Mangrove Growth Research Articles

Assessing climatic change impacts on mangrove structural dynamics on the northern coasts of the Persian Gulf

Abstract. Monitoring long-term trends in structural changes within mangrove ecosystems is essential for understanding their response to climate change and devising effective adaptation strategies in coastal regions. This study examines changes in mangrove patchiness within the Hara Biosphere Reserve (HBR) along the northern coasts of the Persian Gulf (PG) over a 31-year period (1986-2017), focusing on variations in rainfall patterns and drought occurrences. Employing a 35-year time series of monthly Standardized Precipitation Index (SPI) values alongside satellite imagery analysis, trends in both the number of patches (NP) and the Largest Patch Index (LPI) were assessed at the mangrove stand level. The analysis reveals a significant correlation between structural changes in mangroves and drought events. Pre-1998, characterized by wetter conditions, witnessed a decrease in both NP and LPI, indicating patch expansion and habitat extension. Conversely, post-1998, during drought periods, both indices increased, indicating habitat degradation due to heightened drought intensity. Pre-1998 structural changes in the HBR signify habitat expansion, with increased patch extent and core areas reflecting enhanced structural integrity. However, post-1998, a concerning trend of habitat degradation emerged, with increased NP and LPI attributed to intensified droughts. These findings highlight a transitional period marked by favourable conditions for mangrove growth followed by habitat degradation linked to increased drought intensity. This underscores the vulnerability of mangrove ecosystems to climate change impacts, particularly exacerbated droughts, necessitating urgent efforts for conservation and management to preserve biodiversity and ecosystem services in coastal regions.

Coastal urbanization may indirectly positively impact growth of mangrove forests

Coastal urbanization is a key driver of mangrove loss, yet its global impacts on mangroves have yet to be thoroughly understood. Here we present a fine-scale assessment of the hidden impacts of urbanization on mangroves mediated by climate, and the joint effects of urbanization and climate at the global scale. Surprisingly, both urbanization and climate had positive impacts on mangrove growth and carbon stock in some regions, which is different from the general belief of the adverse impacts from previous research. In total, 27.3% of global mangroves received positive impacts from urbanization regarding their extent and carbon stock, among which 59.5% are indirectly mediated by climate. Moreover, mangroves in subtropical/temperate climate zones experienced more indirect positive impacts from urbanization, which enhances local climate conditions for growth by altering temperature, rainfall and sea levels. These findings suggest the feasibility of facilitating mangrove conservation through effective urban planning to achieve coastal sustainability.

Potential Effect of Mangrove Ecosystem on Soil Carbon Sequestration and its Physico-Chemical Properties

The mangrove ecosystem is a natural wetland located in the Red Sea that extends 500 km on the Egyptian western coast. It has great potential to sequestrate soil organic carbon, reduce atmospheric CO2, and enhance soil hydro-physical properties. In this context, this research aims to characterise soil changes induced by mangrove growing. Both modelling and measurements herein were performed on five sampling areas at the Western Strand of the Red Sea (plus one control site - beach without plants). The locations (sites 1 and 2) of mangrove forest were in El-Gouna village with ages of 10 and 5 years, respectively, while (sites 3, 4, and 5) represent mangroves at Hurghada, Abu-Monquar Island, and Safaga, respectively. The mean values of measured soil organic carbon pool (SOCP) at the soil surface (0-90cm) revealed that the lowest values of the SOCP were at Hurghada with 8.81± 0.12 Mgha-1 and the highest values at Abu Monquar island with 59.75 ± 0.15 Mgha-1. At El Gouna 1, 2 and Safaga, the SOCP values were 14.48, 12.86, and 39.98 Mgha-1, respectively. In addition, the SOCP at the control site (beach without plants) was 6.62± 0.25 Mgha-1. Thus, the mangrove ecosystem has a great potential to sequestrate the soil's organic carbon and reduce atmospheric CO2. Soil bulk density (SBD) values varied at El-Gouna1, 2, and Hurghada from 1.63 to 1.75 g/cm³, while the lowest SBD values were observed at Abu-Monquar Island and Safaga with 1.31± 0.02, g/cm³ and 1.53 ± 0.05 g/cm³, respectively. SBD at the control site was 1.75± 0.05 g/cm³, which reflects the higher values. Morphological characteristics reveal that tree height results varied from 110-130 cm, 50-70 cm, 150-200 cm, 200-300 cm, and 200-270 cm for ElGouna1, ElGouna2, Hurghada, Abu-Manqar, and Safaga, respectively. Higher values of tree height, size index, and density are convenient, as are the lower values of SBD at Abu-Monquar and Safaga compared to other site locations. The soil-water HYDRUS-1D model revealed that the soil water storage capacity at Abu-Monquar was higher than the other samples. Thus, the joint use of modelling and measurements enabled deeper insight and a suitable characterisation of soil physicochemical changes induced by mangrove growth.

