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Indonesia's tropical peatlands are crucial global carbon stores but have been heavily degraded in recent decades. We present seven principles for equitable and resilient tropical peatland restoration in Central Kalimantan, Indonesia, host to 19% of Indonesia's tropical peatland area, where local livelihoods, cultural practices, and indigenous social relations remain closely connected. Our collaborative methods employed a Delphi survey and focus group discussions with researchers from various disciplines to develop a shared vision for restoration. This vision served as a boundary object during interviews with diverse stakeholders involved in peatland restoration in Central Kalimantan, allowing for refinement and adaptation of the vision and the development of principles to achieve it. The principles emphasize inclusive and collaborative decision‐making, planning, and implementation; site‐specific approaches adapted to local social and ecological conditions; and ensuring the informed consent of and fair benefit distribution to all local social groups. They also emphasize a holistic, integrated, and long‐term approach to restoration that considers multiple aspects, including hydrological function, vegetation regeneration, fire prevention, locally appropriate livelihood benefits, inclusive governance, and adaptive management practices. These principles serve as a starting point for resilience‐oriented social‐ecological restoration practice and policy formulation, aiming to facilitate equitable, effective, and resilient tropical peatland restoration outcomes. [ABSTRACT FROM AUTHOR]

Climate warming has been linked to shrub expansion in alpine regions and the decomposition of shrub leaf litter and subsequent release of nutrients has been proposed as a mechanism to facilitate shrub growth. We quantified the rate of alpine shrub leaf litter decomposition (measured as mass loss) over the course of a year in four locally occurring alpine shrub species that grow across four alpine summits. We measured a range of environmental attributes at the study sites, and via a standard litter bag approach, we evaluated the effects of site elevation, the depth of litter bag deployment, the removal time, the species‐specific leaf area (SLA) and the accumulated growing degree days at each site on the total per cent and rate of litter decomposition (as mass loss). The higher elevation sites were cooler with more snow days than the lower sites. Soil moisture was higher early in the snow‐free season at the higher elevation sites. Linear mixed effect models indicated no significant effects of elevation on total and rate of litter decomposition, but there were significant positive effects of deployment depth and removal time and a significant negative effect of species SLA. There were significant negative relationships between the rate of decomposition and growing degree days, as decomposition slows through time. The modelled mean rates of shrub litter decomposition for each species indicated that there would be more and faster decomposition if winter and early spring conditions were to persist for a whole year, compared with the modelled rates of average annual conditions persisting for a whole year. Our results indicate that Australian alpine shrub litter decomposes readily, with the highest rates of decomposition occurring soon after deployment, which in this study was after a snowy winter at the start of the growing season in spring. [ABSTRACT FROM AUTHOR]

Peatlands are found on all continents, covering 3% of the global land area. However, the spatial extent and causes of metal enrichment in peatlands is understudied and no attempt has been made to evaluate global patterns of metal enrichment in bog and fen peatlands, despite that certain metals and rare earth elements (REE) arise from anthropogenic sources. We analyzed 368 peat cores sampled in 16 countries across five continents and measured metal and other element concentrations at three depths down to 70 cm as well as estimated cumulative atmospheric S deposition (1850–2009) for each site. Sites were assigned to one of three distinct broadly recognized peatland categories (bog, poor fen, and intermediate-to-moderately rich fen) that varied primarily along a pH gradient. Metal concentrations differed among peatland types, with intermediate-to-moderately rich fens demonstrating the highest concentrations of most metals. Median enrichment factors (EFs; a metric comparing natural and anthropogenic metal deposition) for individual metals were similar among bogs and fens (all groups), with metals likely to be influenced by anthropogenic sources (As, Cd, Co, Cu, Hg, Pb, and Sb) demonstrating median enrichment factors (EFs) > 1.5. Additionally, mean EFs were substantially higher than median values, and the positive correlation (< 0.40) with estimated cumulative atmospheric S deposition, confirmed some level of anthropogenic influence of all pollutant metals except for Hg that was unrelated to S deposition. Contrary to expectations, high EFs were not restricted to pollutant metals, with Mn, K and Rb all exhibiting elevated median EFs that were in the same range as pollutant metals likely due to peatland biogeochemical processes leading to enrichment of these nutrients in surface soil horizons. The global patterns of metal enrichment in bogs and fens identified in this study underscore the importance of these peatlands as environmental archives of metal deposition, but also illustrates that biogeochemical processes can enrich metals in surface peat and EFs alone do not necessarily indicate atmospheric contamination. [ABSTRACT FROM AUTHOR]

