Dan Friess

• Professor at Tulane University

Sea-level rise can threaten the long-term sustainability of coastal communities and valuable ecosystems such as coral reefs, salt marshes and mangroves. Mangrove forests have the capacity to keep pace with sea-level rise and to avoid inundation through vertical accretion of sediments, which allows them to maintain wetland soil elevations suitable f...

Significance This study quantifies the proximate drivers (i.e., replacement land uses) of mangrove deforestation across Southeast Asia between 2000 and 2012. Mangrove forests in the region were lost at an average rate of 0.18% per year. Aquaculture was a major pressure on mangrove systems during this period, but its dominance was lower than expecte...

Mangrove forests store high densitie of organic carbon, which, when coupled with high rates of deforestation, means that mangroves have the potential to contribute substantially to carbon emissions. Consequently, mangroves are strong candidates for inclusion in nationally determined contributions (NDCs) to the United Nations Framework Convention on...

Intertidal mangrove forests are a dynamic ecosystem experiencing rapid changes in extent and habitat quality over geological history, today and into the future. Climate and sea level have drastically altered mangrove distribution since their appearance in the geological record ∼75 million years ago (Mya), through to the Holocene. In contrast, conte...

Much uncertainty exists about the vulnerability of valuable tidal marsh ecosystems to relative sea level rise. Previous assessments of resilience to sea level rise, to which marshes can adjust by sediment accretion and elevation gain, revealed contrasting results, depending on contemporary or Holocene geological data. By analyzing globally distribu...

Mangroves are a critical habitat that provide a suite of ecosystem services and support livelihoods. Here we undertook a global analysis to model the density and abundance of 37 commercially important juvenile fish and juvenile and resident invertebrates that are known to extensively use mangroves, by fitting expert-identified drivers of density to...

The increasing species–area relationship (SAR) is a nearly universal ecological law. But recent theory has predicted that in systems with low large‐scale diversity the law should be violated and the SAR should be nearly flat at intermediate scales, with species richness roughly constant at some value typically greater than one. We tested this predi...

The East Asian-Australasian Flyway (EAAF) is widely recognised to be the most threatened of the eight flyways in the world, with wetlands rapidly lost due to land cover change, unsustainable use, and the wider impacts of climate change. The recently established Regional Flyway Initiative aims to bring a network of priority wetlands in the EAAF unde...

Blue carbon (BC) habitats (e.g., mangroves, tidal marshes, and seagrasses) are important CO2 sinks but are among the most threatened ecosystems on Earth. Substantial research over the last decade has quantified BC to evaluate the climate benefits associated with habitat conservation and restoration. However, the exponential growth in BC science has...

Southeast Asia (SEA) contributes approximately one-third of global land-use change carbon emissions, a substantial yet highly uncertain part of which is from anthropogenically-modified peat swamp forests (PSFs) and mangroves. Here, we report that between 2001–2022 land-use change impacting PSFs and mangroves in SEA generate approximately 691.8±97.2...

Conserving Southeast Asia’s mangroves is a vital natural climate solution, and their protection could be supported by blue carbon credits. However, such financing strategies expose conservation efforts to socioeconomic and climate change permanence risks. Here, we evaluate the potential impacts of permanence risks on the ability of blue carbon fina...

Coastal wetlands are important for their ability to regulate global climate through the sequestration and long‐term storage of carbon. Accurate quantification of ecosystem‐specific carbon dynamics (including sequestration, storage, and fluxes) is needed to develop accurate carbon budgets that inform climate change mitigation. Most work to quantify...

The paper can be downloaded here: https://drive.google.com/file/d/1e6JKz9-0tgyN_cPtLuSMj370JLMzMpeK/view?usp=sharing

The evolution of mangroves in response to sea-level rise will partially depend on the availability of accommodation space, which is influenced by the hydrodynamic setting. Here, we reconstruct mangrove evolution in a paleochannel of Sungei Jurong (i.e., Jurong River), Singapore via litho-, bio-, and chrono-stratigraphical analyses. Paleochannels ar...

Tidal marshes are threatened coastal ecosystems known for their capacity to store large amounts of carbon in their water-logged soils. Accurate quantification and mapping of global tidal marshes soil organic carbon (SOC) stocks is of considerable value to conservation efforts. Here, we used training data from 3710 unique locations, landscape-level...