Factors influencing mangrove carbon storage and its response to environmental stress

Mangrove forests serve as significant carbon sinks and play a crucial role in mitigating climate change. Currently, the response of mangroves to intensified climate change and human activities, and the factors that influence the magnitude of carbon storage in their sediments remain uncertain. To address these questions, two sediment cores were collected from the mangrove reserve in Pearl Bay, Guangxi, China. The activity of 210Pb in the sediment, grain size, bulk elemental composition, stable carbon isotopes, lignin, and different sediment organic matter (OM) fractions were investigated to determine the local mangrove’s response to climate change and human activities, as well as the factors influencing its carbon storage. The results showed mangrove forests with lower tidal ranges, slower sedimentation rates, and where OM predominantly originated locally tend to have larger carbon stocks. The mangrove OM (MOM) decreased progressively from the bottom to the top of the cores, indicating that the mangroves in Pearl Bay have possibly undergone degradation, which was further substantiated by the decrease in lignin content. Based on these results, the entire cores were divided into two stages: stable stage 1 (1963–2001) and degradation stage 2 (2001–2020). The cause of the mangrove degradation is likely due to the impact of human activities; however, these impacts are anticipated to gradually lessen in the future due to mangrove protection policies. Our results indicate that lignin can track and predict mangrove growth trends and provide guidance for the sustainable management of mangrove ecosystems.

Resource Availability and Use in Restored, Unmanaged, and Aquaculture Mangrove Ecosystems in Indonesia

Mangrove ecosystems are some of the most productive on our planet but have declined globally by 30–50%. Many species rely on mangrove habitats; thus, their conversion to aquaculture farms has led to noticeable losses in commodities such as wild fish stocks. This study aimed to assess the influence of aquaculture and restoration projects on the ecosystem’s ability to provide resources. We collected data on mangrove vegetation (i.e., biomass, richness, and abundance), soil nutrients (i.e., organic carbon, aluminium, and nitrogen), crab abundance, and fishing pressure at six sites. We set up 15 plots at each site and collected data between May and July 2023. Via generalised linear mixed models, we found that the abundance and richness of crabs was significantly higher in aquaculture plots than in non-aquaculture plots. Aquaculture plots had higher topsoil aluminium, higher topsoil and subsoil nitrogen, and lower topsoil carbon than non-aquaculture sites. Restored sites had less nitrogen in the topsoil than unmanaged sites. The biomass did not change between aquaculture, restored, and unmanaged plots. We found a negative correlation between crab abundance and richness and mangrove diameter at breast height (DBH), suggesting that the species of crabs present preferred areas with propagules for feeding (e.g., Grapsidae crabs). The content of nitrogen in the subsoil was positively correlated with mangrove richness, diversity, and height, suggesting the importance of nitrogen availability for mangrove growth. The content of aluminium in the subsoil was negatively correlated with the content of organic carbon in both the topsoil and subsoil, suggesting the detrimental effect of aluminium on the carbon cycle. Fishing practices were observed at all sites during the data collection period. Despite the lack of significant impact on most vegetation parameters and the limited differences between managed and unmanaged sites, key variables such as soil aluminium, carbon, and nitrogen contents and crab assemblages exhibited high variability, highlighting the complex interactions within mangrove ecosystems.

