Coastal Vegetation Research Articles

Carbon Cycling in Mangrove Ecosystem of Western Bay of Bengal (India)

Carbon cycling in the mangrove ecosystem is one of the important processes determining the potential of coastal vegetation (mangroves), sediment, and adjoining waters to carbon absorption. This paper investigates the carbon storage capacity of five dominant mangrove species (Avicenia marina, Avicenia officinalis, Excoecaria agallocha, Rhizophora mucronata, and Xylocarpous granatum) on the east coast of the Indian mangrove along with the role they play in the carbon cycling phenomenon. Soil and water parameters were analyzed simultaneously with Above Ground Biomass (AGB) and Above Ground Carbon (AGC) values for 10 selected stations along. The total carbon (TC) calculated from the study area varied from 51.35 ± 6.77 to 322.47 ± 110.79 tons per hectare with a mean total carbon of 117.89 ± 28.90 and 432.64 ± 106.05 tons of carbon dioxide equivalent (CO2e). The alarm of the Intergovernmental Panel on Climate Change for reducing carbon emissions has been addressed by calculating the amount of carbon stored in biotic (mangroves) and abiotic (soil and water) compartments. This paper focuses on the technical investigations on the factors that control the carbon cycling process in mangroves. This blue carbon will help policymakers to develop a sustainable relationship between marine resource management and coastal inhabitants so that carbon trading markets can be developed, and the ecosystem is balanced.

Recent Carbon Storage and Burial Exceed Historic Rates in the San Juan Bay Estuary Peri-Urban Mangrove Forests (Puerto Rico, United States).

Mangroves sequester significant quantities of organic carbon (C) because of high rates of burial in the soil and storage in biomass. We estimated mangrove forest C storage and accumulation rates in aboveground and belowground components among five sites along an urbanization gradient in the San Juan Bay Estuary, Puerto Rico. Sites included the highly urbanized and clogged Caño Martin Peña in the western half of the estuary, a series of lagoons in the center of the estuary, and a tropical forest reserve (Piñones) in the easternmost part. Radiometrically dated cores were used to determine sediment accretion and soil C storage and burial rates. Measurements of tree dendrometers coupled with allometric equations were used to estimate aboveground biomass. Estuary-wide mangrove forest C storage and accumulation rates were estimated using interpolation methods and coastal vegetation cover data. In recent decades (1970–2016), the highly urbanized Martin Peña East (MPE) site with low flushing had the highest C storage and burial rates among sites. The MPE soil carbon burial rate was over twice as great as global estimates. Mangrove forest C burial rates in recent decades were significantly greater than historic decades (1930–1970) at Cañno Martin Peña and Piñones. Although MPE and Piñones had similarly low flushing, the landscape settings (clogged canal vs forest reserve) and urbanization (high vs low) were different. Apparently, not only urbanization, but site-specific flushing patterns, landscape setting, and soil fertility affected soil C storage and burial rates. There was no difference in C burial rates between historic and recent decades at the San José and La Torrecilla lagoons. Mangrove forests had soil C burial rates ranging from 88 g m−2 y−1 at the San José lagoon to 469 g m−2 y−1 at the MPE in recent decades. Watershed anthropogenic CO2 emissions (1.56 million Mg C y−1) far exceeded the annual mangrove forest C storage rates (aboveground biomass plus soils: 17,713 Mg C y−1). A combination of maintaining healthy mangrove forests and reducing anthropogenic emissions might be necessary to mitigate greenhouse gas emissions in urban, tropical areas.

Conservation management rules for reconstructing Moluccan Scrubfowl (Eulipoa wallacei) egg-laying habitats

Abstract This research focused on the efforts of indigenous people invested into the reconstruction of damaged Moluccan Scrubfowl (Eulipoa wallacei) egg-laying habitats, as well as, on the ways how the current conditions of the landscapes are conserved by indigenous people. This is a qualitative and quantitative study that used a combination of observation and interview methods. We also used descriptive analysis and spatial analysis including remote sensing techniques. The results showed that the abrasion process that destroyed the Moluccan Scrubfowl egg-laying habitat left a remaining sandbar with an area of 1,161 m2, or about 17% of the area of the initial sandbar. Even though the habitat has not fully recovered, Moluccan Scrubfowls still lay their eggs there. The details of the reconstruction activities carried out by indigenous people are as follows: making embankments, adding sand to the eroded area, replanting supporting coastal vegetation, and making breeding sites. In addition, efforts were also made to restore the surrounding support areas that were also damaged. The activities carried out were as follows: replantation of coral reefs, turtle breeding, nurseries and mangrove planting, nurseries of other plant species such as cloves and nutmegs, picking up trash along the coast, and early education for children in how to be environmentally conscious.

