Response of Root Exudates of Bruguiera gymnorrhiza (L.) to Exposure of Polycyclic Aromatic Hydrocarbons

Root exudates play a pivotal role in the behaviors of polycyclic aromatic hydrocarbons (PAHs) in mangrove sediments, but the knowledge of how mangrove root exudates response to PAHs pollutants is limited. This study examined the root exudates of Bruguiera gymnorrhiza (L.) (B. gymnorrhiza) under exposure in phenanthrene, pyrene, and benzo[a]pyrene solution through a 45 days hydroponic cultivation. The results showed that the root exudates of B. gymnorrhiza were mainly hydrocarbon compounds. Tartaric acid was the dominant low molecular weight organic acids (LMWOAs) in root exudates. Under PAHs stress, the proportion of hydrocarbon compounds in root exudates decreased, while the proportion of amide compounds increased. At the first 15 days exposure, the amounts of dissolved organic carbon, soluble total sugars, total organic acids and LWMOAs all increased and reached the maximum values, subsequently, the amounts of root exudates had dropped. The degradation rates of PAHs followed the sequence of phenanthrene > pyrene > benzo [a] pyrene, and the presence of root exudates can significantly enhance the degradation of PAHs. The results illustrated that PAHs stress can significantly change the concentrations and species of root exudates. This study provides the scientific reference for understanding the ability of B. gymnorrhiza response to PAHs stress.

Percentage of Mangrove Canopy Cover and Mollusks Abundance in Benoa Bay Mangrove Ecosystem

This research was conducted to determine the condition of the mangrove ecosystem based on its canopy cover and to determine the types of mollusks (Bivalves and Gastropods) associated with the Benoa Bay mangrove ecosystem. Hemispherical photography is a method for observing mangrove canopy cover and line transect method for mollusks. The composition of mangrove species found in the research location were five species, namely Rhizophora stylosa, Rhizophora mucronata, Rhizophora apiculata, Bruguiera gymnorrhiza, and Avicennia marina. The percentage of mangrove canopy cover in the Benoa Bay mangrove ecosystem is in a good category (average = 76.59%). There are eight types of mollusks found in the research location. There are two types of bivalves (Polymesoda bengalensis and Gafrarium pectinatum) and six types of gastropods (Nerita balteata, Nerita picea, Neritina turrita, Pila ampullacea, Cassidula aurisfelis, and Littoraria melanostoma). The relationship between the percentage of mangrove canopy cover and abundance of mollusks in the Benoa Bay mangrove ecosystem is very strong (r) of 0.920. The higher the percentage value of mangrove canopy cover, the higher the mollusks abundance.

The Toxicity Test on Larvae of Shrimp (Artemia salina L.) of Lindur Fruit Peel Extract (Bruguiera gymnorrhiza) and Identification of Its Bioactive Compounds

Indonesia is the most mangrove-rich country, both in terms of area quantity and number of species. Mangrove plants have potential as a source of medicinal compounds. Bruguiera gymnorrhiza is a type of mangrove plant which is a source of medicinal plants from the Rhizoporaceae family. Ethanol extract of the stem bark of B. gymnorhiza has been known to have cytotoxic activity with an IC50 of 508.19 µg/mL against myeloma cancer cells (Rahmah, 2021). The aim of this study was to determine the toxicity of lindur fruit peel extract (B. gymnorrhiza) on Artemia salina Leach shrimp larvae. Lindur fruit peel extraction was carried out by maceration method using methanol solvent which was then fractionated with n-hexane and ethyl acetate as solvent. All extract fractions obtained were then tested for toxicity against shrimp larvae Artemia salina Leach by BSLT (Brine Shrimp Lethality Test) method. Extract fractions with the highest toxicity were identified for their bioactive compounds using UV-Visible and FT-IR spectrophotometers. The results of the toxicity test showed that the lindur fruit peel extract was toxic to A. salina L. and the most toxic fraction was the n-hexane fraction with an LC50 value of 34.109 ppm. The results of the analysis using UV-Visible and FT-IR spectrophotometers the active compound in the hexane fraction of lindur fruit extract (B. gymnorrhiza) contains terpenoid which has double bond conjugated that showed by the existence of an electronic transition of π →π* that was conjugated and there are clusters of -OH, C=O, C=C, aromatic, C-H and C-O groups.

