Mangrove Plant Research Articles

Chromosome-scale genome assembly of the mangrove climber species Dalbergia candenatensis

Consisting of trees, climbers and herbs exclusively in the intertidal environments, mangrove forest is one of the most extreme and vulnerable ecosystems of our planet and has long been of great interest for biologists and ecologists. Here, we first assembled the chromosome-scale genome of a climber mangrove plant, Dalbergia candenatensis. The assembled genome size is approximately 474.55 Mb, with a scaffold N50 of 48.1 Mb, a complete BUSCO score of 98.4%, and a high LTR Assembly Index value of 21. The genome contained 283.46 Mb (59.74%) repetitive sequences, and 29,554 protein-coding genes were predicted, of which 87.54% were functionally annotated in five databases. The high-quality genome assembly and annotation presented herein provide a valuable genomic resource that will expedite genomic and evolutionary studies of mangrove plants and facilitate the elucidation of molecular mechanisms underlying the salt- and water-logging-tolerance of mangrove plants.

Rekayasa Teknik Guludan sebagai Upaya Rehabilitasi Ekosistem Mangrove di Ekowisata Pantai Alam Serdang Bahari, Pantai Labu, Sumatera Utara

Abrasion at Alam Serdang Bahari Beach (ASB) is increasingly worrying, causing the reduction of mangrove forests on the coast. ASB Beach is located in Regemuk Village, Labu Beach. The ASB Mangrove Forest Farmers Group (KTHM) has made many efforts to continue to exist morally and materially to survive in the ecotourism industry and is trying to re-green the beaches to minimize the impact of abrasion. The results of a field assessment involving lecturers, village officials, and KTHM ASB obtained a roadmap for a sustainable development village with a solution to prevent prolonged abrasion using the simplest and most economical way through engineered bund techniques to protect mangrove plants and also act as a wave breaker. Implementing this PKM aims to make new efforts to plant mangrove trees as coastal abrasion protection. Implementing activities uses a participatory action research (PAR) approach. KTHM, as the partner, carried out the construction of the bund enclosure, and the PKM team was the drafter and supervisor. The results of the PKM implementation are three plots of bunds in the shape of a ship's bow as an effort to break the beach waves using the Rhizopora sp. propagules collected from mangrove seeds by KTHM ASB. This innovation is still early to assess because it requires ongoing monitoring. It is hoped that this effort will better protect newly planted mangrove plants from fierce waves and abrasion as a joint effort to prevent abrasion on ASB Beach.

Analysis of subtract quality along the Wiringtasi River, Barru Regency, Indonesia

This research aims to determine the quality of the substrate of the Wiringtasi River, Barru Regency, Indonesia. The research locations include location 1, namely the location around the rice field area; location 2, namely the location around the pond area and beach; and location 3, namely the location around the river estuary where many mangrove plants grow around it. Subtract samples were taken at the research location, then the samples were taken to the laboratory for analysis. The results of laboratory analysis are made in the form of pictures and tables, then analyzed using descriptive analysis. The results of the research show that in this study the substrate quality of the Wiringtasi River, Barru Regency, Indonesia, each had a pH value of the substrate in the range of 8.05-8.64, total nitrogen was in the range. Nitrogen was in the range of 0.049-0.121%. The organic material content of the substrate is in the range of 0.33-0.59. The ammonia (NH3) content of the substrate is in the range of 0.019–0.45 ppm. The nitrite content of the research location is in the range of 0.0025-0.0064 ppm. The substrate texture of location 1 is dusty clay, while locations 2 and 3 are sandy.

