Policies aiming to preserve vegetated coastal ecosystems (VCE; tidal marshes, mangroves and seagrasses) to mitigate greenhouse gas emissions require national assessments of blue carbon resources. Here, we present organic carbon (C) storage in VCE across Australian climate regions and estimate potential annual CO2 emission benefits of VCE conservation and restoration. Australia contributes 5–11% of the C stored in VCE globally (70–185 Tg C in aboveground biomass, and 1,055–1,540 Tg C in the upper 1 m of soils). Potential CO2 emissions from current VCE losses are estimated at 2.1–3.1 Tg CO2-e yr-1, increasing annual CO2 emissions from land use change in Australia by 12–21%. This assessment, the most comprehensive for any nation to-date, demonstrates the potential of conservation and restoration of VCE to underpin national policy development for reducing greenhouse gas emissions. Policies aiming to preserve vegetated coastal ecosystems (VCE) to mitigate greenhouse gas emissions require national assessments of blue carbon resources. Here the authors assessed organic carbon storage in VCE across Australian and the potential annual CO2 emission benefits of VCE conservation and find that Australia contributes substantially the carbon stored in VCE globally.

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Australian vegetated coastal ecosystems as global hotspots for climate change mitigation

https://faculty.washington.edu/jff/Lindenmayer_Franklin_Fischer_Management_Principles_Biodiversity_BC_2006.pdf

General management principles and a checklist of strategies to guide forest biodiversity conservation

Indonesian mangrove carbon stocks are estimated to be 1,083 ± 378 MgC ha−1. In the past three decades Indonesia has lost 40% of its 2.9 Mha of mangroves; this is estimated to have resulted in annual CO2-equivalent emissions of 0.07–0.21 Pg. Mangroves provide a wide range of ecosystem services, including nutrient cycling, soil formation, wood production, fish spawning grounds, ecotourism and carbon (C) storage1. High rates of tree and plant growth, coupled with anaerobic, water-logged soils that slow decomposition, result in large long-term C storage. Given their global significance as large sinks of C, preventing mangrove loss would be an effective climate change adaptation and mitigation strategy. It has been reported that C stocks in the Indo-Pacific region contain on average 1,023 MgC ha−1 (ref. 2). Here, we estimate that Indonesian mangrove C stocks are 1,083 ± 378 MgC ha−1. Scaled up to the country-level mangrove extent of 2.9 Mha (ref. 3), Indonesia’s mangroves contained on average 3.14 PgC. In three decades Indonesia has lost 40% of its mangroves4, mainly as a result of aquaculture development5. This has resulted in annual emissions of 0.07–0.21 Pg CO2e. Annual mangrove deforestation in Indonesia is only 6% of its total forest loss6; however, if this were halted, total emissions would be reduced by an amount equal to 10–31% of estimated annual emissions from land-use sectors at present. Conservation of carbon-rich mangroves in the Indonesian archipelago should be a high-priority component of strategies to mitigate climate change.

https://ir.library.oregonstate.edu/downloads/zw12z709w

The potential of Indonesian mangrove forests for global climate change mitigation

We combined two existing datasets of vegetation aboveground biomass (AGB) (Proceedings of the National Academy of Sciences of the United States of America, 108, 2011, 9899; Nature Climate Change, 2, 2012, 182) into a pan-tropical AGB map at 1-km resolution using an independent reference dataset of field observations and locally calibrated high-resolution biomass maps, harmonized and upscaled to 14 477 1-km AGB estimates. Our data fusion approach uses bias removal and weighted linear averaging that incorporates and spatializes the biomass patterns indicated by the reference data. The method was applied independently in areas (strata) with homogeneous error patterns of the input (Saatchi and Baccini) maps, which were estimated from the reference data and additional covariates. Based on the fused map, we estimated AGB stock for the tropics (23.4 N–23.4 S) of 375 Pg dry mass, 9–18% lower than the Saatchi and Baccini estimates. The fused map also showed differing spatial patterns of AGB over large areas, with higher AGB density in the dense forest areas in the Congo basin, Eastern Amazon and South-East Asia, and lower values in Central America and in most dry vegetation areas of Africa than either of the input maps. The validation exercise, based on 2118 estimates from the reference dataset not used in the fusion process, showed that the fused map had a RMSE 15–21% lower than that of the input maps and, most importantly, nearly unbiased estimates (mean bias 5 Mg dry mass ha−1 vs. 21 and 28 Mg ha−1 for the input maps). The fusion method can be applied at any scale including the policy-relevant national level, where it can provide improved biomass estimates by integrating existing regional biomass maps as input maps and additional, country-specific reference datasets.