Predicting mangrove forest dynamics across a soil salinity gradient using an individual-based vegetation model linked with plant hydraulics

In mangrove forests, soil salinity is one of the most significant environmental factors determining mangrove forest distribution and productivity as it limits plant water uptake and carbon gain. However, salinity control on mangrove productivity through plant hydraulics has not been investigated by existing mangrove models. Thus, we present a new individual-based model linked with plant hydraulics to incorporate physiological characterization of mangrove growth under salt stress. Plant hydraulics was associated with mangroves nutrient uptake and biomass allocation apart from water flux and carbon gain. The developed model was performed for two-coexisting species of Rhizophora stylosa and Bruguiera gymnorrhiza in a subtropical mangrove forest in Japan. The model predicted that the productivity of both species was affected by soil salinity through downregulation of stomatal conductance, while B. gymnorrhiza trees grow faster and suppress the growth of R. stylosa trees by shading that resulted in a B. gymnorrhiza-dominated forest under low soil salinity conditions (< 28 ‰). Alternatively, the increase in soil salinity significantly reduced the productivity of B. gymnorrhiza compared to R. stylosa, leading to an increase in biomass of R. stylosa despite the enhanced salt stress (> 30 ‰). These predicted patterns in forest structures across soil salinity gradient remarkably agreed with field data, highlighting the control of salinity on productivity and tree competition as factors that shape the mangrove forest structures. The model reproducibility of forest structures was also supported by the predicted self-thinning processes, which likewise agreed with field data. In addition, the mangroves morphological adjustment to increasing soil salinity – by decreasing transpiration and increasing hydraulic conductance – was reasonably predicted. Aside from the soil salinity, seasonal dynamics in atmospheric variables (solar radiation and temperature) was highlighted as factors influencing mangrove productivity in a subtropical region. The physiological principle-based improved model has the potential to be extended to other mangrove forests in various environmental settings, thus contributing to a better understanding of mangrove dynamics under future global climate change.

Diversifikasi Produk Olahan Buah Mangrove Dau (Bruguiera Gymnoorhiza) Untuk Cake Gulmerda Dan Sirup Dau Di Desa Maitara Utara Kota Tidore Kepulauan

Mangrove forests are biological resources found in coastal areas that have ecological and economic functions. Bruguiera gymnorrhiza is a type of mangrove that grows in the middle and back zones with a muddy sand substrate. The fruit can be used as a local food source, especially in coastal areas that have the potential of mangrove forests, but of course must pay attention to the sustainability of the mangrove ecosystem. This PKM aims to apply the technology of processing the Bruguiera gymnorrhiza mangrove fruit for gulmerda cake and syrup which has a high selling value. The methods used in the Community Partnership Program (PKM) activities are lectures, practice, hedonic testing and mentoring. The results of PKM have increased public knowledge in utilizing raw materials that are around their environment to be processed into products that have a selling value, motivating people to be more independent and confident in developing businesses to improve community welfare, organoleptic testing, Cake gulmerda products are products that have higher score. The formation of the entrepreneurial group "Let's Feel Creative" in the context of the sustainability of training activities.Keywords: Diversification, processed mangrove fruit, gulmerda cake, Dau syrup, North Maitara

Characteristics of chemical properties of fruit flour of mangrove (Bruguiera gymnorrhiza Lamk.) with lower cyanide content

This study aimed to determine the best method for reducing HCN levels of mangrove (Bruguiera gymnorrhiza Lamk.) flour and analyze mangrove flour's chemical properties. This study used a completely randomized design with a treatment level, namely boiling with water for 30 minutes at 100°C, immersion in distilled water, immersion in 0.8 M NaOH solution, immersion in KOH solution 0.8 M, immersion in 0.8 M Na2CO3 solution, and immersion in 0.8 M Na2HPO4 solution. All immersion treatments were carried out at room temperature for 24 hours. The experimental parameters included HCN, ash, moisture, lipid, carbohydrate and protein contents. The research data were analyzed using analysis of variance and continued with the Tukey test. The results showed that the treatments that were tried to reduce HCN levels could also be used for mangrove fruit flour. The boiling treatment that is usually carried out by the community in Tual, Southeast Maluku is more effective when compared to other treatments in an effort to reduce HCN levels. There were also differences in the chemical characteristics of the mangrove flour with the various techniques that were tried. Boiling treatment for 30 minutes showed the highest reduction (84.14%) with HCN levels of 1.95 mg/kg. The characteristics of mangroves with the lowest levels of HCN were: 14.17% ash content, 12.08% moisture content, 0.51% lipid content, 67.76% carbohydrate content, and 3.64% protein content.

