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Mangrove forests are critical coastal ecosystems that provide great socio‐ecological services, which are also highly vulnerable to climate change, particularly to sea level rise (SLR). Here we assess changes in mangrove forests in four distinct river/tide/wave‐dominant large deltas along the Indo‐Pacific coast based on 1,336 remote sensing images by machine learning techniques. We find that mangroves are migrating seaward at a rate of 18% ± 12% m/yr, which can offset landward mangroves loss, 67% of which caused by land use conversion. The fact that mangroves are expanding seaward with accretion rates exceeding SLR suggests that climate change has not yet triggered substantial loss in deltaic mangrove forests. Assuming that present environmental conditions do not change and that sediment and organic deposition in the deltaic topsets match SLR rates, we project that 90% of deltaic mangrove forests may start to retreat after 132–194 years. Early inundation of mangroves will occur in wave‐dominated delta. Plain Language Summary: Mangrove forests provide significant ecological and societal services, and mitigation global warming. However, large‐scale loss in mangroves could be induced by anthropogenic drivers and sea level rise (SLR). Our study based on deltas along the Indo‐Pacific coast, highlight that mangroves are expanding seaward at a rate of 18% ± 12% m/yr, indicating that there is little impacts from SLR and has not been substantial loss in mangrove forests in these deltas so far. Mangrove expansion here can efficiently offset 67% landward mangrove losses indicates that our new model project that 90% of mangrove shorelines will may start retreating within 132–194 years. We conclude that favoring mangroves expansion seaward would enhance coastal protection and reduce the need of landward mangrove restoration. Key Points: Mangroves along typical deltas are expanding seaward of about 18% ± 12% m/yr, indicating that there is little impacts from sea level riseMangrove expansion here can efficiently offset 67% landward mangrove lossesNew model project that 90% of mangrove fringes may start retreating within 132–194 years, and wave‐dominated delta present early inundation [ABSTRACT FROM AUTHOR]

In the Bamen Bay area of the Qinglan Harbor Mangrove Provincial Nature Reserve in Wenchang, Hainan Province, China, mangrove aboveground biomass (AGB) was estimated using high-resolution UAV ortho-imagery and UAV LiDAR data. The spatial distribution characteristics of AGB were studied using global Moran's I index and hotspot analysis. Optimal geographic detectors and regression models were employed to analyze the relationship between AGB and key environmental factors. The results indicate that (1) the average AGB in the study area was 141.22 Mg/ha, with significant spatial variation. High AGB values were concentrated in the southwestern and northeastern regions, while low values were mainly found in the central and southeastern regions. (2) Plant species, water pH, soil total potassium, salinity, dissolved oxygen, elevation, soil organic matter, soil total phosphorus, and soil total nitrogen were identified as major factors influencing the spatial distribution of AGB. The interaction results indicate either bifactor enhancement or nonlinear enhancement, showing a significantly higher impact compared with single factors. (3) Comprehensive regression model results reveal that soil total nitrogen was the primary factor affecting AGB, followed by soil total potassium, with water pH having the least impact. Factors positively correlated with AGB promoted biomass growth, while elevation negatively affected AGB, inhibiting biomass accumulation. The findings provide critical insights that can guide targeted conservation efforts and management strategies aimed at enhancing mangrove ecosystem health and resilience, particularly by focusing on key areas identified for potential improvement and by addressing the complex interactions among environmental factors. [ABSTRACT FROM AUTHOR]

The restoration of mangrove forests is a crucial endeavor to restore damaged areas. The area that needs restoration is the mangrove forest located in Rambut Island Wildlife Reserve. This particular mangrove forest spans approximately 14.31 hectares, with a research site covering 2.14 hectares in the western part of Rambut Island. The objectives were to accurately map the mangrove forests’s location and size that require restoration, identify mangrove species, and determine suitable restoration techniques. Sentinel-2A imagery data and field surveys conducted from July to August 2022 mapped the forest area and collected primary data on vegetation, soil, inundation, and water salinity. Based on the findings, it has been determined that approximately 0.37 hectares of the area require restoration measures. The recommended mangrove species for restoration consist of Avicennia sp., Bruguiera sp., Rhizophora sp., Ceriops sp., Heritiera sp., Sonneratia sp., and Xylocarpus sp. The planting technique that can be applied to all restoration plots, except for plot number 7, is the cemplongan technique, while the Bronjong technique is recommended for plot number 7. [ABSTRACT FROM AUTHOR]

Estuarine sediments serve as significant reservoirs for mercury (Hg) and methylmercury(MeHg), which can also interconvert in the external environment. The release of Hg in response to human activities raises concerns about its potential ecological and human health effects. Sediment samples were collected in December 2021 from four locations (sites), and Hg cycling by measuring the concentrations of, and controls on, the spatial distribution of total Hg (THg) and methylmercury (MeHg) in high-tidal zone (HTZ) and mid-tidal zone (MTZ) sediments of a mangrove forest (MF) and oyster farm (OF) was examined in northwestern Zhanjiang Bay, including simultaneous determination of sediment particle size, oxidation-reduction potential (Eh), pH, total organic carbon (TOC), sulfide concentration (S2-), and sulfate reducing bacteria (SRB). The research results indicated that concentrations of both THg and MeHg ranged between 20.0–104.0 ng/g and 0.011–0.277 ng/g in the sediments, respectively. The highest methylation potentials within the MF and OF were in sediments located approximately 10–15 cm below the surface. MeHg in the HTZ of the OF was likely derived from exogenous inputs as Hg methylation appears limited, and the formation of MeHg depended not only on the amount of inorganic mercury available for methylation in SRB, but also on the TOC, pH, Eh and S2- content in the sediment. A risk assessment of MeHg during the anthropogenic disturbance of this estuaries conducted on individuals eating oysters demonstrated that health risks are low. [ABSTRACT FROM AUTHOR]

This article focuses on the social skills possessed by the challengers, in this case, charcoal panglong (a place for wood processing and charcoal production) owners, entrepreneurs, and their workers who are able to survive the regulations on the utilization of mangrove forests. The battle in this field began in the days of the Dutch government. The purpose of this study is 1) to reveal how the contestation of stability and change in the charcoal panglong business in Bengkalis. 2) to analyze the social skills possessed by the owner of the charcoal panglong and his workers, hereinafter referred to as challengers, in maintaining the existence of his business until now. The ability to maintain the charcoal panglong business and its business existence. A series of research studies using a qualitative approach, using interviews and observations, were conducted by the author to reveal a series of strategic action fields in the forestry business. The findings obtained show that challengers have always competed with incumbents (mangrove forest policies and regulations) and governance units for a long time. This field contestation has occurred since 1853, starting from the time the Dutch government established a panglong in Bengkalis to meet the demand for wood and charcoal from Singapore and Malaysia. The challenger always maintains its business existence by fulfilling all obligations as a holder of a community forest license granted by the president and also as a charcoal export license holder to Malaysia; of course, to meet these export needs, another skill it has is maintaining a stable supply of charcoal for export. The patron client relationship is one of the challenger's skills in maintaining good relations with the local community and its workers. The market field analysis using Fligstein and McAdam's Field Theory of Strategic Action Field (SAF) helps explore the elements of social skills in SAF so that the structure of stability and change in the forestry charcoal panglong business arena can be illustrated more clearly. [ABSTRACT FROM AUTHOR]