Natural regeneration of white mangrove (Laguncularia racemosa L.) during the dry season in Ejido La solución in Paraíso, Tabasco, México

Objective: To estimate the natural regeneration and growth in the sapling stage of white mangrove during the dry season. Design/methodology/approach: Measurements of the structural variables of white mangrove, diameter at breast height (DBH), height and crown diameter were made in three sampling plots. A statistical analysis was performed with the data obtained and mean data were obtained from the three sampling plots. Results: DBH data were 0.34, 0.37 and 0.42 m; height 1.34, 1.28 and 1.58 m; and crown 44.18, 38.56 and 39.83 cm, in each sampling plot respectively. Limitations on study/implications: In dry seasons, erosion can expose rocky or sandy substrates that are not suitable for mangrove growth. Findings/conclusions: The white mangrove in its sapling stage during the dry season, presented statistically significant differences in growth between sampling plots using the dasometric variables (DBH, height and crown diameter).

Environment and Socio-Economic Impact of Mangroves at Mobil, Dunggoan, Danao City, Cebu, Philippines

This study explored the environmental and socio-economic impacts of the mangrove rehabilitation project in Mobil, Dunggoan, Danao City, Cebu. It examined the demographic profile of residents, their perceptions and contributions to the project, and the effectiveness of project monitoring. In addition, the researchers conducted an actual measurement of the height and spread branches of the planted mangroves. The research employed descriptive method, utilizing surveys and direct measurements to assess the survival rate and growth of mangroves, as well as the distribution of marine life using quadrat method. Findings indicate a significant survival rate of mangroves, with Rhizophora stylosa and Rhizophora apiculata being the predominant species. The project has notably enhanced shoreline protection, erosion prevention, aquatic habitat, water quality, and the aesthetic appeal of the cove. The study underscored the necessity of implementing stricter monitoring, waste management, restoration projects, and community awareness programs to improve mangrove rehabilitation.

PENGELOLAAN VEGETASI DI KAWASAN EKOWISATA MANGROVE PERANCAK, JEMBRANA

Perancak mangrove forest is one of the important supporters for mangrove ecotourism in perancak as an ecosystem that functions ecologically, economically and socially as an effort to preserve the beach in a sustainable manner. This research aims to determine the level of diversity of mangrove vegetation types in the perancak coastal area and conduct mangrove management efforts through vegetation analysis and soil analysis. Sampling carriedout on true mangroves and associated mangroves using purposive sampling technique. The method of flora sampling was carried out by quadrant method by calculating the important value index, diversity index and type distribution pattern. True mangroves consist of 13 species and 1367 individuals, dominated by rhyzophora stylosa, with a total importance index (indeks nilai penting)= 299.86 % (classified as sestable), diversity index 1.1192 and distribution pattern = 0.548 (vegetation is stable and uniform). Associate mangroves consists of 13 types and 649 individuals, dominated by the type Terminalia cattapa. Important index =297.892 %, diversity index = 0.9438 and type distribution pattern = 0.73 i.e vegetation that grows is classified as uniform. Analysis results for the 5 soil samples for total n, p and k elements available and organic c, all support mangrove growth. the development of true mangroves and associations is the main supporting factor for the development of tourism areas in the perancak jembrana ecotourism area which is now developing into a beach park developed by the people of Perancak village. Keywords: Perancak; Mangrove Diversity; Management; Soil Analysis

The effects of mangrove growth on sediment nitrogen mineralization and immobilization are more intense on sandy coasts compared to muddy coasts

Mangroves are important ecosystems on the coasts of southeastern and southern China, which have a significant role in altering microbial communities and nutrient cycles. However, the response of sediment nitrogen (N) mineralization (GNM) and ammonium immobilization (GAI) on the different coastal types (muddy and sandy) to mangrove growth remains poorly understood. Here, surface sediment (0–5 cm) GNM and GAI were examined simultaneously in bare flat and mangrove habitats on both muddy and sandy coasts along a coastal transect of South China, using 15N isotope dilution techniques. The results showed that GNM and GAI rates in sediment ranged from 0.31 to 33.94 μg N g−1 d−1 and 0.24 to 41.02 μg N g−1 d−1, respectively, and mangroves significantly increased the two process rates on both muddy and sandy coasts. The magnitude of increase in GNM and GAI was more pronounced for sandy coasts than for muddy coasts. Mangroves also promoted the ratio of GAI to GNM (RAI), but the ratio of GNM to total N (PAM%) generally did not differ between bare flat and mangrove habitats. Sediment total organic carbon, total N, ammonium, ferrous iron, and microbial abundances were crucial factors in regulating GNM and GAI on both two contrasting coasts, but the process rates on sandy coasts were also related to sediment grain size composition and specific surface area. Our results suggested that mangrove growth is more effective in promoting GNM and GAI on sandy coasts than on muddy coasts, which may be important to improving the nutrient cycle and energy flow on sandy coasts. Overall, these findings provide valuable insights into the N transformations and influencing mechanisms on different coastal types influenced by the growth of mangroves and imply that it is significant to advance mangrove restoration on sandy coasts, yet widely overlooked.