Tidal wetlands are hotspots of soil accumulation due to high sedimentation rates and low soil oxygen concentrations that inhibit organic matter decomposition1. Accordingly, tidal wetlands can sequester “blue carbon” at much higher rates than other ecosystems2,3 helping to offset human emissions. Organic carbon burial is tightly linked to the cyclin...

One of the world’s largest “blue carbon” ecosystems, Louisiana’s tidal wetlands on the US Gulf of Mexico coast, is rapidly being lost. Louisiana’s strong legal, regulatory, and monitoring framework, developed for one of the world’s largest tidal wetland systems, provides an opportunity for a programmatic approach to blue carbon accreditation to sup...

Coastal wetlands are hotspots of carbon sequestration, and their conservation and restoration can help to mitigate climate change. However, there remains uncertainty on when and where coastal wetland restoration can most effectively act as natural climate solutions (NCS). Here, we synthesize current understanding to illustrate the requirements for...

The ‘Mangroves of the Warm Temperate Northwest Atlantic’ province is a regional ecosystem subgroup (level 4 unit of the IUCN Global Ecosystem Typology). It includes the marine ecoregions of Carolinian and Northern Gulf of Mexico. The biota is characterized by 3 species of mangroves: Avicennia germinans, Laguncularia racemosa, and Rhizophora mangle,...

The ‘Mangroves of the Warm Temperate Northwest Atlantic’ province is a regional ecosystem subgroup (level 4 unit of the IUCN Global Ecosystem Typology). It includes the marine ecoregions of Carolinian and Northern Gulf of Mexico. The extent of mangroves in the Warm Temperate Northwest Atlantic in 2020 was 83.1 km2, representing 0.1% of global ma...

Mangroves, tidal marshes and seagrasses have experienced extensive historical reduction in extent due to direct and indirect effects of anthropogenic land use change. Habitat loss has contributed carbon emissions and led to foregone opportunities for carbon sequestration, which are disproportionately large due to high ‘blue carbon’ stocks and seque...

Mangroves are a critical coastal habitat that provides a suite of ecosystem services and supports livelihoods. We undertake the first global analysis to estimate density and abundance of 37 commercially important fish and invertebrates that are known to extensively use mangroves. Geomorphic mangrove type, sea surface salinity and temperature, and l...

Tidal marshes are threatened coastal ecosystems known for their capacity to store large amounts of carbon in their water-logged soils. Accurate quantification and mapping of global tidal marshes soil organic carbon (SOC) stocks is of considerable value to conservation efforts. Here, we used training data from 3,710 unique locations, landscape-level...

Mangroves are one of the most carbon‐dense forests on the Earth and have been highlighted as key ecosystems for climate change mitigation and adaptation. Hundreds of studies have investigated how mangroves fix, transform, store, and export carbon. Here, we review and synthesize the previously known and emerging carbon pathways in mangroves, includi...

Geographic distribution of articles published in WIREs Climate Change in the last 5 years, with bubbles scaled by the number of articles per country. image

Mangrove forests are a highly productive ecosystem with important potential to offset anthropogenic greenhouse gas emissions. Mangroves are expected to respond differently to climate change compared to terrestrial forests owing to their location in the tidal environment and unique ecophysiological characteristics, but the magnitude of difference re...

Mangrove forests show amazing diversity in structure and process across scales, from site-scale patterns of vegetation distribution to global-scale biogeographic patterns of species, Gross Primary Productivity, above-ground biomass, and ecosystem service provision. Spatial patterns are apparent in mangroves because of the myriad links between bioph...

Carbon credits generated through jurisdictional-scale avoided deforestation projects require accurate estimates of deforestation emission baselines, but there are serious challenges to their robustness. We assessed the variability, accuracy, and uncertainty of baselining methods by applying sensitivity and variable importance analysis on a range of...

Blue carbon is attracting substantial interest as a natural climate solution. Focus has been on countries with large blue carbon stocks, though the high carbon densities of blue carbon ecosystems make them suitable for Small Island States with small coastal habitats. Small Island States hold 1806–2892 Tg of blue carbon, and mangroves alone offset >...

Coastal blue carbon ecosystems can be an important nature-based solution for mitigating climate change, when emphasis is given to their protection, management, and restoration. Globally, there has been a rapid increase in blue carbon research in the last few decades, with substantial investments on national scales by the European Union, the USA, Au...