Mangrove forest management is important in striving for environmental conservation in coastal areas. This study aims to 1) know the condition of mangrove forests after rehabilitation, 2) know the impact of mangrove forest rehabilitation activities on the community, 3) know the form of community participation in mangrove forests, 4) know alternative mangrove forest management strategies ideally. This study used a survey approach with interviews and field observations. The population is the entire coastal population in the study area, a sampling technique using "cluster random sampling". The data collection method uses interviews and field observations while data analysis of coastal resource management strategies is carried out with a SWOT Analysis approach. The results showed that 1) mangrove vegetation found included 4species from 3 families, namely the family Avicenniaceae (Avicennia marina), family Euphorbiaceae (Excoecariaagallocha), and family Rhizophoraceae (Rhizophoramucronata, Rhizophoraapiculata, and Bruguieragymnorizum) 2) The impact of mangrove forest rehabilitation in the study area is increasing fish catches, reducing coastal abrasion, resisting sea breezes, increasing biota catches (shrimp, crabs, shellfish) in coastal, and make the area a tourist attraction. 3) the form of participation in the form of thoughts (39.45%), energy (52.94%), expertise (65.91%), and goods/money (50.88%), 4) mangrove management strategies in Tanggul Tlare Village, Jepara Regency consist of 4 main priorities, namely community development in planting based on existing potential, increasing socialization to the community about the dangers of indiscriminate mangrove logging, providing counseling and socialization about the environment and mangrove ecosystem, Provide socialization about the application of government regulations on the environment. [ABSTRACT FROM AUTHOR]

Mangrove forests, being high-yielding ecosystems, often dominate the intertidal sites along equatorial and subtropical coasts. Despite the known significance of mangroves to the coastal ecology, especially fisheries, deforestation remains a severe danger due to coercion for forest products, ground transformation for aquaculture, and seaside urban growth. Remote sensing is integral in mapping and analysing changes in mangrove forests' areal extent and spatial patterns due to natural disasters and anthropogenic causes over the last three decades. This work depicts remote sensing analysis for change detection in mangrove forest land use land cover from 2014 to 2019. Indian Remote-Sensing Satellite Resourcesat-2 LISS-IV datasets have been used for analysis. A comparison with the Sentinel-2A dataset and two machine learning models: Random Forest and Classification and Regression Tree, has been performed with 2019 data. This work identifies CART as a suitable choice for supervised landform classification utilising remotely sensed geophysical data that is used to decipher spatial changes concurred over time. An overall growth in the mangrove cover was observed from 2014 to 2019, from 86.26 to 89.63 km 2 , along the Mumbai coastline. Spatial comparison over the years shows the growth and loss of land-use cover areas. The performance metrics such as overall accuracy, producer accuracy, Kappa coefficient, and Matthews correlation coefficient are computed. The experiments were conducted using the Google Earth Engine, a powerful cloud computing platform. [ABSTRACT FROM AUTHOR]

A century ago, measuring elevation in tidal wetlands proved difficult, as survey leveling of soft marsh soils relative to a fixed datum was error prone. For 60 years, vertical accretion measures from marker horizons were used as analogs of elevation change. But without a direct measure of elevation, it was not possible to measure the total influence of surface and subsurface processes on elevation. In the 1990s, the surface elevation table (SET) method, which measures the movement of the wetland surface relative to a fixed point beneath the surface (i.e., the SET benchmark base), was combined with the marker horizon method (SET-MH), providing direct, independent, and simultaneous measures of surface accretion and elevation and quantification of surface and shallow subsurface process influences on elevation. SET-MH measures have revealed several fundamental findings about tidal wetland dynamics. First, accretion [A] is often a poor analog for elevation change [E]. From 50–66% of wetlands experience shallow subsidence (A > E), 7–10% shallow expansion (A < E), 7% shrink-swell, and for 24–36% A is an analog for E (A = E). Second, biological processes within the root zone and physical processes within and below the root zone influence elevation change in addition to surface processes. Third, vegetation plays a key role in wetland vertical dynamics. Plants trap sediment and increase resistance to erosion and compaction. Soil organic matter accumulation can lead to shallow expansion, but reduced plant growth can lead to subsidence, and plant death to soil collapse. Fourth, elevation rates are a better indicator of wetland response to sea-level rise than accretion rates because they incorporate subsurface influences on elevation occurring beneath the marker horizon. Fifth, combining elevation trends with relative sea-level rise (RSLR) trends improves estimates of RSLR at the wetland surface (i.e., RSLRwet). Lastly, subsurface process influences are fundamental to a wetland's response to RSLR and plant community dynamics related to wetland transgression, making the SET-MH method an invaluable tool for understanding coastal wetland elevation dynamics. [ABSTRACT FROM AUTHOR]

Coastal wetlands adapt to rising seas via feedbacks that build soil elevation, which lead to wetland stability. However, accelerated rates of sea-level rise can exceed soil elevation gain, leading to wetland instability and loss. Thus, there is a pressing need to better understand regional and landscape variability in rates of wetland soil elevation change. Here, we conducted a regional synthesis of surface elevation change data from mangrove forests and coastal marshes in the iconic Greater Everglades region of south Florida (USA). We integrated data from 51 sites in which a total of 122 surface elevation table-marker horizon (SET-MH) stations were installed. Several of these sites have been periodically monitored since the 1990s and are among the oldest SET-MH datasets in the world. Rates of surface elevation change ranged from −9.8 to 15.2 mm year−1, indicating some wetlands are keeping pace with sea-level rise while others are at risk of submergence and conversion to open water. Vertical accretion rates ranged from 0.6 to 12.9 mm year−1, and subsurface change rates ranged from −13.5 to 8.6 mm year−1. Rates of surface elevation change were positively related to subsurface change but not vertical accretion. There were no significant relationships between rates of surface elevation change and elevation (NAVD 88) or rates of sea-level rise. Site-specific examples indicate that hurricanes, plant productivity, hydrologic exchange, and proximity to sediment and nutrient inputs are critical but confounding drivers of surface elevation change dynamics in the Greater Everglades region. Collectively, our results reinforce the value of long-term SET-MH data that incorporate spatial variability for advancing understanding of surface elevation change dynamics in coastal wetlands. [ABSTRACT FROM AUTHOR]

The development of mangrove forest environmental services plays a crucial role in human health, economic development, and the security of countries worldwide. This study aims to establish and validate a model for assessing the factors influencing the willingness-to-pay for mangrove forest environmental services. The proposed model comprises four key factors: attitude, subjective norm, perceived behavior control, and environmental knowledge. Data were collected by surveying 235 individuals from various households in Phu Long commune, Vietnam. The Partial Least Squares—Structural Equation Modeling (PLS-SEM) methodology was employed for data analysis. The research findings reveal that perceived behavior control significantly impacted residents' willingness-to-pay, followed by attitude, environmental knowledge, and subjective norms. Furthermore, certain demographic characteristics such as gender and family size mediate the relationship between independent and dependent variables. Based on the obtained results, several policy recommendations are put forward. Plain language summary: This study aims to establish and validate a model for assessing the factors influencing the willingness-to-pay for mangrove forest environmental services. Data were collected by surveying 235 individuals from various households in Phu Long commune, Vietnam. The Partial Least Squares - Structural Equation Modeling (PLS-SEM) methodology was employed for data analysis. The research findings reveal that perceived behavior control significantly impacted residents' willingness-to-pay, followed by attitude, environmental knowledge, and subjective norms. Furthermore, certain demographic characteristics such as gender and family size mediate the relationship between independent and dependent variables. Based on the analysis results, this study proposes several policy recommendations to encourage the willingness of residents in Phu Long commune, Hai Phong, Vietnam, to pay for FESs. Strategies to improve the implementation of forest environmental service payments in Phu Long should emphasize enhancing the community's understanding of the importance of mangrove forests. Information dissemination should encompass knowledge about the benefits (both economic and environmental), the current status, threats, and consequences of mangrove degradation, as well as the global significance of mangrove forests, particularly concerning climate change. Additionally, to increase the effectiveness and garner community support for environmental service payment programs in Phu Long, implementation efforts should promote residents' sense of responsibility, pride, and love for the recognized biodiversity heritage values associated with mangrove forests [ABSTRACT FROM AUTHOR]