PEMBERDAYAAN MASYARAKAT MELALUI PENGOLAHAN BUAH MANGROVE DAU (Bruguiera gymnorrhiza) SEBAGAI KUE KERING GOOD TIME DAN SELAI DAU DI PULAU MAITARA DESA MAITARA UTARA KOTA TIDORE KEPULAUAN

Buah dari beberapa jenis mangrove dapat digunakan sebagai bahan baku olahan pangan yang saat ini mulai berkembang dengan pesat. Sebagai upaya pemenuhan tersebut maka upaya pengelolaan mangrove dan lingkungan perlu segera dilakukan sehingga ke depan olahan bahan pangan tersebut semakin berkembang dan berfungsi sebagai sumber bahan pangan. Buah lindur dapat diolah menjadi aneka produk makanan seperti kue, cake, dicampur dengan nasi atau dimakan langsung dengan bumbu kelapa. PKM ini dilakukan dengan tujuan memberikan pengetahuan kepada masyarakat tentang teknik pengolahan buah mangrove Bruguiera gymnorrhiza berbasis IPTEK dan teknologi tepat guna. Luaran PKM adalah produk hasil olahan buah mangrove yang memiliki nilai jual yang tinggi yaitu kue kering good time, dan selai dau. Pelaksanaan pengabdian di Desa Maitara Utara Kecamatan Tidore Utara pada bulan September 2021. Metode pelaksanaan kegiatan Pengabdian Kemitraan Masyarakat meliputi : metode survey, metode sosialisasi, metode ceramah, metode praktek, metode pengujiam organoleptic dan metode pendampingan. Kegiatan PKM berdampak positif terhadap masyarakat karena menambah pengetahuan masyarakat tentang pengolahan buah mangrove Bruguiera gymnorrhiza sebagai bahan makanan. Kegiatan platihan ini dianggap berhasil karena semua peserta pelatihan begitu bersemangat dan antusiasme dalam menekuni pelatihan olahan buah mangrove sebagai produk kue good time dan selai dau, hasil uji organoleptik semua produk disukai oleh responden dan produk Good Time merupakan produk yang memiliki nilai skoring lebih tinggi. Terbentuknya kelompok wirausaha “Mari Rasa Kreatif” dalam rangka keberlanjutan kegiatan pelatihan.

Crustacean and mollusk species diversity and abundance in the mangrove communities of Mimika District, Papua, Indonesia

Setyadi G, Rahayu DL, Pribadi R, Hartati R, Wijayanti DP, Sugianto DN, Darmawan A. 2021. Crustacean and mollusk species diversity and abundance in the mangrove communities of Mimika District, Papua, Indonesia. Biodiversitas 22: 4146-4157. A mangrove crustacean and mollusk species diversity study was carried out in four mangrove estuaries in Mimika District, Papua, Indonesia. Two locations were selected on each estuary; for each location, samples of crustaceans and mollusks were collected from 5 m × 5 m plots, and mangrove trees were recorded on 10 m × 10 m plots at a distance of 10 m, 250 m and 500 m perpendicular to the riverbank. This study recorded a total of 41 species of crustaceans and 32 species of mollusks the latter comprising three species of bivalves and 29 gastropod species. The number of crab species found was among the highest compared to similar studies in the world. The average number of species collected from each 25 m2 plot was 7.6 ± 4.2 species for crustaceans, with an average abundance of 87 ± 3.5 individuals; for mollusks, it was 3.3 ± 3 species with an average abundance of 28 ± 48.4. Crustacean abundance and species composition were influenced by inundation frequency. There was a strong correlation between the crab Parasesarma cricotum and the association of Rhizophora apiculata and Bruguiera gymnorrhiza mangroves, and Clistocoeloma amamaparense and the association of B. gymnorrhiza, R. apiculata, and Bruguiera parviflora mangroves. For mollusks, correlations were found between Terebralia palustris and Ellobium aurisjudae and the association of R. apiculata and B. parviflora mangroves. The highest crustacean Shannon-Wiener diversity index was associated with Sonneratia alba and Avicennia marina mangroves, and the highest mollusk Shannon-Wiener diversity index was associated with R. apiculata and B. gymnorrhiza mangroves.

