Status Of Mangroves Research Articles

Analysis of Mangrove Forest Management in Teluk Lembar, West Lombok, Indonesia

Mangrove forests in Teluk Lembar, West Lombok, have an important role in ecological balance and socio-economic benefits. However, these ecosystems face pressure from land conversion for ponds, illegal logging, and pollution. This study aims to describe the condition of mangroves, analyze the socio-economic aspects of the community and the role of stakeholders, assess the value of direct benefits of mangroves, and formulate sustainable management strategies. The results showed significant biodiversity, with 14 species of mangroves and 53 species of fauna, including 44 species of birds. The bird ecological index showed diversity (H') 32, uniformity (E) 0.8, and dominance (D) 0.7, which signified ecosystem stability. However, a serious threat comes from the conversion of land for ponds, houses, factories, and ports. Of the 1703.19 ha of the total area area, only 179.44 ha (10.54%) of mangrove forests remain. Waste pollution, such as mercury and copper levels that exceed the limit, also negatively impacts the ecosystem. Based on the SWOT analysis, the proposed mangrove management strategy includes: (a) strengthening community capacity in mangrove management through training and education, (b) increasing collaboration between stakeholders to strengthen regulation and law enforcement, (c) optimizing economic benefits through the development of mangrove-based ecotourism, and (d) implementing sustainable management practices to maintain a balance between conservation and utilization

A Bayesian network approach to assess the ecosystem integrity of mangroves in Tampamachoco, Veracruz, Mexico

Given the alarming rates of mangrove forest loss, resource managers must count on information regarding the condition of the mangrove forests. We propose a Bayesian network (BN) to assess mangrove forests' ecosystem integrity (EI) to support a mangrove monitoring system in Mexico. This approach allowed us to infer the system's condition based on variables on forest structure and function. We defined the BN structure based on informal interviews with specialists on vegetation and coastal geomorphology. We applied the expectation-maximization learning algorithm to train the model. Data from plots in two mangrove areas of an Avicennia germinans forest, defined based on their undisturbed and disturbed conditions, were used as training datasets. We applied sensitivity analysis to determine the degree of influence of each model variable. We evaluated the prediction capacity of the BN with a k-fold cross-validation (the process is repeated five times, starting from the database in 2 parts). The variables selected for the model were the Holdridge complexity index (HCI, Holdridge et al., 1971), Leaf area index (LAI), litter production (g/month/m2), leaf C, N and P concentration (%), and leaf N:P ratio. The most critical variable to infer mangrove condition was leaf N:P (Variance reduction = 11%), followed by forest structure variables HCI and LAI (Variance reduction > 5%). The cross-validation to test the model resulted in a minimum square error of 0.3, which indicates a reasonable capacity to predict the condition of mangrove integrity. The BN constructed can diagnose the integrity of a monospecific mangrove forest with acceptable precision, considering the environmental factors that define the forest structure and functioning locally. We then asked the experts to review and modify the model to apply to multispecies mangrove ecosystems and environmental contexts.

