Global Ecology and Conservation 23 (2020) e01084

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Global Ecology and Conservation

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Original Research Article Progress of paludiculture projects in supporting peatland ecosystem restoration in Indonesia

* ** Ibnu Budiman a, , Bastoni b, , Eli NN Sari a, Etik E. Hadi b, Asmaliyah b, Hengki Siahaan b, Rizky Januar a, Rahmah Devi Hapsari a a World Resources Institute Indonesia, Wisma PMI, Jl. Wijaya I No. 63, Kebayoran Baru, Jakarta Selatan, 12170, Indonesia b Environment and Forestry Research and Development Institute (EFRDI) of Palembang, Puntikayu, Kotak Pos 179, Jl. Kol. H. Burlian KM.6 No.5, Srijaya, Alang-Alang Lebar, Palembang, South Sumatra, 30961, Indonesia article info abstract

Article history: Sustainable peatland management practices such as paludiculture are crucial for restoring Received 25 September 2019 degraded peatland ecosystems. Paludiculture involves wet cultivation practices in peatland Received in revised form 27 April 2020 and can maintain peat bodies and sustaining ecosystem services. However, information Accepted 27 April 2020 about paludiculture effects on tropical peatlands is limited in the literature. Therefore, this study aimed to analyse the effectiveness and progress of paludiculture projects in sup- Keywords: porting peatland ecosystem restoration in Indonesia that uses approaches of soil rewet- Paludiculture ting, revegetation of peat soil/forest, and the revitalisation of rural livelihoods around Peatland restoration fi Indonesia peatlands. We obtained qualitative and quantitative data from eld measurements, ob- Tropical peatland servations, document reviews, spatial data from open-source web applications, and in- Trade-off terviews with key stakeholders in two projects (agri-silviculture and agro-sylvofishery) that adapt paludiculture principles to Indonesia’s South Sumatra Province. We found that the limited use of paludiculture principles in both projects has a different contribution to peatland restoration. The agri-silviculture project has been utilising jelutung (Dyera poly- phylla), ramin (Gonystylus bancanus), and balangeran (Shorea balangeran) for (forest) revegetation. These species are 3 of the 534 paludiculture species that are adaptive to peat soils and tolerant to acidic conditions and inundation. The revegetation resulted in effective results that supported peatland restoration despite the delayed application of rewetting activities in the initial phase of the project. Additionally, in the agro-sylvofishery project, trade-offs between soil rewetting to maintain high peat water tables and the need to provide short-term economic benefits for local communities through horticulture and fishery practices were noted. During the 2019 El Nino,~ the involvement of a closed-loop canal to support fishery practices appeared to contribute to affecting the water table, which was also influenced by the open canals dug in nearby palm oil plantations. © 2020 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

* Corresponding author. ** Corresponding author. E-mail addresses: [email protected] (I. Budiman), [email protected] (I. Budiman), [email protected] ( Bastoni). https://doi.org/10.1016/j.gecco.2020.e01084 2351-9894/© 2020 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/ licenses/by-nc-nd/4.0/). 2 I. Budiman et al. / Global Ecology and Conservation 23 (2020) e01084

Abbreviations

Balitbang LHK Balai Penelitian dan Pengembangan Lingkungan Hidup dan Kehutanan (Environment and Forestry Research and Development Institute) BCR Benefit-to-cost ratio BRG Peatland Restoration Agency BUMD Village business entities EFRDIP Balai Penelitian dan Pengembangan Lingkungan Hidup dan Kehutanan (Environment and Forestry Research and Development Institute) Palembang GoI Government of Indonesia KHG Peatland hydrological unit/PHU NPP Net primary production OKI Ogan Komering Ilir regency, South Sumatra province, Indonesia

1. Introduction

Following the 2015 fires that accounted for an estimated USD $15 billion of human and environmental damage, the Government of Indonesia (GoI) initiated a national programme to restore 2.6 million hectares of degraded peatlands in seven provinces (BRG, 2016; World Bank, 2016). Peatland restoration is an important environmental agenda in Indonesia because it aids in restraining fire spread, reducing greenhouse gas emissions, and mitigating climate change (Warren et al., 2017). Peatland restoration organised by the GoI combines three activities: soil rewetting, forest revegetation, and livelihood revitalisation (BRG, 2016). It is crucial to identify a sustainable peatland management option to support all three activities. This option should provide arrangements that create (an awareness of) the long-term ecological and economic benefits of peatland restoration, while securing a stable income and food supply (Schaafsma et al., 2017). Paludiculture is considered a sustainable peatland management practice involving plant cultivation in wet conditions. Paludiculture is a swamp cultivation approach to restore degraded peatlands and make them economically useful (Schafer,€ 2012; Wichtmann and Joosten, 2007). It establishes a protective vegetation cover to reduce desiccation and fire hazards. The most important aspect of paludiculture in degraded peatlands is supporting the rewetting of peat to near-natural levels. Aboveground biomass and primary production are of secondary interest (Giesen and Sari, 2018). Paludiculture produces biomass from rewetted peatlands under conditions that maintain the peat body, sustain ecosystem services, and encourage carbon accumulation. Ideally, peatlands should be wet enough to ensure that steady, long-term peat accumulation is maintained. Paludiculture uses the part of net primary production (NPP) that is necessary for peat formation, which is ca. 80%e90% of NPP. (Roxburgh et al., 2005; Wichtmann and Joosten, 2007). In Indonesia, a previous study identified eight projects in Riau, Jambi, South Sumatra, and Central Kalimantan that adapted paludiculture principles (Tata et al., 2016). However, the effectiveness of these paludiculture projects in terms of contributing to peatland restoration has yet to be examined. The present study reviewed and analysed the effectiveness and the progress of paludiculture projects in supporting peatland restoration and determined the extent to which it accommodates and supports restoration activities (such as rewetting, revegetation, and revitalisation of rural livelihoods surrounding peatlands to reduce pressure on communities to clear land by fire) and whether it can support peatland resilience to fire spreads. We have also discussed the socioeconomic and policy aspects related to paludiculture to provide recommendations for increasing the effectiveness of paludiculture in supporting peatland restoration efforts. This research utilises two case studies of the adaptation of paludiculture in a peatland ecosystem in South Sumatra Province, Indonesia.

2. Theory/literature background

This section reviews previous studies on the species that are suitable for paludiculture to support peatland restoration and the indicators that can measure implementation efforts by paludiculture projects to restore peatlands, drawing on an aca- demic literature review. This section is presented before the methods because it describes the reasons that affected the choice of method for data collection and data analysis. Paludiculture originated in temperate regions of North America and Europe (e.g., Germany and Poland). Through pal- udiculture, degraded peatland can be restored and utilised for economic activities (Wichtmann and Joosten, 2007). When paludiculture principles and approach were adopted in Indonesia, the concept of paludiculture was often perceived as a purely revegetative approach to restore degraded peatlands due to a lack of in-depth understanding of the science of pal- udiculture and its principles (Dohong et al., 2018). This issue sometimes resulted in errors in selecting the vegetation and species to be planted, which undermined peatland restoration efforts (Sari et al., 2018). There are at least two common misinterpretations in Indonesia about paludiculture. First, all plants that thrive on peat- lands are often assumed to be part of paludiculture. Due to its economic benefits, dryland species are often assumed to be able I. Budiman et al. / Global Ecology and Conservation 23 (2020) e01084 3

Table 1 The four categories of paludiculture species (adapted from Giesen, 2015).