Background and objectives: In recent decades, the Khamir and Qeshm mangrove forests in southern Iran have suffered significant destruction due to various human activities, including the construction of docks, commercial and tourism ports, deforestation, and unplanned tourism development. These forests, which provide valuable ecosystem services, have faced indiscriminate and unplanned development, as well as insufficient attention from local communities. Therefore, understanding the spatial distribution of plant species in this area is crucial for effective planning and enhancing the protection of these valuable biological resources. This study aims to identify suitable areas and model the presence of the mangrove tree species Avicennia marina (Forssk.) Vierh. in the Khamir and Qeshm mangrove forests to facilitate the restoration and proper distribution of this species. Methodology: The habitat suitability map for A. marina was prepared using MaxEnt modeling. A total of 234 points were randomly recorded using the Global Positioning System (GPS). To investigate the spatial distribution of A. marina, various environmental factors affecting its geographical distribution were analyzed using ArcGIS 10.8 software to generate maps and environmental variables. The environmental variables were selected based on theoretical foundations, previous studies, and expert opinions. The model included 18 climatic variables and 5 physical variables affecting the distribution of A. marina. The physical variables included maximum wave height, beach slope, tidal fluctuations, water salinity, and beach material (sandy- gravel, muddy, back beach (sand material)). All layers were prepared in ASCII format with a cell size of 1 km, and MaxEnt 3.4.4 software was used for modeling. Results: The area under the curve (AUC) obtained from the MaxEnt algorithm indicated excellent predictive power for the presence of A. marina in the study area, demonstrating the model’s ability to distinguish between suitable and unsuitable areas. The overlap of training and test data also confirmed the model’s accuracy. The contribution analysis of each environmental variable in the model showed that maximum wave height, annual average temperature, tidal fluctuations, and water salinity were the most influential variables. Specifically, maximum wave height and annual average temperature had the largest influence on the distribution of A. marina, while the minimum temperature of the coldest month had the least effect. The response curves indicated that maximum wave height (1 to 2 m) and average annual temperature (26.8°C) were the most important independent variables, with an inverse relationship to the probability of A. marina presence. As wave height and average annual temperature increased, the probability of species presence decreased. The suitability map for A. marina in the Khamir and Qeshm mangrove forests showed that the highest suitability was in areas with minimal wave height and less exposure to tidal fluctuations. Favorable areas for the presence and development of A. marina included the northern areas of Khorkhoran Islands, Mardove Island, and the northeast of the Khamir-Lashtghan habitat. In general, the species was more dispersed in areas with low wave height and minimal water level fluctuations. Conclusion: The study provides key information on the impact of environmental variables on the distribution of A. marina, offering an important strategy for protecting the biodiversity and valuable resources of the species in the Khamir and Qeshm mangrove forests. The suitability map serves as essential information for planting and reviving these natural habitats. [ABSTRACT FROM AUTHOR]

The acquisition of microbial symbionts enables animals to rapidly adapt to and exploit novel ecological niches, thus significantly enhancing the evolutionary fitness and success of their hosts. However, the dynamics of host–microbe interactions and their evolutionary implications remain largely underexplored in marine invertebrates. Crabs of the family Sesarmidae (Crustacea: Brachyura) are dominant inhabitants of mangrove forests and are considered keystone species there. Their rapid diversification, particularly after adopting a plant‐feeding lifestyle, is believed to have been facilitated by symbiotic gut microbes, enabling successful colonization of intertidal and terrestrial environments. To investigate the patterns and mechanisms shaping the microbial communities and the role of microbes in the evolution of Sesarmidae, we characterized and compared the gut microbiome compositions across 43 crab species from Sesarmidae and other mangrove‐associated families using 16S metabarcoding. We found that the gut microbiome assemblages in crabs are primarily determined by host identity, with a secondary influence from environmental factors such as microhabitat and sampling location, and to a lesser extent influenced by biological factors such as sex and gut region. While patterns of phylosymbiosis (i.e. when microbial community relationships recapitulate the phylogeny of their hosts) were consistently observed in all beta‐diversity metrics analysed, the strength of phylosymbiosis varied across crab families. This suggests that the bacterial assemblages in each family were differentially shaped by different degrees of host filtering and/or other evolutionary processes. Notably, Sesarmidae displayed signals of cophylogeny with its core gut bacterial genera, which likely play crucial functional roles in their hosts by providing lignocellulolytic enzymes, essential amino acids, and fatty acids supplementation. Our results support the hypothesis of microbial contribution to herbivory and terrestrialization in mangrove crabs, highlighting the tight association and codiversification of the crab holobiont. [ABSTRACT FROM AUTHOR]

The mangrove forest in Macajalar Bay is regarded as an important coastal ecosystem since it provides numerous ecosystem services. Despite their importance, the clearing of mangroves has been rampant and has reached critical rates. Addressing this problem and further advancing its conservation require accurate mangrove mapping. However, current spatial information related to mangroves is sparse and insufficient to understand the historical change dynamics. In this study, the synergy of 1950 vegetation maps and Landsat images was explored to provide multidecadal monitoring of mangrove forest change dynamics in Macajalar Bay, Philippines. Vegetation maps containing the 1950 mangrove extent and Landsat images were used as input data to monitor the rates of loss over 70 years. In 2020, the mangrove forest cover was estimated to be 201.73 ha, equivalent to only 61.99% of the 325.43 ha that was estimated in 1950. Between 1950 and 2020, net mangrove loss in Macajalar Bay totaled 324.29 ha. The highest clearing rates occurred between 1950 and 1990 when it recorded a total of 258.51 ha, averaging 6.46 ha/year. The original mangrove forest that existed in 1950 only represents 8.56% of the 2020 extent, suggesting that much of the old-growth mangrove had been cleared before 2000 and the existing mangrove forest is mainly composed of secondary mangrove forest stands. Across Macajalar Bay, intensified clearing that happened between 1950 and 1990 has been driven by large-scale aquaculture developments. Mangrove gains on the other hand were evident and have increased the total extent by 79.84 ha since 2000 as a result of several afforestation programs. However, approximately half of these gains that were observed since 2010 exhibited low canopy cover. As of writing, approximately 85% of the 2020 mangrove forest stands fall outside the 1950 original mangrove extent. Examining the viability of the original mangrove forest for mangrove reforestation together with promoting site-species matching, and biophysical assessment are necessary undertakings to advance current mangrove conservation initiatives in Macajalar Bay. [ABSTRACT FROM AUTHOR]

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The aim of this study is to uncover the multifaceted environmental threats posed by Oil Spill Water Pollution (OSWP) originating from tanker terminals situated in the Qeshm and Hormozgan regions of Iran. In this region, water pollution arises from diverse sources, mostly from ruptured pipelines, corroded valves, unforeseen accidents, and aging facilities. The Qeshm Canal and Qeshm Tanker Terminal emerged as pivotal sites for investigation within this study. The focus is directed towards pinpointing vulnerable areas at risk of water contamination and delving into the intricate pathways and impacts associated with oil spills. Utilizing the sophisticated modeling capabilities of the National Oceanic and Atmospheric Administration's (NOAA) GNOME model, the research explores various scenarios extrapolated from seasonal atmospheric and oceanic data through 2022. The findings show the OSWP hazard zones located northeast of Qeshm. Notably, the wind and currents greatly affect how OSWPs are destined and dispersed. This underscores the intricate interplay between environmental factors and spill dynamics. In essence, this study not only sheds light on the imminent environmental threats posed by OSWP but also underscores the critical need for proactive measures and comprehensive strategies to mitigate the adverse impacts on marine ecosystems and coastal communities. [ABSTRACT FROM AUTHOR]

Abstract Mangrove forests are critical coastal ecosystems that provide great socio‐ecological services, which are also highly vulnerable to climate change, particularly to sea level rise (SLR). Here we assess changes in mangrove forests in four distinct river/tide/wave‐dominant large deltas along the Indo‐Pacific coast based on 1,336 remote sensing images by machine learning techniques. We find that mangroves are migrating seaward at a rate of 18% ± 12% m/yr, which can offset landward mangroves loss, 67% of which caused by land use conversion. The fact that mangroves are expanding seaward with accretion rates exceeding SLR suggests that climate change has not yet triggered substantial loss in deltaic mangrove forests. Assuming that present environmental conditions do not change and that sediment and organic deposition in the deltaic topsets match SLR rates, we project that 90% of deltaic mangrove forests may start to retreat after 132–194 years. Early inundation of mangroves will occur in wave‐dominated delta.