The 'Mangroves of the Andaman' is a regional ecosystem subgroup (level 4 unit of the IUCN Global Ecosystem Typology) within the Andaman province. It includes intertidal forests and shrublands of the marine ecoregions of the Andaman and Nicobar Islands; the Andaman Sea Coral Coast of Myanmar and Thailand; and northwest Sumatra. The diverse biota is...

Mangroves of the Bay of Bengal is a regional ecosystem subgroup (level 4 unit of the IUCN Global Ecosystem Typology) spanning parts of South and Southeast Asia. It includes coastal areas of eastern India, Bangladesh, and northern and central Myanmar, and contains one of the largest single mangrove ecosystems in the world: the Sundarbans.Mangroves d...

Mangrove forests are highly productive ecosystems with important potential to offset anthropogenic greenhouse gas emissions. Due to their location in the tidal environment and unique ecophysiological characteristics, mangroves are expected to respond differently to climate change compared to terrestrial forests. However, the difference remains larg...

Coastal blue carbon ecosystems can be an important nature-based solution for mitigating climate change, when emphasis is given to their protection, management, and restoration. Globally, there has been a rapid increase in blue carbon research in the last few decades, with substantial investments on national scales by the European Union, the USA, Au...

This study is the first ever to gather local mangrove scientists, forest managers and policy-makers world-wide to identify the future scientific curiosity-driven and managerial need-driven questions to which science, management, and/or governance needs an answer.

Blue carbon ecosystems (mangroves, seagrasses and saltmarshes) are highly productive coastal habitats, and are considered some of the most carbon-dense ecosystems on the earth. They are an important nature-based solution for both climate change mitigation and adaptation. Quantifying blue carbon stocks and assessing their dynamics at large scales th...

Salinity-influenced ecosystems are projected to face a tree-level growth reduction as a response to climate change. Although large and mature trees play a central role in defining carbon dynamics and site conditions, their eco-physiological and functional responses to increasing salinity remain poorly understood. Therefore, we test our hypotheses,...

Mangrove ecosystems in the Caribbean are frequently exposed to hurricanes, leading to structural and regenerative change that elicit calls for recovery action. For those mangroves unaffected by human modifications, recovery can occur naturally. Indeed, observable natural recovery after hurricanes is the genesis of the “disturbance adaptation” class...

The ability of vegetated coastal ecosystems to sequester high rates of “blue” carbon over millennial time scales has attracted the interest of national and international policy makers as a tool for climate change mitigation. Whereas focus on blue carbon conservation has been mostly on threatened rural seascapes, there is scope to consider blue carb...

Mangroves continue to be threatened across their range by a mix of anthropogenic and climate change-related stress. Climate change-induced salinity is likely to alter the structure and functions of highly productive mangrove systems. However, we still lack a comprehensive understanding of how rising salinity affects forest structure and functions b...

Blue (coastal wetlands) and teal (inland wetlands) carbon ecosystems are long-term carbon sinks and are regarded as essential natural climate solutions. Yet, the same biogeochemical conditions favoring high carbon storage also promote the production of two potent greenhouse gases (GHGs)—methane and nitrous oxide—which can reduce the climate change...

Mangrove forests store high amounts of carbon, protect communities from storms, and support fisheries. Mangroves exist in complex social-ecological systems, hence identifying socioeconomic conditions associated with decreasing losses and increasing gains remains challenging albeit important. The impact of national governance and conservation polici...

We identified the function of mangrove ecosystems that underpin ecosystem services, their responses to extreme weather and climatic events, and their role as crucial social-ecological systems as important paradigms shaping mangrove research now and in times to come. Since themes around functions and connectivity, ecological resilience to extreme ev...

Nature-based coastal protection is increasingly recognised as a potentially sustainable and cost-effective solution to reduce coastal flood risk. It uses coastal ecosystems such as mangrove forests to create resilient designs for coastal flood protection. However, to use mangroves effectively as a nature-based measure for flood risk reduction, we m...

Mangroves continue to be threatened across their range by a mix of anthropogenic and climate change-related stress. Climate change-induced salinity is likely to alter the structure and functions of highly productive mangrove systems. However, we still lack a comprehensive understanding of how rising salinity affects forest structure and functions b...