SAGA GIS for Computing Multispectral Vegetation Indices by Landsat TM for Mapping Vegetation Greenness

Summary The study presents a comparative analysis of eight Vegetation Indices (VIs) used to examine vegetation greenness over the northern coasts of Iceland. The geographical extent of the study area is set by the coordinates of the two fjords, Eyjafjörður and Skagafjörður, notable for their agricultural significance. Vegetation in Iceland is fragile due to the harsh climate, climate change, overgrazing and volcanic activity, which increase soil erosion. The study was conducted on a Landsat TM image using SAGA GIS as a technical tool for raster bands calculations. The NDVI dataset shows a range from -0.56 to 0.24, with 0 indicating ‘no vegetation’, and negative values – ‘other surfaces’ (e.g. rocks, open terrain). The DVI, compared to the NDVI, shows statistically non-normalized values ranging from -112 to 0, with extreme negative values while the coastal vegetation areas are badly distinguished from the water areas. The NRVI shows an extent from -0.24 to 0.48 with higher values for vegetation. The NRVI reduces topographic, solar and atmospheric effects and creates a normal data distribution. RVI shows a range in a dataset from 0.2 to 3.2 with vegetation in the river valleys clearly visible and depicted, while the water areas have values 0.8 to 1.0. The CTVI shows corrected TVI, in a data range -0.10 to 1.10, as the dataset of NDVI were negative. The TVI dataset ranges from 0.44 to 0.80 with the ice-covered areas and glaciers distinguishable and water values within a range from 0.60 to 0.64 and the vegetation from 0.60 to 0.44. The TTVI dataset ranges from 0.40 to 0.80 performing similarly to the TVI, but more refined with vegetation values 0.64 to 0.68. SAVI dataset ranges from -0.80 to 0.30 with minimized effects of soil on the vegetation through a constant soil adjustment factor added into the NDVI formula. The paper presents a comparison of eight VIs for Arctic vegetation monitoring. The overall behavior of SAGA GIS in calculation and mapping of the VIs is effective in terms of their use for vegetation mapping of the region.

The role of schools as an opportunity for transmission of local knowledge about useful Restinga plants: experiences in southeastern Brazil

BackgroundThe study of cultural transmission can help identify processes that influence knowledge systems dynamics and evolution, especially during childhood and youth, which are fundamental phases in acquiring survival skills. In this sense, we use the knowledge about useful restinga plants (Brazilian coastal vegetation) as an analytical model to describe, compare, and analyze cultural transmission during youth, while factoring in origin, in the Cabo Frio region, southeastern Brazil. We tested (1) whether transmission of knowledge is conservative, (2) whether immigration events define the transmission modes, (3) whether teaching is the most important social transmission cognitive process, and (4) which type of stimulus/context is most important for the knowledge transmission process.MethodsQuestionnaires and free listings were applied to 150 high school students aged between 15 and 20 to obtain information about socioeconomic characteristics, useful plant knowledge, and cultural transmission. We analyzed the distribution of knowledge according to the informant’s origin and evaluated the models, processes, and context with which this information was transmitted. The chi-square test was used to determine the association between origin, plant knowledge, and transmission as well as to reveal the most important models, modes, and processes during youth.ResultsInformants provided 299 plant citations ( overline{x} = 1.75; s = 1.73) related to 37 species. The categories of the most cited uses were edible (93) and medicinal (32). Statistical results showed that origin did not influence knowledge distribution and transmission. In addition, although the most relevant mode was the conservative (vertical) one, the one-to-many diffuse mode (teacher) was highlighted. The new environmental context for immigrants did not influence transmission, the main transmission process was teaching, and the learning contexts were predominantly school-related.ConclusionPlant knowledge in youth was related to local edible and medicinal plants, indicating adaptive knowledge linked to material demands for survival. While the initial models for cultural transmission are family (vertical), during the development phase of juveniles, other actors become models (one-to-many). In addition, the nature of the information (survival demand) and age are more relevant to cultural transmission than the socio-environmental context.