Drainage associated with land use change in tropical peatlands has increased the rate of decomposition of peat soils and contributed to CO2 emissions. Increased decomposition may result in changes in the composition of the soil organic carbon (SOC). We examined the carbon functional group composition and degree of decomposition of peat soils under five different land uses to understand the effects of changing management intensity on tropical peatland soils. Samples were collected from seven sites spanning five different land uses (forest, shrubland, fernland, revegetation, smallholder oil palm) at the Pedamaran peatland in South Sumatra, Indonesia. SOC composition, measured by Solid-state 13C Nuclear Magnetic Resonance (NMR) spectroscopy, was dominated by the alkyl carbon (C) functional group in managed peatlands. However, in the forest far from drainage canals, the SOC comprised predominantly O-alkyl C. The contributions of the functional groups ketone C, carbonyl C and O-aryl C were low and tended to occur in stable proportions throughout the soil profiles. Drainage and land use change significantly affected peat carbon chemistry. The effects were greatest under oil palm, where O-alkyl C had been depleted rapidly under aerobic conditions leading to a change in the dominant carbon functional group from O-alkyl C to alkyl C. Furthermore, our results indicate that the alkyl C:O-alkyl C ratio is a more useful and informative indicator of the degree of decomposition of peat soil than the traditionally used C:N ratio. This more nuanced understanding of the different types of carbon that make up tropical peat soils under different land uses can be applied to support peatland restoration. In particular, nutrient cycling and water availability are likely to be influenced by carbon functional group and degree of decomposition. In order to reduce fire risk and support Indonesia's aspirations to manage the national forest estate as a net carbon sink, further research into the links between peat soil organic carbon chemistry, revegetation performance and new peat accumulation is recommended. [ABSTRACT FROM AUTHOR]

In this article we propose and apply a methodology for collaboratively creating and reaching agreement over a shared vision for peatland restoration. The purpose is to identify a shared understanding of the various parts of a just, inclusive and sustainable restored peatland as well as productive tensions between and across divergent disciplinary domains focused on peatland restoration. We involved an interdisciplinary group of researchers and practitioners working on various aspects of tropical peatland restoration and management in Indonesia, where there is a recognised need for clearer goals and/or definitions of restoration outcomes to focus manifold stakeholder efforts. To increase opportunities for participation and interaction between participants, our methodology built on and adapted a well-established Delphi survey method by combining it with focus group discussions. This allowed multiple points of view to be considered and new knowledge to emerge. The vision produced through this process bridges across different disciplinary tensions to fulfil ecological and social outcomes. While the vision is specific to the complex political economic and socio-ecological context of Indonesia's tropical peatland, the phased methodology for collaborative visioning can be adapted for application to other social ecological challenges, or to guide planning and practice by other stakeholder groups aiming to articulate a desired future state. [ABSTRACT FROM AUTHOR]

Indonesia is committed to rewetting peatlands to reduce the risk of fires and to decrease national greenhouse gas emissions. The three main approaches currently being implemented for rewetting peatlands in Indonesia are: 1) installing dams in drainage canals - "canal blocking"; 2) filling in drainage canals - "backfilling"; and 3) drilling wells to access water to fight fires - "deep wells". Tumbang Nusa in Central Kalimantan was chosen in 2020 as a pilot village to trial fire management through rewetting, although some engineering and logistical questions remain. Peatland rewetting is a complex process, and it is essential to determine public support as well as the potential for communities to live and work with rewet peat landscapes. Community attitudes to rewetting and their involvement in the process are not well understood. This article reports on 20 interviews conducted with villagers in Tumbang Nusa about their perceptions of rewetting. It identifies that the general attitude to rewetting is positive, but there is confusion and a lack of involvement with regard to where deep wells have been drilled and where canal blocks are located, as well as how they work and can be used. Villagers are concerned about their livelihoods and the impacts of fire. To support communities where rewetting will occur, careful management of the physical processes is needed, but even more important is the need for greater involvement of local communities in actively developing possibilities for their own futures on rewet peat. [ABSTRACT FROM AUTHOR]