Category Description Species Quick harvest Species that can be harvested quickly Eleocharis dulcis (purun tikus) but with a lower unit valuea Ipomoea aquatica (spinach) Momordia charantia (bitter gourd) Uncaria gambir Nephrolepis biserrata and Stenochlaena palustris (pakis) Proven commercial crop Well-known cash crop on peatlands Aquilaria beccariana Melaleuca cajuputi (gelam/cajuput) Metroxylon sagu (sagoo) Dyera polyphylla (D. lowii) (jelutong) Nothophoebe coriacea and Nothophoebe umbelliflora (gemor) Gonystylus bancanus (ramin) Unproven commercial crop More research is required about Garcinia mangostana (mangosteen) its commercial values on peat lands Syzgium aqueum (water apple) Aleurites moluccana (candlenut) Shorea balangeran (balangeran) Potential species 58 species on which further research on ecological suitability and market demand is required (Giesen, 2015).

a The total value of the purchases / sales divided by the sum of the quantities.

to restore peat. Indeed, Liberian coffee, cacao, coconuts and rubber thrive on peatlands and can be cultivated in such eco- systems. However, not all plants that thrive on peatlands should be considered part of paludiculture (Giesen, 2013). Liberian coffee, cacao, coconuts and rubber are not native to peat swamps and thrive only when peatlands are drained and dried (Sheil et al., 2009). Such species are usually planted alongside box dams with overflow outlets to keep water levels at least 40 m below the peatland surface (Giesen, 2013). The species that require drainage to grow will not survive on fully wetted peatlands. Therefore, plant cultivation with drainage cannot be included in paludiculture because it is merely ‘plant culti- vation on peatland’ (Schafer,€ 2012). Although some dryland species, including some horticultural crops, can grow on peatlands in some regions, they cannot restore peat to ideal conditions in the long run due to oxidation (i.e., interaction between oxygen and other substances on peatland caused by drops in groundwater levels) and their impact to subsidence, thus resulting in the decline of organic matter quality in peatland (Blackham et al., 2014). Furthermore, cultivation of dryland species on peatland increases the risk of fires and is thus not sustainable and not recommended on ideal peatland hydrology or rewetted peatlands (Wichtmann et al., 2016). In fact, only local native species and non-native species that adapt to wet peatlands have been proven to form peats (Wichtmann and Joosten, 2007). Second, paludiculture is often assumed compatible in dry peatland. In fact, any planting conducted on dry peatlands cannot be classified as a paludiculture practice (Sari et al., 2018; Tata, 2019a,b). In effective paludiculture practice, peatland rewetting before planting is important to ensure that the plants native to peat swamp can thrive. In wet or rewetted con- ditions, low levels of biological decomposition facilitate the accumulation of peat. The biological decomposition in wet peats is low for various reasons, including low pH, low oxygen levels and high polyphenol concentrations (Giesen, 2015). These characteristics are different in dry peatland, rendering dry peatland non-compatible for paludiculture (Sari et al., 2018; Tata, 2019a,b). Correcting these misinterpretations should encourage stakeholders of peat restoration to base their restoration plans on the latest scientific understanding that native peat swamp plants can both maintain peat body and provide economic benefits to the surrounding communities (Sari et al., 2018). Two types of plants can grow on peatlands: species native to peat swamps and non-native species that adapt to wet peatlands. A core paludiculture principle is the use of those two types of plants on wet or rewetted peatlands without drainage. This practice supports peatland restoration goals to produce biomass (i.e., the biological materials in plants) to support peat formation and to provide economic benefits (Schafer,€ 2012). The report ‘Paludiculture: Sustainable Alternatives on Degraded Peatland in Indonesia’ provides information on the 534 native peat swamp species that can support restoration (Giesen, 2013). These species can adapt to acidic soils and are resistant to inundation. Some of them are sago (Metroxylon sagu), jelutung (Dyera polyphylla), ramin (Gonystylus bancanus), balangeran (Shorea balangeran1), gemor (Alseodaphne spp. and Nothaphoebe spp.), gelam (Melaleuca cajuputi) and Shorea stenoptera (Table 1, Fig. 1). Besides, this report also includes 81 non-timber forest product species of major economic importance (Table 1). These species can be used for crop production and to supply raw material for energy, construction, and biochemical products (Giesen and Sari, 2018). Cultivation of the abovementioned paludiculture species is aimed at restoring biophysical (e.g., by replanting) and ecological (e.g., wet conditions, biomass production, carbon sequestration) conditions and providing economic benefits (Giesen, 2015). In degraded peatlands, the area should be rewetted first by constructing canal blocks or backfilling before

1 According to the IUCN Red Data list, both Shorea balangeran (S.b) and Gonystylus bancanus (G.b) are categorized as “Critically Endangered”. But this listing needs revision as both S.b. and G.b. are being planted and cultivated. 4 I. Budiman et al. / Global Ecology and Conservation 23 (2020) e01084

Fig. 1. Distribution of paludiculture species in seven priority provinces for peatland restoration in Indonesia. revegetation/replanting is implemented. Then, the paludiculture species will create a microclimate that affects evaporation and maintains wet conditions and slows down the lowering of the water table in the dry season (Günther et al., 2017). These concepts are aligned with peatland restoration in Indonesia that comprises three activities: rewetting drained peatlands; revegetating land cover by planting native plants and/or other adaptive cultivation plants; and revitalising rural community livelihoods (BRG, 2016). In peatland revegetation, the government, the private sector and research institutions in Indonesia started to present the concept and practice of paludiculture as a middle ground between conservation principles and economically valuable cultivation practices that benefit communities around peatlands (Sari et al., 2018).

3. Materials and methods

This section explains the indicators and methods utilised for data collection and data analysis in this study. By definition, paludiculture principles align with peatland restoration goals. This study produces a list of indicators to analyse paludiculture effectiveness in supporting peatland restoration. Table 2 presents the indicators utilised to monitor the short-, medium- and long-term impacts of paludiculture on restoration goals. The indicators consist of four aspects: hydrology, vegetation, soil and economic benefits, with each aspect consisting of several variables (Table 2). Hydrology, vegetation, and soil are linked to carbon sequestration in peatlands as rewetting drained peat aims to stop further loss of stored peat and its stored carbon. Restored peatland ecosystems display wet soil conditions that are supported by a microclimate that results from the growth of paludiculture species (Blagodatskaya et al., 2010). In the case of degraded peatlands, revegetation after rewetting can create a local microclimate that maintains peat humidity. To measure the indicators (Table 2), we selected cases of paludiculture for our study population by employing judgemental sampling based on our own knowledge and professional experience. This non-probability sampling technique is appropriate for emerging pilot projects, as is the case with paludiculture in Indonesia (Kothari, 2004). Considering that other studies have focused on Riau, Jambi, and Kalimantan, information about the paludiculture practice in South Sumatra is scarce (Giesen, 2013). Therefore, we chose two case studies that adapted paludiculture principles, in peatland hydrological unit (PHU/ KHG) Burnai-Sibumbung, Ogan Komering Ilir (OKI) regency, South Sumatra Province (Fig. 2). We selected these projects also because we had access to data from these project sites. These sites are managed by the Environmental and Forestry Research I. Budiman et al. / Global Ecology and Conservation 23 (2020) e01084 5

Table 2 Indicators and methods to measure the progressive impact of paludiculture projects towards restoration.

