Mangrove forests are important coastal ecosystems that support the productivity of the coastal zone within the tropics and subtropics. Mangrove provides multiple ecosystem services including the biogeochemical function as carbon storage. Mangrove sequesters carbon within standing biomass and soils and gives significant contribution to coastal sediment carbon storage up to 24 Tg C year-1 1. The removal or conversion of mangrove to other land use could have significant consequences for marine ecosystem primary production and contribute to substantial CO2 emission, ie greenhouse gas (GHG), to the atmosphere 2,3.
The potential CO2 emission from mangrove loss and the capacity of mangrove forests to store carbon show the crucial role of mangrove in climate change. Mangrove conservation and restoration is the key action to preserve the coastal carbon sink habitats, so called ‘blue’ carbon. Indonesia, the home of the largest mangrove area in the world, is facing rapid mangrove degradation 4, 5, thus mangrove conservation and restoration might be complex issues in this region. The efforts in preserving mangrove forests need multiple approaches that encompass multisectoral and spatial scales. One way to place the important role of mangroves in reducing impacts of global climate change is by stressing the value of mangrove ecosystem service as carbon storage and applied it in carbon finance mechanism, such as REDD+.
Estimating carbon stock and GHG emissions from mangroves
Carbon finance mechanism for forests has been established in Indonesia as the government aims to achieve GHG emission reduction targets. The Ministry of Environment and Forestry (MEF) has developed several approaches used to estimate the GHG emission from forests as one of the land-based sectors. However, unlike dryland forests, the information of the carbon stored and emitted from Indonesia mangrove forests is still lacking. This information, indeed, is required to improve the existing estimates of GHG emission from forests that will support sound policy decision and forest management for climate change mitigation and adaptation.
There are many opportunities to introduce science into policy in addressing climate change adaptation and mitigation related to mangrove ecosystem. Large-scale emissions from mangrove forest degradation and mangrove conversion are ongoing but currently not well accounted for in national GHG inventory. I highlight the importance of strengthening GHG inventory by further involvement of mangrove carbon into carbon forest accounting. GHG emission from mangroves can be estimated from carbon stock changes in carbon pools that comprise of several compartments (ie. above and below-ground biomass, litter, deadwood and soils) 6. Carbon stocks and emission from mangrove forests have been well studied recently, but uncertainty may occur as mangrove varies greatly in structure, soil types and environmental condition. The challenge also comes from the facts that standardized methods and protocols of mangrove carbon assessment remain in area of ongoing research.
The MEF is continuously developing approach and systems for improved estimates of annual emission and removals from the forests, however this effort is not a sole route that could strengthen mangrove carbon accounting. Increased cooperation for monitoring, reporting and verification (MRV) emission reductions is needed to bring together scientists and policy makers develop a scientific based policy of carbon accounting. During the ASEAN-US Science and Technology Fellowship period, I share knowledge on MRV emission from the forests and the national carbon accounting (NCA) with the researchers and policy makers from the MEF, as well as other research institutions that have conducted mangrove carbon assessment. This aims to make recommendation that could initiate a consensus to fulfill knowledge gaps in GHG inventories for mangrove forests at national level.
Mitigating climate change through mangrove restoration in Indonesia
The importance of mangrove to global climate change is motivating mangrove conservation and restoration around the globe. As the United Nation Framework Convention on Climate Change (UNFCCC) has provided a mechanism for financing forest restoration and conservation and management of forests, many initiatives in mangrove conservation and restoration have been established that lead to voluntary carbon markets with the primary aims to enhance the carbon stocks and avoid CO2 emission from the forests 7. Since the results of restoration activities may vary within the environmental condition and management regime, assessment of the efficiency of restoration activities in different scenarios is necessary. Thus, our focus should be extended from developing the regulatory framework of carbon accounting to improving management and policy in mangrove restoration as forest carbon stock enhancement. This holistic effort would increase the benefit of mangrove ecosystem services for communities.
About the Author:
Frida Sidik is currently one of the ASEAN-US Science and Technology Fellows 2016 working on climate change. She has BSc from the University of Sydney, Australia and MSc from the University of Warwick, United Kingdom. She obtained her PhD in Marine Sciences from the University of Queensland with focus on mangrove ecology. She has been working as researcher of the Ministry of Marine Affairs and Fisheries and is currently based at the Ministry of Environment and Forestry for her fellowship program. Under the ASEAN-U.S. S&T Fellowship, Frida is developing science-based decision in improving wetland ecosystem conservation and management with potential climate mitigation and adaptation.
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2 Pendleton, L., Donato, D.C., Murray, B.C., Crooks, S., Jenkins, W.A., Sifleet, S., Craft, C., Fourqurean, J.W., Kauffman, J.B., Marbà, N., Megonigal, P., Pidgeon, E., Herr, D., Gordon, D. and Baldera, A. (2012) Estimating global ‘blue carbon’ emissions from conversion and degradation of vegetated coastal ecosystems. PLoS ONE, 7, e43542 doi:10.1371/journal.pone.0043542
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5 Friess, D.A. and Webb, E.L., (2014). Variability in mangrove change estimates and implications for the assessment of ecosystem service provision. Global ecology and biogeography, 23(7), pp.715-725.
6 Kauffman, J.B. and Donato, D.C. (2012) Protocols for the measurement, monitoring and reporting of structure, biomass and carbon stocks in mangrove forests. Working Paper 86. CIFOR, Bogor, Indonesia.
7 Crooks S, Herr D, Laffoley D, Tamelander J, and Vandever J. (2011) Regulating Climate Change Through Restoration and Management of Coastal Wetlands and Near-shore Marine Ecosystems: Mitigation Potential and Policy Opportunities. World Bank, IUCN, ESA PWA, Washington, Gland, San Francisco.