Time series monitoring and analysis of Pakistan’s mangrove using Sentinel-2 data

Sustainable Development Goal-14 (SDG-14) directly demands the protection, conservation, restoration, and sustainable management of the global mangrove ecosystem. Assessment of the development Pakistan has made toward the sustainable management of mangrove ecosystems necessitates the remote sensing-based evaluation of national-level mangrove cover. Using Google Earth Engine (GEE) for geoprocessing 12,000+ 10-m high-spatial resolution Sentinel-2 time-series images (2016–23) and applying random forest (RF) classifier, the current research provides the latest spatial distribution of mangroves along Pakistan’s coastline and changes observed for a duration of 8 years. Additionally, this research provides the first spatiotemporal health assessment of Pakistan’s national mangrove cover as well. Rational analysis of the results indicated splitting the entire timeline based on two seasons (Jan–Jun and Jul–Dec). Results revealed an overall increase of 1,210 km2 (2023) in the mangrove cover on the national-level; a 3.42 km2 average annual increase from 2016 (1,186 km2). Mangrove gain/loss assessment based on the land use land cover (LULC) transition matrix illustrated 223 km2 gain and 199 km2 loss; a 24 km2 net gain. Declines of 20.28% and 7.91% were found in maximum- and mean-NDVI (2016-23), depicting the deteriorating mangrove health conditions. Likewise, significant Sen’s slope analysis (p < 0.05) indicated that 88.8% of all the mangrove-NDVI pixels exhibited an overall decrease, whereas 11.2% pixels showed an overall increase (2016-23). It was concluded that despite showing a growth in the extent, mangrove cover in Pakistan has shown a decline in health, primarily due to deforestation for urban operations and sea-level rise, still making them vulnerable and potentially leading to a disrupted ecosystem, including carbon release in the atmosphere. This study will assist in the formulation of mangrove conservation and management strategies, whereas future research can explore the potentials of land surface temperature (LST) and evapotranspiration in combination to the NDVI for an in-depth analysis of the health status of mangroves.

DIVERSITY OF MANGROVES AND ASSOCIATED PLANTS IN MANDANGISIAO ESTUARY, MISAMIS ORIENTAL, PHILIPPINES

The study aimed to assess the diversity status of mangroves and associates. Four transect lines were established perpendicular to the shoreline, ranging from 20 to 100 meters based on mangrove stand size. Along these transects, three 10 m × 10 m quadrat plots were set up to evaluate mangrove trees, and within each quadrat, a 2 m × 2 m regeneration plot was established. The study calculated the di-versity indices, such as relative frequency, relative density, and relative dominance to determine the species im-portance value. A total of four mangrove species and two associated plants were identified, representing three mangrove families and three genera, as well as three plant families and three genera for associated plants. The record-ed species included Avicennia marina, Nypa fruticans, Rhizophora mucronata, Sonneratia caseolaris, Acanthus ebrac-teatus, and Acrostichum speciosum. The overall diversity value of the mangroves and associated plants was 0.87, indi-cating relatively low species richness. The true mangroves, Rhizophora mucronata exhibited the highest values for relative density (68.07%), while Nypa fruticans is the highest in terms of relative dominance (42.20%). Both have the same highest value in relative frequency (32.43%). All in all, the highest species importance value for true mangroves is Rhizophora mucronata with 126.23%. In associated plants, highest value of relative density and relative frequency belongs to Acanthus ebracteatus with 58% and 60%, respectively. Subsequently, the highest species importance value for associated plants is 118% for Acanthus ebracteatus. The study concluded that the Mandangisiao Estuary in Jasaan, Misamis Oriental has a limited species diversity, contrary to the initial hypothesis. Furthermore, the mangrove forest in the estuary faces potential threats from garbage dumping, tree cutting, boat mooring, and human encroachment, despite all the recorded species having a Least Concern conservation status.

Red berry snail Sphaerassiminea miniata (Gastropoda: Mollusca) and its potential as a bioindicator of environmental health in mangrove ecosystem of Pomalaa, Kolaka District, Indonesia

Abstract. Purnama MF, Prayitno SB, Muskananfola MR, Suryanti. 2024. Red berry snail Sphaerassiminea miniata (Gastropoda: Mollusca) and its potential as a bioindicator of environmental health in mangrove ecosystem of Pomalaa, Kolaka District, Indonesia. Biodiversitas 25: 2330-2339. Sphaerassiminea miniata Habe 1942 has a high sensitivity to environmental changes in mangrove forest areas. Its existence can be confirmed when the overall condition of the mangrove ecosystem is in good condition. The aim of this research is to analyze the density and distribution of the S. miniata gastropod population in relation to the density status of mangroves in the reference site area and overburden exposure areas. This research adopted a purposive sampling method for determining research stations, a simple random sampling technique for placing stations or distributing sampling points (sub-stations), and a hand-picking method for technical sampling of S. miniata in the field. The results showed that the mangrove density at each station was very dense (3,700-6,000 trees/ha), the population density of S. miniata ranged from 8.67-38.33 ind./m2, and the distribution pattern of S. miniata at each station was clumped with a Morishita index (Id) value range of 1.28-1.34. Sphaerassiminea miniata was found at all stations in the reference site area (Totobo mangrove ecosystem). No individual was found in the area with overburden exposure (Dawi-Dawi mangrove ecosystem). Changes in the environmental tone in the Dawi-Dawi mangrove ecosystem, especially the substrate area through the input of sediment waste (overburden), which has been going on for a long time and continuously (until now), directly degrades the living space of the S. miniata population on the ground floor (benthos) of the waters. The vulnerability of this species to environmental changes makes it a limiting factor in the quality of habitat health in mangrove ecosystems (Bioindicators).

