Search Results (158)

Mangrove forests are widely recognized for their effectiveness as carbon sinks and serve as critical ecosystems for mitigating the effects of climate change. Current research lacks comprehensive, large-scale carbon storage datasets for wetland ecosystems, particularly across Mexico and other understudied regions worldwide. Therefore, the objective of this study was to develop a high spatial resolution map of carbon stocks, encompassing both aboveground and belowground components, within the Marismas Nacionales system, which is the largest mangrove complex in northeastern Pacific Mexico. Our approach integrates primary field data collected during 2023–2024 and incorporates some historical plot measurements (2011–present) to enhance spatial coverage. These were combined with contemporary remote sensing data, including Sentinel-1, Sentinel-2, and LiDAR, analyzed using Random Forest algorithms. Our spatial models achieved strong predictive accuracy (R² = 0.94–0.95), effectively resolving fine-scale variations driven by canopy structure, hydrologic regime, and spectral heterogeneity. The application of Local Indicators of Spatial Association (LISA) revealed the presence of carbon “hotspots,” which encompass 33% of the total area but contribute to 46% of the overall carbon stocks, amounting to 21.5 Tg C. Notably, elevated concentrations of carbon stocks are observed in the central regions, including the Agua Brava Lagoon and at the southern portion of the study area, where pristine mangrove stands thrive. Also, our analysis reveals that 74.6% of these carbon hotspots fall within existing protected areas, demonstrating relatively effective—though incomplete—conservation coverage across the Marismas Nacionales wetlands. We further identified important cold spots and ecotones that represent priority areas for rehabilitation and adaptive management. These findings establish a transferable framework for enhancing national carbon accounting while advancing nature-based solutions that support both climate mitigation and adaptation goals. Full article

Coastal blue carbon ecosystems (traditional types such as mangroves, salt marshes, and seagrass meadows; emerging types such as tidal flats and mariculture) play pivotal roles in capturing and storing atmospheric carbon dioxide. Reliable assessment of the spatial and temporal variation and the carbon storage potential holds immense promise for mitigating climate change. Although previous field surveys and regional assessments have improved the understanding of individual habitats, most studies remain site-specific and short-term; comprehensive, multi-decadal assessments that integrate all major coastal blue carbon systems at the national scale are still scarce for China. In this study, we integrated 30 m Landsat imagery (1992–2022), processed on Google Earth Engine with a random forest classifier; province-specific, literature-derived carbon density data with quantified uncertainty (mean ± standard deviation); and the InVEST model to track coastal China’s mangroves, salt marshes, tidal flats, and mariculture to quantify their associated carbon stocks. Then the GeoDetector was applied to distinguish the natural and anthropogenic drivers of carbon stock change. Results showed rapid and divergent land use change over the past three decades, with mariculture expanded by 44%, becoming the dominant blue carbon land use; whereas tidal flats declined by 39%, mangroves and salt marshes exhibited fluctuating upward trends. National blue carbon stock rose markedly from 74 Mt C in 1992 to 194 Mt C in 2022, with Liaoning, Shandong, and Fujian holding the largest provincial stock; Jiangsu and Guangdong showed higher increasing trends. The Normalized Difference Vegetation Index (NDVI) was the primary driver of spatial variability in carbon stock change (q = 0.63), followed by precipitation and temperature. Synergistic interactions were also detected, e.g., NDVI and precipitation, enhancing the effects beyond those of single factors, which indicates that a wetter climate may boost NDVI’s carbon sequestration. These findings highlight the urgency of strengthening ecological red lines, scaling climate-smart restoration of mangroves and salt marshes, and promoting low-impact mariculture. Our workflow and driver diagnostics provide a transferable template for blue carbon monitoring and evidence-based coastal management frameworks. Full article