Impacts on Indicators Methods peatland restoration Suitability of species, based on the list from previous study Field observations and literature review Long-term Hydrology Canal blockings/water management system Field measurements, water logger technologyb (e.g., piezometer and maintained stable fluctuation of (higha) water table observational benchmarks), data collected twice a month in three between seasons years after blocking canal Vegetation Plant growth from revegetation, approximately 1 m/ Annual field measurements year Absorption/deposits of carbon by vegetation Permanent sampling plotsc Changes in vegetation cover Drone and aerial observations Soil Peat subsidence Field measurements, observational benchmarks/subsidence gauge Microclimate support from vegetation to wet soil Field observations Changes of carbon storage/carbon loss in peatlands From subsidence rate, eq. carbon lossd, 32 cm subsidence in degraded peatland ¼ 80 tC/ha/year of carbon loss (Hooijer et al., 2014) Economic (High) productivity of species (i.e., timber products) Interviews, literature review benefits Short-term (High) productivity of species (i.e., non-timber forest Field observations, measurements, interviews with market chain products), income from harvest actorse Cost and benefit of species/commodity Calculating benefitecost ratiof, interviews, literature review Full time Peat Fire events and fire spread Spatial analysis, Peatland Restoration Information and Monitoring resilience System

a Around -0.2 m from peat surface, in dry season. b One water logger was installed in each project area in 2017 and 2018, but the one in the agrisilviculture project was stolen in 2019. c Petak ukur permanen (PSPs) (Vittoz and Guisan, 2007). d Adapted from (Hooijer et al., 2014). e Middlemen, buyers, and farmers. f Using the following data: cost of cultivation (e.g., seeds, manure for fertilizer, dolomite, and labour wages) and total production (based on market price).

and Development Institute (EFRDI) of Palembang, an environment and forestry research institute owned by the Ministry of Environment and Forestry, Indonesia. The EFRDI of Palembang designed an experiment based on selected case studies of two projects. These locations were formerly areas of burned peat in 2006 and 2015. They are dominated by degraded ombrogenous peatlands, with pH values of 4e6, depending on the season. To collect data on different aspects of each indicator (Table 2), a combination of methods was utilised, which incorporated independent field measurements, direct observation, document reviews of project reports, an open-source web application, and interviews with key stakeholders. Table 2 shows that spatial, quantitative and qualitative data were collected on hy- drology, vegetation and soil indicators, primarily through field measurements and observations with the help of technologies such as a water logger and drone (BRG, 2019; Couwenberg et al., 2010; Vittoz and Guisan, 2007). Economic data were collected from academic literature; project reports; field observations and structured interviews with policymakers, development professionals, academics and community and civil society organisation representatives. In the interviews, personal communications were undertaken with stakeholders from organisations (one/two people from each) relating to the case study, including the EFRDI of Palembang, Wetlands International Indonesia, Forestry and Environment Research and Development Innovation Agency Bogor, Peatland Restoration Agency (BRG), the Purun Institute, a farmers’ group and Sriwijaya University. These organisations have practised paludiculture and have been involved in peatland restoration for approximately 10e20 years. Each interview lasted for approximately 1 hour. A number of interviews obtained information that confirmed the results from the literature review and observations. The observations were made at peatland conferences and meetings from January to July 2019. After data collection, results from the literature review, interviews and field observations were transcribed and analysed using content analysis. Coding was based on keywords from the indicators in Table 2. The NVivo software was utilised to support coding and content analysis. Data verification was performed by triangulating different data sources.

4. Results

Using the indicators described in Table 2, this section analyses the effectiveness and progress of the two projects (Fig. 3)in Kedaton village, the peatland hydrological unit (PHU/KHG) of Burnai-Sibumbung. OKI regency, South Sumatra. The extent of the project area is approximately 20 ha of 100,000 ha of the PHU of Burnai-Sibumbung. One project involved agri-silviculture and the other involved agro-sylvofishery. Both projects adapted paludiculture principles to peatland restoration. Due to the latter’s incorporation of a fishery and the fact that neither peatland in either one of the projects was fully rewetted, both projects were considered ‘compromised’ forms of paludiculture. Both projects are located near a canalised peatland 6 I. Budiman et al. / Global Ecology and Conservation 23 (2020) e01084

Fig. 2. Location and condition of the agro-sylvofishery and agri-silviculture projects (in different map scales) that are surrounded by canalised peatland ecosystem in palm oil plantations in the OKI regency, South Sumatra Province. I. Budiman et al. / Global Ecology and Conservation 23 (2020) e01084 7

Fig. 3. Adaptation of paludiculture applications in Indonesia. ecosystem by nearby palm oil plantations (Fig. 2). These areas used to suffer slash and burn practices by the local community. Findings in the results section were observed from 2011 to 2019.

4.1. Progress of agro-sylvofishery and agri-silviculture for peatland restoration

Agro-sylvofishery is a farming or land-use system that integrates potential resources from agriculture, forestry and fisheries in one stretch of land for finding an alternative livelihood for the local individuals (Bastoni, 2019b). The agro- sylvofishery project in this study was established in 2017 and is still refining its cultivation techniques. This project area was burned in 2015 due to local slash and burn practices. The project area occupies 4 ha of peatland (3.5e5.5 m depth) that is located approximately 4 km from Teloko Lake, which has fishery feedstocks (Fig. 2). The project area includes a closed-loop canal for the fishery and embankments that border the inner part planted with estate crops from native species such as Shorea balangeran. The outer part is planted with vegetables such as Ipomoea aquatica, Solanum lycopersicum (tomato), Solanum melongena or eggplant and nine other species, which mostly are dryland species (Fig. 3). Before revegetation occurs, calci- fication at a dose of 0.5 kg/m2 was utilised in the horticulture/vegetables area to increase soil and water pH. This treatment was performed to turn the acidic peatland into a neutral (pH 6.5e7.5) condition that is preferred for horticulture/dryland species. The fishery canal was made to accommodate fish migration from the lake; adapting a ‘beje’ system to trap the fish in the canal, during wet/rainy or flooding season. This system adapts a traditional ‘empang parit’ silvofishery system. The fishery canal is connected to a surrounding canal through a slit gate (Figs. 3 and 4). Meanwhile, agri-silviculture focuses more on revegetation of native forest plants such as S. balangeran, D. polyphylla and G. bancanus (Figs. 3 and 5). This project was initiated in 2010 to restore degraded peatlands due to fires in 2006. Peat depth in the area is approximately 5e6.5 m. In 2017, the Peatland Restoration Agency (BRG) provided additional support to expand the operation. Some crops such as Liberian coffee and areca nut were later introduced during the dry season. These species were selected because it was found to be suitable for peatland in Bram Itam, West Tanjung Jabung regency, Jambi Province. However, the different types of peat and their varying degree of fertility in the project area of agri-silviculture did not allow Liberian coffee and areca nut to grow well. Besides, Liberian coffee and areca nut are actually dryland species that require 8 I. Budiman et al. / Global Ecology and Conservation 23 (2020) e01084

Fig. 4. The agro-sylvofishery project in the Ogan Komering Ilir regency, South Sumatera. Cartoon text boxes point towards the position of canal blockings (Source: Bastoni, 2019a,b)

Fig. 5. Fluctuation of water table before and after construction of the canal blockings in October 2017 in the agri-silviculture project . I. Budiman et al. / Global Ecology and Conservation 23 (2020) e01084 9

Table 3 The progress of ‘compromised’ paludiculture projects in supporting peatland restoration.