Synergistic retrieval of mangrove vital functional traits using field hyperspectral and satellite data

Mangroves play a pivotal role in the attainment of United Nations Sustainable Development Goals. Leaf equivalent water thickness (EWT) and leaf mass per area (LMA) are vital functional trait parameters for monitoring heath status of mangroves. However, their inherent spectral response characteristics remain unclear, which presents a challenge for high-precision estimating EWT and LMA using remote sensing images. In this study, we attempted to synergistic retrieval of mangrove EWT and LMA using field hyperspectral and satellite data. Specifically, we proposed a novel Fractional-order assisted Spectral angle Analysis (FSA) approach to accurately identify sensitive spectral domains of EWT and LMA for three mangrove species based on in situ full-spectrum hyperspectral (350–2500 nm) data. We constructed a new spectral matching index (SMI) to screen the satellite-based sensitive spectral bands based on the field-based spectral domains, and further verified their feasibility of estimating EWT and LMA using three optical satellite sensors (Sentinel-2A, SDGSAT-1, and OHS-3D). Finally, we explored the effectiveness of combining SAR and thermal infrared (TIR) images with sensitive spectral bands on improving retrieval performance in estimating EWT and LMA, respectively. Results indicated that FSA approach could capture the sensitive spectral domains of EWT (1125–1868 nm) and LMA (1419–1999 nm) for three mangrove species. The SMI could effectively realize the spectral matching between field-based sensitive domains and satellite-based bands, and perform the synergistic retrieval of mangrove EWT (R2 = 0.65) and LMA (R2 = 0.70). Intriguing finding is that the additional TIR bands significantly enhanced the EWT and LMA inversion accuracy (R2 increased by 9.8 %–68.3 %) when compared to SAR images. We confirmed that EWT displayed an inverse trend of LMA with the flooding frequency increasing. Our works provide a scientific basis for protection and sustainable management of mangroves.

Mapping the Dynamics of Mangrove Density in Alas Purwo National Park using the ARVI Index

This study aims to compare the sensor/Top-of-Atmospheric (TOA) reflectance correction method and surface reflectance correction in the ARVI (Atmospherically Resistant Vegetation Index) vegetation index transformation application. The resulting comparison of the two has a correlation that is not much different, sensor reflectance correction (R = 0.9723) and surface reflectance correction (R = 0.9781) are both able to represent mangrove forest canopy density well. The model accuracy resulting from the surface reflectance correction RMSE 1.408 and MAPE 0.48%, is higher than that of the sensor correction (TOA) which has an RMSE value of 2.184 and MAPE 1.34%. For advanced remote sensing analysis, it is better to perform radiometric correction of surface reflectance because the reflectance value used for analysis is the true reflectance value. The condition of mangroves in Grajagan Bay in Alas Purwo National Park is very well preserved, this is shown by the mangrove canopy density >50% increased by 49.11 Ha in a period of 7 years from 2016 to 2023.

