Study on the impact of canal blocking on groundwater fluctuation for tropical peatland restoration

The Peatland Restoration Agency of the Republic of Indonesia (BRG-RI), an agency that is mandated to restore 2 million hectares of degraded peatland by 2020, has developed a 3-R approach towards tackling the problem based on the program of rewetting, revegetation, and revitalization of livelihood for the peatlands restoration in Indonesia. The Rewetting program that aims to rehabilitate hydrologically a peatland to a near natural state is carried out by canal blocking, canal backfilling, and construction of deep wells. To know the progress of the restoration activities by BRG, it is very important to understand the effectiveness of canal blocking on rewetting of the tropical peatland. The effectiveness of canal blocking was investigated through the monitoring of groundwater level (GWL) fluctuation around the canal block. This study was carried out at a canal block that is located at the peatland of Sungai Tohor Village, Kepulauan Meranti Regency, Riau Province. For monitoring of GWL fluctuation as the impact of canal blocking, five dipwells were set at the peatland that are perpendicular to the canal with the distance of 20 m, 70 m, 120 m, 170 m, and 220 m respectively. The results of this study show that the impact of canal blocking could raise the water table in the peatland at the radius of about 170 m from the canal. The radius impact of the re-wetting might be bigger or smaller, that strongly depends on the hydrotopography situation of the area.

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Smallholder perceptions of land restoration activities: rewetting tropical peatland oil palm areas in Sumatra, Indonesia

Regional Environmental Change ◽

10.1007/s10113-020-01737-z ◽

2020 ◽

Vol 21 (1) ◽

Author(s):

Caroline Ward ◽

Lindsay C. Stringer ◽

Eleanor Warren-Thomas ◽

Fahmuddin Agus ◽

Merry Crowson ◽

...

Keyword(s):

Smallholder Farmers ◽

Fire Risk ◽

Land Restoration ◽

Peatland Restoration ◽

Drainage Canals ◽

Perceived Impacts ◽

The Government ◽

Restoration Target ◽

Peat Fires ◽

The Impact

AbstractThe Indonesian government committed to restoring over 2 million ha of degraded peatland by the end of 2020, mainly to reduce peat fires and greenhouse gas emissions. Although it is unlikely the government will meet this target, restoration projects are still underway. One restoration strategy involves blocking peatland drainage canals, but the consequences of this for smallholder farmers whose livelihoods are dependent on agriculture are unclear. This paper investigates perceived impacts of canal blocks on smallholder farmers and identifies factors that affect their willingness to accept canal blocks on their land. We use data from 181 household questionnaires collected in 2018 across three villages in Jambi province, Sumatra. We found that the majority of respondents would accept canal blocks on their farms, perceiving that the blocks would have no impact on yields or farm access, and would decrease fire risk. Respondents who would not accept blocks on their farms were more likely to use canals to access their farms and perceive that canal blocks would decrease yields. The majority of farmers unwilling to accept canal blocks did not change their mind when provided with an option of a block that would allow boat travel. Our results improve understanding of why some smallholders may be unwilling to engage with peatland restoration. Further research is needed to understand the impact of canal blocks on smallholders’ yields. Engaging with stakeholders from the outset to understand farmers’ concerns, and perceptions is key if the government is to succeed in meeting its peatland restoration target and to ensure that the costs and benefits of restoration are evenly shared between local stakeholders and other actors.

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REWETTING DESIGN FOR TROPICAL PEATLAND RESTORATION

Sociae Polites ◽

10.33541/sp.v21i3.2245 ◽

2020 ◽

Vol 21 (2) ◽

pp. 111-125

Author(s):

Ainun Hasanah ◽

Muhammad Farouk Setiawan

Keyword(s):

Peat Soil ◽

Tropical Peatland ◽

The Earth ◽

Peatland Restoration ◽

The World ◽

Tropical Areas ◽

Pvc Pipe ◽

The Stability ◽

Tropical Climates ◽

Development Objectives

Peatlands located in tropical climates are estimated to have an area of 11% of the total peatland on earth. The scope of tropical peatland is proportional to the significant role this ecosystem plays in the stability of the earth and everything in it. Various efforts have been made to restore the condition of the peatland ecosystem, especially in tropical areas that have been affected by human activities. This study using the literature review method attempts to collect and summarize various peatland restoration efforts carried out in various countries in the world, then serve as a reference and basis for consideration in redesigning peat rewetting infrastructure. The result of this study is a canal blocking design using a PVC pipe filled with peat soil in its cavity. The layout of this PVC pipe canal blocking is designed by considering various factors. Challenges and prospects related to the idea of this canal blocking with PVC pipe were also taken into consideration in the design. It is hoped that the innovation of canal blocking materials can increase resource efficiency and fund for canal blocking construction while maintaining its function and development objectives. Keywords: peatland rewetting design, canal blocking, PVC pipe