Impact Agro-sylvofishery Agri-silviculture Species suitability Suitable species; Shorea balangeran, Ipomoea Suitable species; Shorea balangeran, Dyera polyphylla, aquatica Gonystylus bancanus Unsuitable species: Solanum lycopersicum (tomato), Unsuitable species; Liberian coffee, areca nut Solanum melongena or eggplant, yardlong bean, eggplant, spinach, spring onion, pineapple, snaps To soil rewetting Range of water table in prolonged dry season Lowest water table in the 2018 dry season was 0.6 m (SeptembereNovember 2019) was 0.85 to 0.9 m (BRG, 2019) Prolonged dry season and absence of sufficient canal Water management was disturbed because of road blockings contributed to inability to maintain high construction near the area, it might affect the 2019 water water table tablea Subsidence data is not yet available Subsidence rate was 3.4 cm/year To revegetation S. balangeran had a survival rate of 85%, height In nine years, trees (S. balangeran) height was 15 m, average increment 97 cm/year, and diameter increment plant growth was higher than 1 m/year, diameter increment 3.25 cm/year 2.25 cm/year Plant growth was disturbed by flooding in wet S. balangeran was predicted to be the most resilient species season to pest and pathogen S. balangeran was predicted to be the most resilient species to pest and pathogen To carbon stock S. balangeran: carbon sequestration was 1.0 ton/ha/ Carbon sequestration by Shorea balangeran was 11.3-ton

year eq. (2 years old) CO2/ha/year eq. Dyera polyphylla absorbed 12.4-ton CO2/ha/year eq. Total carbon sequestration was 167-ton CO2/ha until 2018. Carbon loss (from peat subsidence) was 8.5 tC/ha/year To livelihood revitalisation Although the benefitecost ratio of vegetables Despite its potential long-term benefits, Shorea balangeran, species was >1 and it was harvested consecutively for Dyera lowii, Gonystylus bancanus; were not yet utilised for 10 months in a year, actual profit was still low due to commercial purpose due to biodiversity conservation market/supply chain issues Income from fishery pond was 2,337,500 IDR or USD 171/500 m2/year Community was interested in practice of agro- sylvofishery for livelihood Trade-offs Fishery canal is still debatable in influencing Absence of canal blockings in the initial phase of the project fluctuation of water table, particularly in a prolonged reduced the project to reach optimum impact for restoration dry season To peatland resilience Almost 50% of the area suffered the 2019 fires Survived from large fires in the surrounding area in 2015 and 2019

a Data from 2019 are not available due to the absence of water-logger technology in the area, in that year. drainage. Thus, the cultivation of these crops was ceased, and the project turned back its focus to S. balangeran and D. pol- yphylla, which have survived for almost a decade. In the same year, BRG also supported the project to finally construct canal blocking to rewet the peatlands in the area (BRG, 2019; personal communication, 29 May).

4.2. Hydrological impacts

The agri-silviculture project area is located near two canals (Fig. 2). The absence of canal blocking in the initial phase of the project (2010) had resulted in an increased subsidence rate of 3.4 cm/year. This number is lower than that of the surrounding palm oil plantation (4 cm/year). The absence of canal blocking also resulted in a low depth of the water table in the area, which was 0.6 m2 in September 2017. As shown in Fig. 5, the water table rose slowly after the construction of two canal blockings in one canal in October 2017. This suggests that the agri-silviculture project contributed to efforts to rewet the soil following the construction of the canal blockings in October 2017. Simultaneously, the plant growth in the area also increased, and the vegetative cover created a microclimate in the project area that enhanced wet conditions (Table 3). Yet, the absence of canal blocking in another larger canal near the project area affected the ability to maintain higher water table in the 2018 dry season. In addition, road construction near the project in 2019 also affected water management and may have reduced the effectiveness of the canal blockings. Meanwhile, two open canals are also found next to the agro-sylvofishery project. In 2016, four canal blockings were installed in the closest canal and the other canal was left open (See Fig. 2). In October 2017, revegetation and fishery practices began. The canal blockings contributed to an increase in the water table at the end of 2017. The water reached a minimum depth of 0.2 m in the following dry season (July 2018). The water table increased to a maximum of 1.8 m in the subsequent (peak of) wet season (February 2019) and decreased to 0.9 m in November 2019 during that year’sElNino~ (Fig. 6). Two canal

2 From the peat surface. 10 I. Budiman et al. / Global Ecology and Conservation 23 (2020) e01084

Fig. 6. Fluctuation of water table (cm) in the agro-sylvofishery project from September 2017 to November 2019 after construction of canal blockings in 2016 (Source: Bastoni, 2019a,b).

Fig. 7. Agri-silviculture project with Dyera lowii and Shorea balangeran at 9 years after revegetation (Source: Bastoni, 2019a,b). blockings were damaged due to flooding in the 2018 wet season. In the 2019 prolonged dry season, damaged canal blockings and the existence of surrounding drainage activities from open canals lowered the water table in the project area. The longer dry season also increased evapotranspiration rates, which were higher than precipitation rates. While the 2-year-old plant growth and tree cover in the area were still low, conditions did not allow for the creation of a microclimate that could contribute to the rewetting efforts (Table 3).

4.3. Vegetation cover and carbon sequestration

With respect to forest revegetation efforts, S. balangeran and D. polyphylla were identified as the effective species for carbon sequestration in both projects; both species offered high ecological values. Over the 6-year period (2012e2018), S. 3 balangeran sequestered 11.3 tonne CO2/ha/year eq., increasing 97e115 cm/year in height and 2.25e3.25 cm/year in diameter and exhibiting a survival rate of 85%e97%. Over the 8-year period, D. polyphylla absorbed 12.4 tonne CO2/ha/year eq. from a height growth of 135 cm/year and diameter growth of 2.38 cm/year (Bastoni, 2019b). Over the nine-year period, the average tree height was 15 m, which was higher than that of the same-age oil palm trees near the agri-silviculture project area (Fig. 7). Despite its positive growth results, some scholars have argued that D. polyphylla growth is vulnerable to pest damage due its sweet rubber, which can attract wild boars. In the agri-silviculture project, red-spot disease caused by the parasitic algae Cephaleuros sp. was found in 32.10% of D. polyphylla. This pathogen causes moderate levels of damage and has no impact on plant growth. S. balangeran and G. bancanus were also infected with low but widespread attack rates and damage rates of <10%. In G. bancanus, stemborers were also found in September 2018. The infestation covered >11.63% of the area but caused little damage and had no impact on plant growth.

