research (INPE), São Paulo, Brazil
| | - Felipe S Pacheco
- Earth System Science Center (CCST), National Institute for Space Research (INPE), São Paulo, Brazil
| | - José W Ferreira
- Earth System Science Center (CCST), National Institute for Space Research (INPE), São Paulo, Brazil
| | - Eráclito R de Sousa-Neto
- Earth System Science Center (CCST), National Institute for Space Research (INPE), São Paulo, Brazil
| | - Adam Hastie
- School of GeoSciences, University of Edinburgh, Edinburgh, UK
| | - Guenther C Krieger Filho
- Laboratory of Thermal and Environmental Engineering, Polytechnic School of the University of São Paulo, São Paulo, Brazil
| | - Plínio C Alvalá
- Earth System Science Center (CCST), National Institute for Space Research (INPE), São Paulo, Brazil
| | - Maria C Forti
- Earth System Science Center (CCST), National Institute for Space Research (INPE), São Paulo, Brazil
| | - Jean P Ometto
- Earth System Science Center (CCST), National Institute for Space Research (INPE), São Paulo, Brazil
| |
Collapse
|
10
|
Lupascu M, Akhtar H, Smith TEL, Sukri RS. Post-fire carbon dynamics in the tropical peat swamp forests of Brunei reveal long-term elevated CH 4 flux. GLOBAL CHANGE BIOLOGY 2020; 26:5125-5145. [PMID: 32475055 DOI: 10.1111/gcb.15195] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Revised: 05/19/2020] [Accepted: 05/19/2020] [Indexed: 06/11/2023]
Abstract
Tropical peatlands hold about 15%-19% of the global peat carbon (C) pool of which 77% is stored in the peat swamp forests (PSFs) of Southeast Asia. Nonetheless, these PSFs have been drained, exploited for timber and land for agriculture, leading to frequent fires in the region. The physico-chemical characteristics of peat, as well as the hydrology of PSFs are affected after a fire, during which the ecosystem can act as a C source for decades, as C emissions to the atmosphere exceed photosynthesis. In this work, we studied the longer-term impact of fires on C cycling in tropical PSFs, hence we quantified the magnitude and patterns of C loss (CO2 , CH4 and dissolved organic carbon) and soil-water quality characteristics in an intact and a degraded burnt PSF in Brunei Darussalam affected by seven fires over the last 40 years. We used natural tracers such as 14 C to investigate the age and sources of C contributing to ecosystem respiration (Reco ) and CH4 , while we continuously monitored soil temperature and water table (WT) level from June 2017 to January 2019. Our results showed a major difference in the physico-chemical parameters, which in turn affected C dynamics, especially CH4 . Methane effluxes were higher in fire-affected areas (7.8 ± 2.2 mg CH4 m-2 hr-1 ) compared to the intact PSF (4.0 ± 2.0 mg CH4 m-2 hr-1 ) due to prolonged higher WT and more optimal methanogenesis conditions. On the other hand, we did not find significant differences in Reco between burnt (432 ± 83 mg CO2 m-2 hr-1 ) and intact PSF (359 ± 76 mg CO2 m-2 hr-1 ). Radiocarbon analysis showed overall no significant difference between intact and burnt PSF with a modern signature for both CO2 and CH4 fluxes implying a microbial preference for the more labile C fraction in the peat matrix.
Collapse
Affiliation(s)
- Massimo Lupascu
- Department of Geography, National University of Singapore, Singapore, Singapore
- Integrated Tropical Peatland Research Program, NUS Environmental Research Institute, National University of Singapore, Singapore, Singapore
| | - Hasan Akhtar
- Department of Geography, National University of Singapore, Singapore, Singapore
| | - Thomas E L Smith
- Department of Geography and Environment, The London School of Economics and Political Science, London, UK
| | | |
Collapse
|
11
|
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: 4] [Impact Index Per Article: 1.0] [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.