Assessment of water quality parameters due to longitudinal salinity inundation at Indus Delta: a case study of Kharo Chan, District Sujawal

Deltas are landforms that are formed at the regions where a river meets an ocean. When the freshwater of a river joins the saline water of an ocean, a transitional state of water is obtained. This zone of transition varies on the quantity of freshwater entering the ocean and the quality of both waters. Indus River is facing severe challenges due to climate change which has resulted in reduced water flow in the river. Consequently, seawater intrusion takes place which causes coastal erosion, stunted mangrove growth, and the narrowing of the river towards the seaside. The groundwater in the deltaic regions is unfit for drinking which forces an increased reliance on surface water. Sindh Province of Pakistan, particularly the coastal regions, suffers from severe water quality problems, affecting approximately 41% of the population. The population of this region is deprived of good-quality water for their daily use. This research aims to evaluate the physiochemical parameters of water in the Indus River to identify the zone of salinity inundation and determine safe zones for accessing surface water in the Indus Delta in the Sujawal district. Water samples were collected from Khobar Creek, ending in the Arabian Sea in the areas of Shah Bandar and Kharo Chan at an approximate interval of 5 km. These samples were analyzed for various physical and chemical properties. Properties were compared spatially to develop a relationship between distance and quality of water. Results indicate that the values of dissolved solids in collected samples are between 21,450 and 900 mg/L, pH was between 6.66 and 7.63, conductivity of the samples varied from 33,000 to 1385 µS/cm, acidity values were between 921.14 and 399.84 mg/L, hardness was in the range of 3654 to 192 mg/L, and the turbidity was in between 21 and57 NTU. It was revealed from the results that seawater is having a severe influence upto 15 km from the mouth of the creek in which not a single parameter except the pH was complying with WHO recommendations. In the interval of 15 to 30 km, some properties of water were complying with WHO recommendations, while some of them were deviating from the limits. It has been concluded that turbidity was improving while going toward the ocean, while Total Dissolved Solids, hardness, and chloride concentrations were increasing as water was getting closer to the sea while pH was found almost unaffected. The findings emphasize the need for addressing environmental degradation, social hardships, and economic challenges caused by these water quality issues. Ultimately, the quality of water is crucial for various activities specifically for drinking purposes, and its suitability for specific purposes is of utmost importance.

Effects of catchment land use on temperate mangrove forests

Human land use changes are threatening the integrity and health of coastal ecosystems worldwide. Intensified land use for anthropogenic purposes increases sedimentation rates, pollutants, and nutrient concentrations into adjacent coastal areas, often with detrimental effects on marine life and ecosystem functioning. However, how these factors interact to influence ecosystem health in mangrove forests is poorly understood. This study investigates the effects of catchment human land use on mangrove forest architecture and sedimentary attributes at a landscape-scale. Thirty sites were selected along a gradient of human land use within a narrow latitudinal range, to minimise the effects of varying climatic conditions. Land use was quantified using spatial analysis tools with existing land use databases (LCDB5). Twenty-six forest architectural and sedimentary variables were collected from each site. The results revealed a significant effect of human land use on ten out of 26 environmental variables.Eutrophication, characterised by changes in redox potential, pH, and sediment nutrient concentrations, was strongly associated with increasing human land use. The δ15N values of sediments and leaves also indicated increased anthropogenic nitrogen input. Furthermore, the study identified a positive correlation between human land use and tree density, indicating that increased nutrient delivery from catchments contributes to enhanced mangrove growth. Propagule and seedling densities were also positively correlated with human land use, suggesting potential recruitment success mechanisms. This research underpins the complex interactions between human land use and mangrove ecosystems, revealing changes in carbon dynamics, potential alterations in ecosystem services, and a need for holistic management approaches that consider the interconnectedness of species and their environment. These findings provide essential insights for regional ecosystem models, coastal management, and restoration strategies to address the impacts of human pressures on temperate mangrove forests, even in estuaries that may be relatively healthy.

