Mangrove Woodland Research Articles

Potential Antioxidant Constituent from Leaf of Rhizophora apiculata an Typical Mangrove at Lempasing, South Lampung Coast

The mangrove woodland is a distinct bush or brine habitat characterized by a coastal sedimentation environment in which fine sediment (often rich in organic matter) accumulates in areas protected from high energy waves. Mangrove forests thrive on the coasts of tropical and subtropical regions, including Indonesia. Mangrove forest is a complex ecosystem that has a high diversity of plants, microorganisms, and animals. One of them is the Oil Mangrove (R. apiculata) which grows well on the coast of Lampung. This plant is hard, rich in tannins, and dense, mainly used to make charcoal and firewood. This plant traditionally used to treat diarrhea and nausea. Mangrove plants are tolerant to high salt levels, this special trait is due to the presence of secondary metabolites produced in response to various environmental stresses. Flavonoid compounds, alkaloids, terpenoids and steroids are secondary metabolites produced by mangrove plants. Secondary metabolite compounds from mangroves have bioactivity such as antidiabetic, antimicrobial, antioxidant and anticancer. Exploration of secondary metabolites from mangroves, especially oil mangroves locally named as Bakau Minyak, which are widely grown in the Lempasing area, coastal Lampung for the development of medicinal compounds, has not been intensely reported. This investigation aims to study the potential phytochemicals profile of R. apiculata’s leaf as an antioxidant

Mangrove health along the hyper-arid southern Red Sea coast of Saudi Arabia.

Changes in land use and land cover have severely influenced the sustainability of mangrove vegetation, especially in the hyper-arid, hyper-saline Red Sea coastal waters of Saudi Arabia. The present study investigates the effect of effluents released from an adjoining shrimp farm on the sustainability of a nearby mangrove woodland during operation and after closure of the farm. In addition, the consequences of dredging activities to fill coastal waters for land reclamation to develop a mega seaport at Jazan Economic City are explored. A band image-difference algorithm was applied to Landsat 5 Thematic Mapper and Landsat 08 Operational Land Imager satellite images obtained on different dates, which revealed a prominent vigour boom in the mangrove forest while the shrimp farm operated but a gradual decrease in vigour after its closure. During the investigation time frame of 2016 and 2017, spectral vegetation analysis of Sentinel-2A satellite images highlighted a strong negative correlation between dredging operations for seaport construction and the adjacent fragile mangrove forest. Dredging operations were responsible for a reduction of 19.30% in the Normalized Difference Vegetation Index, 27.5% in the Leaf Area Index, and 19.0% in the Optimized Soil Adjusted Vegetation Index. The results clearly show the potential application of spectral vegetation indices in the monitoring and analysis of anthropogenic impacts on coastal vegetation. We suggest strong management efforts for monitoring, assessing, and regulating measures to offset the negative trends in the sustainability of mangroves in Red Sea coastal regions.

Species composition of the orb-weaving families Araneidae and Tetragnathidae (Araneae: Araneoidea) in natural habitats in Trinidad, West Indies

ABSTRACTThe biodiversity of some spider groups in the neotropics is poorly documented. The species composition of two orb-weaving spider families, Araneidae and Tetragnathidae in 16 natural habitats was examined. Specimens were collected using visual search and sweep-netting methods. Very few species were found to be abundant in natural habitats while some were common and the majority considered rare. There was also little overlap of species among the localities sampled in each habitat type; overlap ranged from one to three species. Species abundance models showed that natural habitats followed a log series model, indicating that they are characterised by low species richness, the presence of few dominant species, and governed by a single factor. Multi-dimensional scaling analysis showed that four habitats (savanna, mangrove woodland, littoral woodland, and herbaceous swamp) possessed distinct species assemblages. However, the savanna habitat was the most dissimilar, probably due to a greater presence of specialist species.