Object-based spectral-phenological features for mapping invasive Spartina alterniflora

Spartina alterniflora (S. alterniflora), a prevailing invasive species in the coastal zones, has resulted in significant ecosystem degradation and economic losses since its introduction to China in 1979. Among the existing studies that incorporate remote sensing to map S. alterniflora, the pixel-based phenological feature composite method (Ppf-CM) has proved to be successful due to its merits to overcome cloud contamination while exaggerating the spectral separability between S. alterniflora and its co-dominant native species. However, one major limitation of the Ppf-CM method is that it extracts phenological features from a single-pixel without accounting for its surrounding geospatial information that proved essential for more accurate mapping. In this study, we aim to ameliorate this problem by incorporating geometric, texture, and contextual information. To this end, we developed a new object-based phenological feature composite method (OPpf-CM). Specifically, we first generated a composite image by stacking two images that were respectively acquired during the distinctive phenological periods of S. alterniflora. Then we derived spectrally homogenous objects on the composite image through an unsupervised multiscale segmentation method. Various features derived from objects served as the input of support vector machine (SVM) classifier to produce a S. alterniflora map. To evaluate the performance of OPpf-CM, we carried out a comparison of classification performance between our developed OPpf-CM method and the previously developed Ppf-CM one (Tian et al., 2020) with the aid of visual interpretation and accuracy statistics (i.e. confusion matrix). The results showed that OPpf-CM achieved a higher overall accuracy (98%) than Ppf-CM (96.67%) when validated with the ground reference data that was visually interpreted by the high spatial resolution imagery and field survey. Meanwhile, the identification of fragmented S. alterniflora patches along with mixed-cover areas can be significantly improved with the OPpf-CM method. We envision that the developed object-based spectral-phenological feature has the potential to be applied to mapping a wide spectrum of coastal vegetations.

Combining gray and green infrastructure to improve coastal resilience: lessons learnt from hybrid flood defenses

ABSTRACT Shoreline erosion and storm tide inundation increasingly threaten coastal populations, infrastructure and economies. Hard infrastructure, known as gray infrastructure (e.g. concrete seawalls), has commonly been used to protect coastal communities but is expensive to build, maintain, and deteriorates coastal vegetation. Green infrastructure (e.g. restored or conserved mangrove and marsh ecosystems) delivers nature-based coastal protection but in comparatively lower density coastal areas. Nowadays a more popularized approach to coastal protection is hybrid eco-engineering. In this study, we discuss lessons-learnt on how the hybridization of engineered structures and wetland restoration practices compared with traditional gray and green approaches. We contrast hybrid applications in mangrove and tidal marsh areas in the UK and south-east Asia. The majority (70%) of successful hybrid infrastructure cases were underpinned by understanding of ecological and hydrological changes in response to infrastructure and involved a wide range of stakeholders. In terms of construction and maintenance cost, limited data suggested that hybrid infrastructure may be more cost effective than gray infrastructure, but more expensive than green; however, data were very limited and therefore we suggest the need for further cost-benefit analyses to inform a robust comparison. Development of new technologies should see growing efficacy of future hybrid infrastructure in mitigating coastal flood risks.

Estimation of Communities and Tourists Willingness to Pay for Tsunami Disaster Mitigation of Marine Tourism in the Kalianda Coastal Area, South Lampung Regency

Indonesia coastal areas have considerable natural disaster potential including in Kalianda District South Lampung Regency. Natural disasters such as earthquakes, tsunamis and volcanic activity are likely to occur in coastal areas. The disaster has an impact on economic losses in the marine tourism area. In order to mitigate tsunami disasters in the marine tourism area of Kalianda District, South Lampung Regency, 3 (three) types of tsunami mitigation are needed, namely: construction of coastal protection, installation of the Tsunami Early Warning System (TEWS) and planting of coastal vegetation. This study aims to determine the value of willingness to pay (WTP) of community and tourists in supporting the management of the three types of tsunami disaster mitigation above by using economic valuation / Contingent Valuation Method (CVM). The results of this study indicate that the WTP value of community for coastal protection management is Rp 15.547/person/month while the WTP value of tourist is Rp 12.030/one time entry. Meanwhile, for the WTP value of TEWS management is obtained Rp 12.174/person/month. WTP value for the management of coastal vegetation is Rp 12.444/person/month. The WTP calculation is based on consideration of 3 (three) factors, namely age, income, livelyhood and education level. This research shows that the community and tourists are willing to pay for the management of the three types of tsunami disaster mitigation through BUMDes and entrance fees for marine tourism area. The three types of tsunami disaster mitigation can protect, provide security and calm to the community and tourists in the marine tourism area of Kalianda District, South Lampung Regency from future tsunami.