3 SI tonnes. I. Budiman et al. / Global Ecology and Conservation 23 (2020) e01084 11

In the agro-sylvofishery project, evidence of attacks by the fireworm Setora nitens, bagworms Cryptothelea sp., Pteroma plagiophelps and Metisa plana was found in S. balangeran. Although the infestation rate exceeded 60%, damage rates were low because the intensity rate of the attack was only 2.52%e12.1%, except for the attack of Cryptothelea sp., which reached an intensity rate of 23.29%. No effects on plant growth were reported. Since the pest and pathogen observations made in 2 years (2018e2019), no interventions have been made to eradicate either pest or pathogen as the project will continue to observe such patterns until the fifth year. Observations to date suggest that compared with other species, S. balangeran is more resilient to pests. For non-forest species, dryland crops in the agri-silviculture project were discontinued due to the unsuitability of the species for cultivation on peatland. Liberian coffee planted in December 2017 did not survive due to a 30 m flood in the 2018 wet season and the unsuitability of the ombrogenous peat in the area. Areca nuts grew for a short time until they were killed by pigs and monkeys who ate the roots during the initial growth phase. This finding draws attention to the common misinterpretation associated with paludiculture in Indonesia, i.e., dryland species such as Liberian coffee and areca nuts that are believed to survive on peatlands do not actually survive. These species thrive only when peatlands are drained and dried. In the agro-sylvofishery project, the two Solanum speciesdS. lycopersicum (tomato) and S. melongena (eggplants)dare dryland species that are not suitable for paludiculture. Fruit-rot disease in the form of the pathogen Phytophthora sp. was found in eggplants (S. melongena). This pathogen is widespread in humid conditions and thrives in wet seasons. It caused the skin of eggplants to turn brown and dry up. The pathogen was distributed to over 40% of the individuals and reduced species productivity. This finding confirms the unsuitability of eggplants for paludiculture.

4.4. Economic benefits

In terms of the economic indicator, both the agro-sylvofishery and agri-silviculture projects have yet to produce optimal benefits to the broader community. A previous study found that Shorea balangeran/balangeran and Dyera polyphylla/jelutung offer higher economic values than current sonor rice practices4 (Ulya et al., 2018). S. balangeran is a well-known balangeran that can produce quality timber for use in construction and furniture (Indriani et al., 2019). The species has the potential to replace acacia in industrial plantations without drainage on peatland. S. balangeran and D. polyphylla requires lengthy return-on-investment periods due to its long-term harvest cycles, which last for 15 years. The agri-silviculture project now has 9 years of experience with S. balangeran and D. polyphylla, another 6 years will be required to utilise its economic benefit. Yet, challenges remain in the market and value chain of S. balangeran. Its market demand is not yet well established (Sari, 2015) due to policy barriers associated with its cultivation on peat domes. Also, the demand of jelutung’s rubber has decreased because of a decline in the chewing gum market. In addition, some practitioners believe that jelutung exploitation is reduced because of the status of the species becoming protected (Nugroho and Msi, 2015). In fact, protection of jelutung species is for wild populations only and not for those cultivated in plantations. Serious community effort and support from other stakeholders are still lacking in order to achieve long-term beneficial/ economic impacts of cultivation of S. balangeran and D. polyphylla. Currently, the EFRDI of Palembang focuses on conservation because the project land belongs to the state and monetisation is not permitted. For non-timber forest product species, the economic benefits are starting to appear in the agro-sylvofishery project. In 2017, 12 species (Ipomoea aquatica, chilli, sweet corn, cung tomato or Solanum lycopersicum var., yardlong bean, cucumber, eggplant, spinach, spring onion, pineapple, snaps, and tomato) were tested. In 2018, some of these dryland crops were partly damaged during a flood in the wet season. In 2019, the species were planted in the dry season in combination and in rotation, with spinach or Ipomoea aquatica combined with tomato and eggplant. These species were planted based on water fluctu- ation in the area. From the list of species tested in the agro-sylvofishery project, most species5 were found to be unsuitable for peatland according to Giesen (2013) and (2015). However, the project manager argued that five (Ipomoea aquatica, chilli, sweet corn, cung tomato or Solanum lycopersicum var., and cucumber) of these species were potentially suitable for peatland because of their growth performance and productivity rate. The benefitecost ratio (BCR) of the species, for which a value > 1is considered acceptable. In 2019, the project manager found that the BCR of the species was encouraging: cung tomato: 1.23; sweet corn: 2.91; chilli: 3.13; cucumber: 1.85; and Ipomoea aquatica: 2.97. Meanwhile, other species such as eggplant and spinach were determined to be unsuitable due to pests and returned unsatisfactory results where the BCR <1. Although there is a market demand for the abovementioned vegetables in local markets, their prices are relatively low. For example, the price of chilli in a city market is approximately 90,000e100,000 IDR or USD 7.32/kg, but brokers typically pay farmers <20,000 IDR/kg. Farmers are unable to sell their vegetable products directly to vendors in local markets due to domination of wholesalers in the supply chain. This presents a classic structural barrier in which the market and supply chain are monopolised by stronger actors such as wholesalers. In the agro-sylvofishery project, additional economic benefit is supplied by the fishery. This practice is considered an alternative livelihood on peatlands. This project attempted to cultivate nine species of local fish; the species with the greatest potential was tembakang (Helostoma temminckii) or kissing gourami. Natural spawning was conducted on fish parents/

4 Burning land in preparation for rice cultivation. 5 Only Ipomoea aquatica is considered to be a paludiculture species by Giesen (2013) and (2015). 12 I. Budiman et al. / Global Ecology and Conservation 23 (2020) e01084 broodstock who travel from the lake during floods in the wet season. The pH of 6 during floods provides conditions for the fish to acclimatise. The harvest was conducted once a year in eight fishponds; each fishpond was 500 m2 in area and produced 93.5 kg of fish. The selling price was 25,000 IDR/kg, and the 2019 harvest generated an income of 18,700,000 IDR or USD 1,360.81. This result was not yet optimal because fish migration to the agro-sylvofishery location was disturbed by canals on the palm oil plantations. Currently, the EFRDI of Palembang is building a partnership with the Fishery Research Institute to find alternative local fish species that can adapt to a pH of 4. The EFRDI of Palembang is considering a plan to build a fish hatchery at a different location to increase the survival rate of fish.