Collapse
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
| |
Collapse
|
12
|
Variation in Soil Properties Regulate Greenhouse Gas Fluxes and Global Warming Potential in Three Land Use Types on Tropical Peat. ATMOSPHERE 2018. [DOI: 10.3390/atmos9120465] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
This study investigated spatial factors controlling CO2, CH4, and N2O fluxes and compared global warming potential (GWP) among undrained forest (UDF), drained forest (DF), and drained burned land (DBL) on tropical peatland in Central Kalimantan, Indonesia. Sampling was performed once within two weeks in the beginning of dry season. CO2 flux was significantly promoted by lowering soil moisture and pH. The result suggests that oxidative peat decomposition was enhanced in drier position, and the decomposition acidify the peat soils. CH4 flux was significantly promoted by a rise in groundwater level, suggesting that methanogenesis was enhanced under anaerobic condition. N2O flux was promoted by increasing soil nitrate content in DF, suggesting that denitrification was promoted by substrate availability. On the other hand, N2O flux was promoted by lower soil C:N ratio and higher soil pH in DBL and UDF. CO2 flux was the highest in DF (241 mg C m−2 h−1) and was the lowest in DBL (94 mg C m−2 h−1), whereas CH4 flux was the highest in DBL (0.91 mg C m−2 h−1) and was the lowest in DF (0.01 mg C m−2 h−1), respectively. N2O flux was not significantly different among land uses. CO2 flux relatively contributed to 91–100% of GWP. In conclusion, it is necessary to decrease CO2 flux to mitigate GWP through a rise in groundwater level and soil moisture in the region.
Collapse
|
13
|
Khasanah N, van Noordwijk M. Subsidence and carbon dioxide emissions in a smallholder peatland mosaic in Sumatra, Indonesia. MITIGATION AND ADAPTATION STRATEGIES FOR GLOBAL CHANGE 2018; 24:147-163. [PMID: 30662320 PMCID: PMC6320748 DOI: 10.1007/s11027-018-9803-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/29/2017] [Accepted: 03/06/2018] [Indexed: 06/09/2023]
Abstract
Most attention in quantifying carbon dioxide (CO2) emissions from tropical peatlands has been on large-scale plantations (industrial timber, oil palm (Elaeis guinensis)), differing in drainage and land-use practices from those of smallholder farms. We measured subsidence and changes in bulk density and carbon organic content to calculate CO2 emissions over 2.5 years in a remnant logged-over forest and four dominant smallholder land-use types in Tanjung Jabung Barat District, Jambi Province, Sumatra, Indonesia: (1) simple rubber (Hevea brasiliensis) agroforest (> 30 years), (2) mixed coconut (Cocos nucifera) and coffee gardens (Coffea liberica) (> 40 years), (3) mixed betel nut (Areca catechu) and coffee gardens (> 20 years), and (4) oil palm plantation (1 year). We quantified changes in microtopography for each site for greater accuracy of subsidence estimates and tested the effects of nitrogen and phosphorus application. All sites had a fibric type of peat with depths of 50 to > 100 cm. A recently established oil palm had the highest rate of peat subsidence and emission (4.7 cm year-1 or 121 Mg CO2 ha-1 year-1) while the remnant forest had the lowest (1.8 cm year-1 or 40 Mg CO2 ha-1 year-1). Other land-use types subsided by 2-3 cm year-1, emitting 70-85 Mg CO2 ha-1 year-1. Fertilizer application did not have a consistent effect on inferred emissions. Additional emissions in the first years after drainage, despite groundwater tables of 40 cm, were of the order of belowground biomass of peat forest. Despite maintaining higher water tables, smallholder landscapes have CO2 emissions close to, but above, current IPCC defaults.