Morphological Evolution of an Intertidal Mudflat in Relation to Mangrove Growth: Implications for Future Erosion Control.

There is limited information regarding the influence of mangrove growth on the morphological evolution of intertidal mudflats. In this study, Tan Phu Dong district, Tien Giang Province, Vietnam, was selected for investigating how mangrove growth influenced the morphological evolution of an intertidal mudflat. The authors analyzed a series of satellite images (from 1995 and 2022), calculated the enhanced vegetation index (EVI), and documented field visits and observations in pursuit of the objective of the study. The findings revealed that fine-grained sediment accumulated as unconsolidated substratum (US) in the first step of the morphological evolution of the intertidal mudflat, with sediment accumulation of 910 ha in 1995. The US provided favorable conditions for mangroves to grow, while mangrove growth helped compact the US into a compact substratum (CS) in addition to promoting continuous sediment accumulation, increased the vegetation cover of the island, and elevated the substrate density of the remaining areas. As a result, the US and CS decreased steadily between 1995 and 2020, from 910 ha in 1995 to 401 ha in 2020 and from 433 ha in 2005 to 111 ha in 2020, respectively. Meanwhile, the low-vegetation area (LVA), medium-vegetation area (MVA), and high vegetation area (HVA) gradually increased between 1995 and 2015, from 0 ha in 1995 to 104 ha in 2015, from 0 ha in 1995 to 96 ha in 2015, and from 0 ha in 1995 to 114 ha in 2015, respectively. However, the LVA decreased slightly between 2015 and 2020 due to significant sand accumulation, which significantly killed the mangrove trees. In contrast, the MVA and HVA steadily increased between 2015 and 2020, from 96 ha in 2015 to 116 ha in 2020 and from 114 ha in 2015 to 221 ha in 2020, respectively. In 2022, there was a steady increase in HVA (298 ha in 2022), although the date of the 2022 satellite retrieval was 28 January 2022. This study recommends that the technical design of the existing coastal protection works should be revised or adapted to take account of sediment accumulation as the first step in the morphological evolution of the examined intertidal mudflat, rather than mangrove growth.

Growth Performance of Mangrove Seedlings Planted with Guludan Technique at Elang Laut Area, Muara Angke, Jakarta

Elang Laut area is one of the mangrove areas on Muara Angke coast in the northern Jakarta. Mangrove rehabilitation with the guludan technique is applied in the Elang Laut to revegetated degraded mangrove in this area. This study aims to measure the growth of planted mangrove (Rhizophora mucronata) seedlings with guludan technique, seedling’s health condition, and their survival rate in the Elang Laut area. The data collected in this study includes the growth of seedlings and their health condition, substrate condition, climatic factors, and water quality. On year after planting, it is observed that the seedlings’ survival rate of 97,27%, average seedling’s stem diameter of 1,42 cm, average seedling’s height of 79,71 cm, average seedling’s leaf number of 25 leaves, and the average seedling’s internode number of 8 internodes, among them 64% of the seedlings are in a healthy condition.

Spatiotemporal distribution of mangrove along the Egyptian Red Sea coast and analysis of hydrological impact on growth patterns

AbstractThis study presents an in-depth spatiotemporal analysis of mangrove ecosystems along Egypt’s Red Sea coast, utilizing satellite imagery and GIS to examine changes from 2003 to 2022. We evaluate the effects of hydrological factors, specifically rainfall and runoff -presented by Stream Power Index-, on mangrove growth patterns. Results indicate a significant increase in mangrove areas, with a notable annual growth rate, despite a reduction in a specific region. This research highlights the integral role of catchment area runoff (R2 = 0.735, R = 0.857, P-value = 0.003 < 0.05, CV = 70.26%), rather than direct rainfall, in mangrove expansion, contributing to the understanding of mangrove resilience and informing sustainable coastal management strategies. The study bridges a significant research gap by mapping decadal mangrove changes, offering insights into the dynamics affecting these crucial ecosystems.