Storm protection services

Coastal Protection![Figure][1] Coastal mangrove forests near Krabi, Thailand PHOTO: CRYSTITE RF/ALAMY STOCK PHOTO The tropics are at increasing risk of storm damage as the climate warms—a major worry, as coasts also concentrate human populations. Many coastlines in the tropics are, or once were, bordered by mangrove woodland. Mangroves colonize and stabilize the intertidal zone, not only providing habitats for terrestrial and marine organisms but also buffering storm surges, winds, and saline intrusion. However, these forests are at risk owing to land reclamation for building, agriculture, and other economic activities. Hochard et al. calculated the global value of mangroves in protecting human activities against tropical cyclone damage. From 23 mangrove-fringed countries, they observed human activity by satellite mapping of nighttime light. Regions with narrow (6-meter) strips of mangrove suffer greater permanent economic loss over the next 6 years than do communities protected by 25 meters of mangroves or more, despite disaster-mitigation responses. This work underscores the importance of restoring natural infrastructure for the benefit of vulnerable communities, as well as biodiversity. Proc. Natl. Acad. Sci. U.S.A. 116 , 12232 (2019). [1]: pending:yes

Ninety years of change on a low wooded island, Great Barrier Reef.

We assess 90 years of change on a Low Wooded Island (Low Isles, Great Barrier Reef), employing drones and topographic profiling to accurately survey ramparts, mangroves, the reef flat and the sand cay. A comparison with maps from the 1928–1929 Great Barrier Reef Expedition revealed the redistribution of an outer rampart and inward movement of shingle ridges. Remarkable lateral expansion of the mangrove woodland some 400 m has occurred as carbonate sand deposition has increased reef flat elevation, obscuring coral microatolls. The sand cay has stayed relatively constant in size, moving approximately 44 m in a northeasterly direction and rotating slightly. We conclude that the existing configuration of landforms probably represents an equilibrium with local biophysical conditions, including sea level, wave dynamics, vegetation growth, storms and cyclones. The variable nature of ramparts and the presence of a trough that prevents the continuous spread of mangroves across a uniformly flat colonization surface precludes the interpretation of landform changes with respect to a geomorphic evolutionary sequence. Moreover, longer-term implications of environmental change for these landforms can only be evaluated once the specific nature of the local carbonate budget, including the relative contribution of corals, foraminifera and Halimeda has been elucidated.

Oil spill in Botany Bay: short term effects and long term implications.

Botany Bay supports wetlands along its southern shores which include about 190 hectares of mangrove woodland, 180 hectares of saltmarch and 88 hectares of freshwater wetlands (State Pollution Control Commission, 1979). These wetlands were formerly more extensive but large scale clearance has occurred since European settlement, and urban and industrial development since 1950 has resulted in the loss of 4 hectares of mangroves and 218 hectares of saltmarsh and freshwater wetlands. The remaining wetland complex is regarded as one of the most important in New South Wales (Australian Littoral Society, 1977). Since 1978 there has been no significant loss of wetlands to development, however, about 5 hectares (two percent) of the remaining mangroves have been lost in die-back following oil spills in 1979 and 1981 (Allaway et al., 1985). A major oil refinery operates at Kurnell (Australian Oil Refining Pty Ltd – A. O. R.) and is supplied with crude oil by pipelines connected to an oil transfer terminal off Kurnell (Fig. 1). The Kurnell terminal comprises a seven-point mooring which holds tankers in a fixed position while oil is transferred to shore via a submerged pipeline. Submerged crude oil and refined product pipelines also traverse the Bay to facilitate the exchange of product between the refinery and other installations on the northern shore.

Estimation of Taylor's Power Law parameters a and b for tidal marsh macrobenthic species.

In the Cananeia region of southeastern Brazil, Spartina alterniflora marshes colonize tidal flatsfringing mangrove woodlands and displaying a zonation typical of monocultures. The pattern observed can be explained by the combined effects of organism resistance to emersion and physical dependence on the plants as habitat. In this context, it is interesting to quantify the aggregation index for the dominant species associated with the salt marsh. A tool which enables us to do it is Taylor´s power law, which combines the mean and the variance distributions of species in a known area. From August 1988 to January 1989, tenrandom samples were taken monthly from the lower and upper marshes using a 20 cm diameter corer (0.03 m2) at a depth of 10 cm. The five most representative species of the system were selected for further analysis, and for each of these, Taylor´s power law parameters were calculated. Epifaunal species present aggregation indexes approaching randomness. The aggregation indexes for the infaunal species were observed to have consistently high values even in clearly different conditions of population density and availability of organic matter. The smaller number of infauna forms in the lower marsh as compared to the upper marsh does not point to a competitive disadvantage since there is no alteration in b values. For the infauna species only, the value of a shows a sharp decrease from the lower to the upper marsh.