Collapse
Affiliation(s)
- Ni’matul Khasanah
- Southeast Asia Regional Programme, World Agroforestry Centre (ICRAF), Jl. CIFOR, Situgede, Sindang Barang, Bogor, 16115 Indonesia
- Plant Production Systems, Department of Plant Sciences, Wageningen University and Research, 6708 PB Wageningen, the Netherlands
| | - Meine van Noordwijk
- Southeast Asia Regional Programme, World Agroforestry Centre (ICRAF), Jl. CIFOR, Situgede, Sindang Barang, Bogor, 16115 Indonesia
- Plant Production Systems, Department of Plant Sciences, Wageningen University and Research, 6708 PB Wageningen, the Netherlands
| |
Collapse
|
14
|
Swindles GT, Morris PJ, Whitney B, Galloway JM, Gałka M, Gallego-Sala A, Macumber AL, Mullan D, Smith MW, Amesbury MJ, Roland TP, Sanei H, Patterson RT, Sanderson N, Parry L, Charman DJ, Lopez O, Valderamma E, Watson EJ, Ivanovic RF, Valdes PJ, Turner TE, Lähteenoja O. Ecosystem state shifts during long-term development of an Amazonian peatland. GLOBAL CHANGE BIOLOGY 2018; 24:738-757. [PMID: 29055083 DOI: 10.1111/gcb.13950] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Revised: 09/27/2017] [Accepted: 10/08/2017] [Indexed: 06/07/2023]
Abstract
The most carbon (C)-dense ecosystems of Amazonia are areas characterized by the presence of peatlands. However, Amazonian peatland ecosystems are poorly understood and are threatened by human activities. Here, we present an investigation into long-term ecohydrological controls on C accumulation in an Amazonian peat dome. This site is the oldest peatland yet discovered in Amazonia (peat initiation ca. 8.9 ka BP), and developed in three stages: (i) peat initiated in an abandoned river channel with open water and aquatic plants; (ii) inundated forest swamp; and (iii) raised peat dome (since ca. 3.9 ka BP). Local burning occurred at least three times in the past 4,500 years. Two phases of particularly rapid C accumulation (ca. 6.6-6.1 and ca. 4.9-3.9 ka BP), potentially resulting from increased net primary productivity, were seemingly driven by drier conditions associated with widespread drought events. The association of drought phases with major ecosystem state shifts (open water wetland-forest swamp-peat dome) suggests a potential climatic control on the developmental trajectory of this tropical peatland. A third drought phase centred on ca. 1.8-1.1 ka BP led to markedly reduced C accumulation and potentially a hiatus during the peat dome stage. Our results suggest that future droughts may lead to phases of rapid C accumulation in some inundated tropical peat swamps, although this can lead ultimately to a shift to ombrotrophy and a subsequent return to slower C accumulation. Conversely, in ombrotrophic peat domes, droughts may lead to reduced C accumulation or even net loss of peat. Increased surface wetness at our site in recent decades may reflect a shift towards a wetter climate in western Amazonia. Amazonian peatlands represent important carbon stores and habitats, and are important archives of past climatic and ecological information. They should form key foci for conservation efforts.