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Millennia-old carbon fluxes from degraded tropical peatland soils

10.5194/egusphere-egu2020-21851 ◽

2020 ◽

Author(s):

Stephanie Evers ◽

Thomas Smith ◽

Mark Garnett ◽

Selvakumar Dhandipani ◽

Massimo Lupascu

Keyword(s):

Land Use ◽

Organic Matter ◽

Land Use Change ◽

Ecosystem Respiration ◽

Critical Element ◽

Tropical Peatland ◽

Agricultural Conversion ◽

C Cycling ◽

The Impact ◽

Global Carbon

Assessing the flux of carbon (C) from terrestrial ecosystems to the atmosphere represents a critical element of global carbon budgeting. In tropical peatlands this has been a fundamental part of assessing the impact of land use change on an ecosystem that represents a significant global carbon store, with peat accumulation being often many meters deep. These systems have formed over thousands of years as a function of incomplete decomposition of organic matter from water-logged swamp forests. However, intact tropical peat swamp forests (PSFs) are under increasing threat from agricultural conversion, deforestation, drainage practices and fires. The resultant alteration of the peat soil results in peat oxidation, increased rates of organic matter decomposition and greenhouse gas (GHG) emissions. Consequently, these peats are reverting from C stores to sources.Radiocarbon (14C) abundance can be used to assess C cycling rates in varied ecosystems and identify rapid or slow C turnover rates from years to centuries, as well as shifts in cycling rates &#8211; for example with land use or hydrological alteration. Within intact peatlands, deep peats generally contain an increasing abundance of 14C depleted content due to radioactive decay, conversely, shallower peats are more abundant in recently produced organic litter enriched with &#8220;Bomb C&#8221;; derived from nuclear testing in the 1960s. Similarly, root derived organic matter and the associated root respiration (autotrophic respiration) also have signatures resembling recent atmospheres, whereas microbial respiration of soil organic matter (heterotrophic respiration) will resemble the mean age of the soil carbon being utilised by the microbial community, and as such can be a tracer for sources of carbon being decomposed.&#160;Yet while an increasing body of knowledge exists on tropical peatland carbon flux rates or net ecosystem respiration in association with land-use change, these approaches fail to delineate the sources of carbon being used within the soil profile and thus fully address questions linked to changing carbon cycling rates with land use change.Here we provide what we believe to be the first data on 14CO2 fluxes from tropical peatland soils in relation to varying land use classes with the aim of determining if peats which were previously long-terms C stores are being utilised within short, fast C cycles and thus contributing to modern GHG budgets. CO2 flux rates were measured using soil chambers and emitted CO2 was subsequently trapped on a zeolite molecular sieve cartridge. An aliquot of the recovered CO2 was graphitised and analysed for 14C by accelerator mass spectrometry. Associated soil age profiles were also determined.Results indicate significant fluxes of multi-millennia old carbon from peatlands under altered land use classes and clear evidence for a shift to C cycling speed, with previously long-term stored C contributing to modern C budgets. Result highlight the instability of the peat profile under altered land-use classes and minimal to no contribution of modern C from recently produced organic matter to these carbon budgets. Findings clearly indicate the unsustainability of these agricultural practices and the need for burn- and drain-free land-use strategies.

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N fertilization effects on N2O fluxes from oil palm plantation on tropical peatland

10.5194/egusphere-egu21-10546 ◽

2021 ◽

Author(s):

Auldry Chaddy ◽

Lulie Melling ◽

Kiwamu Ishikura ◽

Ryusuke Hatano

Keyword(s):