The restoration of mangrove forests is a crucial endeavor to restore damaged areas. The area that needs restoration is the mangrove forest located in Rambut Island Wildlife Reserve. This particular mangrove forest spans approximately 14.31 hectares, with a research site covering 2.14 hectares in the western part of Rambut Island. The objectives were to accurately map the mangrove forests’s location and size that require restoration, identify mangrove species, and determine suitable restoration techniques. Sentinel-2A imagery data and field surveys conducted from July to August 2022 mapped the forest area and collected primary data on vegetation, soil, inundation, and water salinity. Based on the findings, it has been determined that approximately 0.37 hectares of the area require restoration measures. The recommended mangrove species for restoration consist of Avicennia sp., Bruguiera sp., Rhizophora sp., Ceriops sp., Heritiera sp., Sonneratia sp., and Xylocarpus sp. The planting technique that can be applied to all restoration plots, except for plot number 7, is the cemplongan technique, while the Bronjong technique is recommended for plot number 7.

The Lower Mekong Region (LMR) faces significant loss of mangrove forests, yet limited studies have explored this decline in the region. Here, we employ Google Earth Engine and Landsat satellite imagery to assess changes in mangrove forest cover across Myanmar, Thailand, Vietnam, and Cambodia between 1989 and 2020, with a five-year interval. Accordingly, we estimated carbon stock changes due to changes of forest cover. Our analysis yielded an overall average accuracy of 92.10% and an average kappa coefficient of 0.89 across the four countries. The findings reveal a 0.9% increase in mangrove area in Myanmar, 2.5% in Thailand, and 1.3% in Cambodia, while Vietnam experienced a 0.2% loss annually between 1989 and 2020. Carbon stocks in mangrove forests were estimated at 577.0 ​Tg of carbon or TgC, 250.0 TgC, 61.6 TgC, and 269.0 TgC in 1989 for Myanmar, Thailand, Cambodia, and Vietnam respectively, and increased to 736.0 TgC, 443.0 TgC, 86.7 TgC, and 254 TgC in 2020. Increase in mangrove areas resulted in carbon removals of 42.8 TgCO2 year−1 over the same period above. Depending on policies in these respective countries, such carbon removals could be used to claim for result-based payment under the REDD ​+ ​scheme of the United Nations Framework Convention on Climate Change.

This study aimed to: (1) identify the condition of the Bedul Banyuwangi mangrove forest area for sustainable ecotourism; (2) evaluate the fitness of the Bedul Banyuwangi mangrove forest for sustainable ecotourism; (3) evaluate collaboration between the community and the management of Alas Purwo National Park in conserving Bedul mangrove forest areas; and (4) design a management strategy for the Bedul mangrove forest for developing sustainable ecotourism. This research is a descriptive analytic study with a survey technique constructed using a remote sensing approach and a Geographic Information System (GIS). Landsat and Quickbird satellite imagery are used to identify temporal changes in mangrove forests and temperature over the last decade. Quickbird remote sensing data are used to evaluate the current land use associated with community activities in mangrove areas and government policies related to the presence of mangrove forests. The results showed that: 1) the condition of the Bedul Banyuwangi mangrove area from 1995-2022 was in a stable state. ; 2) the fitness of the Bedul Banyuwangi mangrove forest for sustainable ecotourism is included in the S2 category or following with the Bedul mangrove ecotourism fitness index; 3) the collaborative management of the Bedul mangrove ecotourism between the community (fishing community, local government) and the management of Alas Purwo National Park is continuing good to maintain the condition of the mangroves and provide economic benefits to the community in a sustainable manner; 4) the management strategy implemented is to maintain the quality and quantity of Bedul mangroves and supporting facilities in a sustainable manner. This research can be used as a reference for future research into sustainable ecotourism, as well as for the government to create policies that support sustainable ecotourism.

Plants' leaf stomata are crucial for various scientific research, including identifying species, studying ecology, conserving ecosystems, improving agriculture, and advancing the field of deep learning. This dataset, containing 1083 images, encompasses 11 species from two distinct locations in Bangladesh: nine from the Sundarbans mangrove forest and two from the Ratargul Swamp Forest. It is a valuable tool for refining machine learning algorithms that specialize in detecting stomata and categorizing species accurately. Researchers can explore a deeper understanding of plant physiology, adaptation mechanisms, and environmental interactions by employing pattern recognition, deep learning, and feature extraction techniques. Additionally, this dataset could be a potential tool for enhancing research in macroscopic metamaterials, extending its impact beyond traditional biological studies into interdisciplinary fields of technology and material science.

There is increasing recognition of the importance of local knowledge in conservation governance and sustainable use of natural resources. This article studies three social-ecological systems: Bigi Pan, Noord Coronie, and Noord Saramacca – each designated as a Multiple Use Management Area (MUMA) by the Surinamese government. The main focus of this article is how local knowledge and user perspectives may contribute to the management of a MUMA, including to making decisions about biodiversity and natural resources. We use an action research approach that includes qualitative case study methodology, participant observations, group and individual interviews. The analytical framework is based on the SES model from Ostrom (2009) to understand interactions between subsystems as mediated by local and other forms of knowledge. We also explore how participatory engagement with MUMA resource users includes local knowledge and user perspectives. The findings show how local knowledge can offer tools and solutions to improve conservation governance by supporting the development of realistic management plans and by supporting better understanding of the interactions between social and ecological subsystems. Moreover, action research helps to recognize local knowledge as valuable for science and promotes social learning among stakeholders. This paper concludes that local knowledge has contributed to policy decisions that are connected to the use practices of the people who are of the place and know the context well. The inclusion of local knowledge through participatory drafting of management plans has contributed to overcoming some major management challenges and helped to build a supportive social environment for conservation.

Mangroves provide essential ecosystem services including coastal protection by acting as coastal greenbelts; however, human-driven anthropogenic activities altered their existence and ecosystem functions worldwide. In this study, the successive degradation of the second largest mangrove forest, Chakaria Sundarbans situated at the northern Bay of Bengal part of Bangladesh was assessed using remote sensing approaches. A total of five multi-temporal Landsat satellite imageries were collected and used to observe the land use land cover (LULC) changes over the time periods for the years 1972, 1990, 2000, 2010, and 2020. Further, the supervised classification technique with the help of support vector machine (SVM) algorithm in ArcGIS 10.8 was used to process images. Our results revealed a drastic change of Chakaria Sundarbans mangrove forest, that the images of 1972 were comprised of mudflat, waterbody, and mangroves, while the images of 1990, 2000, 2010, and 2020 were classified as waterbody, mangrove, saltpan, and shrimp farm. Most importantly, mangrove forest was the largest covering area a total of 64.2% in 1972, but gradually decreased to 12.7%, 6.4%, 1.9%, and 4.6% for the years 1990, 2000, 2010, and 2020, respectively. Interestingly, the rate of mangrove forest area degradation was similar to the net increase of saltpan and shrimp farms. The kappa coefficients of classified images were 0.83, 0.87, 0.80, 0.87, and 0.91 with the overall accuracy of 88.9%, 90%, 85%, 90%, and 93.3% for the years 1972, 1990, 2000, 2010, and 2020, respectively. By analyzing normalized difference vegetation index (NDVI), soil adjusted vegetation index (SAVI), and transformed difference vegetation index (TDVI), our results validated that green vegetated area was decreased alarmingly with time in this study area. This destruction was mainly related to active human-driven anthropogenic activities, particularly creating embankments for fish farms or salt productions, and cutting for collection of wood as well. Together all, our results provide clear evidence of active anthropogenic stress on coastal ecosystem health by altering mangrove forest to saltpan and shrimp farm saying goodbye to the second largest mangrove forest in one of the coastal areas of the Bay of Bengal, Bangladesh. [ABSTRACT FROM AUTHOR]

