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Hooijer A, Vernimmen R, Mulyadi D, Triantomo V, Hamdani, Lampela M, Agusti R, Page SE, Doloksaribu J, Setiawan I, Suratmanto B, Swarup S. Benefits of tropical peatland rewetting for subsidence reduction and forest regrowth: results from a large-scale restoration trial. Sci Rep 2024; 14:10721. [PMID: 38729962 PMCID: PMC11087581 DOI: 10.1038/s41598-024-60462-3] [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: 12/03/2023] [Accepted: 04/23/2024] [Indexed: 05/12/2024] Open
Abstract
Drainage and deforestation of tropical peat swamp forests (PSF) in Southeast Asia cause carbon emissions and biodiversity loss of global concern. Restoration efforts to mitigate these impacts usually involve peatland rewetting by blocking canals. However, there have been no studies to date of the optimal rewetting approach that will reduce carbon emission whilst also promoting PSF regeneration. Here we present results of a large-scale restoration trial in Sumatra (Indonesia), monitored for 7.5 years. Water levels in a former plantation were raised over an area of 4800 ha by constructing 257 compacted peat dams in canals. We find peat surface subsidence rates in the rewetted restoration area and adjoining PSF to be halved where water tables were raised from ~ - 0.6 m to ~ - 0.3 m, demonstrating the success of rewetting in reducing carbon emission. A total of 57 native PSF tree species were found to spontaneously grow in the most rewetted conditions and in high densities, indicating that forest regrowth is underway. Based on our findings we propose that an effective PSF restoration strategy should follow stepwise rewetting to achieve substantial carbon emission reduction alongside unassisted regrowth of PSF, thereby enabling the peat, forest and canal vegetation to establish a new nature-based ecosystem balance.
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Affiliation(s)
- A Hooijer
- Data for Sustainability, 4571 AK, Axel, The Netherlands.
- NUS Environmental Research Institute (NERI), National University of Singapore, 1 Engineering Drive, Singapore, 117411, Singapore.
| | - R Vernimmen
- Data for Sustainability, 4571 AK, Axel, The Netherlands
- NUS Environmental Research Institute (NERI), National University of Singapore, 1 Engineering Drive, Singapore, 117411, Singapore
| | - D Mulyadi
- PT Alas Rawa Khatulistiwa, Jl. M.H. Thamrin Kav. 28-30, Jakarta, 10350, Indonesia
| | - V Triantomo
- PT Alas Rawa Khatulistiwa, Jl. M.H. Thamrin Kav. 28-30, Jakarta, 10350, Indonesia
| | - Hamdani
- PT Alas Rawa Khatulistiwa, Jl. M.H. Thamrin Kav. 28-30, Jakarta, 10350, Indonesia
| | - M Lampela
- Geological Survey of Finland, Vuorimiehentie 5, 02151, Espoo, Finland
| | - R Agusti
- NUS Environmental Research Institute (NERI), National University of Singapore, 1 Engineering Drive, Singapore, 117411, Singapore
- Tumbuhan Asli Nusantara, BTN Korpri Blok C1 No. 96, Kawatuna, Mantikulore, Palu, 94233, Indonesia
| | - S E Page
- School of Geography, Geology and the Environment, University of Leicester, Leicester, LE1 7RH, UK
| | - J Doloksaribu
- Asia Pulp and Paper Group, Sinar Mas Land Plaza, Jakarta, 10350, Indonesia
| | - I Setiawan
- Asia Pulp and Paper Group, Sinar Mas Land Plaza, Jakarta, 10350, Indonesia
| | - B Suratmanto
- Asia Pulp and Paper Group, Sinar Mas Land Plaza, Jakarta, 10350, Indonesia
| | - S Swarup
- NUS Environmental Research Institute (NERI), National University of Singapore, 1 Engineering Drive, Singapore, 117411, Singapore
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Langston JD, Mendham DS, Sakuntaladewi N. Dreaming of wetscapes: Waking to the realities of restoration. AMBIO 2024; 53:351-354. [PMID: 38064114 PMCID: PMC10774500 DOI: 10.1007/s13280-023-01956-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Revised: 10/12/2023] [Accepted: 10/16/2023] [Indexed: 01/09/2024]
Affiliation(s)
- James Douglas Langston
- CSIRO Environment, Building 101, Clunies Ross Street, Black Mountain, ACT, 2601, Australia.