Oil Palm ◽

Elaeis Guineensis ◽

Pore Space ◽

Anthropogenic Activities ◽

N Uptake ◽

N Fertilization ◽

Soil N ◽

Tropical Peatland ◽

Oil Palm Plantation ◽

The Impact

Anthropogenic activities, and in particular the use of synthetic nitrogen (N) fertilizer, have a significant influence on soil nitrous oxide (N2O) emission from oil palm plantation on tropical peatland. Finding a suitable N rate for optimum N uptake efficiency and yield with low environmental impact and production cost is crucial for the economic growth of Malaysia&#8217;s oil palm sector. However, studies on the impact of N fertilizers on N2O emissions&#160;from&#160;tropical peatland are limited. Thus, long-term monitoring was conducted to investigate the effects of N fertilization on soil N2O emissions. This study was conducted in an oil palm (Elaeis guineensis Jacq.) plantation located in a tropical peatland in Sarawak, Malaysia. Monthly soil N2O fluxes were measured using the closed-chamber method in a control (T1, without N fertilization), and under three different N treatments: low N (T2, 31.1 kg N ha&#8722;1), moderate N (recommended rate) (T3, 62.2 kg N ha&#8722;1), and high N (T4, 124.3 kg N ha&#8722;1), from January 2010 to December 2013 and from January 2016 to December 2017. The only N fertiliser rate to significantly increase (p<0.05) annual cumulative N2O emissions was 124.3 kg N ha-1 (T4). Increased&#160;in water-filled pore space (WFPS) (>70%) with a decrease in both N2O flux and nitrate (NO3&#8722;) implies that complete denitrification has taken place.&#160;Increased in NO3-&#160;uptake by oil palm with an increase in WFPS decreased NO3- concentration in soil, resulting in the reduction of N2O emission. This study highlights the importance of WFPS on denitrification and N uptake by oil palm in tropical peatland. This needs to be taken into account for the accurate assessment of N dynamics in oil palm plantations on tropical peatland in order to enhance N fertilization management strategies and counteract anthropogenic activities that produce greenhouse gases.Keywords: WFPS, oil palm yield, NO3-, N uptake

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Impact of fire on vegetation, soil microbes and CH4 emission from a degraded tropical peatland

10.5194/egusphere-egu2020-12743 ◽

2020 ◽

Cited By ~ 1

Author(s):

Hasan Akhtar ◽

Massimo Lupascu ◽

Omkar S. Kulkarni ◽

Aditya Bandla ◽

Rahayu S. Sukri ◽

...

Keyword(s):

Southeast Asia ◽

Water Table ◽

Vegetation Structure ◽

High Throughput Sequencing ◽

Microbial Community Composition ◽

Tropical Peatland ◽

Tropical Peatlands ◽

Peat Profile ◽

The Impact

Over the past few decades, tropical peatlands in Southeast Asia have been heavily degraded for multiple land uses, mainly by employing drainage and fire. More importantly, the extent of these degraded areas, primarily covered with ferns and sedges, have increased to almost 10% of the total peatland area in Southeast Asia. In particular, the role of sedges in plant-mediated gas transport to the atmosphere has been recognized as a significant CH4 pathway in northern peatlands, however, in the Tropics this is still unknown. Within this context, we adopted an integrated approach using on-site measurements (CH4, porewater physicochemical characteristics) with genomics to investigate the role of hydrology, vegetation structure, and microbiome on CH4 emission from fire-degraded tropical peatland in Brunei.&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160; We found for the first time that in degraded tropical peatlands of Southeast Asia, sedges transported 70-80% of the total CH4 emission and significantly varied with values ranging from 1.22&#177;0.13 to 6.15&#177;0.57 mg CH4 m-2 hr-1, during dry and wet period, respectively. This variation was mainly attributed to water table position along with changes in sedge cover and porewater properties, which created more optimal methanogenesis conditions. Total emissions via this process might increase in the future as the extent of degraded tropical peatlands expands due to more frequent fire episodes and flooding.&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160; Further, we used 16S rRNA high-throughput sequencing to investigate the microbiomes in peat profile (above and below water table) as well as rhizo-compartments (Rhizosphere, Rhizoplane, Endosphere) of sedges. We found that the peat profile as well as rhizo-compartments of sedge harboured a higher number of methanogenic archaea in the order Methanomicrobiales and Methanobacteriales, compared to non-burnt and bulk soil, which further explains our findings of higher CH4 emission from degraded tropical peatland areas covered with sedges. These insights into the impact of fire on hydrology, vegetation structure, and microbial community composition on CH4 emissions provide an important basis for future studies on CH4 dynamics in degraded tropical peatland areas.