The decomposition of mangrove litter plays a crucial role in material circulation and energy flow within mangrove forests. Evaluating the decomposition-based variation in biogenic elements in litter is important for improving our understanding about their biogeochemical cycling in ecosystems. The main objective of this study was to examine the interaction effect during the decomposition process of mixed Kandelia obovata and Avicennia marina litter. Variations in C and N were also determined in the decomposing leaf litter mixtures. Our findings revealed that the decomposition rates were faster in summer than in winter, and increased with the proportion of A. marina litter. After 35 days of decomposition in summer, the remaining weights for different proportions of K. obovata (KO) and A. marina (AM) were 22.9% (KO:AM = 1:2), 27.2% (KO:AM = 1:1), and 31.2% (KO:AM = 2:1), respectively. Similarly, after 49 days of decomposition in winter, the remaining weights for the different KO:AM proportions were 27.7%, 35.4%, and 44.0%, respectively. Additionally, the decomposition of mixed K. obovata and A. marina litter had an influence on C content and N release dynamics. These results provide a scientific basis for understanding the decomposition of mixed mangrove litter and its implications for material circulation and energy flow within these ecosystems. [ABSTRACT FROM AUTHOR]

This research was conducted with the aim of determining the biodiversity of Pertaran communities in three areas with mangrove cover and in 9 stations including one station in Gowatr Bay and 4 stations in each of Gowatr bay and Bahu Kalat on the eastern coast of Chabahar port. From each station, from the winter of 2019 to the fall of 2014, three sediment samples were collected seasonally for the separation and identification of sediments and one sample for the analysis of grain size and total organic matter of the sediments by Grab van Veen with a cross-sectional area of 0.028 square meters. In total, 12 genera belonging to 10 families were identified. Among the groups of the detected families of spionidae, the highest percentage of the average frequency with 13.70% was related to the Spionidae family. The survey of the density of the birds in total is 17800 ± 180 in the mentioned seasons, the average density of the birds in winter is 8720 ± 42 and the average density of the birds in the autumn is 9080 ± 181.63 in the mentioned seasons, the lowest average in winter is related to the Nereidae family: 0.5 600±67 and the most number was for Spionidae family: 1280±31.47 individuals in one square meter. The lowest average in autumn was related to the Nereidae family: 560 ± 32.65 and the highest to the Spionidae family: 1160 ± 62.94 individuals per square meter. The results of the parametric one-way analysis of variance test showed that the abundance of Pertaran communities in different seasons and stations had a significant difference (P<0.05) and the average abundance was higher in winter than in autumn. A positive and significant correlation was obtained between the parameters of total organic matter and sediment granularity with density. The low diversity and the low percentage of organic matter in the winter season show the negative effect of the winter monsoon on the biodiversity patterns of the wetlands of the Goater Bay and the decrease in turbulence and stress caused by waves and temperature along with the abundance of organic matter causes an increase in the diversity and predominance of species in It is autumn season. [ABSTRACT FROM AUTHOR]

Mangrove forest is a critical primary producer, biological habitat, and carbon sink in the subtropical-tropical coast zone, and the natural variation of mangrove coverage deserves study for a better understanding of the dynamics of mangrove coastal evolution. In this study, multispectral Landsat images from 1985 to 2018 are used to reconstruct the change in the coverage of mangrove (dominant species is Aegiceras corniculatum) and salt marsh (dominant species is Cyperus malaccensis) in the Nanliu River estuary. Tidal flat elevation measuring and 210Pb dating is used to study the substrate elevation when mangroves first colonize salt marsh. Historical temperature records, river discharge records, and the time series N/P concentration in sediment are analyzed. It is found that the mangrove forests have expanded rapidly in salt marsh since the mid-1980s. The change in factors such as accommodation space, cold event frequency, and nutrient supply cannot explain the origin of mangrove expansion. A low river discharge episode lasting for 8 years since 1986 is considered to have triggered the mangrove expansion in this area, as previously established salt marsh plants died due to germination restriction caused by high salinity and mangroves colonized the salt marsh habitat during this period. This case proves again that estuarine wetlands are very sensitive to salinity variation. [ABSTRACT FROM AUTHOR]

Background: Sesarmid crabs dominate mangrove habitats as the major primary consumers, which facilitates the trophic link and nutrient recycling in the ecosystem. Therefore, the adaptations and mechanisms of sesarmid crabs to herbivory are not only crucial to terrestrialization and its evolutionary success, but also to the healthy functioning of mangrove ecosystems. Although endogenous cellulase expressions were reported in crabs, it remains unknown if endogenous enzymes alone can complete the whole lignocellulolytic pathway, or if they also depend on the contribution from the intestinal microbiome. We attempt to investigate the role of gut symbiotic microbes of mangrove-feeding sesarmid crabs in plant digestion using a comparative metagenomic approach. Results: Metagenomics analyses on 43 crab gut samples from 23 species of mangrove crabs with different dietary preferences revealed a wide coverage of 127 CAZy families and nine KOs targeting lignocellulose and their derivatives in all species analyzed, including predominantly carnivorous species, suggesting the crab gut microbiomes have lignocellulolytic capacity regardless of dietary preference. Microbial cellulase, hemicellulase and pectinase genes in herbivorous and detritivorous crabs were differentially more abundant when compared to omnivorous and carnivorous crabs, indicating the importance of gut symbionts in lignocellulose degradation and the enrichment of lignocellulolytic microbes in response to diet with higher lignocellulose content. Herbivorous and detritivorous crabs showed highly similar CAZyme composition despite dissimilarities in taxonomic profiles observed in both groups, suggesting a stronger selection force on gut microbiota by functional capacity than by taxonomy. The gut microbiota in herbivorous sesarmid crabs were also enriched with nitrogen reduction and fixation genes, implying possible roles of gut microbiota in supplementing nitrogen that is deficient in plant diet. Conclusions: Endosymbiotic microbes play an important role in lignocellulose degradation in most crab species. Their abundance is strongly correlated with dietary preference, and they are highly enriched in herbivorous sesarmids, thus enhancing their capacity in digesting mangrove leaves. Dietary preference is a stronger driver in determining the microbial CAZyme composition and taxonomic profile in the crab microbiome, resulting in functional redundancy of endosymbiotic microbes. Our results showed that crabs implement a mixed mode of digestion utilizing both endogenous and microbial enzymes in lignocellulose degradation, as observed in most of the more advanced herbivorous invertebrates. [ABSTRACT FROM AUTHOR]

Mangrove forests protect the coastal environment and reduce shoreline shift, deforestation, and flood inundation. Global sea-level rise (SLR) and Bay of Bengal (BoB) cyclonic effects in the Bay of Bengal (BOB) is gradually trigger environmental degradation, flood inundation, and mangrove deforestation. Bangladesh Sundarbans are also affected by SLR and flood inundation every year. Sundarban Biosphere Reserve (SBR) is vulnerable because of extreme climatic conditions and anthropogenic activities. Those environmental effects are measurable through remote sensing (RS) and GIS approaches. Three types of satellite data, like Landsat 8 OLI/TIRS, Sentinel-1 GRD and Sentinel-2 MSI datasets, were applied with the Google Earth Engine (GEE) cloud computing platform. Around 11.57 km2 of mangrove forest will be lost from 2017 to 2022. The cyclone effects are located twice, like Mora (2017) and Sitrang (2022), while affected landforms are 77.15 km2 (1.38%) and 218.75 km2 (3.93%), respectively. Vegetation monitoring indices are also good outcomes for forest land change assessment over the examined area. Forest degradation index (FDI) values were observed in 1950 (2017) and 2620 (2022), which mentioned that north, middle, and near-shore areas are affected lands. Some adaptation planning implemented by the local government includes future disaster management, early warning system, reduction of river bank erosion, restricted forest area, and mangrove plantation. Putney Island, Bangabandhu Island, and Dimer Island are the most deforested lands. These investigation outcomes are helpful for future disaster planning, coastal environment management, awareness, mangrove forest restoration, and novel approaches to protect the coastal environment with healthier improvement policies. [ABSTRACT FROM AUTHOR]