Tropical peatlands in Indonesia have attracted international and domestic attention and concern in recent decades. Indonesian peatlands provide globally significant climate regulation and biodiversity provisioning ecosystem services and are central to the lives of local communities, yet they have undergone significant degradation via drainage and fire. There is a growing call for scientific knowledge of the social, environmental and practice dimensions of peatland restoration in Indonesia. This Special Volume of Mires and Peat is a collaborative effort by an Indonesian and Australian team of biophysical and social scientists to showcase primary research and systematic reviews that engage with the complexity of tropical peatland fire, conservation and restoration in Indonesia. We explore lives above ground (people and plants) and below ground (microbes, plants and the dynamic peat itself) and identify the following four themes that cut across the individual articles: 1) Livelihoods and land use; 2) Community engagement; 3) Bringing together multiple knowledges; and 4) Carbon; and draw out globally applicable lessons. We suggest that these themes highlight future directions for research which engage with the complexity of tropical peatland restoration in Indonesia, while centring the voices of local communities to support equity and sustainability in the transition to rewet peatlands. [ABSTRACT FROM AUTHOR]

Savanna ecosystems comprise 22% of the global terrestrial surface and 25% of Australia (almost 1.9 million km2) and provide significant ecosystem services through carbon and water cycles and the maintenance of biodiversity. The current structure, composition and distribution of Australian savannas have coevolved with fire, yet remain driven by the dynamic constraints of their bioclimatic niche. Fire in Australian savannas influences both the biophysical and biogeochemical processes at multiple scales from leaf to landscape. Here, we present the latest emission estimates from Australian savanna biomass burning and their contribution to global greenhouse gas budgets. We then review our understanding of the impacts of fire on ecosystem function and local surface water and heat balances, which in turn influence regional climate. We show how savanna fires are coupled to the global climate through the carbon cycle and fire regimes. We present new research that climate change is likely to alter the structure and function of savannas through shifts in moisture availability and increases in atmospheric carbon dioxide, in turn altering fire regimes with further feedbacks to climate. We explore opportunities to reduce net greenhouse gas emissions from savanna ecosystems through changes in savanna fire management. [ABSTRACT FROM AUTHOR]

Bog peat soils have been accumulating at Wellington Plain peatland, Victoria, Australia for the last 3300 years. Now, dried peat soils are common adjacent to bog peats. The 14C basal age of dried peat is not different from the 14C basal age of bog peat, which supports the theory that dried peat formed from bog peat. A novel application of 210Pb dating links the timing of this change with the introduction of livestock to Wellington Plain in the mid-1800s. Physical loss of material appears to have been the dominant process removing material as bog peats drained to form dried peats, as indicated by the mass balances of carbon and lead. This research has implications for the post-fire and post-grazing restoration of bogs in Victoria's Alpine National Park, and the contribution of peat soils to Australia's carbon emissions. [ABSTRACT FROM AUTHOR]

Over recent decades, the combination of deforestation, peat drainage and fires have resulted in widespread degradation of Southeast Asia's tropical peatlands. These disturbances are generally thought to increase peat soil bulk density through peat drying and shrinkage, compaction, and consolidation. Biological oxidation and fires burning across these landscapes also consume surface peat, exposing older peat strata. The prevalence and severity of deforestation, peat drainage and fire are typically greater closer to canals, built to drain peatlands and provide access routes for people. We compared bulk densities of 240 cm peat profiles from intact forests and degraded peatlands broadly, and also assessed differences between degraded peatlands near-to-canals (50–200 m from the nearest canal) and far-from-canals (300+ m from the nearest canal). The effects of vegetation type and fire frequency on bulk density, irrespective of the distance from canal, were also investigated. Mean bulk density values ranged between 0.08 and 0.16 g cm−3 throughout the 240 cm peat profiles. Drainage of peat near-to-canals increased bulk density of peat above the minimum water table depth. Degradation by deforestation and fire also increased bulk densities of upper peat strata, albeit with greater variability. Peat sampled further from canals experienced less intense water table drawdowns, buffering them from drainage effects. These areas were also more commonly forested and burnt less frequently. Differences in bulk densities below minimum water table levels are less clear, but may reflect lowering of the current peat surface in degraded peatlands broadly. These results clearly show that important differences in bulk density exist across degraded peatlands that are spatially dependent on distance from canals and disturbance history. These landscape features should be taken into account when designing future bulk density sampling efforts and peatland restoration programs, or when extrapolating from existing sources in order to make accurate inferences from them. Unlabelled Image • Calculated degradation and distance from canal effects on peat bulk density (BD). • Measured peat BD at regular intervals down 2.4 m peat profiles • BD changed in relation to degradation history, distance from canal and peat depth. • Factors increasing bulk density appear compounded nearer to canals. • Processes which may have led to these effects on BD are discussed. [ABSTRACT FROM AUTHOR]

