Parameterization of Mangrove Root Structure of Rhizophora stylosa in Coastal Hydrodynamic Model

Mangroves are able to attenuate tsunamis, storm surges, and waves. Their protective function against wave disasters is gaining increasing attention as a typical example of the green infrastructure/Eco-DRR (Ecosystem-based Disaster Risk Reduction) in coastal regions. Hydrodynamic models commonly employed additional friction or a drag forcing term to represent mangrove-induced energy dissipation for simplicity. The well-known Morison-type formula (Morison et al. 1950) has been considered appropriate to model vegetation-induced resistance in which the information of the geometric properties of mangroves, including the root system, is needed. However, idealized vegetation configurations mainly were applied in the existing numerical models, and only a few field observations provided the empirical parameterization of the complex mangrove root structures. In this study, we conducted field surveys on the Iriomote Island of Okinawa, Japan, and Tarawa, Kiribati. We measured the representative parameters for the geometric properties of mangroves, Rhizophora stylosa, and their root system. By analyzing the data, significant correlations for hydrodynamic modeling were found among the key parameters such as the trunk diameter at breast height (DBH), the tree height H, the height of prop roots, and the projected areas of the root system. We also discussed the correlation of these representative factors with the tree age. These empirical relationships are summarized for numerical modeling at the end.

Struktur Komunitas Vegetasi Mangrove Di Pesisir Pantai Kepulauan Karimunjawa

Mangrove merupakan tumbuhan yang berada di wilayah intertidal pesisir laut. Tujuan penelitian ini yaitu menganalisis struktur vegetasi mangrove (frekuensi, kerapatan, dominan) dan karakteristik habitatnya (kualitas lingkungan) di kawasan pesisir pantai kepulauan Karimunjawa. Penelitian dilakukan pada Desember 2019 di 3 stasiun dengan metode plot bertingkat, masing-masing stasiun dibuat 3 transek yang berukuran 10m x 10m (pohon), 5m x 5m (pancang), dan 2m x 2m (semai). Hasil penelitian ditemukan 7 jenis mangrove yaitu Rhizophora stylosa, Avicennia marina, Rhizophora apiculata, Ceriops tagal, Excoecaria agallocha, Lumnitzera racemosa, dan Ceriops decandra. Indeks nilai penting tumbuhan mangrove pada strata pohon, pancang, dan semai paling tinggi adalah Rhizopora stylosa (244,77%), (163,03%), dan (157,96%). Nilai kerapatan Rhizopora stylosa tingkat pohon, tingkat pancang dan semai yaitu (2.500-10.100 ind/ha), (10.400-48.400 ind/ha), dan (97.500-280.000 ind/ha). Kondisi lingkungan di sekitar kawasan mangrove yaitu rata-rata suhu (28,75%), pasir (10,75%), lanau (51,46%/), lempung (37,79%), salinitas (26,60%), pH (7,26), DO (3,28 mg/L), N total tanah (0,24%), P total tanah (120,49 ppm), C Organik tanah (2,10%), N total air (0,28%), P total air (0,27 mg/L), C Organik air (1,56 mg/L).ABSTRACTMangroves are a plant that are found in the intertidal area of marine coastal environments. The study aim to analyze structure of mangrove vegetation (frequency, density, and dominance) and the mangrove habitat (environmental condition) in Coastal Coast Karimunjawa Island. The research was conducted in December 2019 at the three stations using the stratified plot method, and one stations divided three observation transects sized 10m x 10m (trees), 5m x 5m (saplings), and 2m x 2m (seedlings). The result of the study found seven mangroves species were Rhizophora stylosa, Avicennia marina, Rhizophora apiculata, Ceriops tagal, Excoecaria agallocha, Lumnitzera racemosa, and Ceriops decandra. The highest value index of mangroves for trees, saplings and seedlings is the highest Rhizopora stylosa (244,77%), (163,03%), and (157,96%). Density value Rhizopora stylosa in tree level, saplings, and seedlings were (2.500-10.100 ind/ha), (10.400-48.400 ind/ha), dan (97.500-280.000 ind/ha). The environmental conditions around the mangrove area are average temperature (28,75%), sand (10,75%), silt (51,46%/), clay (37,79%), salinity (26,60%), pH (7,26), Dissolved Oxygen (3,28 mg/L), N total land (0,24%), P total land (120,49 ppm), C Organic land (2,10%), N total water (0,28%), P total water (0,27 mg/L), C Organic water (1,56 mg/L).