| | - Daniel Steven Mendham
- CSIRO Environment, Building 101, Clunies Ross Street, Black Mountain, ACT, 2601, Australia
| | - Niken Sakuntaladewi
- Research Center for Ecology and Ethnobiology, National Research and Innovation Agency (BRIN), Jalan Raya Jakarta-Bogor km 46, Cibinong, 16911, Indonesia
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Mayer M, Baltensweiler A, James J, Rigling A, Hagedorn F. A global synthesis and conceptualization of the magnitude and duration of soil carbon losses in response to forest disturbances. GLOBAL ECOLOGY AND BIOGEOGRAPHY : A JOURNAL OF MACROECOLOGY 2024; 33:141-150. [PMID: 38516344 PMCID: PMC10953364 DOI: 10.1111/geb.13779] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 10/06/2023] [Accepted: 10/13/2023] [Indexed: 03/23/2024]
Abstract
Aim Forest disturbances are increasing around the globe due to changes in climate and management, deteriorating forests' carbon sink strength. Estimates of global forest carbon budgets account for losses of plant biomass but often neglect the effects of disturbances on soil organic carbon (SOC). Here, we aimed to quantify and conceptualize SOC losses in response to different disturbance agents on a global scale. Location Global. Time Period 1983-2022. Major Taxa Studied Forest soils. Methods We conducted a comprehensive global analysis of the effects of harvesting, wildfires, windstorms and insect infestations on forest SOC stocks in the surface organic layer and top mineral soil, synthesizing 927 paired observations from 151 existing field studies worldwide. We further used global mapping to assess potential SOC losses upon disturbance. Results We found that both natural and anthropogenic forest disturbances can cause large SOC losses up to 60 Mg ha-1. On average, the largest SOC losses were found after wildfires, followed by disturbances from windstorms, harvests and insects. However, initial carbon stock size, rather than disturbance agent, had the strongest influence on the magnitude of SOC losses. SOC losses were greatest in cold-climate forests (boreal and mountainous regions) with large accumulations of organic matter on or near the soil surface. Negative effects are present for at least four decades post-disturbance. In contrast, forests with small initial SOC stocks experienced quantitatively lower carbon losses, and their stocks returned to pre-disturbance levels more quickly. Main Conclusions Our results indicate that the more carbon is stored in the forest's organic layers and top mineral soils, the more carbon will be lost after disturbance. Robust estimates of forest carbon budgets must therefore consider disturbance-induced SOC losses, which strongly depend on site-specific stocks. Particularly in cold-climate forests, these disturbance-related losses may challenge forest management efforts to sequester CO2.
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Affiliation(s)
- Mathias Mayer
- Forest Soils and BiogeochemistrySwiss Federal Institute for Forest, Snow and Landscape Research (WSL)BirmensdorfSwitzerland
- Forest Ecology, Institute of Terrestrial Ecosystems (ITES)ETH ZurichZurichSwitzerland
- Institute of Forest Ecology, Department of Forest and Soil SciencesUniversity of Natural Resources and Life Sciences (BOKU)ViennaAustria
| | - Andri Baltensweiler
- Forest Resources and ManagementSwiss Federal Institute for Forest, Snow and Landscape Research (WSL)BirmensdorfSwitzerland
| | | | - Andreas Rigling
- Forest Ecology, Institute of Terrestrial Ecosystems (ITES)ETH ZurichZurichSwitzerland
- Forest DynamicsSwiss Federal Institute for Forest, Snow and Landscape Research (WSL)BirmensdorfSwitzerland
| | - Frank Hagedorn
- Forest Soils and BiogeochemistrySwiss Federal Institute for Forest, Snow and Landscape Research (WSL)BirmensdorfSwitzerland
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Assessing Sumatran Peat Vulnerability to Fire under Various Condition of ENSO Phases Using Machine Learning Approaches. FORESTS 2022. [DOI: 10.3390/f13060828] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
In recent decades, catastrophic wildfire episodes within the Sumatran peatland have contributed to a large amount of greenhouse gas emissions. The El-Nino Southern Oscillation (ENSO) modulates the occurrence of fires in Indonesia through prolonged hydrological drought. Thus, assessing peatland vulnerability to fires and understanding the underlying drivers are essential to developing adaptation and mitigation strategies for peatland. Here, we quantify the vulnerability of Sumatran peat to fires under various ENSO conditions (i.e., El-Nino, La-Nina, and Normal phases) using correlative modelling approaches. This study used climatic (i.e., annual precipitation, SPI, and KBDI), biophysical (i.e., below-ground biomass, elevation, slope, and NBR), and proxies to anthropogenic disturbance variables (i.e., access to road, access to forests, access to cities, human modification, and human population) to assess fire vulnerability within Sumatran peatlands. We created an ensemble model based on various machine learning approaches (i.e., random forest, support vector machine, maximum entropy, and boosted regression tree). We found that the ensemble model performed better compared to a single algorithm for depicting fire vulnerability within Sumatran peatlands. The NBR highly contributed to the vulnerability of peatland to fire in Sumatra in all ENSO phases, followed by the anthropogenic variables. We found that the high to very-high peat vulnerability to fire increases during El-Nino conditions with variations in its spatial patterns occurring under different ENSO phases. This study provides spatially explicit information to support the management of peat fires, which will be particularly useful for identifying peatland restoration priorities based on peatland vulnerability to fire maps. Our findings highlight Riau’s peatland as being the area most prone to fires area on Sumatra Island. Therefore, the groundwater level within this area should be intensively monitored to prevent peatland fires. In addition, conserving intact forests within peatland through the moratorium strategy and restoring the degraded peatland ecosystem through canal blocking is also crucial to coping with global climate change.