4.5. Managing trade-offs in ‘compromised’ paludiculture operations

Both the agro-sylvofishery and agri-silviculture projects faced different degrees of trade-offs. In the agri-silviculture project, absence of canal blockings before the revegetation decreased the chances of achieving optimum impact for resto- ration. However, the project still survived large fires in 2015 and 2019. Restoration in the area restrained the spread of fires from nearby areas (Fig. 2). Meanwhile, the agro-sylvofishery project is still searching for a suitable cultivation method that accommodates both economic and conservation goals. From 2017, the project has been planting 11 dryland species and 1 native species on peatland, with calcification treatment. Among them, 7 species were found incapable of providing optimum economic benefits for the local communities, whereas the remaining 4 dryland species and 1 native species succeeded in providing positive economic benefits, according to benefitecost ratio calculations. In addition, the fishery practice also contributed in adding positive economic benefits. The agro-sylvofishery project is trying to follow the governmental restoration strategy (e.g., rewetting, revegetation, and revitalisation of livelihood) and dealing with the local context by mixing suitable paludiculture species, dryland crops and fishery practices. Yet, trade-offs are identified when conducting calcification to cultivate dryland species, selecting suitable species, and merging agroforestry practices with a fishery. These practices have more consideration to livelihoods goals and less to restoration/conservation purposes. Successful strategies to achieve both conservation and economic goals are still elusive. Trade-offs are increasing the vulnerability of peatland to fire. In the 2019 El Nino,~ almost 50% of the agro-sylvofishery area burned. In 2020, the project is trying to measure peat subsidence and peat loss from the fires. The causes of fires in the project area are being argued, while considering both external and internal factors. Externally, it was triggered by a prolonged dry season and slash and burn practices near the project area by the surrounding community. Internally, it was affected by the water management system in the project area. The fishery canal has mixed (potential) contribution in influencing the water table and peatland vulnerability to fires. First, it affects hydraulic conductivity and the water table of peat in the area. Second, the fishery canal is a source of water for fighting fires. A feasibility study to determine benchmarks for both the agri-silviculture and agro-sylvofishery projects was based on institutional experiences involving trial and error and more than 35 species. Modification and adaptive learning occurred continuously, along with debates among national and local experts. After 10 years of adaptive learning and adjustment with national restoration policy, the EFRDI of Palembang argued that compromised paludiculture should not be conducted in peat domes, but can be implemented in peripheral areas of peatland ecosystems, such as topogenous peatlands near rivers (Bastoni, 2019a). In this area, there is trade-off between the goals to increase community incomes and to conserve peat through restoration. An effective strategy is required to manage the trade-offs in compromised paludiculture. To keep the goals aligned with peatland restoration purposes, the EFRDI of Palembang argued that cultivation practices must be adjusted according to changes in the water table throughout the season. For example, dryland species can be planted during the dry season and fish farmed during the wet season. This strategy can minimise drainage activities that undermine conservation goals. However, the involvement of calcification for cultivating dryland species on peatland remains an issue. Calcification might have ecological impact by altering peat structure and increasing the decomposition of organic matter, thereby leading to peat subsidence and carbon emission (Radjagukguk, 2000). The EFRDI of Palembang is currently developing guidelines for agro-sylvofisheries based on the experience and obser- vations from the project. It comprises guidelines for the selection of locations, patterns of cultivation based on yearly fluc- tuations of the water table, utilisation of water bodies between canal blockings for fishponds, and potential to merge operations with ecotourism. The EFRDI of Palembang is planning to expand its current agro-sylvofishery project to 250 ha by utilising existing canals that have been blocked by national governments. These canals will be used for fishery practices. The EFRDI of Palembang argued that this strategy will not make new drainage but accelerate revegetation progress. These ideas present risks and opportunities for the restoration of peatland ecosystems.