Mangroves form the dominant coastal plant community of low-energy tropical intertidal habitats and provide critical ecosystem services to humans and the environment. However, more frequent and increasingly powerful hurricanes and storm surges are creating additional pressure on the natural resilience of these threatened coastal ecosystems. Advances in remote sensing techniques and approaches are critical to providing robust quantitative monitoring of post-storm mangrove forest recovery to better prioritize the often-limited resources available for the restoration of these storm-damaged habitats. Here, we build on previously utilized spatial and temporal ranges of European Space Agency (ESA) Sentinel satellite imagery to monitor and map the recovery of the mangrove forests of the British Virgin Islands (BVI) since the occurrence of back-to-back category 5 hurricanes, Irma and Maria, on September 6 and 19 of 2017, respectively. Pre- to post-storm changes in coastal mangrove forest health were assessed annually using the normalized difference vegetation index (NDVI) and moisture stress index (MSI) from 2016 to 2023 using Google Earth Engine. Results reveal a steady trajectory towards forest health recovery on many of the Territory’s islands since the storms’ impacts in 2017. However, some mangrove patches are slower to recover, such as those on the islands of Virgin Gorda and Jost Van Dyke, and, in some cases, have shown a continued decline (e.g., Prickly Pear Island). Our work also uses a linear ANCOVA model to assess a variety of geospatial, environmental, and anthropogenic drivers for mangrove recovery as a function of NDVI pre-storm and post-storm conditions. The model suggests that roughly 58% of the variability in the 7-year difference (2016 to 2023) in NDVI may be related by a positive linear relationship with the variable of population within 0.5 km and a negative linear relationship with the variables of northwest aspect vs. southwest aspect, island size, temperature, and slope. Full article

Stand structural configuration dictates ecosystem functional performance. Mangrove ecosystems, located in ecologically sensitive coastal ecotones, require efficient acquisition of stand structure parameters and health assessments based on these parameters for practical applications. Effective assessment of mangrove ecosystem health, crucial for their functional performance in ecologically sensitive coastal ecotones, relies on efficient acquisition of stand structure parameters. This study developed a UAV (Unmanned Aerial Vehicle)-based framework for mangrove health evaluation integrating stand structure parameters, utilizing UAV visible-light imagery, field plot surveys, and computer vision techniques, and applied it to the assessment of a national nature reserve. We obtained the following results: (1) A deep neural network, combining UAV visible-light data with tree height constraints, achieved 88.29% overall accuracy in simultaneously identifying six dominant mangrove species; (2) Stand structure parameters were derived based on individual tree extraction results in seedling zones along forest edges (with canopy individual tree segmentation accuracy ≥ 78.57%), and a stand health evaluation model was constructed; (3) Health assessment revealed that the core zone exhibited significantly superior stand health compared to non-core zones. This method demonstrates high efficiency, significantly reducing the time and effort for monitoring, and offers robust support for future mangrove forest health assessments and adaptive conservation strategies. Full article

As climate change intensifies the frequency and magnitude of extreme weather events, such as storm surges, understanding how extreme weather events alter mangrove carbon dynamics is critical for predicting the resilience of blue carbon ecosystems under climate change. Mangrove forests are generally recognized for their resilience to natural disturbances, a characteristic largely attributed to the evolutionary development of species-specific functional traits. However, limited research has explored the impacts of storm surges on carbon flux dynamics in both natural and restored mangrove ecosystems. In this study, we analyzed short-term responses of storm surges on carbon dioxide flux and methane flux in natural and restored mangroves. The results revealed that following the storm surge, CO₂ uptake decreased by 51% in natural mangrove forests and increased by 20% in restored mangroves, while CH₄ emissions increased by 14% in natural mangroves and decreased by 22% in restored mangroves. GPP is mainly driven by PPFD and negatively affected by VPD and RH, while Reco and CH₄ flux respond to a combination of temperature, humidity, and hydrological factors. NEE is primarily controlled by GPP and Reco, with environmental variables acting indirectly. These findings highlight the complex, site-specific pathways through which extreme events regulate carbon fluxes, underscoring the importance of incorporating ecological feedbacks into coastal carbon assessments under climate change. Full article

Mangrove forests, vital coastal ecosystems that provide critical biodiversity habitats and carbon sequestration services, face increasing heavy metal pollution that threatens their ecological functions through bioaccumulation and toxicity to marine organisms. However, existing studies lack dynamic insights into temporal and spatial variations of heavy metals in mangrove sediments. This study systematically analyzed two mangrove reserves in Hainan Island, China (Hainan Dongzhaigang National Nature Reserve [DZG] and Hainan Qinglan Provincial Nature Reserve [QL]), by collecting sediment samples in 2014 and 2022, analyzing metals (Cr, Cu, Zn, As, Cd, and Pb) via ICP-MS, and applying the geo-accumulation index, potential ecological risk index, Markov transition matrix, and statistical analyses. Results showed that DZG exhibited rising Cu and Zn levels but declining Cr, As, Cd, and Pb, with Cd showing the most significant decrease (66.83%). In contrast, QL saw only a 42.7% reduction in Cd, while other heavy metals increased. Spatial heterogeneity linked higher concentrations to anthropogenic hotspots, DZG’s southeast (industrial/aquaculture inputs), and QL’s northwest (urban/industrial discharges). Although ecological risks were generally low, Cd in QL reached a moderate risk level (E_Cd = 46.44, 40 ≤ E_i < 80). The large-scale pond-to-mangrove conversion significantly increased vegetation cover, which enhanced sedimentation rates and exerted a “dilution effect” on sediment heavy metals. These findings underscore anthropogenic activities as the dominant driver of heavy metal contamination. We recommend (1) stringent wastewater control near QL, (2) enhanced shipping regulation, and (3) the establishment of mangrove buffers in heavy metal accumulation zones to improve ecological status. Full article