Phytochemical Associes of Fungal Endophytes in Nigeria Riverine Mangrove Ecosystem

The interaction between endophytic fungi and phytochemicals in the dominant mangroves (Rhizophora mangle, Lacugularia racemosa, and Avicennia africana) of the Iko River Estuary in Nigeria was investigated. Standard analytical procedures were employed to measure antioxidant levels, while endophytic fungi were isolated, morphologically characterized, and identified using culture-dependent methods. The study identified various bioactive compounds, including alkaloids, saponins, tannins/phenols, flavonoids, deoxy-sugars, cardiac glycosides, and steroids, with their concentrations varying depending on the mangrove species and plant parts. Alkaloids were present in all mangrove samples, with particularly high concentrations in the leaves of white (5%) and red (4.2%) mangroves. Principal Component Analysis (PCA) was used to analyze the interaction between the endophytic fungi and phytochemicals, revealing a distinct affinity of certain fungal species for specific antioxidants in the mangroves. Fungal species such as Phoma sp., Rhizopus arrhizus, Aspergillus niger, and others exhibited a negative relationship with tannins, flavonoids, deoxysugars, and cardiac glycosides, but a positive affinity for saponins, alkaloids, and steroids. Conversely, Candida pseudotropicalis, Fusarium oxysporum, P. italicum, and others showed a positive affinity for tannins, flavonoids, cardiac glycosides, and deoxysugars, but a negative affinity for alkaloids, saponins, and steroids. Notably, Absidia sp. was the only frequently isolated species with a strong correlation (r value ≥75 at a 95% confidence limit) with deoxy-sugars, while Aspergillus niger, Aspergillus terreus, and Absidia sp. demonstrated significant relationships with alkaloids, saponins, and steroids. These phytochemicals, which serve as precursors to antioxidants with promising biotechnological applications, likely play a crucial role in determining the association of endophytic fungi with deltaic mangroves in Nigeria.

Cytochalasin H enhances sensitivity to gefitinib in non-small-cell lung cancer cells through inhibiting EGFR activation and PD-L1 expression

In our previous study, we have isolated cytochalasin H (CyH) from endophytic fungus derived from mangrove plant and found that CyH inhibited the proliferation of non-small cell lung cancer (NSCLC) cells. Recently, epidermal growth factor receptor (EGFR) activation and programmed cell death 1 ligand (PD-L1) expression have been demonstrated to mediate NSCLC resistance to gefitinib, first-generation EGFR tyrosine kinase inhibitor (EGFR-TKI). Here, we further investigated the effect of CyH on EGFR activation, PD-L1 expression, and gefitinib sensitivity in NSCLC cell lines, A549 (wild-type EGFR), HCC827 (EGFR mutation), and NCI-H1975 (dual EGFR mutations and acquired gefitinib resistance) and animal model. Our results showed that CyH significantly inhibited EGFR activation and PD-L1 expression in NSCLC cells. Additionally, CyH dramatically promoted the inhibitory effect of gefitinib on the proliferation of A549 and HCC827 cells, and enhanced the sensitivity to gefitinib in NCI-H1975 cells. Moreover, CyH increased the inhibitory effect of gefitinib on EGFR activation and PD-L1 expression in HCC827 and NCI-H1975 cells. Animal experiments further demonstrated that CyH significantly promoted the inhibitory effect of gefitinib on the growth of NSCLC and the expression of Ki-67, p-EGFR, and PD-L1 in NCI-H1975 NSCLC xenograft tumors of nude mice. Furthermore, CyH inhibited the activation of JAK3/STAT signaling pathway. Taken together, our findings suggest that CyH promotes the sensitivity to gefitinib in NSCLC cells through the inhibition of EGFR activation and PD-L1 expression.

Steroids produced by Cladosporium anthropophilum, an endophytic fungus Isolated from Avicennia marina (Forssk.) Vierh and Their Antibacterial Activity