Quantitative studies of mangrove leaf functional traits will help us understand the adaptive evolutionary strategies of mangrove plants and the relationship between mangrove biodiversity and ecosystem functions. Because of the special environment of the intertidal zone where mangroves are located, it is very difficult to obtain the functional traits of mangrove canopies from the ground, and relevant studies are lacking. The maturity of Unmanned Aerial Vehicle (UAV) hyperspectral remote sensing technology provides a new means of conducting such research. This study considered mangroves on Qi'ao Island, Zhuhai, as the research object. Based on UAV hyperspectral data, two UAV hyperspectral data processing methods, which combined Partial Least Squares Regression with Normalized Difference Vegetation Index (PLSR+NDVI) and Partial Least Squares Regression with Continuous Wavelet Transform (PLSR+CWT), were used to estimate the 10 canopy leaf functional traits of mangroves on Qi'ao Island. The results showed that the PLSR + NDVI method was more suitable for the inversion of mangrove canopy-specific leaf weight (LMA), phosphorus content per unit mass (Pmass), and nitrogen content per unit area (Narea), whereas the PLSR + CWT method was more suitable for the estimation of the nitrogen/phosphorus ratio (N/P), chlorophyll content (Cab), and carotenoid content (Cxc). However, the results of the above two methods for retrieving the nitrogen content per unit mass (Nmass), potassium content per unit mass (Kmass), phosphorus content per unit area (Parea), and potassium content per unit area (Karea) were not ideal (R2

Very complex aquatic ecosystem, the mangrove forest colonizes coastal lagoons, estuaries and deltas in tropical and subtropical zones. This study investigates the impact of mangrove vegetation on tidal propagation in the Somone Coastal Lagoon, located on the Senegalese small coast. The analysis of new field data is complemented with the application of a 3D circulation model accounting for vegetation. The analysis of well-reproduced water levels and currents over the whole lagoon make it possible to spatially study the amplitudes of the main tidal harmonics, semi-diurnal (M2), diurnal (K1) and the major overtide (M4). The comparison between our baseline model accounting for vegetation and a configuration without vegetation reveals firstly that the mangrove strongly attenuates tidal propagation in the lagoon, whit a stronger impact on semi-diurnal waves than diurnal waves. Tidal currents are also strongly reduced when the mangrove is accounted for, even close to the inlet mouth, far away from vegetation areas. The mangrove also enhances tidal asymmetry and promotes ebb dominance, both in terms of duration (ebbs last from 0.5 up to 3 h more than floods) and current magnitude (ebb currents are about 50% stronger). Spring tides accentuate ebb-dominance compared to neap tides, where tidal asymmetry is weaker. [ABSTRACT FROM AUTHOR]

This study investigated the avifauna within the mangrove forests along the Epe Lagoon in Lagos, Nigeria, with a focus on promoting sustainable tourism. Its primary objective was to establish a foundational knowledge base for future research endeavors and to aid in the development of conservation strategies aimed at safeguarding bird diversity. The research site was divided into three zones: undisturbed forest, secondary forest, and wetland areas. Bird species diversity was assessed using the line transect method, with a total of 30 transect lines randomly distributed across the study area, with 10 in each zone. These lines were surveyed three times a week over three months, encompassing both wet (May, July, and September) and dry (November, January, and March) seasons in 2023. Surveys were conducted from 6:00 to 10:00 in the morning and from 4:00 to 6:00 p.m., during which all birds observed on the ground, in vegetation, or flight were identified and counted. The findings revealed a total of 198 bird species belonging to 44 families and 18 orders, with an abundance of 481 individual birds recorded in the study area, highlighting its significance in supporting bird species diversity. Analysis of the family composition of bird species identified Pycnonotidae as the most abundant with 13 species, followed by Muscicapidae and Accipitridae, each with 12 species. [ABSTRACT FROM AUTHOR]

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Considered a unique biodiversity hotspot of the world, the Sundarbans mangrove harbours a wide variety of wild and plant species. This popular tiger land is now under threat to tiger survival. In this study, I venture to assess the tiger status, population, trends, extent, threats, and conservation process in the Sundarbans. My study finds that there were nearly 693 Bengal tigers (Panthera tigris tigris) in the Sundarbans mangrove forest in 2004. Ten years later, the tiger population reached 182 individuals. However, a slight increase in the tiger number was noticed in 2018 when the tiger constituted 202 individuals. Due to data deficiency, TX2 goal of doubling the tiger population by 2022 was not considered. This study finds that there are numerous factors work behind the extinction of the tiger population in the Sundarbans, such as habitat loss, deforestation, land cover change, human interventions into the forests, poaching, hunting, illegal wildlife trade, climate change, and natural disasters, salinity, scarcity of prey species, lack of capability of the forest staff and personnel, poor and weak legal frameworks are prominent. Therefore, this paper endeavours to assess the efforts of Bangladesh and the Indian government to double the Bengal tiger population by 2022 and analyse the factors and threats to eliminate tiger numbers in the world's largest mangrove forest Sundarbans. [ABSTRACT FROM AUTHOR]

Mangrove wetlands are hotspots of global biodiversity and blue carbon reserves in coastal wetlands, with unique ecological functions and significant socioeconomic value. Annual fine-scale monitoring of mangroves is crucial for evaluating national conservation programs and implementing sustainable mangrove management strategies. However, annual fine-scale mapping of mangroves over large areas using remote sensing remains a challenge due to spectral similarities with coastal vegetation, tidal periodic fluctuations, and the need for consistent and dependable samples across different years. In previous research, there has been a lack of strategies that simultaneously consider spatial, temporal, and methodological aspects of mangrove extraction. Therefore, based on an approach that considers mangrove habitat, tides, and a semantic segmentation approach, we propose a method for fine-scale mangrove mapping suitable for long time-series data. This is an optimized hybrid model that integrates spatial, temporal, and methodological considerations. The model uses five sensors (GF-1, GF-2, GF-6, ZY-301, ZY-302) to combine deep learning U-Net models with mangrove habitat information and algorithms during low-tide periods. This method produces a mangrove map with a spatial resolution of 2 m. We applied this algorithm to three typical mangrove regions in the Beibu Gulf of Guangxi Province. The results showed the following: (1) The model scored above 0.9 in terms of its F1-score in all three study areas at the time of training, with an average accuracy of 92.54% for mangrove extraction. (2) The average overall accuracy (OA) for the extraction of mangrove distribution in three typical areas in the Beibu Gulf was 93.29%. When comparing the validation of different regions and years, the overall OA accuracy exceeded 89.84% and the Kappa coefficient exceeded 0.74. (3) The model results are reliable for extracting sparse and slow-growing young mangroves and narrow mangrove belts along roadsides. In some areas where tidal flooding occurs, the existing dataset underestimates mangrove extraction to a certain extent. The fine-scale mangrove extraction method provides a foundation for the implementation of fine-scale management of mangrove ecosystems, support for species diversity conservation, blue carbon recovery, and sustainable development goals related to coastal development. [ABSTRACT FROM AUTHOR]

