Subsidence and carbon loss in drained tropical peatlands
Tóm tắt
Abstract. Conversion of tropical peatlands to agriculture leads to a release of carbon from previously stable, long-term storage, resulting in land subsidence that can be a surrogate measure of CO2 emissions to the atmosphere. We present an analysis of recent large-scale subsidence monitoring studies in Acacia and oil palm plantations on peatland in SE Asia, and compare the findings with previous studies. Subsidence in the first 5 yr after drainage was found to be 142 cm, of which 75 cm occurred in the first year. After 5 yr, the subsidence rate in both plantation types, at average water table depths of 0.7 m, remained constant at around 5 cm yr−1. The results confirm that primary consolidation contributed substantially to total subsidence only in the first year after drainage, that secondary consolidation was negligible, and that the amount of compaction was also much reduced within 5 yr. Over 5 yr after drainage, 75 % of cumulative subsidence was caused by peat oxidation, and after 18 yr this was 92 %. The average rate of carbon loss over the first 5 yr was 178 t CO2eq ha−1 yr−1, which reduced to 73 t CO2eq ha−1 yr−1 over subsequent years, potentially resulting in an average loss of 100 t CO2eq ha−1 yr−1 over 25 yr. Part of the observed range in subsidence and carbon loss values is explained by differences in water table depth, but vegetation cover and other factors such as addition of fertilizers also influence peat oxidation. A relationship with groundwater table depth shows that subsidence and carbon loss are still considerable even at the highest water levels theoretically possible in plantations. This implies that improved plantation water management will reduce these impacts by 20 % at most, relative to current conditions, and that high rates of carbon loss and land subsidence are inevitable consequences of conversion of forested tropical peatlands to other land uses.
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Alkhatib, M., Jennerjahn, T. C., and Samiaji, J.: Biogeochemistry of the Dumai river estuary, Sumatra, Indonesia, a tropical blackwater river, Limnol. Oceanogr., 52, 2410–2417, 2007.
Andriesse, J. P.: Nature and management of tropical peat soils, FAO Soils Bulletin, 59, 248 pp., 1988.
Anshari, G. Z., Afifudin, M., Nuriman, M., Gusmayanti, E., Arianie, L., Susana, R., Nusantara, R. W., Sugardjito, J., and Rafiastanto, A.: Drainage and land use impacts on changes in selected peat properties and peat degradation in West Kalimantan Province, Indonesia, Biogeosciences, 7, 3403–3419, https://doi.org/10.5194/bg-7-3403-2010, 2010.
Asner, G. P.: Painting the world REDD: addressing scientific barriers to monitoring emissions from tropical forests, Environ. Res. Lett., 6, 021002, https://doi.org/10.1088/1748-9326/6/2/021002, 2011.
Baum, A., Rixen, T., and Samiaji, J.: Relevance of peat draining rivers in central Sumatra for the riverine input of dissolved organic carbon into the ocean, Estuar. Coast. Shelf S., 73, 563–570, 2007.
Berg, B.: Litter decomposition and organic matter turnover in northern forest soils, Forest Ecol. Manag., 133, 13–22, 2000.
Berg, B. and Laskowski, R.: Litter decomposition: a guide to carbon and nutrient turnover, Woods Hole Oceanographic Institute, Massachusetts, USA, 449 pp., 2006.
Berry, P. L.: Application of consolidation theory for peat to the design of a reclamation scheme by preloading, Q. J. Eng. Geol., 16, 103–112, 1983.
Brady, M. A.: Organic matter dynamics of coastal peat deposits in Sumatra, Indonesia, Ph.D. thesis, University of British Columbia, Vancouver, 258 pp., 1997.
Couwenberg, J., Dommain, R., and Joosten, H.: Greenhouse gas fluxes from tropical peatlands in southeast Asia, Global Change Biol., 16, 1715–1732, 2010.
Deverel, S. J. and Rojstaczer, D. A.: Subsidence of agricultural lands in the Sacramento-San Joaquin Delta, California: Role of aqueous and gaseous carbon fluxes, Water Resour. Res., 32, 2359–2367, 1996.
Deverel, S. J. and Leighton, D. A: Historic, recent, and future subsidence, Sacramento-San Joaquin Delta, California, USA, San Francisco Estuary and Watershed Science, 8, 23 pp., 2010.
DID Malaysia: Western Jahore integrated Agricultural Development Project, Peat Soil Management Study, Department of Irrigation and Drainage, Kuala Lumpur and Land and Water Research Group (LAWOO), Wageningen, 100 pp., 1996.