5. Discussion

This novel study can be an important lesson for paludiculture development in other tropical peatlands such as in Southeast Asia, the Democratic Republic of Congo and Peru. This discovery of the effectiveness and the progress of ‘compromised’ paludiculture for peatland restoration provide an alternative approach to the challenge of ecological conservation in tropical peatlands. Both studied projects adapted some paludiculture principles and merged them with alternative livelihoods such as the fishery and dryland species. The findings show the agro-sylvofishery and agri-silviculture projects made a different degree of contributions to peatland restoration, considering the different starting time of each project. With respect to I. Budiman et al. / Global Ecology and Conservation 23 (2020) e01084 13 rewetting, both projects were associated with limited impacts because very few canal blockings were constructed in some canals. Neither project area was fully rewetted. When it came to revegetation and revitalisation of livelihoods, the EFRDI of Palembang was forced to trade-off conservation and economic goals to obtain social acceptance from donors and the local community. For example, the agro-sylvofishery project is considered a winewin solution to increase land productivity and minimise peat degradation. This project received little support in managing trade-offs and the research institute operator also had limited resources. The agro-sylvofishery has been a well-known peatland restoration concept that adapts paludiculture principles. However, the concept of this project does not fully adopt the principles of paludiculture. First, it does not fully utilise suitable species that can grow well in acidic peat conditions. To derive quick economic benefits, the project instead used calcification to adjust the peat pH to neutral (pH 6.5e7.5) conditions required to plant dryland species. This explains why four species (chilli, sweet corn, cung tomato or Solanum lycopersicum var., and cucumber), argued to be potential species by the EFRDI of Palembang, mostly differ from those in the paludiculture species list prepared by Giesen (2013) and Giesen (2015). Considering ecological impact of calcification on peatland and the inability of dryland species to support peat formation, agroforestry can be an alternative to mixing species such as jelutung with horticulture species such as mangosteen that are suitable in acidic peat conditions (Giesen and Sari, 2018). Second, the agro-sylvofishery concept involves a fishery canal that relates to peatland water management systems. Due to its contribution in accomplishing rapid economic returns for the local community, another institution such as Sriwijaya University has been trying to replicate the concept in another area. Experts have argued that the closed-loop fishery canal will not drain peatlands due to the existence of canal blockings in the area. However, in this study, there are two canals near the project and the blockings were only constructed in a small canal. The canal blockings were also constructed in 2016, whereas the project was initiated in 2017. The project therefore did not have enough time to fully rewet the peatland before it was replanted. In addition, because there has not been any canal blocking on the primary and secondary canals surrounding the project site, the hydraulic conductivity of peat is high, the changes in water level fluctuations in the agro-sylvofishery site are still very dynamic, and it was impacted by its surrounding water level. These conditions have not been able to maintain a high water level near the peat surface. A study found that a specific water management system with a trench and controlled irrigation rate per trench can manage evapotranspiration rates and saturated hydraulic conductivity in peatlands (Iiyama et al., 2005), but such a system was not found in the agro-sylvofishery operation examined in this study. Thus, it was difficult to manage the evapotranspiration rate and hydraulic conductivity in the agro-sylvofishery project. The water table in the closed-loop canal is influenced by drainage activities in the surrounding area, the subsidence rate is also affected. This relationship is relatively stronger during prolonged dry seasons. The construction of more and improved canal blockings is therefore required in the canals near the project area, along with a specific water management system with a trench and controlled irrigation rate per trench, to manage evapo- transpiration rates and saturated hydraulic conductivity (Giesen and Sari, 2018). In the agri-silviculture project, some conservation goals showed positive progress in the form of tree height, carbon sequestration performance, and less unstable fluctuation in the water table. This outcome can be further enhanced by paying attention to hydrological parameters, nutrient content, acidity-alkalinity gradients, and base cation content, which are closely related to the composition of the vegetation. The influence of hydrological parameters on water chemistry regimes is important as they control the chemical and biotic processes in peatland ecosystems. The water chemistry regimes in degraded peatland were found to differ significantly from their natural counterparts (Iqbal and Tachibana, 2007). Regarding rewetting goals in both projects, it was difficult to comply with ideal requirements to maintain the water table at 0.2 m. In the 2018 dry season, the water table at the agro-sylvofishery project reached 0.4 m, and in the 2017 dry season, the water table at the agri-silviculture project sank to 0.6 m. These figures worsened during the 2019 El Nino,~ and the results confirmed those of previous research in other areas (BRG, 2019). These figures partly met the Indonesian regulatory re- quirements for the 0.4 water table, although the regulation is unclear as to whether the 0.4 m is an average number or for the wet or the dry season (Sari, 2020). Scholars have argued that the regulatory requirement concerning water tables is not a scientific standard but a compromise between environment and plantation owners (Gunawan, 2018). Studies have shown that maintaining the peatland ground water levels at 0.4 m results in a reduction in the subsidence rate of 25%e30% and in emissions of 25%e30%. Although this level is better than that the lower levels such as 0.65 m, in the long term, the 0.4-m level is still far from sustainable (Evans et al., 2019). For the economic goals of paludiculture in both projects, a lack of market demand and a strategy for market creation remain pressing issues, particularly for Shorea balangeran, Dyera polyphylla, and Gonystylus bancanus. Previous research has suggested similar conclusions (Tata et al., 2016). Economic metrics were further complicated by different values for Dyera polyphylla or jelutung among different islands. The jelutung in Sumatra differ from those in Kalimantan or Borneo. There are intraspecific regional differences that are not apparent at the species level. Another top peat species is sago palm. It has high proven economic and commercial value and it is more popular in some areas and therefore enjoys a stronger market and value chain. For example, sago is the main cash crop on some peat islands in Riau Province such as Tebing Tinggi, Bengkalis and Padang, where it provides a stable livelihood for many farmers (Jong, 2001). In Jambi, sago used to be cultivated until a few decades ago, but according to provincial government staff, this tradition was lost and the cultivation of sago disappeared (Giesen, 2015; Tata, 2019a,b). In South Sumatra, sago palm is not a common cash crop in peatlands (Ehara et al., 2017). A popular peatland species with economic benefit in South Sumatra is purun or sedge (Lepironia articulate)(Goib et al., 2019). Purun is a wild plant that is not used for cultivation. This species is not found in paludiculture projects in South Sumatra. The 14 I. Budiman et al. / Global Ecology and Conservation 23 (2020) e01084 diversity of commercial paludiculture species in different areas shows that local socioeconomic contexts need to be considered when selecting suitable paludiculture species. Assessment of community perceptions towards agro-sylvofishery and agri-silviculture on peatlands revealed that some community groups are aware of mixed cropping patterns (i.e., agroforestry) that combine tree crops typical of peat swamps with agricultural crops and fish farming. This has led to increased interest in agri-silviculture and agro-sylvofishery culti- vation (Tampubolon et al., 2019). However, some stakeholders also fear that flooding in wet season will threaten the quality of agri-food crops on peatlands (Tata et al., 2016). Overall, stakeholder awareness regarding the potential of alternative peatland management techniques, such as paludiculture, is increasing; however, many participants are uninformed about the urgency of rewetting as the first step in paludiculture practices, the risk of drainage, and potential suitable species. Beyond agro-sylvofishery and agri-silviculture, the EFRDI of Palembang also introduced an agri-silvo-pasture concept as another compromised paludiculture practice. The agro-silvo-pasture adds livestock management of a buffalo swamp to a paludiculture operation (EFRDIP, 2017). Silvo-pasturing has been practised by the local community as the main livelihood for several years. However, while agro-sylvofishery and agri-silviculture have been fully practised, an agri-silvo-pasture has yet to be fully implemented in South Sumatra. The EFRDI had completed a design for such a project but still must obtain funding for its implementation. Experts differ on the knowledge of the agri-silvo-pasture plan. Shrestha et al. (2004) argued that an agri-silvo-pasture should integrate trees, forage and the grazing of buffalo in a mutually beneficial manner, while utilising the principles of managed grazing as one of several distinct forms of agroforestry. Land stewardship and diversification of income are major strengths of silvo-pasturing, which offers potential environmental benefits and enjoys government support (Payne, 2012; Shrestha et al., 2004). Another expert doubts that this application will result in true paludiculture. Instead, enhanced emissions can be expected because the presence of buffaloes can increase peatland degradation through soil mixing/churning and the addition of manure (Campanile et al., 2010). Silvo-pasture operations are also prohibited by the Indonesian Peatland Restoration Agency (BRG) due to contradictory reactions from ruminants (such as buffaloes) and vegetation. Duck rearing has been proposed as an alternative to buffalo rearing and herding (Bastoni, 2019b). Agro-sylvofishery, agri-silviculture and agri-silvo-pasture are examples of ‘compromised’ paludiculture in tropical peat- lands in middle-income countries such as Indonesia. These projects make trade-offs between the conservation goal of peatland restoration and the economic goals of village communities, with a greater emphasis on the latter due to requests from donors and/or stakeholders, such as policymakers or local governments. Ideally, paludiculture for peatland restoration should utilise the principle of socioeecological restoration where benefits will come in tangible economic benefits such as cash income and intangible benefits such as maintaining healthy ecosystems (Tata, 2019a,b). In both paludiculture projects studied here, a lack of resources hampered monitoring and evaluation, thus aggravating undesirable environmental impacts that tend to be ignored. This situation can be worsened by paludiculture projects that are scattered and fragmented in the country (Giesen, 2013), thereby undermining the opportunity for adaptive learning (Budiman and Smits, 2020). For practitioners, the ability of paludiculture to provide significant benefits to farmers and/or industries is still being examined. In central Europe, the feasibility and competitiveness of harvesting paludiculture species are principally influenced by the availability of mature technology, legal restrictions, agricultural subsidies, remuneration for external benefits and opportunity costs of present farming activities. Moreover, the laws and policies in central Europe determine whether a balanced provision of ecosystem services is hindered or promoted by peatlands used for agriculture (Wichmann, 2017). Comparatively, mature technology, legal codes, agricultural subsidies and remuneration for external benefits to paludiculture are not yet available in most tropical peatland countries. To address the abovementioned challenges, integrated policies and institutional approaches are necessary (Wichtmann et al., 2016). Specific regulations that support paludiculture development will open opportunities to address those chal- lenges. These policies must meet the demands of climate justice and respect the rights of smallholders (Budiman, 2019). Multi-sectoral and multi-stakeholder collaborations and joint financing mechanisms can be initiated to strengthen and expand the existing paludiculture operations and fund new projects (Joosten et al., 2016). This collaboration can be developed into a special pilot zone for paludiculture and restoration of peatland ecosystems (Budiman et al., 2020; Damuri et al., 2015). To facilitate collaboration, an existing paludiculture association of practitioners and scholars can be empowered. This collaboration initiative should include capacity building for institutions and communities in the form of learning hub plat- forms that connect farmers, investors, non-governmental organisations and buyers (Budiman, 2018; Tanneberger and Wichtmann, 2011). Increasing the generic and specific capacity of stakeholders can influence the desired outcomes of the project (Ismail et al., 2019). In addition, a local institutional arrangement could also help tackle the issue of a low market demand and a weak supply chain for paludiculture products. Village business entities (BUMD) and microfinance can provide financial and policy support to paludiculture farmers by partnering with local markets and retailers to resolve supply chain issues (Budiman et al., 2016). Such an arrangement provides opportunities to increase the competitiveness of paludiculture products and to deliver better economic benefits to the local community. Moreover, it can enhance farmers’ motivation to develop paludiculture for peatland restoration. Furthermore, data-driven monitoring and evaluation processes need to be applied to both the existing and new projects (Berube and Lavoie, 2000; Bonn et al., 2016) to enable adaptive learning and increase the quality of paludiculture practices, its project management and its business development (Abel and Joosten, 2012; Berube and Lavoie, 2000; Schroder€ et al., 2015). For example, continuous monitoring must be conducted to control and protect plants from pests that tend to increase due to I. Budiman et al. / Global Ecology and Conservation 23 (2020) e01084 15 the rise of peatlands humidity6. Water loggers are required to monitor water tables in paludiculture and peatland restoration projects. Future research on these policy and institutional topics are required to integrate paludiculture into regulated sus- tainable peatland management. In the long term, the upscaling of paludiculture operations may challenge peat restoration efforts in term of logistics and available infrastructure. Large-scale paludiculture implementation may require adaptation of machinery for harvesting (Joosten et al., 2016) in exceptional circumstances. It involves the use of machinery that can cause peat subsidence due to compaction, which is the shrinkage and compression of aerated peat (Evans et al., 2019; Schroder€ et al., 2015). Therefore, development of machinery and harvesting practice that reduces pressure on peat soils is required. Ensuring an efficient harvesting process is essential to reduce production costs and boost economic benefits from paludiculture. Improving effi- ciency rates indicate the elimination of logistical bottlenecks and increase in track stability on rewetted peat areas across multiple harvest access points, which otherwise can lead to multiple crossings on peat areas (Schroder€ et al., 2015). Pal- udiculture needs to be supported by sustainable environmentally friendly technologies. Thereafter, schemes such as rewards for environmental services will be suitable in paludiculture for peatland restoration (Tata, 2019a,b).