Collapse
Affiliation(s)
| | | | - Bronwen Whitney
- Department of Geography and Environmental Science, Northumbria University, Newcastle upon Tyne, UK
| | - Jennifer M Galloway
- Geological Survey of Canada / Commission géologique du Canada, Calgary, Canada & Department of Geoscience, University of Calgary, Calgary, AB, Canada
| | - Mariusz Gałka
- Department of Biogeography and Palaeoecology, Adam Mickiewicz University, Poznań, Poland
| | - Angela Gallego-Sala
- Geography, College of Life and Environmental Sciences, University of Exeter, Exeter, UK
| | - Andrew L Macumber
- School of Natural and Built Environment, Queen's University Belfast, Belfast, UK
| | - Donal Mullan
- School of Natural and Built Environment, Queen's University Belfast, Belfast, UK
| | - Mark W Smith
- School of Geography, University of Leeds, Leeds, UK
| | - Matthew J Amesbury
- Geography, College of Life and Environmental Sciences, University of Exeter, Exeter, UK
| | - Thomas P Roland
- Geography, College of Life and Environmental Sciences, University of Exeter, Exeter, UK
| | - Hamed Sanei
- Geological Survey of Canada / Commission géologique du Canada, Calgary, Canada & Department of Geoscience, University of Calgary, Calgary, AB, Canada
| | - R Timothy Patterson
- Ottawa-Carleton Geoscience Center and Department of Earth Sciences, Carleton University, Ottawa, ON, Canada
| | - Nicole Sanderson
- Geography, College of Life and Environmental Sciences, University of Exeter, Exeter, UK
| | - Lauren Parry
- School of Interdisciplinary Studies, University of Glasgow, Glasgow, UK
| | - Dan J Charman
- Geography, College of Life and Environmental Sciences, University of Exeter, Exeter, UK
| | - Omar Lopez
- Panama Instituto de Investigaciones Científicas y Servicios de Alta Tecnología, Panamá & Smithsonian Tropical Research Institute, Panama City, Panama
| | - Elvis Valderamma
- Facultad de Biologia, Universidad Nacional de la Amazonia Peruana, Pevas 5ta cdra, Iquitos, Peru
| | | | - Ruza F Ivanovic
- School of Earth and Environment, University of Leeds, Leeds, UK
| | - Paul J Valdes
- School of Geographical Sciences, University of Bristol, Bristol, UK
| | | | - Outi Lähteenoja
- School of Life Sciences, Arizona State University, Tempe, AZ, USA
| |
Collapse
|
15
|
Warren M, Hergoualc'h K, Kauffman JB, Murdiyarso D, Kolka R. An appraisal of Indonesia's immense peat carbon stock using national peatland maps: uncertainties and potential losses from conversion. CARBON BALANCE AND MANAGEMENT 2017; 12:12. [PMID: 28527145 PMCID: PMC5438333 DOI: 10.1186/s13021-017-0080-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Accepted: 05/09/2017] [Indexed: 06/07/2023]
Abstract
BACKGROUND A large proportion of the world's tropical peatlands occur in Indonesia where rapid conversion and associated losses of carbon, biodiversity and ecosystem services have brought peatland management to the forefront of Indonesia's climate mitigation efforts. We evaluated peat volume from two commonly referenced maps of peat distribution and depth published by Wetlands International (WI) and the Indonesian Ministry of Agriculture (MoA), and used regionally specific values of carbon density to calculate carbon stocks. RESULTS Peatland extent and volume published in the MoA maps are lower than those in the WI maps, resulting in lower estimates of carbon storage. We estimate Indonesia's total peat carbon store to be within 13.6 GtC (the low MoA map estimate) and 40.5 GtC (the high WI map estimate) with a best estimate of 28.1 GtC: the midpoint of medium carbon stock estimates derived from WI (30.8 GtC) and MoA (25.3 GtC) maps. This estimate is about half of previous assessments which used an assumed average value of peat thickness for all Indonesian peatlands, and revises the current global tropical peat carbon pool to 75 GtC. Yet, these results do not diminish the significance of Indonesia's peatlands, which store an estimated 30% more carbon than the biomass of all Indonesian forests. The largest discrepancy between maps is for the Papua province, which accounts for 62-71% of the overall differences in peat area, volume and carbon storage. According to the MoA map, 80% of Indonesian peatlands are <300 cm thick and thus vulnerable to conversion outside of protected areas according to environmental regulations. The carbon contained in these shallower peatlands is conservatively estimated to be 10.6 GtC, equivalent to 42% of Indonesia's total peat carbon and about 12 years of global emissions from land use change at current rates. CONCLUSIONS Considering the high uncertainties in peatland extent, volume and carbon storage revealed in this assessment of current maps, a systematic revision of Indonesia's peat maps to produce a single geospatial reference that is universally accepted would improve national peat carbon storage estimates and greatly benefit carbon cycle research, land use management and spatial planning.