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Forty Years of Soil and Water Conservation Policy, Implementation, Research and Development in Indonesia: A Review. SUSTAINABILITY 2022. [DOI: 10.3390/su14052972] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Dominated by mountainous topography, high rainfall, and erosion-sensitive soil types, and with the majority of its population living in rural areas as farmers, most of Indonesia’s watersheds are highly vulnerable to erosion. In 1984, the Government of Indonesia established 22 priority watersheds to be handled, which marked the start of formal soil and water conservation activities. Although it has not fully succeeded in improving watershed conditions from all aspects, something which is indicated by fluctuations in the area of degraded land, over the past 40 years the Indonesian government has systematically implemented various soil and water conservation techniques in various areas with the support of policies, laws and regulations, and research and development. These systematic efforts have shown positive results, with a 40% reduction in the area of degraded land over the last 15 years from 2004–2018. This paper reviews policy, implementation, and research and development of soil and water conservation activities in Indonesia over the last 40 years from the 1980s to 2020 and explores the dynamics of the activities.
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Abstract
Indonesia has the second-largest biodiversity of any country in the world. Deforestation and forest degradation have caused a range of environmental issues, including habitat degradation and loss of biodiversity, deterioration of water quality and quantity, air pollution, and increased greenhouse gas emissions that contribute to climate change. Forest restoration at the landscape level has been conducted to balance ecological integrity and human well-being. Forest restoration efforts are also aimed at reducing CO2 emissions and are closely related to Indonesia’s Nationally Determined Contribution (NDC) from the forestry sector. The purpose of this paper is to examine the regulatory, institutional, and policy aspects of forest restoration in Indonesia, as well as the implementation of forest restoration activities in the country. The article was written using a synoptic review approach to Forest Landscape Restoration (FLR)-related articles and national experiences. Failures, success stories, and criteria and indicators for forest restoration success are all discussed. We also discuss the latest silvicultural techniques for the success of the forest restoration program. Restoration governance in Indonesia has focused on the wetland ecosystem such as peatlands and mangroves, but due to the severely degraded condition of many forests, the government has by necessity opted for active restoration involving the planting and establishment of livelihood options. The government has adapted its restoration approach from the early focus on ecological restoration to more forest landscape restoration, which recognizes that involving the local community in restoration activities is critical for the success of forest restoration.
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Terzano D, Attorre F, Parish F, Moss P, Bresciani F, Cooke R, Dargusch P. Community‐led Peatland Restoration in Southeast Asia: 5Rs approach. Restor Ecol 2022. [DOI: 10.1111/rec.13642] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Dilva Terzano
- Department of Environmental and Evolutionary Biology Sapienza University of Rome Italy
- School of Earth and Environmental Sciences The University of Queensland St Lucia Australia
- International Fund for Agricultural Development Rome Italy
| | - Fabio Attorre
- Department of Environmental and Evolutionary Biology Sapienza University of Rome Italy
| | - Faizal Parish
- Global Environment Center Petaling Jaya Selangor Malaysia
| | - Patrick Moss
- School of Earth and Environmental Sciences The University of Queensland St Lucia Australia
| | | | - Roshan Cooke
- International Fund for Agricultural Development Rome Italy
| | - Paul Dargusch
- School of Earth and Environmental Sciences The University of Queensland St Lucia Australia
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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.
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