Mangroves as an agent of rapid coastal change in a tidal-dominated environment, Gulf St Vincent, South Australia: implications for coastal management

The northeastern shore of Gulf St Vincent, South Australia is a mesotidal, low-wave-energy coastline, characterised by tidal-dominated bioclastic carbonate sedimentation. Distinctive assemblages of subtidal, intertidal and supratidal marine plants and invertebrate animals have resulted in well defined, adjacent bio- and litho-facies that lie parallel to each other across broad areas of coastal sedimentation. At Port Gawler, the intertidal zone is bounded by a landward high-tide beach and a subtidal Posidonia australis seagrass meadow seaward. Thirty years ago, within the immediate study area, this intertidal zone comprised an inner sandflat and an outer muddy seagrass meadow dominated by Zostera muelleri, the two areas separated by a shallow tidal distributary. Avicennia marina is a species of mangrove that has colonised much of the protected, tidal-dominated coasts of South Australia. Propagules of this tree readily take root in intertidal mud, with a natural ecological succession of Z. muelleri followed by A. marina. Over the time of observation, juvenile mangroves have progressively colonised a narrow zone along the landward side of the muddy seagrass meadow; they appear unable to colonise a sandy substrate. Juveniles advanced rapidly southward from mature woodland in the north towards equally mature woodland in the south. From the initial tap root, juvenile plants send out radial roots from which project, snorkel-like, an array of vertical pneumatophores. Redistributed algal, seagrass and other organic flotsam collect around these vertically protruding pneumatophores, promoting accumulation of organic sediment. Within the newly forming mangrove woodland, there has been pronounced sediment aggradation of >0.5 m, greatly altering the dynamics of tidal flow. Tidal flow is now largely constrained to a channel between the mature southern woodland and that formed most recently. Higher velocity flows through this channel have exhumed populations of infaunal bivalves, and floodtide and ebbtide deltas of coarse bioclastic sediments are a consequence. The aggraded sediment of the new woodland shelters the area landward. Consequently, more muddy sediments are now covering what was formerly bare sandflat, thus providing new areas for mangrove colonisation. Migration of mangroves towards the high-tide beach is inevitable and will be limited only by their need for regular flushing of accumulated salt from their roots by seawater at high tide. Thus, A. marina drives rapid geomorphic change in the tidal-dominated coasts of the South Australian gulfs. In similar coastal areas of southeast Asia, where intertidal muddy sediments predominate, this species appears to be an ideal candidate for reforestation projects. Juvenile plants should grow successfully and rapidly, so preparing coastal environments for the establishment of more ecologically diverse mangrove communities.

Vegetation and vascular flora of Faure Island, Shark Bay, Western Australia

The vegetation and flora of Faure Island, the second largest island in the Shark Bay World Heritage Site, is documented. The island has five major plant communities (Acacia shrublands, Mallee shrublands, Spinifex grasslands, Samphire and Atriplex shrublands and Mangrove woodlands) of which the Mallee shrublands and Mangrove woodlands are rarely recorded on offshore islands. A vascular flora of 163 species was recorded consisting of 142 native and 21 naturalized aliens.

Habitat preferences of tigers Panthera tigris in the Sundarbans East Wildlife Sanctuary, Bangladesh, and management recommendations

AbstractWe examined the habitat preferences of tigers Panthera tigris in four habitat types in the Sundarbans East Wildlife Sanctuary, Bangladesh. Transect sampling was used to count tiger signs. Mean densities of signs of feeding, resting, defaecation and interaction were significantly different between the four main habitat types (mangrove woodlands, grasslands, sea beaches and transitional areas), whereas movement, scratch-scent-urinal and other signs were not significantly different. This indicates that tigers have habitat preferences for at least some activities. Similar patterns were found in the densities of movement and feeding signs, as well as of resting and defaecation signs, across the four different habitat types. Tigers were found to use soft-barked trees for scratching more often than other types.