Changes in the structure and composition of mangroves may be influenced by anthropogenic and natural causes. Mangrove coverage in Marismas Nacionales Nayarit –a Biosphere Reserve in northwestern Mexico—has declined in the last decades, mostly related to human activities (e.g., opening of the Cuautla inlet) and climate variability (e.g., El Niño Southern Oscillation and hurricanes), leading to diverse ecological and socioeconomic consequences. This contribution reports the impact of Cissus verticillata—a climbing plant species—in the structure of mangroves distributed in this Natural Protected Area during 2019 and 2022. Forest structure analysis was compared in four plots of 20 m × 20 m each, all of them influenced by San Pedro Mezquital river. Two plots (Unión de Corrientes) showed the presence of Cissus verticillata, while two nearby plots (Boca de Camichín) recorded no presence of this species. A poor mangrove structure, no natural seedling recruitment and high mortality was observed in those sites with the presence of C. verticillata. These results highlight the vulnerability of mangroves to C. verticillata in Marismas Nacionales Nayarit Biosphere Reserve, which in addition to other human and climate stressors may compromise its ecological integrity in the future. Full article

In Thailand, mangrove forests form a major component of the Andaman coastal ecosystems in the southern provinces. However, studies on their microbial assemblage largely revolved around groups of bacteria, fungi, and eukaryotic microalgae, while the diversity of cyanobacteria in these regions remains almost unknown. This taxonomic study applied the polyphasic approach to examine seven cyanobacterial strains collected from different mangrove environments (including soil crust, tree bark, wood, and rock surface) across Ranong, Phang-Nga, and Phuket provinces. The comprehensive analysis combining morphology, ecology, 16S rRNA phylogenetic relationships, genetic identity, ITS secondary structure, and ITS dissimilarity resulted in the first records of the genera Picosynechococcus, Allocoleopsis, and Sirenicapillaria in Thailand, and led to the description of a new species, Picosynechococcus mangrovensis sp. nov. This new species was differentiated from the type species P. fontinalis based on the distinct 16S rRNA gene phylogenetic position, low 16S rRNA genetic similarity, its slightly halophilic nature, and ability to form pseudo-filaments with up to 160 cells. Our research significantly expands the documented cyanobacterial diversity of Southeast Asian mangrove ecosystems, establishing a critical foundation for future ecological and biotechnological investigations in these understudied yet vital tropical habitats. Full article

Mangrove forests are intertidal ecosystems that harbor diverse microbial communities essential for biogeochemical cycles and energy flow. This study investigated the seasonal and spatial patterns of bacterial communities in the artificially introduced mangrove sediments of the Ao River estuary using 16S rRNA gene amplicon high-throughput sequencing. Alpha diversity analyses indicated that the bacterial community diversity in the mangrove sediments of the Ao River estuary was similar to those of natural-formed mangroves, with the Shannon index ranging from 5.16 to 6.54, which was significantly higher in winter compared to other seasons. The dominant bacterial phyla included Proteobacteria (43.65%), Actinobacteria (11.55%), Desulfobacterota (11.16%), and Bacteroidetes (5.52%), while beta diversity analysis revealed substantial differences in bacterial community structure across different seasons and regions. For instance, the relative abundance of Woeseiaceae and Bacteroidota during the summer was significantly higher than that observed in other seasons. And the relative abundance of Bacillaceae in autumn and winter increased by one order of magnitude compared to spring and summer. Woeseiaceae, Desulfobulbaceae, Thermoanaerobaculaceae, and Sva1033 (family of Desulfobacterota) exhibited significantly higher relative abundance in the unvegetated area, whereas Bacillaceae and S085 (family of Chloroflexi) demonstrated greater abundance in the mangrove area. Seasonal variations in bacterial community structure are primarily attributed to changes in environmental factors, including temperature and salinity. Regional differences in bacterial community structure are primarily associated with environmental stressors, such as wave action, fluctuations in salinity, and organic matter content, which are further complicated by seasonal changes. This study is significant for understanding the microbial diversity and seasonal dynamics of estuarine mangrove wetlands, and it contributes to the assessment of mangrove wetland restoration efforts in Zhejiang Province, providing important guidance for the development of strategies to maintain the health of mangrove ecosystems in the future. Full article