6. Conclusion

Theoretically and by definition, paludiculture should be a winewin solution to restoring degraded peatlands, reducing emissions, avoiding fire risks, improving food security and eradicating poverty. At sites designated for conservation, pal- udiculture is considered a cost-effective management option that can mitigate drainage and fire damage. For local com- munities, paludiculture can also cause socioeconomic impacts and enhance horticulture industries (Joosten et al., 2014). Both of the projects studied here are categorised as ‘compromised’ paludiculture because they did not follow all the paludiculture principles. The agri-silviculture project did not rewet the peatland before beginning revegetation. The project focused on native species (such as Dyera polyphylla) for peat swamp forest, which have been found to be effective for revegetating peatland and its ecosystem restoration. In the sixth year, the project conducted soil rewetting and attempted to plant dryland species, but the dryland species failed. The agri-silviculture project follows paludiculture principles for selecting native species and avoiding drainage to maintain peat bodies. In the agro-sylvofishery project, although the soil rewetting was conducted 1 year before revegetation, this duration was found to be insufficient to fully rewet the area. Moreover, the rewetting was not completed as canal blocking was not installed in a big open canal near the project area. The agro-sylvofishery project also experienced difficult trade-offs between restoring peat bodies and providing immediate economic benefits to the local community. The project integrated a fishery canal into the landscape and conducted peat calcification to support dryland species. The progress of the agro-silvifishery was found to be rather limited to supporting the rewetting of the peatland in the project area; however, the project reported positive progress and resulted in economic benefits from dryland species and the fishery. This project is still searching for a suitable pattern to align the cultivation of dryland species and the construction of a closed-loop fishing canal with efforts to minimise its ecological impact. A more specific water management system involving additional and better canal blockings are required in the area to fully rewet the peatland. The EFRDI of Palembang plans to incorporate more water loggers to monitor water table levels in the area. Trade-offs were made by the agro-sylvofishery project due the need to find alternative livelihoods for local people near the peatlands and to mitigate them from slash and burn practices. The agro-sylvofishery project is a compromised paludiculture practice that provided economic benefits. Harvests from dryland crops and the fishery in the agro-sylvofishery project provided income for the community. However, the fishery canal and the use of unsuitable dryland crops for long time could potentially undermine restoration goals to maintain peat bodies and sustain ecosystem services. The project owner is currently managing this trade-off through adjustments of cultivation and livelihood patterns with seasonal changes of water table fluctuation. Beyond the project, debate and misconceptions or misinterpretations among scientists and practitioners about pal- udiculture principles remain, such as in water management and the selection of species. Agro-sylvofishery is often criticised due to the involvement of a fishery canal and embankments. The existence of the canal next to other open canals without sufficient and proper blocking poses the threat of draining peatlands. Further research is required on a specific water management system and its impact on water tables, peat hydraulic conductivity and soil moisture in the agro-sylvofishery approach. Regarding the selection of species, some scientists and practitioners argue that more strategic selection is required along with improvements to business strategies. Despite the challenges faced by the compromised paludiculture projects detailed in this study, farming activities in the form of agro-sylvofishery, agri-silviculture and agri-silvo-pasture in Indonesia present opportunities for revitalisation of community livelihoods on peatland as alternative conservation strategy. These livelihoods can help communities avoid slash and burn practices that degrading peatlands. Further research is warranted to investigate the long-term impacts of livelihood revitalisation to ecological restoration and conservation. As a way forward, continuous monitoring and impact evaluation studies are required for projects that adapt paludiculture principles to tropical peatlands. The ability of compromised paludiculture to restore peatland ecosystem services, produce

6 Caused by more frequent extreme rainfalls. 16 I. Budiman et al. / Global Ecology and Conservation 23 (2020) e01084 food and wood and regulate climate and water management needs to be monitored. The result can help policymakers and implementing agencies to balance conservation (e.g., rewetting and revegetation) with economic goals, particularly in the case of agro-sylvofishery. Furthermore, equal cooperation among stakeholders (i.e., government, private sectors, community and non-governmental organisations) is required to scale up paludiculture practices and ensure they have sustainable im- pacts. These lessons should be noted by other paludiculture applications on tropical peatlands.

Funding

This work was supported by the World Resources Institute Indonesia and the Norwegian Ministry of Foreign Affairs (NMFA). The paludiculture project implementation was funded by the ITTO, BRG and EFRDI of Palembang.

Declaration of competing interest

There are no conflicts of interest to declare.

Acknowledgements

Thanks to Balitbang LHK or EFRDI of Palembang, which has been working hard to develop and inspire adaptations of paludiculture principles in South Sumatra. Thanks to WRI South Sumatra (especially Chandra Irawadi Wijaya and Jasnari), Septika Sihite and Dean Affandi for helping writing process of this paper.

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