Struktur Dan Komposisi Vegetasi Mangrove Di Kawasan Laguna Segara Anakan Cilacap

In coastal areas, mangrove communities have many functions economically, physically, and ecologically. One of the mangrove forest areas that is experiencing rapid decline in area is the Segara Anakan Lagoon, Cilacap. The purpose of this study was to determine the structure and composition of mangrove vegetation. Vegetation data was collected by purposive sampling method and each station was made 9 sampling plots. The results found that there are 12 species consisting of 4 major mangrove families, 1 minor mangrove family and 2 associated mangrove families. In general, the mangrove tree vegetation in the eastern part of Segara Anakan is dominated by Aegiceras corniculatum with an INP ranging from 38.99-67.23%, the middle part is dominated by Nypa fruticans with an INP ranging from 47.80-70.18% and the western part is dominated by Sonneratia alba with an INP of 56.32%. Environmental quality measures include water temperature, salinity, dissolved oxygen, soil pH, water pH, TSS, total soil N, organic C, soil phosphate still support mangrove life.

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.

Comparison of four species diversity indices in mangrove community

Mulya H, Santosa Y, Hilwan I. 2021. Comparison of four species diversity indices in mangrove community. Biodiversitas 22: 3648-3655. Mangrove communities have a tidal environment that affects their species composition, which may be finite but the abundance may vary between species individuals. Many ecologists have used indices to measure species diversity without knowing the best suitable index for the community and its statistical characteristics. Therefore, this study aimed to compare species diversity indices in mangrove communities to obtain the best and most appropriate index for mangrove diversity. The comparison was done using the Simpson (1-D), Shannon, Menhinick, and Margalef indices, which were widely used and considered the best measures in various communities. The data was obtained from the field sampling using a single plot of 80×40 m2, and then it was simulated to obtain standardized variables so that the indices got the same treatment. It was calculated with descriptive statistics and species diversity indices among other Simpson, Margalef, Shannon, and Menhinick indices. Pearson correlation and UPGMA cluster were used to get conformity based on the best index criteria. The results showed the Margalef index was the best in performance that passed the assessment criteria more than Simpson (1-D), Shannon, and Menhinick index. It had a low correlation with sample variance and normality marker but had high variability of the index value. It was also sensitive to the number of species, good reduced individual sample, and good correlation with similar indices. Thus, we concluded that the Margalef index was the best index for mangrove community diversity measurement. The index was recommended for monitoring and evaluating the species diversity assessment for the mangrove community. It should not use several species diversity indices with similar meaning.

Response of Brazilian peppertree (Schinus terebinthifolia) and four mangrove species to imazamox and carfentrazone-ethyl herbicides

Mangroves are a critical component of many coastal ecosystems in Florida. Woody species including Brazilian peppertree (Schinus terebinthifolia) have invaded thousands of hectares of mangrove habitat. The difficulty associated with ground-based management of invasive plants in mangrove communities has warranted a need to identify selective herbicides that can be applied aerially. Recent work suggests that Florida mangrove species are extremely sensitive to synthetic auxin herbicides; however, other herbicides have yet to be tested for selectivity. Greenhouse studies in 2018 and 2019 evaluated broadcast foliar applications of the acetolactate synthase (ALS) inhibitor imazamox and protoporphyrinogen oxidase (PPO) inhibitor carfentrazone-ethyl, both as individual treatments and in combinations, for control of S. terebinthifolia and injury to four non-target mangrove species. Across all post-treatment sample dates and species tested, there were no significant interactions between imazamox applied at 0.28 or 0.56 kg ai ha−1 in combination with carfentrazone-ethyl applied at 0 or 0.1 kg ha−1. Main effects of imazamox applied at 0.56 kg ai ha−1 and carfentrazone-ethyl applied at 0.1 kg ha−1 resulted in 99 and 97% defoliation, respectively, to Schinus terebinthifolia at 180 DAT. However, S. terebinthifolia % survival was 56 and 44% for the same treatments. Both herbicides severely injured all four mangroves by 90 DAT and resulted in 58 to 100% defoliation across species. At 180 DAT, significant increases in % cambium kill were also observed for all four species. Across species, mangrove survival varied but Rhizophora mangle survival was reduced to 6% when imazamox was applied at 0.56 kg ha−1. These results indicate both imazamox and carfentrazone-ethyl exhibit activity on S. terebinthifolia, but also injure all four mangroves enough to preclude their use as selective treatments.