Quantitative studies of mangrove leaf functional traits will help us understand the adaptive evolutionary strategies of mangrove plants and the relationship between mangrove biodiversity and ecosystem functions. Because of the special environment of the intertidal zone where mangroves are located, it is very difficult to obtain the functional traits of mangrove canopies from the ground, and relevant studies are lacking. The maturity of Unmanned Aerial Vehicle (UAV) hyperspectral remote sensing technology provides a new means of conducting such research. This study considered mangroves on Qi'ao Island, Zhuhai, as the research object. Based on UAV hyperspectral data, two UAV hyperspectral data processing methods, which combined Partial Least Squares Regression with Normalized Difference Vegetation Index (PLSR+NDVI) and Partial Least Squares Regression with Continuous Wavelet Transform (PLSR+CWT), were used to estimate the 10 canopy leaf functional traits of mangroves on Qi'ao Island. The results showed that the PLSR + NDVI method was more suitable for the inversion of mangrove canopy-specific leaf weight (LMA), phosphorus content per unit mass (Pmass), and nitrogen content per unit area (Narea), whereas the PLSR + CWT method was more suitable for the estimation of the nitrogen/phosphorus ratio (N/P), chlorophyll content (Cab), and carotenoid content (Cxc). However, the results of the above two methods for retrieving the nitrogen content per unit mass (Nmass), potassium content per unit mass (Kmass), phosphorus content per unit area (Parea), and potassium content per unit area (Karea) were not ideal (R²<0.3). The optimal method established in this study was used to estimate the contents of LMA, Pmass, Narea, N/P, Cab, and Cxc of the mangrove canopy leaves in the study area and map their spatial distribution. Mangrove canopy leaf functional traits obtained using UAV hyperspectral data inversion better reflect the horizontal structure and function of the mangrove community. Regarding the spatial distribution patterns of canopy leaf functional traits, the spatial distribution patterns of Narea, Cab, Cxc, and N/P were relatively consistent with higher values in the middle region and lower values in the edge region. The spatial distribution patterns of the LMA and Pmass were similar, and the distribution was relatively uniform throughout the study area. Combined with ground survey data, the internal relationship between species composition and spatial patterns of functional traits, as well as ecosystem functions and processes, can be deeply explored, and rapid investigation and assessment of mangrove forests can be realized at the community and ecosystem scales. The spatial distribution pattern of functional traits was closely related to the spatial distribution pattern of canopy structure and species. The inversion model of hyperspectral functional traits was constructed by separating mangrove species with different life types, which is expected to further improve the inversion accuracy of the model. Constructing a specific functional trait inversion model for each mangrove species, combined with the species identification results of visible-light images, will effectively improve the inversion accuracy of mangrove canopy leaf functional traits. [ABSTRACT FROM AUTHOR]

Background: Sommeratia caseolaris is considered the most important mangrove species for reforestation and conservation programs. Therefore, the knowledge of genetic diversity and the population structure of the species has important implications both for the conservation of existing genetic resources and development programs. In the present study, the genetic diversity and structure population of eight populations of S. caseolaris from the Northern to the Southern Coast of Vietnam were determined using nine ISSR molecular markers. Results: Eight populations of the mangrove species Sonneratia caseolaris were sampled across the natural range in Vietnam to evaluate the genetic diversity of the species. Nine ISSR markers were used to analyse 30 individuals from each population. There were moderate to high levels of genetic diversity (I = 0.447; h = 0.300). PCoA analysis gave very similar results to UPGMA dendrogram construction with the eight populations clustered into three genetic groups which mostly aligned with geographical distances among them. AMOVA analysis results indicated that most (81 %) of the genetic variation was within populations. Conclusion: The current study also indicates the high level of genetic variation existing among and within the natural population of S. caseolaris in Vietnam. These results open new perspectives towards the conservation of the species' genetic resources and their future use in conservation and reforestation programs.

The distribution of mangrove plants is influenced by various factors, including the physical characteristics of the soil. The study was conducted to determine the physical characteristics of the soil in the mangrove ecosystem in Bone Bay, Palopo City. Soil sampling was performed using the purposive sampling method in five points with three replications based on the equations of growth and density of mangrove vegetation. Physical characteristics of the soil sample, including texture, color, permeability, bulk density, and soil porosity, were analyzed in the laboratory. The results showed that the dominant soil textures were squirming and sandy loam. The dominant soil color was very dark gray. Soil permeability is high and belongs to the fast criteria, with the highest value of 20.0 cm/hour at the fourth depth point of 0-30. The highest bulk density at the fourth depth point is 31-60 cm, with a value of 0.81 gr/cm3. At the same time, the porosity of the soil is classified as a high or good criterion, with the highest value found at the third depth point of 0-30 cm with a value of 77%. In the future, soil physical characteristics data can be used as preliminary information or databases for the government to organize and preserve mangrove forests.

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Canopy equivalent water thickness (EWT) is an essential indicator of plant water status related to plant growth, temperature maintenance and transpiration. To our knowledge, this study was the first to map the mangrove canopy EWT using Sentinel-2 image at the reserve scale, aiming to explore three modeling strategies in retrieving mangrove canopy EWT, including machine learning models (Random Forest Regression (RFR) and Adaptive Boosting (Adaboost)), radiative transfer models (RTMs, PROSAIL-D and biophysical processor in Sentinel application platform) and hybrid models (PROSAIL-D + RFR and PROSAIL-D + Adaboost). We further investigated the impacts of four ecogeographical factors (species distribution, slope, elevation and distance to dam) on the spatial distribution of canopy EWT using Geodetector method. The results showed that Adaboost (R2 = 0.593, RMSE = 0.771 kg/m2 and RPIQ = 1.820), PROSAIL-D (R2 = 0.451, RMSE = 0.937 kg/m2 and RPIQ = 1.537) and PROSAIL-D + Adaboost (R2 = 0.501, RMSE = 0.890 kg/m2 and RPIQ = 0.887) was the optimal machine learning, RTM and hybrid model in retrieving mangrove canopy EWT, respectively. The red-edge3, NIR and SWIR bands of Sentinel-2 imagery were sensitive to canopy EWT. Moreover, Geodetector analysis demonstrated that species distribution had the most significant impact on canopy EWT, with the interaction between species and distance to dams contributing the most to the spatial difference of canopy EWT. In conclusion, this study suggests that Adaboost model and the hybrid method of PROSAIL-D and Adaboost were promising to map large-scale canopy water conditions in mangrove ecosystems using Sentinel-2 imagery.

Temporary freshwater lenses can form in saline environments after rainfall, providing essential resources for species including drinking water and dispersal routes. However, there is limited indication that these lenses can also be used for breeding. Herein, we provide evidence of the green and golden bell frog, Litoria aurea, performing breeding activities, including calling and amplexus, in tidal mangrove creeks on Kooragang Island, NSW, Australia. Our findings suggest that these creeks intermittently phase into a low salinity state after the influx of fresh water from rainfall, forming temporary freshwater lenses that can be exploited before the creeks revert to a saline state. These lenses had salinities (1.4 ppt and 4.5 ppt) within the tolerance limit of L. aurea tadpoles, although we are unsure whether oviposition took place and offspring survival to metamorphosis was achieved. It is possible that anthropogenic disturbances to hydrology on Kooragang Island have benefited L. aurea by restricting tidal influences in mangrove creeks, prolonging the duration of freshwater lenses. [ABSTRACT FROM AUTHOR]