/pdf/an-integrated-pan-tropical-biomass-map-using-multiple-3vgog4avkt.pdf

An integrated pan‐tropical biomass map using multiple reference datasets

In many parts of the world forest disturbance regimes have intensified recently, and future climatic changes are expected to amplify this development further in the coming decades. These changes are increasingly challenging the main objectives of forest ecosystem management, which are to provide ecosystem services sustainably to society and maintain the biological diversity of forests. Yet a comprehensive understanding of how disturbances affect these primary goals of ecosystem management is still lacking. We conducted a global literature review on the impact of three of the most important disturbance agents (fire, wind, and bark beetles) on 13 different ecosystem services and three indicators of biodiversity in forests of the boreal, cool- and warm-temperate biomes. Our objectives were to (i) synthesize the effect of natural disturbances on a wide range of possible objectives of forest management, and (ii) investigate standardized effect sizes of disturbance for selected indicators via a quantitative meta-analysis. We screened a total of 1958 disturbance studies published between 1981 and 2013, and reviewed 478 in detail. We first investigated the overall effect of disturbances on individual ecosystem services and indicators of biodiversity by means of independence tests, and subsequently examined the effect size of disturbances on indicators of carbon storage and biodiversity by means of regression analysis. Additionally, we investigated the effect of commonly used approaches of disturbance management, i.e. salvage logging and prescribed burning. We found that disturbance impacts on ecosystem services are generally negative, an effect that was supported for all categories of ecosystem services, i.e. supporting, provisioning, regulating, and cultural services (P < 0.001). Indicators of biodiversity, i.e. species richness, habitat quality and diversity indices, on the other hand were found to be influenced positively by disturbance (P < 0.001). Our analyses thus reveal a 'disturbance paradox', documenting that disturbances can put ecosystem services at risk while simultaneously facilitating biodiversity. A detailed investigation of disturbance effect sizes on carbon storage and biodiversity further underlined these divergent effects of disturbance. While a disturbance event on average causes a decrease in total ecosystem carbon by 38.5% (standardized coefficient for stand-replacing disturbance), it on average increases overall species richness by 35.6%. Disturbance-management approaches such as salvage logging and prescribed burning were neither found significantly to mitigate negative effects on ecosystem services nor to enhance positive effects on biodiversity, and thus were not found to alleviate the disturbance paradox. Considering that climate change is expected to intensify natural disturbance regimes, our results indicate that biodiversity will generally benefit from such changes while a sustainable provisioning of ecosystem services might come increasingly under pressure. This underlines that disturbance risk and resilience require increased attention in ecosystem management in the future, and that new approaches to addressing the disturbance paradox in management are needed.

https://www.onlinelibrary.wiley.com/doi/pdf/10.1111/brv.12193

Natural disturbance impacts on ecosystem services and biodiversity in temperate and boreal forests.

This report describes the approaches necessary for the measurement, monitoring and reporting of structure, biomass and carbon stocks in mangrove forests. Mangroves are coastal ecosystems providing numerous ecosystem services affecting both marine and terrestrial resources. In addition, they contain substantial carbon stocks and, due to high rates of deforestation, are significant sources of carbon emissions. Because of their value as carbon stocks and sinks and their numerous other benefits, mangroves could be excellent candidates for carbon mitigation programmes including Reducing Emissions from Deforestation and Forest Degradation, and Enhancing Forest Carbon Stocks in Developing Countries (REDD+). This publication outlines biologically relevant and statistically valid approaches to the efficient and accurate assessment of ecosystem structure, biomass and carbon stocks of mangrove forests.