The Mangrove Landscape and Zonation following Soil Properties and Water Inundation Distribution in Segara Anakan Cilacap

The mangrove zoning and landscape express the correlation between mangrove vegetation (density, biodiversity and species distribution) with environment factors like as water inundation, seatide, and soil properties. The research was conducted in Segara Anakan Lagoon to analysis community structure and mangrove landscape based on species distribution, biodiversity, environment factors, and mangrove zoning. The results showed that (a) Segara Anakan Lagoon had 4 mangrove zone's were dominated by Sonneratia alba, Rhizophora mucronata, Avicennia marina, Rhizophora apiculata, Rhizophora styllosa, and Nypa frutican; (b) the structure of ecosystem was showed by trend of mangrove ecosystem with equation y = 35.34x2 923.85x + 12817 with x = time (year) and y = mangrove area (ha), mangrove density between 1333367 ind ha-1 (West Segara Anakan) and 899–567 ind ha-1 (East Segara Anakan), dominated species were Nypa frutican, Rhizophora stylosa, Rhizophora apiculata, and Aegiceras corniculatum and mangrove biodiversity between 2,572,65 (moderate); (c) structure of environment factor showed single and semi double-type tides, water debit between 0.360.73 m s-1; water depth between 0.20–23.7 m and water inundation between 480cm; soil texture was clay and loam, soil nitrate of 1.5 mg 100 g-1, soil phosphate of 1.5 mg 100 g-1, C organic of 1.31%, soil pH of 6–7, and soil salinity of 6.5–10 ppt.

ESTIMASI POTENSI KARBON SEDIMEN MANGROVE PADA HUTAN ALAM DAN HUTAN REHABILITASI DI TAMAN HUTAN RAYA NGURAH RAI BALI

Sediments play an important role in coastal ecosystems. Apart from being a growing medium, sediment is also a place for accumulation and storage of various components including carbon. Ngurah Rai Forest Park is the largest mangrove in Bali with a large potential for sediment carbon stocks. To determine the carbon storage of mangrove sediments in natural forest and rehabilitation forest and the relationship between diameter size and vegetation type to sediment carbon in two forest types, a study was conducted using purposive sampling method based on canopy density level with three repetitions with a plot size of 10 mx. 10 meters. Sampling was divided into three depths, namely 0-30 cm, 31-60 cm and 61-100 cm. The total carbon content of mangrove sediments in natural forest is 363,491.17 Mg C or equivalent to 363,491.17 tons C and rehabilitation forest is 160,401.33 Mg C or equivalent to 160,401.33 tons C. The total sediment carbon content in Ngurah Rai Forest Park is 523,892.50 Mg C or equivalent to 523,892.50 tons C. Tree diameter had no significant effect on sediment carbon content, while vegetation type significantly affected sediment carbon content. Sonneratia alba had a significant negative effect on natural forests, while Rhizophora stylosa had a significant positive effect on rehabilitation forests. The results of the study suggest that it is necessary to maintain the preservation of mangroves and carry out rehabilitation in damaged areas. To increase the carbon content of sediments in mangrove forests, consider selecting the type of vegetation Rhizophora stylosa for the implementation of rehabilitation activities, because the type of Rhizophora stylosa makes a positive contribution to increasing the carbon content of sediments, with a note that the rehabilitation location is suitable for Rhizoporaceae species. Keywords: Mangrove; Nature Forest; Rehabilitation; Sediment.

The First De Novo Transcriptome Assembly and Transcriptomic Dynamics of the Mangrove Tree Rhizophora stylosa Griff. (Rhizophoraceae)

Mangroves are salt-tolerant plant species that grow in coastal saline water and are adapted to harsh environmental conditions. In this study, we de novo assembled and functionally annotated the transcriptome of Rhizophora stylosa, the widely distributed mangrove from the largest mangrove family (Rhizophoraceae). The final transcriptome consists of 200,491 unigenes with an average length, and N50 of 912.7 and 1334 base pair, respectively. We then compared the genome-wide expression profiles between the two morphologically distinct natural populations of this species growing under different levels of salinity depending on their distance from the ocean. Among the 200,491 unigenes, 40,253 were identified as differentially expressed between the two populations, while 15,741 and 24,512 were up- and down-regulated, respectively. Functional annotation assigned thousands of upregulated genes in saline environment to the categories related to abiotic stresses such as response to salt-, osmotic-, and oxidative-stress. Validation of those genes may contribute to a better understanding of adaptation in mangroves species. This study reported, for the first time, the transcriptome of R. stylosa, and the dynamic of it in response to salt stress and provided a valuable resource for elucidation of the molecular mechanism underlying the salt stress response in mangroves and other plants that live under stress.