Laguncularia racemosa is widely planted in coastal mudflats as a pioneer species of mangrove afforestation in China; however, whether it exhibits invasiveness as an exotic species has been a topic of debate. In this study, we investigated the distribution, community structure, and population characteristics of L. racemosa on Hainan Island, China, to discuss its potential invasiveness. The results showed that Hainan Island has become an important distribution area for L. racemosa in China, covering a total area of 64.90 ha. In this investigation, a total of 11 true mangrove species, belonging to six families and 11 genera, were discovered in the L. racemosa community throughout Hainan Island. Furthermore, L. racemosa exhibited a strong adaptive range to seawater salinity and demonstrated a high capacity for natural dispersion. L. racemosa exhibited high importance values in the tree, shrub, and seedling layers of this artificial community, indicating its dominance and potential exclusion of other mangrove species. Over time, the importance values of L. racemosa in the tree and shrub layers initially decreased and then increased, while the opposite trend was observed in the seedling layer. Overall, the diversity indexes, including the Simpson index, Shannon–Wiener index, and Pielou community evenness index, were low in the planted L. racemosa forest on Hainan Island, suggesting a relatively simple species composition within the L. racemosa community. Additionally, based on the height levels of the L. racemosa population, we found that it mainly belonged to the first level, characterized by a large number of seedlings on Hainan Island. The number of L. racemosa seedlings gradually decreased in subsequent levels, and higher height levels of L. racemosa appeared with longer planting times, indicating a growing trend of potential invasiveness of L. racemosa on Hainan Island over an extended period. We suggest that the government should be able to list L. racemosa as an invasive species that can be harvested in the future. Based on this, this study provides fundamental data and theoretical references for the sustainable prevention, control, and management of the exotic species L. racemosa on Hainan Island, and also in other mangrove wetlands in China. [ABSTRACT FROM AUTHOR]

Unmanned aerial vehicles (UAV) imagery has proved to be useful in the efficient protection and management of mangrove forests. However, there have been few attempts to show that UAV-RGB images may be used for mapping trees at the species level. Our objective, in this study, is to identify two mangrove species using object-based classification. Height information was used to segment trees to obtain maximum spectral purity in each segment for classification using the Canopy Height Model (CHM) in Sirik mangrove forest (Azini Creek) located in southern Iran. The object-based classification (using a random forest algorithm) of UAV imagery with dominant mangrove features (i.e., Rhizophora mucronata, Avicennia marina, ground/sand, and water) achieved an overall accuracy (OA) of 98% and Kappa coefficient of 0.97. The results showed that the overall accuracy and Kappa were upgraded from 94 to 98% and 0.91–0.97, respectively. The water and ground classes were identified with a producer's accuracy of 100%. The random forest algorithm accuracy for both of the trees was more than 90% (produce accuracy 95 and 98% and user accuracy 98 and 97% for R. mucronata and A. marina, respectively). The results demonstrated proof for the potential and usefulness of spectral data, i.e., UAV–RGB derived orthomosaic, and structural, i.e., CHM data for mangrove trees identification. [ABSTRACT FROM AUTHOR]

Crab and soil samples were seasonally collected at four mangrove sites (Cacha Prego, CP; Ponta Grossa, PG; Ilha de Maré, IM; and Pitinga, PT) in Todos os Santos Bay, in NE Brazil. Total Cu levels in soils ranged from 2.5 to 89.4 mg kg−1, while in crab organs (muscles, hepatopancreas, and gills), Cu ranged from 20 to 1,320 mg kg−1, with the highest concentrations found in the Ilha de Maré population, where soils showed a clear Cu enrichment. Total Cu content did not explain the abnormally high Cu concentrations observed in crabs from Pitinga, where total content in soil was low. Geochemical partitioning indicated that most of the potentially bioavailable Cu was found in the oxidizable fractions, pyrite and organic matter. Pyrite oxidation during the dry season led to increased Cu bioavailability. This process was of relevance in soils of the Pitinga mangrove, where sulfide oxidation led to soil acidification and to an increase in Cu associated with the most labile fractions. [ABSTRACT FROM AUTHOR]

Mangrove forests, benefitting millions of people, experience significant degradation. Global recognition of the urgency of halting and reversing this trend have initiated numerous restoration activities. Restoration success is typically evaluated by estimating mangrove survival and area restored, while diversity and structure of vegetation, as proxies for functional forests, are rarely considered. Here we assess mangrove species richness along sea‐landward transects and evaluate restoration outcomes by comparing number of mangrove species, relative species abundance, biomass, diameter, and canopy cover in "Monoculture Reforestation", "Mixed Species Regeneration" and adjacent "Reference" forest stands, 14 (Tiwoho site) and 16 years (Likupang site) after restoration activities took place. In the "Monoculture Reforestation" plots, mangrove diversity and structure still closely reflected the original restoration actions, with only one and two "new" species having established among the originally densely planted "foundation" species. In contrast, the "Mixed Species Regeneration" plots were more similar to the "Reference" plots in terms of tree diameter and canopy coverage, but species number, abundance and biomass were still lower. The trajectory of the "Mixed Species Regeneration" plots suggests their similarity with the "Reference" stands will increase over time, whereas such "smooth" transition is unlikely to happen in the planted "Monoculture Reforestation" stands, in the foreseeable future. Implementing frequent small‐scale disturbances in restored forest management would increase stand structure and diversity, accelerating the establishment of a more natural, and likely more functional and resilient forest. [ABSTRACT FROM AUTHOR]

Photoautotrophic microorganisms, such as microalgae and cyanobacteria, are known to perform an essential role in ecological functions. Besides, they are considered cell factories, producing various bioproducts of commercial interest. In mangroves, these microorganisms are primarily responsible for the ecosystem's high productivity. Moreover, the unique natural characteristics of mangroves, coupled with the intense pressure from anthropic activities that these ecosystems typically experience, make mangrove photoautotrophic microbiota biotechnologically attractive. In this work, the ecological role and biotechnological potential of photoautotrophic mangrove microorganisms worldwide were evaluated, highlighting, their ecosystem services and bioproducts with environmental and commercial appeal, as well as their strategic and technological application through patent analysis. © 2023 Society of Industrial Chemistry and John Wiley & Sons Ltd. [ABSTRACT FROM AUTHOR]

There are positive effects on climate, water availability, and temperature that may be attributed to the presence of mangrove forests. In addition, mangroves provide natural infrastructure and protection to human communities that are located nearby by preventing erosion and absorbing the effects of storm surges caused by large weather events such as hurricanes. Regrettably, the disappearance of mangroves harms the ecology and the environment's viability. Using secondary sources and a descriptive approach to study, this article investigates the impact that the destruction of mangrove forests in India has had on the surrounding ecosystem. The research findings indicate that India's most significant contributors to environmental destruction are development activities and other reasons. Deforestation may lead to many negative outcomes, including changes in climate, a reduction in biodiversity, the destruction of habitat, and armed conflict. [ABSTRACT FROM AUTHOR]

Trees in wetlands emit a significant amount of methane (CH4) into the atmosphere which is produced in the soil where anaerobic conditions prevail. However, only very few studies have considered the role of trees in the CH4 budget of mangrove forests. How tree CH4 emissions (FCH4$$ {F}_{{\mathrm{CH}}_4} $$) vary between and within individuals, and how these emissions vary with the day/night alternation and the tidal cycle, have not yet been elucidated. We measured FCH4$$ {F}_{{\mathrm{CH}}_4} $$ from buttress roots and stems on individuals of Bruguiera gymnorrhiza of different sizes. We also measured FCH4$$ {F}_{{\mathrm{CH}}_4} $$ from trees and sediments over a 24‐h cycle. Higher FCH4$$ {F}_{{\mathrm{CH}}_4} $$ was measured on the buttress roots than on the stems, with a decreasing trend with height along the stems on a majority of trees. FCH4$$ {F}_{{\mathrm{CH}}_4} $$ exhibited large variations over a 24‐h cycle which were observed for the first time in this study. FCH4$$ {F}_{{\mathrm{CH}}_4} $$ from sediment was twice higher at low tide compared to just before or after the flood period. FCH4$$ {F}_{{\mathrm{CH}}_4} $$ from non‐submerged stem positions at high tide was four times higher during the day than during the night. On buttress roots and on stem portion which were submerged, high FCH4$$ {F}_{{\mathrm{CH}}_4} $$ were measured at the beginning of the ebb tide even at night. A better understanding of FCH4$$ {F}_{{\mathrm{CH}}_4} $$ variability from mangrove trees and its controls, at different time scales and along spatial gradients is needed for accurate estimation of CH4 budgets of mangrove forests. [ABSTRACT FROM AUTHOR]