This work was conducted to isolate the steroid compounds from an endophytic fungus Cladosporium anthropophilum and determine their effects against 4 strains of bacteria. The fungi were afforded from a mangrove plant Avicennia marina (Forssk.) Vierh of Acanthaceae family, growing in West Java, Indonesia. The fermentation and isolation of C. anthropophilum yielded 3 ergostane-type steroids including a highly oxidized one, identified as penicisteroid A (1), ergosterol (2), and ergosterol-5,8-peroxide (3), together with 2 stigmastanes, characterized as stigmasterol (4), and stigmasterol-5,8-peroxide (5). The elucidation structure of all isolated steroids was performed by extensive spectroscopic measurements (MS, IR, 1D, and 2D NMR) and supported by a comparison of previously reported spectral data. Subsequently, the potential of the 5 steroids as well as methanol, n-hexane, and ethyl acetate extracts were evaluated against 2 Gram-positive bacteria, Staphylococcus aureus ATCC 29213 and Enterococcus faecalis ATCC 29212 and 2 Gram-negative bacteria, Vibrio harveyi ATCC 5339 and Escherichia coli ATCC 25922. The results showed that none of the isolated steroids were active, while the 3 extracts exhibited significant inhibition against all the tested bacteria’s growth and enabled us to propose the synergistic effects between active compounds in these extracts and their antibacterial activity. HIGHLIGHTS An isolated and identified endophytic fungus, Cladosporium anthropophilum, from a mangrove plant Avicennia marina (Forssk.) Vierh yielded five steroids. A chromatography technique and spectroscopic method were utilized for separation processes and structure determination, respectively. An antibacterial assay against two Gram-positive bacteria ( aureus and E. faecalis) and two Gram-negative bacteria (V. harveyi and E. coli) implied the synergistic effects between five isolated steroids and their parent extracts. A further investigation is highly recommended to explore the possibility of these five steroids as a potential source of active compounds. GRAPHICAL ABSTRACT

Mangrove afforestation as an ecological control of invasive Spartina alterniflora affects rhizosphere soil physicochemical properties and bacterial community in a subtropical tidal estuarine wetland

Background The planting of mangroves is extensively used to control the invasive plant Spartina alterniflora in coastal wetlands. Different plant species release diverse sets of small organic compounds that affect rhizosphere conditions and support high levels of microbial activity. The root-associated microbial community is crucial for plant health and soil nutrient cycling, and for maintaining the stability of the wetland ecosystem. Methods High-throughput sequencing was used to assess the structure and function of the soil bacterial communities in mudflat soil and in the rhizosphere soils of S. alterniflora, mangroves, and native plants in the Oujiang estuarine wetland, China. A distance-based redundancy analysis (based on Bray–Curtis metrics) was used to identify key soil factors driving bacterial community structure. Results S. alterniflora invasion and subsequent mangrove afforestation led to the formation of distinct bacterial communities. The main soil factors driving the structure of bacterial communities were electrical conductivity (EC), available potassium (AK), available phosphorus (AP), and organic matter (OM). S. alterniflora obviously increased EC, OM, available nitrogen (AN), and NO3−-N contents, and consequently attracted copiotrophic Bacteroidates to conduct invasion in the coastal areas. Mangroves, especially Kandelia obovata, were suitable pioneer species for restoration and recruited beneficial Desulfobacterota and Bacilli to the rhizosphere. These conditions ultimately increased the contents of AP, available sulfur (AS), and AN in soil. The native plant species Carex scabrifolia and Suaeda glauca affected coastal saline soil primarily by decreasing the EC, rather than by increasing nutrient contents. The predicted functions of bacterial communities in rhizosphere soils were related to active catabolism, whereas those of the bacterial community in mudflat soil were related to synthesis and resistance to environmental factors. Conclusions Ecological restoration using K. obovata has effectively improved a degraded coastal wetland mainly through increasing phosphorus availability and promoting the succession of the microbial community.

Growth, Morphology and Respiratory Cost Responses to Salinity in the Mangrove Plant Rhizophora Stylosa Depend on Growth Temperature.

Mangrove plants, which have evolved to inhabit tidal flats, may adjust their physiological and morphological traits to optimize their growth in saline habitats. Furthermore, the confined distribution of mangroves within warm regions suggests that warm temperature is advantageous to their growth in saline environments. We analyzed growth, morphology and respiratory responses to moderate salinity and temperature in a mangrove species, Rhizophora stylosa. The growth of R. stylosa was accelerated in moderate salinity compared with its growth in fresh water. Under warm conditions, the increased growth is accompanied by increased specific leaf area (SLA) and specific root length. Low temperature resulted in a low relative growth rate due to a low leaf area ratio and small SLA, regardless of salinity. Salinity lowered the ratio of the amounts of alternative oxidase to cytochrome c oxidase in the mitochondrial respiratory chain in leaves. Salinity enhanced the leaf respiration rate for maintenance, but under warm conditions this enhancement was compensated by a low leaf respiration rate for growth. In contrast, salinity enhanced overall leaf respiration rates at low temperature. Our results indicate that under moderate saline conditions R. stylosa leaves require warm temperatures to grow with a high rate of resource acquisition without enhancing respiratory cost.

