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).

Expression of some salt tolerance genes isolated from Egyptian gray mangrove (Avicennia marina)

Mangroves are well-adapted halophytes that thrive in coastal saline environments. They live under difficult environmental conditions, such as high light intensity and external salt concentrations, as well as low-oxygen environments, such as water-logged muck, that are typically inappropriate for the survival of other plants. Salinity is a major abiotic factor that affects plant growth, productivity, and dispersal in tropical and semitropical intertidal areas. Furthermore, it affects approximately 20% of all cultivable land and 50% of all irrigated land on the planet. Mangroves have developed a sophisticated salt filtration mechanism and a complicated root structure to withstand salty water exposure and tidal movement. The expression patterns of five salt tolerance genes (amFer1, amDhna, amSod1, amCat1, and amUbc2) in the Egyptian gray mangrove (Avicennia marina Forssk.) grown under different environmental conditions in South Sinai protectorates (Nabq, Ras Mohamed, Safaga, and Wadi El-Gemal), Egypt, were investigated in this study. This study aimed to assess and examine the genetic behavior of mangroves in response to salinity by using quantitative real-time PCR. Findings revealed differences in the expression patterns of the investigated genes under various conditions, showing that salinity influences plant genetic response. Ferritin gene expression was high in all locations, indicating that ferritin represents an essential component of the mangrove response mechanisms.

Standing Crop Biomass and Carbon Content of Mangrove Avicennia marina (Forssk.) Vierh. along the Red Sea Coast of Saudi Arabia

A number of Avicennia marina mangrove forests exist along the 1134 km stretch of the Saudi Red Sea coast. Three areas, one in each of the north, centre, and south of the coast, were selected for this investigation into the relationship between total biomass (above-ground, AGB, and below-ground, BGB), and biomass carbon stocks of A. marina, along the nutrient availability (combined with a salinity gradient). To estimate the total biomass stock, this research employed equations formulated through a regression approach. Various population characteristics (tree crown diameter, height, and density) and measurements of carbon (C) in the trees were captured, and other measurements were gathered to represent the environmental properties: electrical conductivity (EC), total dissolved solids (TDS), and total phosphorus (TP) and total nitrogen (TN) levels. With this data from the 21 stands and 7 sites of A. marina covered by the three locations chosen along the coast, it was concluded that a discernible influence is exerted by the concentrations of TP and TN in the sea water and sediments over the population characteristics of this plant. The resulting estimates also demonstrated a steady increase in total biomass and total biomass carbon storage from the mangroves in the north toward the south, with values changing overall from 197.9 to 1188.2 Mg DM ha−1 and from 87.6 to 412.5 Mg C ha−1 respectively. This illustrates that the biomasses held by the southern mangroves are 6 times (total) and 4.7 times (total carbon storage) higher than those in the north.

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.

Effects of Mangrove Plant Extraction on Adhesion Strength in Coating of Epoxy

Steel is an alloy of ferrous metal with a maximum carbon content of 2%. This material is widely used for jetty building structures at rivers, estuary, and coastal areas. Corrosion of steel can occur due to several factors, such as the steel material itself and the surrounding environmental factors. One of the corrosion is biocorrosion that occurs due to the presence of biofouling. This study aims to determine the effect of adding extraction of mangrove (Avicennia marina) as an antifouling compound mixed in epoxy paint through adhesion strength parameter. Then the alloy was applied as a coating on the ASTM A36 steel specimen. The variation of coating composition were 100% of epoxy paint, 90%:10% (epoxy paint and extraction of Avicennia marina), 80% : 20% and 70% : 30%. The results showed that the adhesion strength occurred in 100% of epoxy paint (10.15 ± 0.64 Mpa). The adhesion strength was 8.86 ± 0.21 Mpa, 8.50 ± 0.03 Mpa, and 8.19 ± 0.07 Mpa at ratio of composition coating 90%: 10%, 80%: 20%, and 70%: 30%, respectively. In conclusion, the more mangrove extraction was added, the smaller the adhesion strength.