Natural climate solutions are crucial interventions to help countries and companies achieve their net-zero carbon emissions ambitions. Blue carbon ecosystems such as mangroves, seagrasses, and tidal marshes have attracted particular attention for their ability to sequester and store carbon at densities that can far exceed other ecosystems. The scie...

Protecting existing mangrove forests is a priority for global conservation because of the wide range of services that these coastal forests provide to humankind. Despite the recent reduction in global rates of mangrove loss, high historical loss rates mean that there are at least 800,000 ha globally that are potentially suitable for mangrove re-est...

The world's nations are committed to keeping global temperature rises to less than 2°C to avoid the worst impacts of climate change. Such a target is crucial for mangrove forests, because they are located primarily in tropical and subtropical regions that are expected to see large changes in climatic conditions; their intertidal location and sensit...

Blue Carbon Ecosystems (BCEs) help mitigate and adapt to climate change but their integration into policy, such as Nationally Determined Contributions (NDCs), remains underdeveloped. Most BCE conservation requires community engagement, hence community-scale projects must be nested within the implementation of NDCs without compromising livelihoods o...

Coastal cities and their natural environments are vulnerable to the impacts of climate change, especially sea-level rise (SLR). Hard coastal defences play a key role in protecting at-risk urban coastal populations from flooding and erosion, but coastal ecosystems also play important roles in the overall sustainability and resilience of cities and u...

The global carbon sequestration and avoided emissions potentially achieved via blue carbon is high (∼3% of annual global greenhouse gas emissions); however, it is limited by multidisciplinary and interacting uncertainties spanning the social, governance, financial, and technological dimensions. We compiled a transdisciplinary team of experts to elu...

There are ambitious plans to restore hundreds of thousands of hectares of mangrove forests over the next 5 years to restore habitats and mitigate climate change. However, if not properly planned, such actions have the potential to fail. We outline a transdisciplinary plan for mangrove restoration based on strong scientific principles.

The purpose of the paper is to explore the potential coexistence of building with nature solution with existing civil coastal engineering approaches, in order to establish a deeper understanding of hybrid solutions and their potential role in shoreline protection. Civil coastal engineering approaches can play a vital supportive role in the establis...

There is an urgent need to halt and reverse loss of mangroves and seagrass to protect and increase the ecosystem services they provide to coastal communities, such as enhancing coastal resilience and contributing to climate stability.1,2 Ambitious targets for their recovery can inspire public and private investment in conservation,3 but the expecte...

The ability of seagrass meadows to reduce surface erosion and maintain or increase surface elevation is recognised as an important ecological function, which is expected to help protect coastlines. However, much of the evidence supporting this expectation is limited to large, broad leaf, subtidal populations of seagrass from temperate regions. In t...

Extreme weather events are a cause of mangrove forest loss and degradation globally. Almost half of the world’s mangroves are found in the tropical cyclone belt, and forests often experience disturbance in structure, functioning and ecosystem service provision. Understanding the factors that increase the vulnerability of mangroves to such disturban...

Seagrass meadows are important sinks of organic carbon (C org), in particular the near-surface C org pool (≤ 15 cm) compared to deeper sediments. Near-surface carbon is highly susceptible to disturbance and loss to the atmosphere , however, inadequate accounting for variability in this pool of carbon limits their uptake into carbon accounting frame...

Seagrass meadows are important sinks of organic carbon (Corg), in particular the near-surface Corg pool (≤ 15 cm) compared to deeper sediments. Near-surface carbon is highly susceptible to disturbance and loss to the atmosphere, however, inadequate accounting for variability in this pool of carbon limits their uptake into carbon accounting framewor...

Blue carbon ecosystems (BCEs), including mangrove forests, seagrass meadows and tidal marshes, store carbon and provide co-benefits such as coastal protection and fisheries enhancement. Blue carbon sequestration has therefore been suggested as a natural climate solution. In this Review, we examine the potential for BCEs to act as carbon sinks and t...

The status and potential degradation of an ecosystem is often difficult to identify, quantify, and characterize. Multiple, concurrent drivers of degradation may interact and have cumulative and confounding effects, making mitigation and rehabilitation actions challenging to achieve. Ecosystem status assessments generally emphasize areal change (gai...

Ecosystems play a potentially important role in sustainably reducing the risk of disaster events worldwide. Yet, to date, there are few comprehensive studies that summarize the state of knowledge of ecosystem services and functions for disaster risk reduction. This paper builds scientific evidence through a review of 529 English-language articles p...