Rhizophora stylosa as a protector against overwhelming copper (Cu) and lead (Pb) metal substances and how they affect on Belawan’s water quality

Rhizopohora stylosa, Rhizopohora mucronata, Rhizopohora apiculata, and Bruguiera gymnorhyza are among the rare types of mangrove found in coastal areas. The presence of these mangrove species in the coastal environment could be a boon to the environment. R. stylosa is one of the many species, and it can be used as a plant that collects heavy metals present in coastal areas. As a result of out-of-collection metals from various mechanical exercises that exist surrounding waterways and estuaries. From May to August 2021, researchers studied the capacity of R. stylosa to withstand the heavy metals copper (Cu) and lead (Pb) and their impact on water quality. This investigation took place at the Belawan Stream Estuary in Baristan Medan, as well as the Office of Timberland Development’s research center at the College of North Sumatra. Different types of mengrove plants found in coastal areas have unique strategies for dealing with contaminaton caused by heavy metals. Constructing various types of overpowering netal at various portions of the tree is one of the few methodologies used by mangroves. R. stylosa is a type of mangrove that may collect a lot of metal in its roots and stem before clearing it out. Overwhelming metals will degrade water quality, which will, in turn, degrade the condition of the biological system as a whole. The overpowering metal substance of Cu and Pb in the R. stylosa mangrove was found to be higher than that of Pb. The Cu component was found to be more notable than Pb in the water contained within the developing put of R. stylosa. Meanwhile, the mud material in which the R. stylosa mangrove grows creates an abundance of metal substance that is less than that of Pb.

Morphological identification of phosphate solubilizing and cellulolytic fungi from mangrove soil under Rhizophora stylosa stands

Mangrove forest is one of the forest ecosystems that can be found in tidal areas. Mangrove forest have ecological, socio-economic benefits for organisms that live in the sea. One of the microorganism that live in mangrove forest is fungus. Therefore, this study aimed to isolate and identify phosphate solubilizing and cellulolytic fungi from mangrove soil. Soil samples were collected from a stands of Rhizophora stylosa in Lubuk Kertang Village, West Brandan District, Langkat Regency, North Sumatra. Soil samples were taken randomly with a dept of 0-20 cm. Isolation of phosphate solubilizing fungi was carried out using Pikovskaya medium and cellulolytic fungi using carboxyl methyl cellulose (CMC) medium. To determine the effectiveness of fungi qualitatively, the phosphate solubility and cellulolytic index were calculated. All isolates obtained were identified morphologically by observing colonies macroscopically and microscopically. This study obtained 12 isolates of phosphate solubilizing and 8 isolates of cellulolytic fungi. Phosphate solubility index ranging from 2.06-2.87 and cellulolytic index of 0.33-3.00. Morphological identifications showed that all isolates of phosphate solubilizing fungi belonged to the genus Aspergillus, while all isolates of cellulolytic fungi belonged to the genus Chaetomium.

Mangrove potential and community characteristics for strengthening the utilization of environmental services based on ecotourism: A case study in Karangsong, Indramayu, West Java

Mangrove rehabilitation is often challenged by a lack of support from local communities. The success of mangrove rehabilitation can increase the chances of success by increasing the local economy, which will help increase public awareness. This study was conducted in the mangrove forest of Karangsong Village with the aim to identify the potential of mangroves and the characteristics of local communities as capital for the use of environmental services based on mangrove ecotourism. The interview method with semi-structured guidelines was applied to obtain social, economic and public perceptions data. Karangsong mangrove forest is dominated by three species of mangroves, namely Rhizophora mucronata, Rhizophora stylosa and Rhizophora apiculate. It has also become a habitat for various bird species such as javan pond heron, wandering whistling duck, lesser adjutant, imperial pied pigeon, and common sandpiper, which are potential ecotourism objects. The results showed that positive perceptions derived from the economic benefits obtained from mangroves, which have become feedback for mangrove conservation. The role of the driving group is also crucial to maintain the consistency of stakeholders’ enthusiasm to conserve mangroves. Sustainable ecotourism development needs to involve local communities in its management.

Biolarvicidal activity of Rhizophora stylosa leaf extract against Aedes sp.

The research focus on biolarvicidal activity of Rhizophora Stylosa leaf extract against Aedes sp. R. stylosa leaf was collected from Gampong Pande, Banda Aceh. This research was conducted at laboratory of Marine Chemistry and Fisheries Biotechnology, Marine and Fisheries Faculty, Universitas Syiah Kuala from Desember 2020 to March 2021. The objective of this study was to figure out the secondary metabolites content in the methanol extract of the mangrove leaf and its biolarvicidal activity against Aedes sp. larvae. The secondary metabolites were screened out using phytochemical screening. The extract was tested for its biolarvicidal activity against third instar larvae of the Aedes sp. mosquito at incubation’s time of 48 hours. The biolarvicidal activity is expressed in LC50 which was determined by probit analysis using SPSS. The results of qualitative test showed that the extract contained of flavonoids, saponins, triterpenoids and tannins. Based on the results of probit analysis, the LC50 value of the extract against Aedes sp. was 858.89 ppm.

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.