Assessing the mangrove community structure and aquatic environmental factors of the mangrove ecosystem in Jangkaran Village

Coastal areas have the potential for damage caused by abrasion, strong winds, and tsunamis. Seeing the high potential for damage that might occur, the appropriate approach is to conserve mangrove forests, one of which is found in Jangkaran Village, Temon District, Kulon Progo Regency. This study aims to identify mangrove community structure and aquatic environmental factors in Jangkaran Village. Mangrove community structure was analyzed using the importance value index and the Shannon-Wiener diversity index. Aquatic environmental factors were analyzed using temperature, pH, dissolved oxygen, and salinity parameters. Data collection was carried out in three locations in Jangkaran Village. Mangrove vegetation data were taken from each transect using the 10 m x 10 m quadrat transect method. Data on aquatic environmental factors were taken directly at the location using a refractometer, DO meter, and pH meter. The results of this study are species with the highest importance index value in location 1, namely Rhizophora apiculata (117.094%), location 2, Avicennia marina (207.203%), and location 3, Avicennia marina (97.0362%). Shannon Wiener diversity indexes in the three locations are 0.6943, 0.4056, and 0.6841. The results of measurements of aquatic environmental factors are temperature 25.7-30.3 °C; pH 7.2-7.7; salinity 25-34; and dissolved oxygen 6.5-6.7. Thus mangrove diversity in Jangkaran village is included in the low category and the aquatic environmental factors is favorable for mangrove growth so that the mangrove ecosystem can be further developed.

Decomposition rate of Rhizophora mucronata leaf litter and identification of fungi in mangrove ecosystems in Pulau Sembilan, Pangkalan Susu District, Langkat Regency

Mangrove leaves that fall to the ground play an important role in transferring organic matter from plants into the soil. Organic matter from leaf decomposition is important for mangrove growth and as a food source for ecosystems in the surrounding waters. This study aims to determine the rate of decompositionof Rhizophora mucronate leaves, thelevels of carbohydrates and proteins contained in the decomposed leaves, and the species of fungi present in the leaves. Research samples were taken from mangrove forest areas in Pulau Sembilan, Pangkalan Susu District, Langkat Regency, decomposition rate testing and fungi identification were carried out at the forest cultivation laboratory, Faculty of forestry, University of North Sumatra. The research was conducted from June to December 2022. The results showed that the decomposition rate was 5.9 and there were 5 species of fungi found in the leaves that had undergone decomposition, namely Aspergillus niger, Aspergillus oryzae, Aspergillus fumigatus, Aspergillus glaucus, Aspergillus clatavus. The carbohydratecontent decreased during decomposition, with the highest content in the control on day 30 at10.7% and at the end of the 90th day observation only 1.89%. The remaining leaf litter of R.mucronata was 9.16 g with a weight loss of 30.84 g and a decomposition rate percentage of 22.89% on day 15 had the lowest weight loss of leaf litter, the remaining leaf litter was 22.86g with a weightloss of 17.14 gand a decomposition ratepercentage of 57.15%.

An inflection point-based method for estimating metrics of mangrove phenology combining climatic factors and Landsat NDVI time series

ABSTRACT The present research evaluated the prospects of utilizing rainfall and temperature combined with Landsat-8 derived HANTS (Harmonic Analysis of Time Series) reconstructed NDVI for estimating the metrics of the mangrove phenology. The selected period of the study was from 2013 to 2020 for the Pichavaram mangroves of Tamil Nadu. The NDVI and ERA5 (ECMWF Re-Analysis) datasets of rainfall and temperature were the input datasets for developing the new algorithm. The ‘z-score sum’ provided a measure of the cumulative impact of rainfall and temperature, displaying its most negative value coinciding with the peak positive value of the NDVI time series datasets. The algorithm developed for phenological metrics estimation identified the common inflection points of the z-score sum and NDVI curves. The temporal analysis of metrics revealed the average Length of Season (LoS) as 230 days. The metrics also identified the drought year 2016 with the shortest LoS and the least Gross Primary Productivity (GPP) values. The analysis showed the influences of the preceding year’s monsoon rainfall on the GPP values of the later part of the phenological cycle. The temperatures during the days of PoS were found to be the optimum temperature for the growth of mangroves.