Coastal ecosystems, particularly mangroves, are essential for ecological stability and human livelihoods, yet they face significant degradation from natural and anthropogenic pressures. This study focuses on the Chaungkaphee Protected Public Forest (PPF) in the Tanintharyi region of Myanmar, which hosts diverse mangrove species critical for carbon storage. Between 2010 and 2020, mangrove forest cover in Myanmar decreased from 540,000 ha to 431,228 ha, resulting in a loss of 108,772 ha. This decline is primarily attributed to illegal logging and agricultural expansion. Our research aims to assess the structural characteristics, biomass, and carbon storage potential of mangrove ecosystems within the Chaungkaphee PPF. Field data collected in early 2024 applied non-destructive sampling methods to gather information on tree structure, species composition, and soil carbon stocks. We identified six dominant mangrove species, with Rhizophora apiculata Blume showing the highest biomass and carbon storage potential. The total biomass was measured at 493.91 Mg ha⁻¹, yielding a carbon stock of 218.76 Mg C ha⁻¹. Soil carbon assessments revealed an average organic carbon stock of 921.09 Mg C ha⁻¹, underscoring the vital role of soil in carbon sequestration. Our findings highlight the significant contribution of mangrove ecosystems to climate change mitigation, emphasizing the urgent need for effective conservation strategies and community involvement in restoration efforts. This study enhances the understanding of mangrove resilience and sustainability, advocating for the protection of these crucial ecosystems amidst ongoing environmental challenges. By recognizing the ecological functions and services provided by mangroves, we can better address the threats they face and promote their restoration for future generations. Full article

Topsoil organic carbon (SOC, 0–20 cm) is crucial for terrestrial carbon stocks and the global carbon cycle. This study integrated field survey data, re-analysis climatic data, and remote sensing-derived environmental factors to examine SOC distribution and its drivers across forest types on Hainan Island using machine learning models and statistical analysis. The results showed that univariate analysis had limited explanatory power for forest SOC, with terrestrial plantations exhibiting significantly lower SOC than mangroves and natural forests. For mangroves, vapor pressure deficit (VPD) was the most influential factor, followed by precipitation (PRE), the normalized difference vegetation index (NDVI), and forest age; meanwhile, for terrestrial forests, VPD, altitude, PRE, and NDVI were vital drivers. The optimal models demonstrated relatively stronger predictive performance (R² = 0.71 for mangroves; R² = 0.81 for terrestrial forests). Mangroves showed higher average SOC (27.91 g/kg) than terrestrial forests (15.82 g/kg), while higher concentrations in the central–western region were attributed to natural terrestrial forests. This study reveals the spatial variation patterns of forest SOC and its environmental regulation mechanisms on Hainan Island, providing important references for forest carbon stock management and environmental protection. Full article

(1) Background: Mangroves are critical ecosystems that provide essential services, including coastal protection, biodiversity support, and carbon storage. However, urbanization and infrastructure development increasingly threaten their sustainability. This study investigates the spatio-temporal trends of mangrove canopy cover in Benoa Bay, Bali, Indonesia, which is an urban area and a center of tourism activities with various supporting facilities. The analysis was conducted from 2013 to 2023, using Landsat 8 satellite imagery and Normalized Difference Vegetation Index (NDVI) analysis. In addition, the analysis was also linked to mangrove area management policies. (2) Methods: The annual NDVI time series based on Landsat 8 imagery, obtained through the Google Earth Engine (GEE), was used to characterize the vegetation canopy cover in the study area. Statistical analysis of the annual linear trend of the NDVI was conducted to examine the spatio-temporal variation in canopy cover. Additionally, policies related to regional spatial planning and area protection were analyzed to assess their role in preserving mangrove forests in urban areas. (3) Results: There was a net decrease in mangrove area in Benoa Bay of 3.97 hectares, mainly due to infrastructure development and tourism facilities. The NDVI trend shows an overall increase in canopy cover due to reforestation and natural regeneration efforts, although there was a local decrease in some areas. Conservation policies, such as the establishment of the Ngurah Rai Forest Park, have supported mangrove protection. (4) Conclusions: The analysis demonstrated that mangroves surrounded by urban areas and tourism activity centers can still be maintained quite well with the right policies. Full article