Wildlife Bio-Geography on Mangrove Communities in Saparua Island, Maluku

On the island of Nusalaut, an orange crested white cockatoo (Cacatua moluccensis) was found. The interviews with several community leaders from the island of Nusalaut, including Raja Negeri Sila, reveal that there have been no Cacatua moluccensis birds in recent years worldwide Nusalaut. it is predicted that the Cacatua moluccensis bird has moved to Saparua island as the closest island. This bird is no longer found because of changes in the forest's structure and composition into agricultural land for cloves (Eugenia aromatica) because it does not need shade trees. The mangrove community along the coast of the island of Saparua for the last few years has experienced various pressures of development dynamics that have disrupted their lives. Therefore, at the same time, they impact the activities of wildlife that use them as habitat. This research was conducted by applying direct and indirect survey methods to determine the types and distribution of the mangrove community's wildlife inhabitants, both permanently and temporally. Seven species of mammals use the mangrove communities in Saparua Bay, Haria Bay and Tuhaha Bay, nine reptile species, and 18 species of birds.

Hibiscus tiliaceus (coast cottonwood).

H. tiliaceus is a medium-sized tree, normally 8-12 m tall (maximum 20 m) and stem to 50 cm dbh, with a dense crown and spreading branches. The bark is grey, smooth on young trees with brown, horizontally elongated lenticels; hard and thick with black, vertical fissures on larger trees. It has mucilaginous sap. The original natural distribution is obscure, but H. tiliaceus is now widely distributed in the sub-humid and humid tropics. It grows on coastal foreshores on sand or rock, behind mangrove communities that border brackish swamp forest and littoral subtropical rainforest on alluvial flats near the sea. It is infrequent on atolls. The timber is very fine and smooth, easy to work and takes a good polish. The leaves, bark and sap are used medicinally: leaves are wrapped around bone fractures; and fluid from young stems is used as an antiseptic for skin eruptions. The roots, flowers and young leaves are edible. The inner bark is used for its fibre to make twine, cordage for ropes, nets, basketware, fishing line and making skirts for ceremonial occasions. The bushy habit and decorative flowers make this species an attractive shade or ornamental tree for coastal gardens, although it is easily damaged by sea winds. It is a short-lived pioneer species that can become invasive and the extensive root system can become a problem to cultivation. It is thought to be a host for insect vectors of foliar decay disease of coconuts.

Impact of Climate Change and Ongoing Adaptation Measures in the Bangladesh Sundarbans

The climate of Bangladesh has changed drastically which may put considerable adverse impacts on mangrove fishers but very few studies focused on this professional group. An attempt was made to perceive the impact and adaptation measures of the Sundarbans mangrove resource users, employing interviews and focus group discussions. A total of 150 respondents were randomly selected from the Sundarbans west under Shyamnagar Upazila of Satkhira District. It was revealed that the abundance of fishes, fuel woods, honey, golpata (Nypa fruticans), and shrimp post-larvae (PL) was reduced considerably. The resource users have adapted themselves by changing their occupation and becoming jobless and depending on the other family members. PL collection, honey collection, shrimp culture, and wood collection were found professional adapting strategies to adopt cyclone, flood, salinity intrusion, river erosion, and drought. Several recommendations are elicited, the implementation of which is important to ensure livelihood sustainability of the mangrove communities.

Probabilistic Mangrove Species Mapping with Multiple-Source Remote-Sensing Datasets Using Label Distribution Learning in Xuan Thuy National Park, Vietnam

Mangrove forests play an important role in maintaining water quality, mitigating climate change impacts, and providing a wide range of ecosystem services. Effective identification of mangrove species using remote-sensing images remains a challenge. The combinations of multi-source remote-sensing datasets (with different spectral/spatial resolution) are beneficial to the improvement of mangrove tree species discrimination. In this paper, various combinations of remote-sensing datasets including Sentinel-1 dual-polarimetric synthetic aperture radar (SAR), Sentinel-2 multispectral, and Gaofen-3 full-polarimetric SAR data were used to classify the mangrove communities in Xuan Thuy National Park, Vietnam. The mixture of mangrove communities consisting of small and shrub mangrove patches is generally difficult to separate using low/medium spatial resolution. To alleviate this problem, we propose to use label distribution learning (LDL) to provide the probabilistic mapping of tree species, including Sonneratia caseolaris (SC), Kandelia obovata (KO), Aegiceras corniculatum (AC), Rhizophora stylosa (RS), and Avicennia marina (AM). The experimental results show that the best classification performance was achieved by an integration of Sentinel-2 and Gaofen-3 datasets, demonstrating that full-polarimetric Gaofen-3 data is superior to the dual-polarimetric Sentinel-1 data for mapping mangrove tree species in the tropics.