Coupling Scirpus recruitment with Spartina control guarantees recolonization of native sedges in coastal wetlands

Recruiting native coastal vegetation and preventing the reinvasion of exotic Spartina alterniflora is a major challenge in China, due to harsh tidal environment for vegetation establishment and rapid Spartina colonization. This paper first reviewed the revegetation course of native Scirpus mariqueter in a coastal wetland in the Yangtze Estuary, where the adjacent Spartina was effectively eliminated. From 2014 to 2019, the area of planted Scirpus increased by 26.7 times, and the plant density and biomass growth amounted to the levels of mature sedge community. The establishment of Scirpus promoted the sedimentary accretion with an annual sedimentary rate of 9.2 cm yr−1, which was significantly higher than that in the mudflat. Six years of monitoring revealed that the revegetation approach with belowground propagules (corms) was effective for Scirpus establishment under strong hydrodynamic disturbances in the tidal mudflat because the morphology and germination rate of corms benefited the anchoring function of seedlings. Both recruited Scirpus and the original community expanded constantly due to positive feedback between plant progradation and sedimentary accretion. Then, we implemented a model simulation under the scenario of Spartina retention. The prediction showed that the high-speed invasion of Spartina would colonize and replace the whole Scirpus community in the study area during the period of 2014–2019. Hence, our results highlighted the importance of coupling Scirpus recruitment with Spartina eradication in guaranteeing recolonization of native coastal sedges. As a long-lasting management strategy, unremitting field monitoring and assistant decision-making tools (such as the forecasting models) on Spartina reinvasion risk are highly suggested for preserving the restoration of native marshes.

Evaluation of environmental heterogeneity and its effect on arbuscular mycorrhizal interaction in coastal dunes

Background: Coastal dune scrub vegetation is established on a substrate that favors biodiversity, but this is currently restricted to small patches.
 Objective: To determine the status of the arbuscular mycorrhizal fungi (AMF) in this vegetation under different anthropogenic pressures and to propose actions addressing its conservation and restoration.
 Methods: Plant and fungal community was characterized through taxonomic identification of the AMF and determination of their percentage of viability, number of infective propagules (NIP) and percentage of mycorrhizal colonization. Three contrasting sites were identified in the Ría Lagartos Biosphere Reserve: C = Conserved, IPS = Intermediate perturbation by the salt industry and HPA = high perturbation of anthropogenic origin. In each site, fine roots were collected from 12 common species and compound soil samples were taken.
 Results and conclusions: Eight AMF species were identified, in IPS, the highest values were presented in terms of percentage of colonization 55.43 ± 6.5, NIP = 142.07 ± 91.2 and viability = 27.6 ± 15.21 % while, in HPA, a higher number of healthy spores were found 43.6 ± 11.5/50 g. Infective propagules are an indicator of a “healthy ecosystem” and were found at a higher proportion in the conserved site.

VEdge_Detector: automated coastal vegetation edge detection using a convolutional neural network

ABSTRACT Coastal communities, land covers, and intertidal habitats are vulnerable receptors of erosion, flooding or both in combination. This vulnerability is likely to increase with sea level rise and greater storminess over future decadal-scale time periods. The accurate, rapid, and wide-scale determination of shoreline position, and its migration, is therefore imperative for future coastal risk adaptation and management. This paper develops and applies an automated tool, VEdge_Detector, to extract the coastal vegetation line from high spatial resolution (Planet’s 3 to 5 m) remote-sensing imagery, training a very deep convolutional neural network (holistically nested edge detection), to predict sequential vegetation line locations on annual to decadal timescales. Red, green, and near-infrared (RG-NIR) was found to be the optimum image spectral band combination during neural network training and validation. The VEdge_Detector outputs were compared with vegetation lines derived from ground-referenced positional measurements and manually digitized aerial photographs, which were used to ascertain a mean distance error of <6 m (two image pixels) and >84% producer accuracy (P A) at six out of the seven sites. Extracting vegetation lines from Planet imagery of the rapidly retreating cliffed coastline at Covehithe, Suffolk, United Kingdom, has identified a landward retreat rate >3 m year−1 (2010–2020). Plausible vegetation lines were successfully retrieved from images in The Netherlands and Australia, which were not used to train the neural network, although significant areas of exposed rocky coastline proved to be less well recovered by VEdge_Detector. The method therefore promises the possibility of generalizing to estimate retreat of sandy coastlines from Planet imagery in otherwise data-poor areas, which lack ground-referenced measurements. Vegetation line outputs derived from VEdge_Detector are produced rapidly and efficiently compared to more traditional non-automated methods. These outputs also have the potential to inform upon a range of future coastal risk management decisions, incorporating future shoreline change.