DID Sarawak: Water management guidelines for agricultural development in lowland peat swamps of Sarawak, Report of the Department of Irrigation and Drainage, Sarawak, Malaysia, 78 pp., 2001.
Dradjad, M., Soekodarmodjo, S., Hidayat, M. S., and Nitisapto, M.: Subsidence of peat soils the tidal swamplands of Barambai, South Kalimantan, Jurnal Ilmu Tanah dan Lingkungan, 4, 32–40, 2003.
Drexler, J. Z., DeFontaine, C. S., and Deverel, S. J.: The legacy of wetland drainage on the remaining peat in the Sacramento-San Joaquin Delta, Journal of the Society of Wetlands Scientists, 29, 372–386, 2009.
Driessen, P. M. and Soepraptohardjo, M.: Soils for agricultural expansion in Indonesia, Publication of Soil Research Institute, Bull. 1, Bogor, Indonesia, 41–63, 1974.
Ewing, J. M. and Vepraskas, M. J.: Estimating primary and secondary subsidence in an organic soil 15, 20, and 30 yr after drainage, WETLANDS, 26, 119–130, 2006.
Gambolati, G., Putti, M., Teatini, P., and Stori, G. G.: Subsidence due to peat oxidation and its impact on drainage infrastructure in a farmland catchment south of Venice Lagoon, RMZ – Materials and Geoenvironment, 50, 125–128, 2003.
Hambright, K. D. and Zohary, T.: Lakes Hula and Agmon: destruction and creation of wetland ecosystems in northern Israel, Wetl. Ecol. Manag., 6, 83–89, 1998.
Hergoualc'h, K. and Verchot, L. V.: Stocks and fluxes of carbon associated with land use change in Southeast Asian tropical peatlands: A review, Global Biogeochem. Cy., 25, GB2001, https://doi.org/10.1029/2009GB003718, 2011.
Hirano, T., Jauhiainen, J., Inoue, T., and Takahashi, H.: Controls on the carbon balance of tropical peatlands, Ecosystems, 12, 873–887, 2009.
Hooijer, A.: Hydrology of tropical wetland forests: recent research results from Sarawak peat swamps, in: Forests-Water-People in the Humid Tropics, edited by: Bonell, M. and Bruijnzeel, L. A., Cambridge University Press, 447–461, 2005.
Hooijer, A., Silvius, M., Wösten, H., and Page, S.: PEAT-CO2 Assessment of CO2 emissions from drained peatlands in SE Asia, Delft Hydraulics report Q3943, 36 pp., 2006.
Hooijer, A., Page, S., and Jauhiainen, J.: Kampar Peninsula Science Based Management Support Project, Interim Summary Report 2007–2008; first findings on hydrology, water management, carbon emissions and landscape ecology, Deltares report, 37 pp., 2009.
Hooijer, A., Page, S., Canadell, J. G., Silvius, M., Kwadijk, J., Wösten, H., and Jauhiainen, J.: Current and future CO2 emissions from drained peatlands in Southeast Asia, Biogeosciences, 7, 1505–1514, https://doi.org/10.5194/bg-7-1505-2010, 2010.
Hutchinson, J. N.: The record of peat wastage in the East Anglian Fenlands at Holme Post, 1848–1978 AD, J. Ecol., 68, 229–49, 1980.
Jauhiainen, J., Takahashi, H., Heikkinen, J. E. P., Martikainen, P. J., and Vasander, H.: Carbon fluxes from a tropical peat swamp forest floor, Glob. Change Biol., 11, 1788–1797, 2005.
Jauhiainen, J., Limin, S., Silvennoinen, H., and Vasander, H.: Carbon dioxide and methane fluxes in drainage affected tropical peat before and after hydrological restoration, Ecology, 89, 3503–3514, 2008.
Jauhiainen, J., Hooijer, A., and Page, S. E.: Carbon dioxide emissions from an Acacia plantation on peatland in Sumatra, Indonesia, Biogeosciences, 9, 617–630, https://doi.org/10.5194/bg-9-617-2012, 2012.
Koh, L. P., Miettinen, J., Liew, S. C., and Ghazoul, J.: Remotely sensed evidence of tropical peatland conversion to oil palm, Proc. Natl. Acad. Sci. USA, 108, 5127–5132, 2011.
Kool, D. M., Buurman, P., and Hoekman, D. H.: Oxidation and compaction of a collapsed peat dome in Central Kalimantan, Geoderma, 137, 217–225, 2006.