KONDISI VEGETASI DAN PERUBAHAN TUTUPAN LAHAN EKOSISTEM MANGROVE PULAU TANAKEKE KABUPATEN TAKALAR PROVINSI SULAWESI SELATAN

Ekosistem mangrove merupakan salah satu ekosistem pesisir dengan tingkat produktivitas yang tinggi, sehingga keberadaannya dapat memperkaya kawasan pesisir dan menjaga keseimbangan ekosistem. Penelitian ini bertujuan untuk menjelaskan perubahan luasan dan sebaran ekosistem mangrove dalam kurun waktu 20 tahun, yakni dari tahun 2000 sampai dengan 2020 dan untuk mengetahui kondisi vegetasi ekosistem mangrove di Pulau Tanakeke. Penelitian ini dilakukan pada bulan Januari hingga April 2020 di Pulau Tanakeke. Penentuan lokasi penelitian menggunakan metode purposive sampling. Analisis perubahan luasan ekosistem mangrove dari tahun 2000 sampai 2020 menggunakan metode supervised classification dengan analisis maximum likelihood, sedangkan kondisi vegetasi ekosistem mangrove menggunakan metode analisis indeks nilai penting (INP) dan indeks keanekaragaman jenis. Hasil penelitian menunjukkan bahwa ekosistem mangrove di Pulau Tanakeke dari tahun 2000 sampai 2020 mengalami degradasi seluas -337,41 ha (28,32% dari luas tahun 2000). Pada lokasi penelitian ditemukan 9 jenis mangrove, yaitu Bruguiera gymnorrhiza, Ceriops tagal, Rhizophora stylosa, Rhizophora apiculata, Rhizophora mucronata, Sonneratia alba, Phemphis acidula, Lumnitzera racemosa dan Ceriops decandra. Mangrove jenis Rhizophora mucronata memiliki indeks nilai penting tertinggi yaitu sebesar 192,55%, sementara untuk keanekaragaman jenis secara umum tergolong rendah.

Mangrove diversity and community structure of Mimika District, Papua, Indonesia

Setyadi G, Pribadi R, Wijayanti DP, Sugianto DN. 2021. Mangrove diversity and community structure of Mimika District, Papua, Indonesia. Biodiversitas 22: 3562-3571. Despite being one the largest mangrove forest in the world, there are few studies on mangrove diversity and community structure in Mimika, Papua Province. The study collected data from 4 estuaries of Mimika Region, i.e. Kamora, Tipuka, Ajkwa and Minajerwi. Mangrove species, tree diameter at breast height and canopy height data were collected in 10 m x 10 m plot with three replicates for distance, specifically 0, 250, and 500m perpendicular to the riverbank. This study found 66 mangroves species consisting of 20 major, 10 minor, and 36 associate mangrove species. Their density ranged from 577-1,345 trees ha-1 with diversity Shannon-Weiner diversity indices (H’) ranging from 0.62-1.19 and Evenness Index (J’) ranging from 0.09-0.18. The canopy height of the mangrove trees was ranged from 9-42.5 m. The highest density species was Rhizophora apiculata (333 ha-1) followed by Avicennia marina, Bruguiera gymnorrhiza, and Camptostemon schultzii, while B. parviflora, S. alba, and X. granatum were the least dominant. Regarding basal area, R. apiculata and B. gymnorrhiza were the highest with medians of 7,853 cm2 ha-1 and 5,201 cm2 ha-1 respectively. In the low tidal zone area, mangrove was dominated by A. marina, Sonneratia alba and R. mucronata. Medium low to medium high tidal zones were dominated by B. gymnorrhiza, R. apiculata, and B. parviflora. The high tidal zone was more dominated by Nypa fruticans.