Coastal Wetlands Exposure to Storm Surge and Waves in the Albemarle-Pamlico Estuarine System during Extreme Events

Coastal wetlands provide a series of ecosystem services, including flood risk reduction. However, the flood risk reduction from such a complex ecosystem is dependent on incoming extreme hurricane-driven hydrodynamic and wave conditions. This study develops a numerical modeling-based approach for investigating coastal wetlands exposure to storm surge and waves during hurricanes by combining maximum water depth (MWD) and significant wave height (MHs) model outputs with the National Wetland Inventory for the Albemarle-Pamlico Estuarine System. Results show that various hurricanes lead to similar bimodal and bidirectional spatiotemporal flood patterns as a function of the lagoon’s geometry and storm track, with most overland hydrodynamic extremes impacting western Pamlico Sound and the bayside-Outer Banks. Clear positive dependency between MWD and MHS were observed over most wetland classes, with significantly higher magnitudes over estuarine emergent vegetation. In contrast to MWD, sharp MHS attenuation was found as the water propagates inland, leading to high MWD but lower MHS eventually reaching palustrine woody vegetation hundreds of meters away from the coastline. Improved understanding of how storm surge dynamics move across the bays and through the different wetland types, demonstrates the importance of considering the bay-side flood impacts over the coastal vegetation. The spatially distributed MWD and MHS estimates, along with the temporal patterns identified through the use of the TMax, allow coastal managers and engineers to better understand where, when, and by how much, the estuarine APES wetlands are more likely to be exposed to high water depths and waves.

제주 올레길 생태문화자원 경관생태학적 해석기법 연구†

This study applied the theory of Landscape Ecology to representative resources of Jeju Olle-gil, which is a representative subject of walking tourism, to identify ecological characteristics and to establish a technique for landscape ecological analysis of Olle-gil resources. Jeju Olle Trail type based on the biotope type, major land use, vegetation status around Olle Trail and roads were divided into 12 types. Based on the type of ecological tourism resource classification, the Jeju Olle-gil walking tourism resource classification was divided into seven types of natural resources and seven types of humanities resources, and each resource was characterized by Geotope, Biotope, and Anthropopope, just like the landscape ecology system. Geotope resources are strong in landscape characteristics such as coast and beach, rocks, bedrocks, waterfalls, geology and Jusangjeolli Cliff, Oreum and craters, water resources, and landscape viewpoints. The Biotope resources showed strong ecological characteristics due to large tree and protected tree, Gotjawal, forest road and vegetation communities, biological habitat, vegetation landscape view point. Antropotope include Culture of Jeju Haenyeo and traditional culture, potting and lighthouses, experience facilities, temples and churches, military and beacon facilities, other historical and cultural facilities, and cultural landscape views. Jeju Olle Trail The representative resources for each type of Jeju Olle Trail are coastal, Oreum, Gotjawal, field and Stonewall Fencing farming land, Jeju Village and Stone wall of Jeju. In order to learn about the components and various functions of the resources representing the Olle Trail’s ecological culture, the landscape ecological technique was interpreted. Looking at the ecological and cultural characteristics of coastal, the coast includes black basalt rocks, coastal vegetation, coastal grasslands, coastal rock vegetation, winter migratory birds and Jeju haenyeo. Oreum is a unique volcanic topography, which includes circular and oval mountain bodies, oreum vegetation, crater wetlands, the origin and legend of the name of Oreum, the legend of the name of Oreum, the culture of grazing horses, the use of military purposes, the object of folk belief, and the view from the summit. Gotjawal features rocky bumps, unique microclimate formation, Gotjawal vegetation, geographical names, the culture of charcoal being baked in the past, and bizarre shapes of trees and vines. Field walls include the structure and shape of field walls, field cultivation crops, field wall habitats, Jeju agricultural culture, and field walls. The village includes a stone wall and roof structure built from basalt, a pavilion at the entrance of the village, a yard and garden inside the house, a view of the lives of local people, and an alleyway view. These resources have slowly changed with the long lives of humans, and are now unique to Jeju Island. By providing contents specialized for each type of Olle Trail, tourists who walk on Olle will be able to experience the Olle Trail in depth as they learn the story of the resources, and will be able to increase the sustainable use and satisfaction of Jeju Olle Trail users.