Leifeld, J., Müller, M., and Fuhrer, J.: Peatland subsidence and carbon loss from drained temperate fens, Soil Use Manage., 27, 170–176, 2011.
Malhi, Y.: The carbon balance of tropical forest regions, 1990–2005, Environmental Sustainability, 2, 237–244, 2010.
Melling, L., Hatano, R., and Goh, K. J.: Soil CO2 flux from three ecosystems in tropical peatland of Sarawak, Malaysia, Tellus B, 57, 1–11, 2005.
Mesri, G. and Aljouni, M.: Engineering properties of fibrous peats, J. Geotech. Geoenviron., 133, 850–866, 2007.
Miettinen, J. and Liew, S. C.: Degradation and development of peatlands in Peninsular Malaysia and in the islands of Sumatra and Borneo since 1990, Land Degrad. Dev., 21, 285–296, 2010.
Miettinen, J., Hooijer, A., Tollenaar, D., Page, S., Malins, C. Chenghua Shi, C., and Soo Chin Liew, S. C.: Historical analysis and projection of oil palm plantation expansion on peatland in SE Asia, White Paper no. 17 of the International Council of Clean Transportation, Washington, 2012.
Mohammed, A. T., Othman, H., Darus, F. M., Harun, M. H., Zambri, M. P., Bakar, I. A., and Wösten, H.: Best management practices on peat: water management in relation to peat subsidence and estimation of CO2 emission in Sessang, Sarawak, Proceedings of the PIPOC 2009 International Palm Oil Congress (Agriculture, Biotechnology and Sustainability), 2009.
Moore, S., Gauci, V., Evans, C. D., and Page, S. E.: Fluvial organic carbon losses from a Bornean blackwater river, Biogeosciences, 8, 901–909, https://doi.org/10.5194/bg-8-901-2011, 2011.
Murayama, S. and Bakar, Z. A.: Decomposition of tropical peat soils, estimation of in situ decomposition by measurement of CO2 flux, JARQ-JPN. Agr. Res. Q., 30, 153–158, 1996.
Murdiyarso, D., Hergoualch, K., and Verchot, L. V.: Opportunities for reducing greenhouse gas emissions in tropical peatlands, P. Natl. Acad. Sci. USA, 107, 19655–19660, 2010.
Neller, J. R.: Oxidation loss of lowmoor peat in fields with different water tables, Soil Sci., 58, 195–204, 1944.
Page, S. E., Siegert, F., Rieley, J. O., Boehm, H. D. V., Jaya, A., and Limin, S.: The amount of carbon released from peat and forest fires in Indonesia during 1997, Nature, 420, 61–65, 2002.
Page, S. E., Rieley, J. O., and Banks, C. J.: Global and regional importance of the tropical peatland carbon pool, Global Change Biol., 17, 798–818, 2011.
Schothorst, C. J.: Subsidence of low moor peat soils in the Western Netherlands, Geoderma, 17, 265–291, 1977.
Stephens, J. C. and Speir, W. H.: Subsidence of organic soils in the USA, IAHS-AIHS Publication, 89, 523–534, 1969.
Stephens, J. C., Allen, L. H., and Chen, E.: Organic soil subsidence, Geological Society of America, Reviews in Engineering Geology, Vol. VI, 107–122, 1984.
Suhardjo, H. and Widjaja-Adhi, I. P. G.: Chemical characteristics of the upper 30 cm of peat soils from Riau, Sumatra (Indonesia), in: Final Report, Agricultural Technical Assistance Programme (Indonesia – The Netherlands) 1974–1977, 74–92, Lembaga Penelitian Tanah, Bogor, Indonesia, 1977.
Vernimmen, R. R. E., Hooijer, A., Mamenun, Aldrian, E., and van Dijk, A. I. J. M.: Evaluation and bias correction of satellite rainfall data for drought monitoring in Indonesia, Hydrol. Earth Syst. Sci., 16, 133–146, https://doi.org/10.5194/hess-16-133-2012, 2012.
Volk, B. G.: Everglades histosol subsidence – Part 1: CO2 evolution as affected by soil type, temperature and moisture, Proceedings Soil and Crop Science Society of Florida, 32, 132–135, 1973.
Wösten, J. H. M., Ismail, A. B., and van Wijk, A. L. M.: Peat subsidence and its practical implications: a case study in Malaysia, Geoderma, 78, 25–36, 1997.
Wösten, J. H. M. and Ritzema, H. P.: Land and water management options for peatland development in Sarawak, Malaysia, International Peat Journal, 11, 59–66, 2001.