Integrating mangrove growth and failure in coastal flood protection designs

Mangrove forests reduce wave attack along tropical and sub-tropical coastlines, decreasing the wave loads acting on coastal protection structures. Mangrove belts seaward of embankments can therefore lower their required height and decrease their slope protection thickness. Wave reduction by mangroves depends on tree frontal surface area and stability against storms, but both aspects are often oversimplified or neglected in coastal protection designs. Here we present a framework to evaluate how mangrove belts influence embankment designs, including mangrove growth over time and failure by overturning and trunk breakage. This methodology is applied to Sonneratia apetala mangroves seaward of embankments in Bangladesh, considering forest widths between 10 and 1000 m (cross-shore). For water depths of 5 m, wave reduction by mangrove forests narrower than 1 km mostly affects the slope protection and the bank erodibility, whereas the required embankment height is less influenced by mangroves. Sonneratia apetala trees experience a relative maximum in wave attenuation capacity at 10 years age, due to their large submerged canopy area. Once trees are more than 20 years old, their canopy is emergent, and most wave attenuation is caused by trunk and roots. Canopy emergence exposes mangroves to wind loads, which are much larger than wave loads, and can cause tree failure during cyclones. These results stress the importance of including tree surface area and stability models when predicting coastal protection by mangroves.

Kondisi habitat mangrove di Kelurahan Mapane Kecamatan Poso Pesisir Kabupaten Poso

The aim of this study is to assess the mangrove habitat condition in Mapane Village, Poso Coastal District, Poso Regency. Field surveys were conducted to determine representative mangrove habitat conditions (physical and chemical) in Mapane Village. Soil and water samples were collected to assess mangrove habitat conditions, using purposive sampling method with 3 repetitions. The soil and water quality in the research area is still conducive for mangrove growth, with suitable soil texture for Rhizophora sp. and stable salinity at 34‰. Although soil pH is slightly below standard, it remains suitable for mangrove growth (pH 6-7). Water quality parameters approach quality standards, albeit some below, remaining productive according to previous studies. The optimal pH for mangrove growth is neutral (pH 6.6-7.5). In conclusion, the soil and water quality in the research area strongly support mangrove growth. Despite slightly below-standard soil pH, it remains suitable for mangrove growth. Previous studies indicate the optimal soil pH for mangroves ranges from 6-7, while water pH approaches quality standards, remaining productive despite some below, and below pH levels.

Monitoring Mangrove Forest Degradation in Mangrove Nature Tourism Park Angke Kapuk, North Jakarta, Indonesia Using NDVI

Mangrove forests in Angke Kapuk, North Jakarta, are integral parts of the coastal ecosystem and play important roles in supporting environmental sustainability. One component of the Angke Kapuk Mangrove Forest is the Mangrove Nature Tourism Park (MNTP), Angke Kapuk, covering an area of 99.82 hectares. This study aims to analyze mangrove forest degradation in Angke Kapuk Nature Reserve using the Normalized Difference Vegetation Index (NDVI, which allows for mapping mangrove vegetation density and monitoring changes in the vegetation density over time. The objective of this study is to determine the degradation of mangrove forests from 2018 to 2023 using the NDVI derived from Landsat 8 and Landsat 9 satellite imagery. The findings of this study showed a change of 13.16 hectares in forested areas between 2018 and 2023, suggesting forest degradation. Accuracy assessment resulted in %80 overall accuracy with a kappa coefficient of % 76.2. Based on the literature, our results are similar to the acceptable level of accuracy, which is considered to be above %80. Monitoring mangrove forest areas can serve as a preventive measure to address the issue of mangrove forest degradation. These results underscore the necessity of sustainable forestry monitoring efforts in the MNTP area, as it contributes significantly to providing ecosystem services and maintaining environmental sustainability.