Evaluation of the stock enhancement effect of Phascolosoma esculenta on macrobenthic communities using diversity and biotic indices in Yueqing Bay, East China Sea

Stock enhancement activities have many benefits but also negative impacts. The macrobenthic diversity index and the M-AMBI index were adopted to assess the effects of stock enhancement of Phascolosoma esculenta on macrobenthic communities and the local ecosystem in Yueqing Bay. The results revealed that the Shannon–Wiener diversity index (H’) and Margalef richness index (d) increased in October 2022 after stock enhancement, indicating a positive ecological restoration effect. The average M-AMBI in the intertidal zone of Yueqing Bay was 0.59, indicating good benthic ecological quality. Excluding seasonal factors, the M-AMBI in the intertidal zone increased after stock enhancement, indicating that stock enhancement by Phascolosoma esculenta had a certain positive effect on the intertidal ecological environment of Yueqing Bay. The increase in the M-AMBI occurred mainly in the low-tide zone, increased slightly in the mid-tide zone, and remained basically unchanged in the high-tide zone. On the one hand, Phascolosoma esculenta can accumulate heavy metals from the environment and release a large amount of organic matter throughout its lifecycle, promoting nutrient cycling, which plays a positive role in the environment. On the other hand, Phascolosoma esculenta is an economic species; however, the planting of mangroves in the low tide zone causes fishers to fish in the mid- and high-tide zones, so the changes in the M-AMBI values in each tidal zone are related mainly to Phascolosoma esculenta and anthropogenic disturbances.

Biopriming of Solanum Lycopersicum seeds with novel root endophytic bacterial consortium retrieved from halotolerant Sundarban Mangroves to sustain growth and yield with salt resilience

Mangroves are often found in coastal areas and tropical wetlands that can withstand high salinity. We hypothesized that endophytes that are harbouring in the roots of mangrove plants may improve the innate immunity of host plants to survive naturally in saline environment. Retrieving these endophytes and sequential characterization may function as a novel bio-effector for non-host food crops as well. We focused on the integrated approach towards formulating a novel bacterial consortium. Thirty-one bacterial endophytes isolated from the roots of mangrove plants were screened for plant growth promoting potential by inoculating our model crop (Tomato). Seven most promising isolates impacting plant growth were identified. In-vitro plant growth promoting characters were also analysed. The root colonization by the isolates was confirmed by Scanning Electron Microscopy (SEM). Among the screened isolates, four of them were found to be compatible with each other when grown together and were selected to formulate a novel biostimulant consortia. The consortia treated Tomato plants exhibited superior phenological characters. In the pot experiment, plant height of the treated plants was about ≈43cm while the non-treated plants under salt stress could grow only up to a height of ≈26cm. Similarly, a total fruit yield of ≈6.8 kg was observed in case of treated plants under salt stress whereas the non-treated plants under salt stress could only produce ≈4.7 kg of fruit. This study demonstrated that the beneficial bacteria inhabiting in mangrove roots can increase the potential of conferring salt tolerance to non-host crops, thereby contributing to sustainable agriculture.

Socialization of mangrove planting among coastal communities: A collaborative approach for conservation and ecosystem sustainability

Socialization of mangrove planting among coastal communities: A collaborative approach for conservation and ecosystem sustainability

Comparison of organelle genomes between endangered mangrove plant Dolichandrone spathacea to terrestrial relative provides insights into its origin and adaptative evolution.