Application of ecotoxicological tools to evaluate the quality status of mangroves under restoration in the Yucatán Peninsula, Mexico

Ecotoxicological tools, namely biomarkers and bioassays, may provide insights on the ecological quality status of mangroves under restoration. We investigated how 1) physicochemical parameters and water bioassays using Artemia franciscana; and 2) quantification of sublethal (osmoregulatory capacity, biochemical, and oxidative stress) and individual biomarkers (density, length-weight relationship [LWR], parasitic prevalence) in the sentinel fiddler crab Minuca rapax, can improve restoration indicators in mangroves from the Yucatán Peninsula, Southern Gulf of Mexico. We showed that water quality was improved with restoration, but still presented toxicity. Regarding sublethal biomarkers, M rapax from restored areas lower osmotic regulatory capacity, higher oxidative stress, and showed lipid peroxidation. As to the individual biomarkers, the density, LWR, and the prevalence of parasites in M. rapax was higher in restored areas. The use of bioassays/biomarkers were useful as early warning indicators to better assess the health of mangroves under restoration.

Mapping of Mangrove Conditions Using Sentinel-2 Imagery

Mapping of Mangrove Conditions Using Sentinel-2 Imagery

Zoning Patterns of Mangrove Forests in Lampung Timur Regency

Mangrove forests form due to vegetative distribution along coastlines with varying growing conditions concerning substrate, freshwater intake, and oceanic currents. These disparities facilitate zoning and subsequent distinct growth patterns. The research objective was to identify the zoning structure of mangrove ecosystems in Lampung Timur Regency, Lampung Province, Indonesia. The degradation of mangrove forests in Lampung Timur Regency was thought to be caused by anthropogenic activities and inappropriate zoning patterns. Concerning data collection, the cluster sampling method was employed, which was selected based on the preliminary study's findings that the mangrove status in the study area exhibits a variety of substrates, freshwater supply, and strong ocean currents. There are five clusters on the study site, with each cluster containing sample plots measuring 10m x 10m. The sampling method employed a striped path starting from the outermost part of the mangrove ecosystem, with the number of plots in each cluster dependent on the thickness of the mangrove vegetation. A regional map and GIS applications were used for mangrove zonation mapping, and the factors influencing the zonation of mangrove ecosystems were analyzed descriptively. The research findings demonstrated that the mangrove ecosystem located in Lampung Timur comprises three distinct zones: the outer zone, the middle zone, and the terrestrial zone

Floristic composition of mangrove community in Ngurah Rai Forest Park and Nusa Lembongan, Bali, Indonesia

Abstract. Wijaya IMS, Sugiana IP, Astarini IA, Ginantra IK, Rahim KAA. 2024. Floristic composition of mangrove community in Ngurah Rai Forest Park and Nusa Lembongan, Bali - Indonesia. Biodiversitas 25: 300-309. The floristic composition of mangroves can be influenced by various factors, one of which is the size of the island. In Bali, Ngurah Rai Forest Park is one of the mangrove areas in the mainland of Bali, while Nusa Lembongan on the southeastern mainland represents the mangrove on the small island. This research aimed to study the floristic composition of the mangrove species in Ngurah Rai Forest Park and Nusa Lembongan based on the species diversity and the structure of mangrove community. Based on the explorative method, both locations have 20 true mangrove species cumulatively, with 18 species in Ngurah Rai Forest Park and 15 species in Nusa Lembongan. The mangrove community structure is majorly composed by Sonneratia alba and Rhizophora (R. apiculata, R. mucronata, and R. stylosa) in trees, saplings, and seedlings. Sonneratia alba has more impact in relative dominance, while the Rhizophora has more impact in relative density. Based on the Shannon-Wiener Index of Diversity, the mangrove community status is Moderate in both locations in all growth forms (trees, saplings, and seedlings). The Index of Dominance and Index of Evenness indicates the mangrove community is in stable condition with no extremely dominated species and fairly even species distribution. The mangrove condition is categorized as Good with Dense Trees based on the Decree of the Minister of Environment number 201 of 2004.