Tropical coastal waters are highly dynamic and amongst the most biogeochemically active zones in the ocean. This review compares nitrogen (N) and phosphorus (P) cycles in temperate and tropical coastal waters. We review the literature to identify major similarities and differences between these two regions, specifically with regards to the impact o...

Mangrove restoration has become a popular strategy to ensure the critical functions and economic benefits of this ecosystem. This study conducts a meta-analysis of the peer-reviewed literature on the outcomes of mangrove restoration. On aggregate, restored mangroves provide higher ecosystem functions than unvegetated tidal flats but lower than natu...

A global review of mangrove forests - extent, condition, protection, ecosystem services, restoration, global mapping, policy, economics, community engagement

Decision makers are calling for actionable science to protect coastal ecosystems from adverse impacts. Future sea level rise (SLR) is expected to alter the spatial configuration of coastal habitats and their services. Ensuring conservation efforts are in optimal areas can be achieved using systematic conservation planning, yet plans rarely address...

Integration of mangroves in projects to reduce coastal flood risk is increasingly being recognised as a sustainable and cost-effective alternative. In addition to the construction of conventional hard flood protection infrastructure, mangroves not only contribute to attenuating flood events (functionality), they also recover in, and adapt to, a cha...

Coastal habitats have faced decades of loss caused by urbanization. Global recognition of the ecosystem services that coastal habitats provide has led to an emphasis on cities to adopt nature-based solutions (NBS). However, a broad assessment of urban areas and their potential to conserve remaining coastal habitat has not been undertaken. Here we a...

The vulnerability of the world’s tidal marshes to sea-level rise threatens their substantial contribution to fisheries, coastal protection, biodiversity conservation and carbon sequestration. Feedbacks between relative sea-level rise (RSLR) and the rate of mineral and organic sediment accumulation in tidal wetlands, and hence elevation gain, have b...

Mangroves have among the highest carbon densities of any tropical forest. These “blue carbon” ecosystems can store large amounts of carbon for long periods, and their protection reduces greenhouse gas emissions and supports climate change mitigation. Incorporating mangroves into Nationally Determined Contributions to the Paris Agreement and their v...

Aim Mangrove wetlands span broad geographical gradients, resulting in functionally diverse tree communities. We asked whether latitudinal variation, allometric scaling relationships and species composition influence mangrove forest structure and biomass allocation across biogeographical regions and distinct coastal morphologies. Location Global....

As urbanisation pressures on ecosystems are set to increase, trade-offs between ecosystem service are also likely to increase. Management strategies that minimise trade-offs and promote sustainable development to optimise ecosystem multi-functionality are therefore needed. Many coastal cities may however struggle to find the resources and capacity...

Despite the outsized role of mangrove forests in sustaining biodiversity, ecosystem function, and local livelihoods, the protection of these vital habitats through blue carbon financing has been limited.¹,² Here, we quantify the extent of this missed conservation and financial opportunity, showing that the protection of ∼20% of the world’s mangrove...

Positioned in the intertidal zone, mangrove forests are a key model ecosystem with which to observe and test biogeomorphological concepts. Understanding how mangroves interact with their intertidal environment, particularly tidal inundation, is important if we are to assess their vulnerability or resilience to accelerated sea-level rise. While vari...

Mangrove-mud coasts across the world erode because of uninformed management, conversion of mangrove forests into aquaculture ponds, development of infrastructure and urbanization, and/or extraction of groundwater inducing land subsidence. The accompanied loss of ecosystem values, amongst which safety against flooding, has far reaching consequences...

Mangroves have long been associated with human populations, as coastal communities rely on the various ecosystem services that mangroves provide. However, human degradation and destruction of mangrove forests is common, despite and because of our reliance on them as valuable ecosystems. Mangrove research and management must elucidate and reconcile...

Ecosystem services are now strongly applied to mangrove forests, though they are not a new way of viewing mangrove-people interactions; the benefits provided by such habitats, and the negative interactions (ecosystem disservices) between mangroves and people have guided perceptions of mangroves for centuries. This study quantified the ecosystem ser...

For centuries, mangrove forests and adjacent ecosystems have been cast in a negative light due to their (often perceived) ecosystem disservices. We give contemporary examples of how such viewpoints about mangroves continue to be communicated today, with potentially adverse consequences for mangrove conservation and public support. Since public perc...