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Analisis Pengaruh Penyekatan Kanal Untuk Untuk Pembahasan Lahan Gambut Tropis

Rekayasa Sipil ◽

10.21776/ub.rekayasasipil.2020.014.02.7 ◽

2020 ◽

Vol 14 (2) ◽

pp. 129-135

Author(s):

Gina Khusnul Khotimah ◽

◽

Sigit Sutikno ◽

Indradi Wijatmiko ◽

◽

...

Keyword(s):

Ground Water ◽

Water Level ◽

Good Effect ◽

Fire Prevention ◽

Emission Rates ◽

Groundwater Levels ◽

Peatland Restoration ◽

Peatland Rewetting ◽

One Year ◽

The Impact

Peatlands rewetting for hydrological restoration plays an important role for fire prevention and peatland restoration of degraded peatland. One of the methods for the rewetting is canal blocking. The impact of canal blocking for peatland rewetting is further analyzed in this research. This study focused in Pulau Tebing Tinggi peatland hydrological unit (PHU), which is located in Kepulauan Meranti Regency, Riau Province. To analysis the rewetting impact, 15 dipwells were installed with the distance of 1 m, 51 m, 101 m, 201 and 301 m from the canal for each transect of the three transects. A transect was set in the downstream and two transects were set in the upstream of canal block. The ground water level (GWL) in the 15 dipwells was recorded using water-loggers for one year. This research found that canal blocking has a good effect on maintaining groundwater levels and keeping peatlands in always wet or humid conditions up to a distance of 201 m perpendicular to the canal if the rise in water level in the canal due to canal blocking is more than 0.6 m. It is able to maintain the ground water depth in peatlands around 0.4 m, where the peatlands become low risk to the fire, emission rates and subsidence.

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The Impact of Peatland Restoration on Local Climate: Restoration of a Cool Humid Island

Journal of Geophysical Research Biogeosciences ◽

10.1029/2019jg005156 ◽

2019 ◽

Vol 124 (6) ◽

pp. 1696-1713 ◽

Cited By ~ 1

Author(s):

Fred Worrall ◽

Ian M. Boothroyd ◽

Rosie L. Gardner ◽

Nicholas J. K. Howden ◽

Tim P. Burt ◽

...

Keyword(s):

Local Climate ◽

Peatland Restoration ◽

The Impact

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Estimation of Drought Indices for Assessing the Impact of Climatic Variables on Groundwater Fluctuation over Upper Bhima Sub Basin

IOP Conference Series Earth and Environmental Science ◽

10.1088/1755-1315/597/1/012002 ◽

2020 ◽

Vol 597 ◽

pp. 012002

Author(s):

A B Jipkate ◽

D S Londhe ◽

Y B Katpatal

Keyword(s):

Climatic Variables ◽

Drought Indices ◽

Groundwater Fluctuation ◽

The Impact

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An Estimate of the Financial Cost of Peatland Restoration in Indonesia

Case Studies in the Environment ◽

10.1525/cse.2017.000695 ◽

2018 ◽

Vol 2 (1) ◽

pp. 1-8 ◽

Cited By ~ 8

Author(s):

Amanda Hansson ◽

Paul Dargusch

Keyword(s):

Large Scale ◽

Classification Scheme ◽

Financial Cost ◽

Tropical Peatland ◽

Academic Literature ◽

Premature Deaths ◽

Peatland Restoration ◽

International Donor ◽

History Of ◽

Plantation Development

The peat forests of Indonesia have experienced extensive deforestation and degradation over recent decades. High demand for Indonesian timber and plantation development has driven large-scale draining and clearing of peat forest, resulting in extensive fires and smoke haze problems across the region. These fires caused more than 100,000 premature deaths in 2015 alone, increased the pressure on several already threatened species, and placed Indonesia among the top greenhouse gas emitting countries globally. In response, the Indonesian government has launched an initiative to restore more than 2 million ha of peatland between now and 2020. Although there is a substantial body of academic literature that deals with technical aspects of tropical peatland restoration, little is published on the costs of tropical peatland restoration activities. In this study, we examine the case of peatland restoration in the provinces of Kalimantan, Sumatra, and Papua in Indonesia, and propose a restoration activity classification scheme based on fire, drainage, and logging history of peatland areas. We use this scheme to identify the restoration activity needs of different areas and then develop a preliminary gross financial cost estimate for the restoration activities proposed under the national 2-million-ha peatland restoration initiative. We find that it is likely to cost more than US$4.6 billion to complete the national 2-million-ha restoration initiative, which is substantially more than the funds currently allocated to the challenge across Indonesian and international donor budgets.

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