Foraminiferal biofacies eco-succession and Holocene sealevels, Port Pirie, South Australia

At Port Pirie, on the eastern coast of Northern Spencer Gulf, South Australia, 10 cores taken along a 3 km transect recovered a succession of Holocene marine sediments. Facies representing shallow subtidal Posidonia seagrass and intertidal sandflat, mangrove and back-storm ridge coastal lagoon environments are recognized on the basis of lithological characteristics and their preserved foraminifera. An assemblage dominated by Nubecularia lucifuga, Peneroplis planatus and Discorbis dimidiatus signifies sediments of shallow subtidal Posidonia seagrass meadows. Subtle changes in the numerical distribution of these species upcore are used to infer the change from subtidal to intertidal sandflat facies; Elphidium crispum and Elphidium macelliforme become more numerous across this transition. The mangrove facies is characterized by Trochammina inflata. This species is present significantly in only one seaward core where modern mangrove woodland continues to grow today and no equivalent biofacies are recognized in other cores. The lagoonal sediments preserve a rich assemblage of species of euryhaline foraminifera. Together with those of the mangrove woodland, they exhibit an ecological succession which can be related to decreasing intervals of tidal inundation and increasing salinity. Helenina anderseni, with subordinate Ammonia beccarii, and Elphidium cf. articulatum are the pioneer species in the euryhaline setting, giving way to Trichohyalus tropicus and Miliolinella schauinslandi. Late stages of hypersaline sedimentation are characterized by Triloculina inflata+ Triloculina oblonga. In the mangroves, H. anderseni, A. beccarii and Elphidium cf. articulatum are replaced by Trochammina inflata as the dominant species. In turn, as further sediment aggradation leads to ever shorter intervals of tidal inundation at the landward side of the mangrove woodland, Trochammina inflata is overtaken by Ammobaculites barwonensis. Quantitative foraminiferal biofacies analysis confirms and refines the sedimentological interpretation of intertidal sediment facies from macro-observations of the core materials. It provides independent estimates of the elevation of key facies boundaries in cores and confirmation of a general relative fall in sealevel in Northern Spencer Gulf over the past 7000 yr.

Concentrations and spatial distribution of trace metals in mangrove sediments from the Brisbane River, Australia

Fifty surface sediment samples were collected from 12 transects through a mangrove woodland near the mouth of the Brisbane River, Australia. Samples were analyzed for 10 trace metals; measured concentrations (μg g −1) were: Cu 3·1–34·1; Pb 7·7–84·7; Zn 40·8–144·0; Ag nd-2·8; Cr 7·6–116·8; V 16·4–57·9; Mo 7·6–82·6; Ni 2·4–57·6; As nd-13·0; and Cd nd-2·0. Coefficients of variation ranged from 22–153%. Sediments were moderately contaminated, with Mo being enriched by up to thirty times background levels. Spatial variation was considerable, and canonical trend analysis showed concentrations of all metals but Ag and Cr tended to increase downshore, suggesting tidal deposition was important in determining metal concentrations. Silver and Cr concentrations appeared to be a consequence of contamination from landward point sources. An investigation of different random sampling intensities showed the spatial variation required that many samples be taken for a satisfactory assessment of metal burdens. Even so, mean values were not a good indication of the possible environmental effects of the metal contamination. Since metal concentrations increase downshore in inter-tidal environments, a more appropriate sampling strategy would be to take a downshore series of samples normal to the shoreline.

Land subsidence and sea level rise in the Port Adelaide estuary: Implications for monitoring the greenhouse effect