Dolichandrone spathacea is a mangrove associate with high medicinal and ecological values. However, due to the dual-pressure of climate change and human activities, D. spathacea has become endangered in China. Moreover, misidentification between D. spathacea and its terrestrial relative D. cauda-felina poses further challenges to field protection and proper medicinal usage of D. spathacea. Thus, to address these problems, we sequenced and assembled mitochondrial (mt) and chloroplast (cp) genomes for both D. spathacea and D. cauda-felina. Comparative analysis revealed apparently different size and scaffold number between the two mt genomes, but a high similarity between the cp genomes. Eight regions with high sequence divergence were identified between the two cp genomes, which might be used for developing candidate DNA markers for distinguishing the two species. The splitting between D. spathacea and D. cauda-felina was inferred to occur at ~6.8 - 7.7 million years ago (Mya), which may be driven by the environment fluctuations in late Miocene. In the cp genome, 12 genes related to the expression of photosynthesis-associated proteins were detected with signatures of positive selection, which may contribute to the origin and evolutionary adaptation of Dolichandrone mangrove species. These new findings do not only enrich organelle genomic resources of Dolichandrone species, but also provide important genetic clues for improving the conservation and proper usage of endangered mangrove associate D. spathacea.

Carbohydrate accumulation patterns in mangrove and halophytic plant species under seasonal variation

This study investigates the impact of carbohydrate accumulation in mangrove and halophytic plants on their response to abiotic stress. Using soil analysis and FT-IR spectroscopy, key species (Sueda nudiflora, Aeluropus lagopoides, Avicennia marina) were examined for seasonal changes in sugar content (reducing sugars, total soluble sugars, starch). The elevated carbohydrate levels may serve as an indication of the plant’s ability to adapt to different environmental conditions throughout the year. This accumulation enables plants to adapt to variations in their environment, assuring their survival and functionality during periods of environmental fluctuation. Halophytic plants’ sugar content peaked during the monsoon, suggesting biotic adaptations. The mangrove Avicennia marina had year-round sugar levels. PCA and Hierarchical Cluster Analysis revealed sugar accumulation trends across species and seasons. Partial Least Squares (PLS) analysis revealed correlations between soil characteristics and sugar content, suggesting plant-microbe interactions. K-means clustering and correlation analysis of FT-IR data revealed sugar composition and resource allocation trade-offs. These findings shed light on the role of carbohydrate metabolism in enabling coastal plants to endure stress. Gaining insight into these mechanisms can enhance sustainable agriculture in challenging environments and shed light on plant adaptations to evolving environmental conditions, especially biotic interactions.

Halotolerant Endophytic Bacteria Priestia flexa 7BS3110 with Hg2+ Tolerance Isolated from Avicennia germinans in a Caribbean Mangrove from Colombia.

The mangrove ecosystems of the Department of Atlántico (Colombian Caribbean) are seriously threatened by problems of hypersalinization and contamination, especially by heavy metals from the Magdalena River. The mangrove plants have developed various mechanisms to adapt to these stressful conditions, as well as the associated microbial populations that favor their growth. In the present work, the tolerance and detoxification capacity to heavy metals, especially to mercury, of a halotolerant endophytic bacterium isolated from the species Avicennia germinans located in the Balboa Swamp in the Department of Atlántico was characterized. Diverse microorganisms were isolated from superficially sterilized A. germinans leaves. Tolerance to NaCl was evaluated for each of the obtained isolates, and the most resistant was selected to assess its tolerance to Pb2+, Cu2+, Hg2+, Cr3+, Co2+, Ni2+, Zn2+, and Cd2+, many of which have been detected in high concentrations in the area of study. According to the ANI and AAI percentages, the most halotolerant strain was identified as Priestia flexa, named P. flexa 7BS3110, which was able to tolerate up to 12.5% (w/v) NaCl and presented a minimum inhibitory concentrations (MICs) of 0.25 mM for Hg, 10 mM for Pb, and 15 mM for Cr3+. The annotation of the P. flexa 7BS3110 genome revealed the presence of protein sequences associated with exopolysaccharide (EPS) production, thiol biosynthesis, specific proteins for chrome efflux, non-specific proteins for lead efflux, and processes associated with sulfur and iron homeostasis. Scanning electron microscopy (SEM) analysis showed morphological cellular changes and the transmission electron microscopy (TEM) showed an electrodense extracellular layer when exposed to 0.25 mM Hg2+. Due to the high tolerance of P. flexa 7BS3110 to Hg2+ and NaCl, its ability to grow when exposed to both stressors was tested, and it was able to thrive in the presence of 5% (w/v) NaCl and 0.25 mM of Hg2+. In addition, it was able to remove 98% of Hg2+ from the medium when exposed to a concentration of 14 mg/L of this metalloid. P. flexa 7BS3110 has the potential to bioremediate Hg2+ halophilic contaminated ecosystems.