Development of Learning Video: Mangroves and Phytoplankton in Batu Ampar, West Kalimantan

Background: Mangrove forests experience rapid destruction; nonetheless, Indonesia has the widest mangrove area in the world. Conservation efforts must involve all parties, including education. This research was to develop learning video media about mangroves and phytoplankton. Methods: The method used was development research with a 4D model (defined, designed, developed, and disseminated) to develop a video containing the environmental conditions of mangroves and their unique roots in Batu Ampar. The video was evaluated by validators using a questionnaire as a research instrument. The assessment used a Likert scale. The video was also tested limitedly. Data were analyzed to calculate the content validity ratio (CVR) and the percentage category of students as respondents. Results: Learning video media about mangroves and phytoplankton in Batu Ampar obtained CVR 1,00 and categorized it as valid and suitable for learning media. Based on the limited test, students showed that both cognitive and affective were very good, but psychomotor was only a good category.

Mollusks diversity to support mangrove tourism attractions in the mangrove forest of Nusa Lembongan, Bali, Indonesia

Research on the diversity of molluscs has been carried out in the mangrove forest of Nusa Lembongan. The purpose of this study was to determine the species of mollusks that interact in the mangrove habitat, to support a scientific interpretation of the existence of mollusks in the mangrove forest of Nusa Lembongan. The research was conducted in seven mangrove forest sites, from April to June 2022 using the quadratic method. At each research site determined five sampling squares. Identification of mollusk species based on morphological characters (shape, size, shell texture and shell color). The abundance of each species was calculated based on the number of individuals per unit area (m2). The diversity of molluscs was calculated using the Shanon-Wiener diversity index. The results showed that 24 species were found in the mangrove forest of Nusa Lembongan, 19 species from the gastropod class and 5 species from the bivalves class. Several species that were quite dominant were the mangrove periwinkle Littoria scabra, with a density of 28.4 individuals/5 m2, sulcate swamp Terebralia sulcata, a density of 10.2 individuals/5m2, mud creeper Cerithidea obtusa, with a density of 7.2 individuals/5m2. The diversity of mollusks species in the mangrove area of Nusa Lembongan is included in the moderate category with a diversity index of 2.79 and an evenness index of 0.88. Based on the diversity index, it shows that the condition of mangroves in Nusa Lembongan is still relatively good or steady. The diversity of mollusks, the abundance of each species, the unique characteristics of each species, and the presence of mollusks in the substrate or mangrove vegetation are scientific interpretations and attractive attractions for eco-friendly mangrove tours.

DISTRIBUSI KAWASAN MANGROVE DI PULAU POTO KABUPATEN BINTAN MELALUI PENGINDERAAN JAUH

Mangrove is a unique vegetation type growing along the coastline and estuarine in tropical and subtropical countries. Mangroves in Indonesia are distributed in all major islands and small islands from Aceh on westside stretched to Papua on the east. This study is to monitor the mangrove area in Poto island a small island part of Kabupaten Bintan, Province of Riau Kepulauan. The difference in spatial resolution of remote sensing data Sentinel 2A and Pleiades were used to classify the land use including the mangrove area. The supervised classification by maximum likelihood classification showed the high-resolution image using Pleiades has higher accuracy for mangroves 81.99% and overall accuracy 90% (kappa 0.86) compared to Sentinel 2A for mangrove 72,34% and overall accuracy 80% (kappa 0.73). The mangrove area approximately 257 ha is strip-lining along the coastline with the largest mangrove area located on the southside of the island. Further research is to identify the mangroves’ formation and the serial condition of mangroves on the different times.