The historic tide gauge records from Port Adelaide and Outer Harbour are one of the more important datasets from the Australian region purporting to show a significant rate of local sea level rise. However, geological evidence including radiocarbon dated palaeosea level indicators, indicates that most of this rise is due to subsidence of the land. The subsidence is significant but localized, and can be largely attributed to human activities associated with port development, reclamation and industrialization. Two principal contributing factors are reclamation of Holocene wetlands and groundwater extraction from deeper Tertiary aquifers. Wetland reclamation has caused surficial soil compaction as a result of artificial lowering of the water table, oxidation of peat and pyrite, and leaching of the substrate by soil acidification. Surficial subsidence at rates of up to 10 mm/year has occurred in reclaimed mangrove woodlands as a result of these processes. Extraction of groundwater from deeper aquifers over the past 50 years has created a potentiometric cone of depression in excess of 20 m beneath the Port Adelaide estuary. Land subsidence estimated at 2.8 mm/year is associated with the central zone of depressed groundwater levels. The tide gauge data from Port Adelaide and Outer Harbour have been used in global sea level rise calculations without adequate local neotectonic correction. Although outside the zone of greatest land subsidence, three‐quarters of the secular rise in mean sea level of 2.5–2.9 mm/year indicated by the tide gauge records can be attributed to land level changes. Hence the local sea level trend is a rise of ∼0.7 mm/year. As many of the world's historic tide gauge sites are expected to be affected by similar anthropogenic effects, it is imperative that local neotectonic corrections be applied to all tide gauge data before drawing any conclusions regarding global or local eustatic sea level change.

Biomass of the mangrove Avicennia marina (Forsk.) Vierh. Near Brisbane, South-eastern Queensland

Above- and below-ground biomass of A. marina were estimated on three plots with different vegetation characteristics in a subtropical mangrove woodland at Boggy Creek near Brisbane. Total photosynthetic and non-photosynthetic above-ground biomasses of mangroves in the plots were 16.2, 34.1 and 11.0 kg m-2, below-ground plus pneumatophore biomasses were 10.9, 12.1 and 12.6 kg m-2. Although the study site is in an industrialized, moderately polluted estuary, the biomass of Avicennia here is similar to that of Avicennia communities elsewhere.

The Holocene non-tropical coastal and shelf carbonate province of southern Australia

Carbonate-dominant sediments are currently forming and accumulating over the extensive marine shelf of the passive margin of southern Australia. A dearth of continental detritus results from both a very low relief and a predominantly arid climate. The wide continental shelf is bathed by cold upwelling ocean waters that support luxuriant growths of bryozoans and coralline algae, together with sponges, molluscs, asteroids, benthic and some planktonic foraminifera. The open ocean coast is battered by a persistent southwest swell, resulting in erosion of calcrete-encrusted Pleistocene eolianites. Much sediment is reworked and overall shelf sedimentation rates are low. High-energy microtidal beach/dune systems occur between headlands and along the very long ocean beach in the Coorong region. The northern, more arid coastal areas also contain saline lakes that precipitate gypsum from infiltrated sea water, and display marginal facies of aragonite boxwork to fenestral carbonate crusts, with stromatolites and tepee structures. In contrast, the southern, seasonally humid Coorong region, has a predominantly continental groundwater regime where sulphate is rare, and the high summer evaporation precipitates dolomite, magnesite and aragonite muds. Fenestral crusts, breccias, tepees and some stromatolites are also present. St. Vincent and Spencer gulfs both afford some protection from ocean swell, but tidal amplitude and currents increase, and a depth and inundation-related zonation of plants and animals is established. Muddy carbonate sand accumulates on the sea floor below 30 m, where filter-feeding bryozoans, bivalves and sponges dominate. In shallower regions, seagrass meadows contain a rich fauna that results in rapid accumulation of an unsorted muddy bioclastic sand. Mangrove woodlands backed by saline marsh with cyanobacterial mats are common, and accumulate mud-rich and gastropod-bearing sediment. As tidal amplitude and desiccation increase northward into both gulfs, a supratidal zone bare of vegetation (sabkha) becomes the site for deposition of gypsum-rich and fenestral calcitic mud.

Litter Fall and Decompostion in a Mangrove Stand, Avicennia marina (Forsk.) Vierh., in Middle Harbour, Sydney

Leaf and other litter falling in a mangrove woodland was estimated by litter trapping for 13 months. Mean annual litter fall was 5.8 t ha-1 year-1 (dry matter) of which 79% was leaf material. Largest fortnightly collections of litter were found in the summer months, and little litter fell in winter. Data suggested that mangrove litter is rapidly incorporated into the rest of the estuarine ecosystem: the leaf litter layer in the swamp was estimated on two occasions (about 9 g m-2 in winter and about 62 g m-2 in summer, dry leaf material) and a litter-bag experiment gave a leaf decomposition half- time of about 8 weeks.