Safety evaluation of Avicenna germinans leaf extracts in rats

BackgroundAvicenna germinans is one of Nigeria's dominant mangrove plants and has valuable pharmacological and therapeutic activity. It is widely employed in traditional medicine to treat many ailments and diseases, including cancer. However, little is known about the safety of the plant. Acute and sub-acute toxicity profiles of the plant extracts were assessed in this study. MethodsThe oral acute toxicity was determined with 5000 mg/kg body weight each of n-hexane, ethyl acetate, and ethanol extracts of Avicenna germinans leaf in rats. The rats were monitored for mortality, clinical manifestations, and weight changes over 14 days. During the sub-acute toxicity study, twenty-five female rats were fed with 0–1000 mg/kg ethanol extracts of Avicenna germinans for 21 days. The body weight was monitored during treatment, while changes in gross organ morphology, relative organ weights, hematology, serum biochemistry, and limited histological analysis were evaluated after treatment. ResultsAcute administration of the three extracts did not result in mortality or any obvious adverse effects. The gross pathology, relative organ weights, hematology, serum biochemistry, and histopathology were similar to the control, except for the 1000 mg/kg dose that evoked marked increases in relative heart, intestinal, thymus, and adrenal weights. In addition, foci of inflammatory cells in the interstitium and lymphoid hyperplasia were found in the heart and lungs, respectively, in the 1000 mg/kg group. ConclusionThe findings indicate that LD50 of the three extracts of Avicenna germinans were > 5000 mg/kg and sub-acute administration of the ethanol extract is relatively safe at least up to 750 mg/kg body weights.

Optimizing mangrove afforestation: Mollusc biodiversity comparisons reveal optimal mudflat-mangrove area ratio.

In recent decades, mangrove wetlands globally have suffered from human activities and climate change, leading to issues like area reduction, degraded ecological functions and declining biodiversity. Restoration efforts, primarily through mangrove afforestation (i.e. mangrove plantation in mudflats), have been widespread, yet they often overlook the significance of unvegetated mudflats. In addition, under the condition that the total area of suitable mudflats is limited, the problem of what is the threshold of mangrove forests and unvegetated mudflats to better protect mangrove biodiversity has not been solved. Therefore, this study conducted a field survey of molluscs in mangrove wetlands in Hainan Island in China and explored the relative importance of mangroves and unvegetated mudflats through taxonomic alpha diversity and functional diversity. The results showed that (1) mollusc abundance of unvegetated mudflats was notably higher than this of mangrove forests, and the species richness, functional richness and functional vulnerability were significantly lower than those of mangrove forests; (2) the abundance and functional vulnerability of molluscs were mainly affected by sediment properties (pH, interstitial water salinity, median diameter, total nitrogen, C/N ratio), while the species richness and functional richness of molluscs were primarily influenced by vegetation structure (plant density); and (3) retaining at least 20% of the unvegetated mudflat area could well protect the biodiversity of mangrove wetlands. To our knowledge, our study is the first to propose the proportion of mangrove forests and unvegetated mudflats on the basis of benthic biodiversity, providing theoretical support and decision-making reference for mangrove protection and restoration.