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Protocols for the measurement, monitoring and reporting of structure, biomass and carbon stocks in mangrove forests.

We present data from a study of early conifer regeneration and fuel loads after the 2002 Biscuit Fire, Oregon, USA, with and without postfire logging. Natural conifer regeneration was abundant after the high-severity fire. Postfire logging reduced median regeneration density by 71%, significantly increased downed woody fuels, and thus increased short-term fire risk. Additional reduction of fuels is necessary for effective mitigation of fire risk. Postfire logging can be counterproductive to the goals of forest regenration and fuel reduction.

/pdf/post-wildfire-logging-hinders-regeneration-and-increases-4tqszkbm3w.pdf

Post-wildfire logging hinders regeneration and increases fire risk.

Coastal mangrove forests provide a broad array of ecosystem services including fisheries production, sediment regulation, wood production and protection from storms and tsunamis. Similarly, peat swamp forests harbour a diverse range of flora and fauna, regulate water regimes and store large amounts of carbon deposited in organic materials below the ground. In Southeast Asia, the conversion rates of mangrove to other land uses, such as shrimp farms and settlements, are among the highest for any forest type. Furthermore, the conversion of peat swamp forests to oil palm and pulp wood plantations and the associated fires have been the main sources of greenhouse gas (GHG) emissions in the region during the past decade. With deforestation accounting for around 17% of global anthropogenic GHG emissions, the upcoming global mechanism known as Reducing Emissions from Deforestation and forest Degradation (REDD+) provides an important climate change mitigation option. This scheme offers economic incentives for conserving forests and associated carbon (C) stores in developing countries. Mangrove and peat swamp ecosystems are well suited to such strategies. However, although their high rates of C assimilation and export (fluxes) are known, their total C storage—the amount that may be emitted upon conversion—has not been well quantified. We measured total ecosystem C storage (above and below ground) in mangrove ecosystems in North Sulawesi, Central Kalimantan and Central Java, Indonesia. We assessed variations in mangrove C-pools along transects running inland from the ocean edge, as well as their vulnerability to sea-level rise and land use. In addition, in Tanjung Puting National Park, Central Kalimantan, we sampled both the total aboveground biomass and the belowground peat horizons to ascertain total ecosystem C-pools. Summary Our measurements show that total carbon storage in mangrove ecosystems is exceptionally high compared with most forest types, with a mean of 968 Mg C ha -1 and range of 863-1073 Mg C ha -1 . These carbon stocks result from a combination of large-stature forest (trees up to ~2 m in diameter) and organic-rich peat soils to a depth of 5 m or more. Aboveground C-stocks vary widely depending on stand composition and history, but belowground pools comprise a large portion of ecosystem C storage in most sites. Although mangrove composition is often stratified with distance from the ocean edge, C storage does not vary consistently along this gradient. Ecosystem C-pools at Tanjung Puting exceed 1000 Mg ha -1 in many of the sampled locations. All sampled stands had a depth to mineral soil of less than 1 m, with a mean peat depth of 45.5 ± 6.8 cm. Mean total C-stock was 894.3 Mg C ha -1 , with a range of 558- 1213 Mg C ha -1 . It should be noted, when considering these estimates of ecosystem pools, that peat depths of tropical peat swamp forests may be as much as 20 m (with an average depth of 3-5 m). Projected rates of sea-level rise (~1 cm yr -1 over the next century) are ~5-10 times higher than typical mangrove sediment accrual rates (1-2 mm yr -1 ), suggesting high susceptibility and a potential positive feedback via loss of C-stocks. Thus, the combination of very high C-stocks, susceptibility to land use activities and numerous ecosystem services makes tropical mangroves ideal candidates for REDD+, particularly if climate change mechanisms can be applied to promoting synergies between adaptation to climate change (e.g. local migration) and mitigation. However, additional studies to better quantify ecosystem C-pools and the potential impact of land cover change and fire are greatly needed in order to make sound policy decisions related to carbon financing through the REDD+ mechanism