Mangrove condition at a marine conservation area at Moramo Bay, Sulawesi, Indonesia

Abstract. Oetama D, Hakim L, Lelono TD, Musa M. 2023. Mangrove condition at a marine conservation area at Moramo Bay, Sulawesi, Indonesia. Biodiversitas 24: 6536-6544. The mangrove ecosystem is one ecosystem that supports biodiversity at the Marine Conservation Area (MCA) in Moramo Bay, Southeast Sulawesi, Indonesia. The area of the mangrove ecosystem in Moramo Bay is approximately 1,933.09 hectares, with an MCA of 1,281.46 hectares. This ecosystem plays an important role in protecting the coastline from erosion due to the seawater filtration process in the bay. This study aims to provide information regarding the status of mangrove ecosystem in the MCA, including species, density, basal area, dominance, and canopy cover percentage, which was used to state the standard criteria for mangrove ecosystem damage. The methods involved a 10×10 m² transect and hemispherical photography using a fisheye lens with a 180° field of view. Seven species of mangrove were found in Moramo Bay MCA, including Bruguiera gymnorrhiza (L.) Lam. (dominating with a basal area value of 136,963.66), followed by Sonneratia alba Sm. (153,111.90), Rhizophora mucronata Lam. (113,708.04), Rhizophora stylosa Griffith (28,869.95), Xylocarpus moluccensis (Lam.) M.Roem. (9,326.59), Avicennia marina (Forssk.) Vierh. (3,419.46), and Rhizophora apiculata Blume with a basal area value of 1,690.11. The density of mangrove vegetation was in the criteria of rare to dense, with approximately 800-4,200 individuals per hectare. Furthermore, the mangrove ecosystem in the MCA was found to be damaged up to good condition, with canopy cover percentage values of 45.85%-98.88%. The condition of the mangrove ecosystem in Moramo Bay MCA preserves a basic deliberation for the Indonesian government for adaptive and sustainable management of conservation areas. Protection, preservation, and utilization of mangrove ecosystems should be maximized in all coastal areas to improve the quality of biodiversity.

Assessing the conservation status of mangroves in Rakhine, Myanmar

Abstract Ecosystem degradation is a key challenge that human society faces, as ecosystems provide services that are tied to human well‐being. Particularly, mangrove ecosystems provide important services to communities but are suffering heavy degradation, loss and potential collapse due to anthropogenic activities. The IUCN Red List of Ecosystems is a transparent and consistent framework for assessing ecosystems' risk of collapse and is increasingly used to inform legislation and ecosystem management globally. Satellite data have become increasingly common in environmental monitoring due to their extensive spatial and temporal coverage. Here, recent advances in analyses using satellite‐derived data were implemented to reassess the conservation status of the ‘Rakhine mangrove forest on mud’, an important intertidal ecosystem in Myanmar, extending a previous national Red List assessment that assessed the ecosystem as Critically Endangered. By incorporating additional data sources and analyses, the extended assessment produced more robust results and reduced the uncertainty in the previous assessment. Overall, the ecosystem was assessed as Critically Endangered (range: Vulnerable to Critically Endangered) as a result of historical mangrove extent loss. Recent losses and biotic disruptions were also observed, which would have led to the ecosystem being assessed as Vulnerable. While the final outcome of the Red List assessment remained at Critically Endangered due to the historical state of the mangroves pre‐dating the temporal coverage from satellite data, the uncertainty of the ecosystem's status was reduced, and the reassessment highlighted the recent areal changes and mangrove degradation that has occurred. The importance of conducting reassessments when new data become available is discussed, and a template for future mangrove Red List assessments that use satellite data as their primary source of information to improve the robustness of their results is presented.

Analysis of mangrove ecosystem sustainability in the Biringkassi mangrove area, Pangkep District, Indonesia

Mangrove forests are found on coastlines in tropical and subtropical areas. The mangrove tree looks strange because its roots are partially above water, making it look like it is standing. Mangrove forests are coastal forests and critical habitats that act as nurseries and protect coasts from erosion. Determining the current status of sustainable management of mangroves is very important as a basis for planning future policies. The purpose of this study was to review the current status of mangroves and analyze the sustainability value of the mangrove ecosystem sustainability in the Biringkassi mangrove area, Pangkep district, Indonesia. This study is descriptive with a quantitative approach to conducting an inventory of mangrove ecosystems, including biophysical, social, economic and institutional data. Analysis of the sustainability of mangrove management The sustainability of the mangrove ecosystem was analyzed using the Rapid Assessment Fisheries (RAPFISH) software with the Multidimensional Scaling Method (MDS) method. The four aspects assessed were ecological, economic, social and institutional. The results of the sustainability analysis from the four dimensions showed that the ecological and institutional aspects have a moderate state of sustainability, but the economic and social aspects have a less sustainable state. Multidimensional analysis showed less sustainable management. Leverage analysis of 24 multidimensional attributes revealed eight highly influential attributes that can lead to change in management if not implemented correctly. Meanwhile, the analysis results should be maintained for properties that achieve low leverage so that the management value does not decrease.