Collapse
Affiliation(s)
- Matthew Warren
- USDA Forest Service, Northern Research Station, 271 Mast Rd., Durham, NH, 03824, USA.
| | - 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
| | - J Boone Kauffman
- Center for International Forestry Research, Jl. CIFOR, Situgede, Bogor, 16115, Indonesia
- Department of Fisheries and Wildlife, Oregon State University, 104 Nash Hall, Corvallis, OR, 97331, USA
| | - Daniel Murdiyarso
- Center for International Forestry Research, Jl. CIFOR, Situgede, Bogor, 16115, Indonesia
- Department of Geophysics and Meteorology, Bogor Agricultural University, Kampus Darmaga, Bogor, 16680, Indonesia
| | - Randall Kolka
- USDA Forest Service, Northern Research Station, 1831 Hwy 169 East, Grand Rapids, MN, 55744, USA
| |
Collapse
|
16
|
Zhou X, Zhang Z, Tian L, Li X, Tian C. Microbial communities in peatlands along a chronosequence on the Sanjiang Plain, China. Sci Rep 2017; 7:9567. [PMID: 28852134 PMCID: PMC5575048 DOI: 10.1038/s41598-017-10436-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Accepted: 08/09/2017] [Indexed: 02/01/2023] Open
Abstract
Microbial communities play crucial roles in the global carbon cycle, particularly in peatland ecosystems under climate change. The peatlands of the Sanjiang Plain could be highly vulnerable to global warming because they are mainly located at the southern limit of northern peatlands. In this study, the alpha diversity and composition of bacterial communities in three different minerotrophic fens along a chronosequence were investigated. We captured a rich microbial community that included many rare operational taxonomic units (OTUs) but was dominated by a few bacterial classes that have frequently been detected in other peatland ecosystems. Notably, a large diversity of methanotrophs affiliated with Alpha- and Gammaproteobacteria was also detected. Bacterial alpha diversity and composition varied as a function of peat depth and its associated physical-chemical properties, such as total carbon, total nitrogen, pH and bulk density. We also found that bacterial community turnover (beta diversity) to be significantly correlated with soil age, whereas bacterial alpha diversity was not.
Collapse
Affiliation(s)
- Xue Zhou
- Key Laboratory of Mollisols Agroecology, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun, 130102, China
| | - Zhenqing Zhang
- Key Laboratory of Wetland Ecology and Environment, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun, 130102, China
| | - Lei Tian
- Key Laboratory of Mollisols Agroecology, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun, 130102, China.,University of the Chinese Academy of Sciences, Beijing, 100049, China
| | - Xiujun Li
- Key Laboratory of Mollisols Agroecology, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun, 130102, China
| | - Chunjie Tian
- Key Laboratory of Mollisols Agroecology, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun, 130102, China.
| |
Collapse
|
17
|
How temporal patterns in rainfall determine the geomorphology and carbon fluxes of tropical peatlands. Proc Natl Acad Sci U S A 2017; 114:E5187-E5196. [PMID: 28607068 DOI: 10.1073/pnas.1701090114] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Tropical peatlands now emit hundreds of megatons of carbon dioxide per year because of human disruption of the feedbacks that link peat accumulation and groundwater hydrology. However, no quantitative theory has existed for how patterns of carbon storage and release accompanying growth and subsidence of tropical peatlands are affected by climate and disturbance. Using comprehensive data from a pristine peatland in Brunei Darussalam, we show how rainfall and groundwater flow determine a shape parameter (the Laplacian of the peat surface elevation) that specifies, under a given rainfall regime, the ultimate, stable morphology, and hence carbon storage, of a tropical peatland within a network of rivers or canals. We find that peatlands reach their ultimate shape first at the edges of peat domes where they are bounded by rivers, so that the rate of carbon uptake accompanying their growth is proportional to the area of the still-growing dome interior. We use this model to study how tropical peatland carbon storage and fluxes are controlled by changes in climate, sea level, and drainage networks. We find that fluctuations in net precipitation on timescales from hours to years can reduce long-term peat accumulation. Our mathematical and numerical models can be used to predict long-term effects of changes in temporal rainfall patterns and drainage networks on tropical peatland geomorphology and carbon storage.