Peatlands account for 15 to 30% of the world's soil carbon (C) stock and are important controls over global nitrogen (N) cycles. However, C and N concentrations are known to vary among peatlands contributing to the uncertainty of global C inventories, but there are few global studies that relate peatland classification to peat chemistry. We analyzed 436 peat cores sampled in 24 countries across six continents and measured C, N, and organic matter (OM) content at three depths down to 70 cm. Sites were distinguished between northern (387) and tropical (49) peatlands and assigned to one of six distinct broadly recognized peatland categories that vary primarily along a pH gradient. Peat C and N concentrations, OM content, and C:N ratios differed significantly among peatland categories, but few differences in chemistry with depth were found within each category. Across all peatlands C and N concentrations in the 10-20 cm layer, were 440 ± 85.1 g kg-1 and 13.9 ± 7.4 g kg-1, with an average C:N ratio of 30.1 ± 20.8. Among peatland categories, median C concentrations were highest in bogs, poor fens and tropical swamps (446-532 g kg-1) and lowest in intermediate and extremely rich fens (375-414 g kg-1). The C:OM ratio in peat was similar across most peatland categories, except in deeper samples from ombrotrophic tropical peat swamps that were higher than other peatlands categories. Peat N concentrations and C:N ratios varied approximately two-fold among peatland categories and N concentrations tended to be higher (and C:N lower) in intermediate fens compared with other peatland types. This study reports on a unique data set and demonstrates that differences in peat C and OM concentrations among broadly classified peatland categories are predictable, which can aid future studies that use land cover assessments to refine global peatland C and N stocks., Competing Interests: There are no competing interests, (Copyright: This is an open access article, free of all copyright, and may be freely reproduced, distributed, transmitted, modified, built upon, or otherwise used by anyone for any lawful purpose. The work is made available under the Creative Commons CC0 public domain dedication.)

Designed, green infrastructures are becoming a customary feature of the urban landscape. Sustainable technologies for stormwater management, and biofilters in particular, are increasingly used to reduce stormwater runoff volumes and peaks as well as improve the water quality of runoff discharged into urban water bodies. Although a lot of research has been devoted to these technologies, their effect in terms of greenhouse gas fluxes in urban areas has not been yet investigated. We present the first study aimed at quantifying greenhouse gas fluxes between the soil of stormwater biofilters and the atmosphere. N2O, CH4, and CO2 were measured periodically over a year in two operational vegetated biofiltration cells at Monash University in Melbourne, Australia. One cell had a saturated zone at the bottom, and compost and hardwood mulch added to the sandy loam filter media. The other cell had no saturated zone and was composed of sandy loam. Similar sedges were planted in both cells. The biofilter soil was a small N2O source and a sink for CH4 for most measurement events, with occasional large emissions of both N2O and CH4 under very wet conditions. Average N2O fluxes from the cell with the saturated zone were almost five-fold greater (65.6 μg N2O-N m(-2) h(-1)) than from the other cell (13.7 μg N2O-N m(-2) h(-1)), with peaks up to 1100 μg N2O-N m(-2) h(-1). These N2O fluxes are of similar magnitude to those measured in other urban soils, but with larger peak emissions. The CH4 sink strength of the cell with the saturated zone (-3.8 μg CH4-C m(-2) h(-1)) was lower than the other cell (-18.3 μg CH4-C m(-2) h(-1)). Both cells of the biofilter appeared to take up CH4 at similar rates to other urban lawn systems; however, the biofilter cells displayed occasional large CH4 emissions following inflow events, which were not seen in other urban systems. CO2 fluxes increased with soil temperature in both cells, and in the cell without the saturated zone CO2 fluxes decreased as soil moisture increased. Other studies of CO2 fluxes from urban soils have found both similar and larger CO2 emissions than those measured in the biofilter. The results of this study suggest that the greenhouse gas footprint of stormwater treatment warrant consideration in the planning and implementation of engineered green infrastructures., (Copyright © 2013 Elsevier B.V. All rights reserved.)