An Assessment of Mangrove Ecosystem Condition by Foliar Stable Nitrogen Isotope Ratio Index in Okinawa, Japan

Despite providing valuable ecosystem services, mangroves are endangered under the recent global natural as well as anthropogenic changes. Conservation of mangroves is now one of the pillars of Sustainable Development Goals (SDG) 2030. An assessment of mangrove is essential before initializing any conservation strategy. This paper aimed to assess the ecosystem conditions of mangroves and the relative changes in ecosystem conditions from the natural background under different scales of anthropogenic interruption in Okinawa Prefecture, Japan. To assess mangrove’s ecosystem condition, foliar stable nitrogen isotope ratio (δ15N) of mangroves is used as ecosystem monitoring indicator. Whereas, a difference index (DI) of mangrove foliar δ15N is established to compare the relative deviation in ecosystem conditions of anthropogenically impacted mangroves from reference mangroves. Results showed that the mean foliar δ15N values of Bruguiera gymnorrhiza, Kandelia obovata, and Rhizophora stylosa on Okinawa Island (Is.) are 5.12 ± 2.32‰, 7.54 ± 2.85‰ and 7.09 ± 3.29‰, respectively, on Iriomote Is., 1.83 ± 1.93‰, 2.01 ± 0.31‰ and 1.04 ± 2.38‰, respectively, and on Ishigaki Is., foliar δ15N values of Bruguiera gymnorrhiza and Rhizophora stylosa are 5.23 ± 3.33‰ and 6.00 ± 3.63‰, respectively. A range of negative to positive values from -0.54 to 3.66 of DI indicates different level of changes in ecosystem conditions of the mangroves compared to the reference sites, which is set at zero. A significant negative correlation between DI values and the forest area ratio of the watersheds has been observed. It indicates that the forest cover is the driver of maintaining pristine condition of an ecosystem. Findings of the study recommended that Todoroki and Manko mangrove watersheds in Okinawa, Japan should be taken into consideration for necessary conservation on priority basis.

Distribution and ecological status of mangroves in the Nias Islands-North Sumatra Province

Distribution and ecological status of mangroves in the Nias Islands-North Sumatra Province

The Structure of Mangrove Community in The Waters of Pare Mas Jerowaru East Lombok

Mangrove communities grow well in the tropics and are able to adapt to extreme environments, such as: high temperature, high salinity, extreme tides, high sedimentation, and oxygen-poor growing substrate conditions. Information about mangrove ecology is very important to provide an overview of the current condition of mangroves. The aim of this research is to determine the structure of the mangrove community in Pare Mas Jerowaru, East Lombok. This research used a purposive sampling method and a combination of line and quadrat transects. The research results obtained 3 types of mangroves in Pare Mas waters. The diversity index value is in the low category and the dominance index value is medium to high. The species Rhizophora apiculata had the highest frequency value (0.57 ind/m²) and the lowest was Avicennia marina (0.10 ind/m²). Density at the tree level is in the sparse category, while at the pole, sapling and seedling level it is in the medium to very dense category. The types of mangroves that have the highest cover values in the tree, pole and stake categories are Sonneratia alba and Rhizophora apiculata. The highest INP values in the categories of trees, poles, saplings and seedlings were 272.99% (Sonneratia alba), 173.58% (Sonneratia alba), 215.51% (Rhizophora apiculata) and 200.00% (Rhizophora apiculata).