Collapse
|
18
|
Warren M, Frolking S, Dai Z, Kurnianto S. Impacts of land use, restoration, and climate change on tropical peat carbon stocks in the twenty-first century: implications for climate mitigation. MITIGATION AND ADAPTATION STRATEGIES FOR GLOBAL CHANGE 2017; 22:1041-1061. [PMID: 30093822 PMCID: PMC6054005 DOI: 10.1007/s11027-016-9712-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Accepted: 03/20/2016] [Indexed: 05/13/2023]
Abstract
The climate mitigation potential of tropical peatlands has gained increased attention as Southeast Asian peatlands are being deforested, drained and burned at very high rates, causing globally significant carbon dioxide (CO2) emissions to the atmosphere. We used a process-based dynamic tropical peatland model to explore peat carbon (C) dynamics of several management scenarios within the context of simulated twenty-first century climate change. Simulations of all scenarios with land use, including restoration, indicated net C losses over the twenty-first century ranging from 10 to 100 % of pre-disturbance values. Fire can be the dominant C-loss pathway, particularly in the drier climate scenario we tested. Simulated 100 years of oil palm (Elaeis guineensis) cultivation with an initial prescribed burn resulted in 2400-3000 Mg CO2 ha-1 total emissions. Simulated restoration following one 25-year oil palm rotation reduced total emissions to 440-1200 Mg CO2 ha-1, depending on climate. These results suggest that even under a very optimistic scenario of hydrological and forest restoration and the wettest climate regime, only about one third of the peat C lost to the atmosphere from 25 years of oil palm cultivation can be recovered in the following 75 years if the site is restored. Emissions from a simulated land degradation scenario were most sensitive to climate, with total emissions ranging from 230 to 10,600 Mg CO2 ha-1 over 100 years for the wettest and driest dry season scenarios, respectively. The large difference was driven by increased fire probability. Therefore, peat fire suppression is an effective management tool to maintain tropical peatland C stocks in the near term and should be a high priority for climate mitigation efforts. In total, we estimate emissions from current cleared peatlands and peatlands converted to oil palm in Southeast Asia to be 8.7 Gt CO2 over 100 years with a moderate twenty-first century climate. These emissions could be minimized by effective fire suppression and hydrological restoration.
Collapse
Affiliation(s)
- Matthew Warren
- USDA Forest Service, Northern Research Station, 271 Mast Rd., Durham, NH 03824 USA
| | - Steve Frolking
- Institute for the Study of Earth, Oceans, and Space, University of New Hampshire, Durham, NH USA
| | - Zhaohua Dai
- Institute for the Study of Earth, Oceans, and Space, University of New Hampshire, Durham, NH USA
| | - Sofyan Kurnianto
- Department of Fisheries and Wildlife, Oregon State University, Corvallis, OR USA
| |
Collapse
|
19
|
|
20
|
Fire carbon emissions over maritime southeast Asia in 2015 largest since 1997. Sci Rep 2016; 6:26886. [PMID: 27241616 PMCID: PMC4886261 DOI: 10.1038/srep26886] [Citation(s) in RCA: 210] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Accepted: 05/09/2016] [Indexed: 11/09/2022] Open
Abstract
In September and October 2015 widespread forest and peatland fires burned over large parts of maritime southeast Asia, most notably Indonesia, releasing large amounts of terrestrially-stored carbon into the atmosphere, primarily in the form of CO2, CO and CH4. With a mean emission rate of 11.3 Tg CO2 per day during Sept-Oct 2015, emissions from these fires exceeded the fossil fuel CO2 release rate of the European Union (EU28) (8.9 Tg CO2 per day). Although seasonal fires are a frequent occurrence in the human modified landscapes found in Indonesia, the extent of the 2015 fires was greatly inflated by an extended drought period associated with a strong El Niño. We estimate carbon emissions from the 2015 fires to be the largest seen in maritime southeast Asia since those associated with the record breaking El Niño of 1997. Compared to that event, a much better constrained regional total carbon emission estimate can be made for the 2015 fires through the use of present-day satellite observations of the fire's radiative power output and atmospheric CO concentrations, processed using the modelling and assimilation framework of the Copernicus Atmosphere Monitoring Service (CAMS) and combined with unique in situ smoke measurements made on Kalimantan.