Mangrove forests are vital for flood reduction, yet their failure mechanisms during storms are poorly known, hampering their integration into engineered coastal protection. In this paper, we aimed to unravel the relationship between the resistance of mangrove trees to overturning and root distribution and the properties of the soil, while avoiding damage to natural mangrove forests. We therefore (i) tested the stability of 3D-printed tree mimics that imitate typical shallow mangrove root systems, mimicking both damaged and intact root systems, in sediments representing the soil properties of contrasting mangrove sites, and subsequently (ii) tested if the existing stability models for terrestrial trees are applicable for mangrove tree species, which have unique shallow root systems to survive waterlogged soils. Root systems of different complexities were modeled after Avicennia alba, Avicennia germinans, and Rhizophora stylosa, and printed at a 1:100 scale using material densities matching those of natural tree roots, to ensure the geometric scaling of overturning moments. The mimic stability increased with the soil shear strength and root plate surface area. The optimal root configuration for mimic stability depended on the sediment properties: spreading root systems performed better in softer sediments, while concentrating root biomass near the trunk improved stability in stronger sediments. An adapted terrestrial tree resistance model reproduced our measurements well, suggesting that such models could be adapted to predict the stability of shallow-rooted mangroves living in waterlogged soils. Field tree-pulling experiments are needed to further confirm our conclusions with real-world data, examine complicating factors like root intertwining, and consider mangrove tree properties like aerial roots. Overall, this work establishes a foundation for incorporating mangrove storm damage into hybrid coastal protection systems. Full article

Mangrove forests protect coastlines from erosion, enhance biodiversity, store carbon, and support coastal communities. These ecosystems rely on hydrological conditions. This paper reviews past, present, and future hydrological characteristics of Bangladesh’s Sundarbans to guide restoration and sustainable development. It examines historical and projected hydrological indicators, addressing knowledge gaps and suggesting strategies. Renowned for productivity, biodiversity, and socio-economic benefits, the Sundarbans depend on seasonal freshwater from the Ganges River. However, threats from climate change and human activities, including reduced freshwater flow due to India’s Farakka Barrage on the Ganges, rising salinity, cyclones, and pollution, endanger these ecosystems. The primary threat is mangrove destruction for alternate land use and reduced sediment supply due to upstream dam construction. Sea-level rise is a secondary concern, as a healthy Sundarbans delta could naturally accrete with adequate sediment input and mangrove growth. Sustainable management practices are critical, including maintaining upstream water flow, minimizing deforestation, and rehabilitating degraded areas. Alternative livelihoods and strategies addressing salinity rise are essential. Long-term approaches should adopt adaptive management and ensure sustainable resource use. Policy actions must regulate human activities, mitigate cyclone impacts, ensure freshwater availability, halt harmful industries, and promote awareness and surveillance. Protecting mangroves to reduce CO₂ emissions and advancing research are vital. Full article

The Pacitan Regency is at risk of megathrust earthquakes and tsunamis due to the seismic gap along the southern region of Java Island, making risk-reduction efforts crucial. This research aims to analyse the tsunami risk associated with a potential megathrust earthquake scenario in Pacitan’s coastal areas and develop sustainable mitigation strategies. The research employs spatial analysis to evaluate the risk and subsequently formulate strategies for long-term mitigation. A weighted overlay method was utilised to integrate hazard (H) and vulnerability (V) datasets to produce a tsunami risk map (R). The hazard component was modelled using a tsunami propagation simulation based on the Shallow Water Equations in the Delft3D-Flow software, incorporating an earthquake scenario of Mw 8.8 and H-loss calculations in ArcGIS Pro 10.3. The vulnerability assessment was conducted by overlaying population density, land use, and building footprint from the Global Human Settlement Layer (GHSL) datasets. Finally, sustainable strategies were proposed to mitigate the tsunami risk effectively. The results show that Pacitan faces significant tsunami disaster risk, with tsunami waves at the coast reaching 16.6 m. Because the coast of Pacitan is densely populated, mitigation strategies are necessary, and in the present contribution, the authors developed holistic spatial planning, which prioritise the preservation and restoration of natural barriers, such as mangroves and coastal forests. Full article