Strengthening Community Capacity Through Tsunami Education Programs in the Mangrove Community of Kebumen

Coastal communities, such as the Mangrove Community of Kebumen, face significant risks from tsunamis due to their geographical location. This community service initiative aimed to enhance tsunami disaster preparedness through education and mangrove conservation. The objectives were to improve community knowledge on tsunami mitigation and to empower locals in mangrove planting and maintenance practices. The methodology involved a structured program conducted at Pantai Sawangan, Desa Puring, involving 30 participants from the mangrove community and local residents. The activities included pre-tests, educational sessions on tsunami mitigation and mangrove conservation, and post-tests to evaluate knowledge retention. Expert-led discussions highlighted the role of mangroves as natural barriers against tsunamis. Results showed a significant increase in participants' understanding of tsunami risks and mitigation strategies post-training. Participants actively engaged in practical sessions, demonstrating enhanced skills in mangrove planting and maintenance. Feedback indicated strong community support and a desire for continued educational initiatives. In conclusion, the program effectively improved community resilience through enhanced knowledge and practical skills in disaster preparedness and mangrove conservation. Continued socialization and educational programs are recommended to sustain community involvement and deepen understanding of disaster mitigation across diverse societal groups, ensuring long-term resilience against coastal hazards.

PERAN MODAL SOSIAL DALAM PELESTARIAN TANAMAN MANGROVE DI DESA TONGKE-TONGKE KECAMATAN SINJAI TIMUR

This research was conducted with the aim of examining the role of social capital in preserving mangrove plants in Tongke Tongke Village, East Sinjai District, Sinjai Regency. This research uses a qualitative descriptive research method with data collection techniques using observation, interviews, and questionnaires. The results of this research show that there are three important indicators in the application of social capital, namely trust, norms, and networking. The application of social capital is considered important for the people of Tongke Tongke Village because the application of trust indicators can form social interactions that can last for a long time, and the application of norms can help the community comply with the rules in managing mangrove forests as a source of life and the existence of a network built by the Tongke Tongke Village government. both internal and external help in preserving mangrove forests which must be maintained by all parties, both government and community. The condition of the mangrove forests in Tongke - Tongke Village, East Sinjai District requires effective forest rehabilitation and integrated management. In integrated mangrove forest management, the role of each stakeholder involved in the management is very necessary. Mangrove forest management in Tongke - Tongke Village involves local communities and the condition of the mangrove forests in the village is starting to improve and some are still experiencing damage, this cannot be separated from the social capital of the local community who manage and utilize the mangrove forests.

Differential allelopathic effects of mangrove plants Kandelia obovata and Aegiceras corniculatum on harmful algal species: Potential applications in algal bloom control

This study examined effects of mangrove plants Kandelia obovata and Aegiceras corniculatum on harmful algal species. While A. corniculatum leaf extract had no inhibitory effect, K. obovata leaf extract significantly inhibited the growth of two harmful algal species Alexandrium tamarense and Karenia mikimotoi. The inhibitory effect was concentration-dependent, with over 90 % inhibition at the highest concentration. Morphological changes and cell size reduction were observed in both microalgae. Excessive production of reactive oxygen species and damage to algal photosynthetic system were found. The allelopathic effect of K. obovata on K. mikimotoi with low-concentration repeated exposure was more effective than high-concentration single exposure. The EC50 of K. obovata (0.33 g L−1) was lower than reported values on other coastal plants. Higher inhibitory effects of K. obovata were found on naked algal species than the armoured ones. These findings suggest potential applications of K. obovata leaf extract in controlling harmful algal blooms.

Penanaman Mangrove sebagai Revitalisasi Ekowisata Desa Kartika Jaya, Kecamatan Patebon, Kabupaten Kendal

The community service program in Kartikajaya Village aims to develop local economic potential through mangrove planting as a tourist attraction. Kartikajaya Village has geographical conditions that support the development of ecotourism, but the lack of public awareness and understanding of the benefits of mangroves is a major obstacle. This activity involves local communities in the process of planting and maintaining mangroves, as well as providing education about the importance of mangroves in maintaining the balance of coastal ecosystems and increasing village tourism attractiveness. The results of this program showed an increase in community awareness of environmental conservation as well as an increase in tourist visits to the village. Thus, mangrove planting not only serves as an environmental conservation effort, but also as a driver of economic growth through the tourism sector in Kartikajaya Village.