/pdf/carbon-storage-in-mangrove-and-peatland-ecosystems-a-4jnvs6zbka.pdf

Carbon storage in mangrove and peatland ecosystems: a preliminary account from plots in Indonesia

The extent of tropical wetlands, the magnitude of loss, and the related socioeconomic ramifications of the destruction of Indonesian wetlands are of global significance The carbon density and rates of land-cover change in these ecosystems are amongst the highest of any forest type on Earth Therefore, addressing interrelated issues of climate change and land use could be valuable in generating new options on how mangroves and peatlands should be best managed This paper is produced by bringing together Indonesian and international scientists from diverse backgrounds and with diverse experiences in both freshwater and coastal tropical wetlands It describes the state of the science, significant research needs, and potential transdisciplinary approaches necessary to implement climate change adaptation and mitigation strategies

/pdf/tropical-wetlands-for-climate-change-adaptation-and-2g8d625az7.pdf

Tropical wetlands for climate change adaptation and mitigation: science and policy imperatives with special reference to Indonesia

Tropical peat swamp forests contain among the largest terrestrial carbon stocks on Earth. They support unique biological diversity, providing habitats for such charismatic species as the orangutan, Sumatran tiger, the Java rhino and the clouded leopard. Paradoxically, these peat swamps are also being deforested at alarming rates and, as a result, have shifted from being carbon sinks to sources of atmospheric greenhouse gasses. Tropical peat forests are strong candidates for inclusion in any climate change mitigation action (e.g. Reduced emissions from Deforestation and Degradation + (REDD+) and Nationally Appropriate Mitigation Actions (NAMAs)) because of (1) their large carbon stocks; (2) the large emissions that arise from their conversion; and (3) the loss of other important ecosystem services when the forests are converted to other uses. The purpose of this publication is to provide a convenient resource for those wishing to undertake the necessary field measurements of ecosystem C dynamics in peat swamp forests - especially C stocks, biomass, structure and fluxes. General approaches to laboratory procedures and data analysis for estimating C stocks are included. As a reference document, the handbook can be taken to the field as a quick guide to the procedures for measuring major C pools as defined by the Intergovernmental Panel on Climate Change (IPCC). The ecosystem C pools covered by this handbook are: aboveground biomass, belowground biomass, standing and downed coarse wood (CWD), understory biomass, forest litter and soil organic carbon. Although these protocols were designed for peat swamp forests, they can easily be adapted to other land use types or disturbed sites on organic wetland soils. For example, with only slight modifications in approaches to plant sampling, these methods can also be used to quantify stocks and fluxes in oil palm and other plantations on peat soils. It is our hope that practitioners of ecosystem C assessments will find this handbook a useful resource when measuring ecosystem C storage in the field.

/pdf/protocols-for-the-measurement-monitoring-and-reporting-of-2pfn2rkbeb.pdf

Protocols for the measurement, monitoring, and reporting of structure, biomass, carbon stocks and greenhouse gas emissions in tropical peat swamp forests

J.B. Kauffman

Papers

Protocols for the measurement, monitoring and reporting of structure, biomass and carbon stocks in mangrove forests.

Post-wildfire logging hinders regeneration and increases fire risk.

Carbon storage in mangrove and peatland ecosystems: a preliminary account from plots in Indonesia

Tropical wetlands for climate change adaptation and mitigation: science and policy imperatives with special reference to Indonesia

Protocols for the measurement, monitoring, and reporting of structure, biomass, carbon stocks and greenhouse gas emissions in tropical peat swamp forests