Collapse
|
21
|
Abrams JF, Hohn S, Rixen T, Baum A, Merico A. The impact of Indonesian peatland degradation on downstream marine ecosystems and the global carbon cycle. GLOBAL CHANGE BIOLOGY 2016; 22:325-337. [PMID: 26416553 DOI: 10.1111/gcb.13108] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Accepted: 09/10/2015] [Indexed: 06/05/2023]
Abstract
Tropical peatlands are among the most space-efficient stores of carbon on Earth containing approximately 89 Gt C. Of this, 57 Gt (65%) are stored in Indonesian peatlands. Large-scale exploitation of land, including deforestation and drainage for the establishment of oil palm plantations, is changing the carbon balance of Indonesian peatlands, turning them from a natural sink to a source via outgassing of CO2 to the atmosphere and leakage of dissolved organic carbon (DOC) into the coastal ocean. The impacts of this perturbation to the coastal environment and at the global scale are largely unknown. Here, we evaluate the downstream effects of released Indonesian peat carbon on coastal ecosystems and on the global carbon cycle. We use a biogeochemical box model in combination with novel and literature observations to investigate the impact of different carbon emission scenarios on the combined ocean-atmosphere system. The release of all carbon stored in the Indonesian peat pool, considered as a worst-case scenario, will increase atmospheric pCO2 by 8 ppm to 15 ppm within the next 200 years. The expected impact on the Java Sea ecosystems is most significant on the short term (over a few hundred years) and is characterized by an increase of 3.3% in phytoplankton, 32% in seagrass biomass, and 5% decrease in coral biomass. On the long term, however, the coastal ecosystems will recover to reach near pre-excursion conditions. Our results suggest that the ultimate fate of the peat carbon is in the deep ocean with 69% of it landing in the deep DIC pool after 1000 years, but the effects on the global ocean carbonate chemistry will be marginal.
Collapse
Affiliation(s)
- Jesse F Abrams
- Systems Ecology, Leibniz Center for Tropical Marine Ecology, Fahrenheitstrasse 6, 28359, Bremen, Germany
- Faculty of Physics & Earth Sciences, Jacobs University Bremen, Campus Ring 1, 28759, Bremen, Germany
| | - Sönke Hohn
- Systems Ecology, Leibniz Center for Tropical Marine Ecology, Fahrenheitstrasse 6, 28359, Bremen, Germany
| | - Tim Rixen
- Carbon and Nutrient Cycling, Leibniz Center for Tropical Marine Ecology, Fahrenheitstrasse 6, 28359, Bremen, Germany
| | - Antje Baum
- Carbon and Nutrient Cycling, Leibniz Center for Tropical Marine Ecology, Fahrenheitstrasse 6, 28359, Bremen, Germany
| | - Agostino Merico
- Systems Ecology, Leibniz Center for Tropical Marine Ecology, Fahrenheitstrasse 6, 28359, Bremen, Germany
- Faculty of Physics & Earth Sciences, Jacobs University Bremen, Campus Ring 1, 28759, Bremen, Germany
| |
Collapse
|