Ecological connectivity in fragmented agricultural landscapes and the importance of scattered trees and small patches

BackgroundFragmentation and habitat loss can restrict species movement and reduce connectivity, negatively impacting biodiversity. Characterising the overall connectivity of an area can inform better management of human modified landscapes. Contemporary connectivity modelling methods seldom incorporate fine-scale movement patterns associated with movement between fine-scaled structural connectivity elements such as scattered trees, roadside corridors and small patches of habitat. This study aims to characterise connectivity within the Karuah-Myall catchments, a typical woodland ecosystem that is fragmented by agriculture, using least-cost path analysis and a graph-theoretic approach; it focuses on how fine-scaled vegetation such as scattered trees support connectivity. We mapped scattered (and paddock) trees within this agricultural landscape where the main human modified land use was pasture. We modelled connectivity for a general representative woodland species using an interpatch dispersal distance and gap crossing threshold, and resistance from different land cover types. The gap crossing distance threshold was used to model movement between fine-scaled vegetation features. We compared the least-cost paths modelled with and without scattered trees.ResultsOur results show that by excluding scattered trees, least-cost paths across the cleared pasture landscape did not reflect the types of movement patterns typically observed from field studies, such as those associated with a foray-search strategy used by small and medium mammals and birds. The modelling also shows that the Karuah-Myall catchments are well connected and provide value to biodiversity beyond the catchment borders, by connecting coastal vegetation to the Great Eastern Ranges national wildlife corridor initiative.ConclusionConnectivity models that exclude fine-scale landscape features such as scattered trees and small, linear patches risk misrepresenting connectivity patterns. Models of regional-scale connectivity can be influenced by the presence or absence of even the smallest features, such as scattered trees.

Assembly of species’ climatic niches of coastal communities does not shift after invasion

AbstractQuestionDo invasions by invasive plant species with contrasting trait profiles (Arctotheca calendula, Carpobrotus spp., Conyza bonariensis, and Opuntia dillenii) change the climatic niche of coastal plant communities?LocationAtlantic coastal habitats in Huelva (Spain).MethodsWe identified the species composition of 216 paired (non‐invaded and invaded) 10 × 10 m plots along the coast. For each species, we calculated its climatic niche based on the two main axis of a PCA constructed with nine climatic variables. We defined the community ensemble niche by the union of the overall climate niches of co‐occurring species within a plot. We compared niche overlap metrics between non‐invaded and invaded paired communities.ResultsThere was an almost complete overlap in the community ensemble niches between non‐invaded and invaded plots for the four invaders. Plots invaded by Carpobrotus spp. presented the lowest niche stability and those invaded by A. calendula had the highest. Plots invaded by Carpobrotus spp. showed the highest values of niche unfilling and expansion. In contrast, plots invaded by O. dillenii exhibited the lowest niche unfilling. Species similarity between non‐invaded and invaded plots was on average 58%. The community ensemble niches differed depending on the invasive species and were related to differences in community species similarity between non‐invaded and invaded plots. Overall, there was a positive correlation between community species similarity and climatic niche stability, and a negative correlation between community difference in taxonomic richness and climatic niche stability.ConclusionsSpecies assemblages in coastal vegetation did not change their community ensemble climatic niches after invasion by plants with contrasted life forms. This pattern is likely the result of invasion which did not trigger major changes in species richness and composition, or alternatively, because the species that were locally displaced by invasion have been substituted by others with similar climatic requirements.

Reciprocal facilitation between annual plants and burrowing crabs: Implications for the restoration of degraded saltmarshes

Abstract Increasing evidence shows that facilitative interactions between species play an essential role in coastal wetland ecosystems. However, there is a lack of understanding of how such interactions can be used for restoration purposes in saltmarsh ecosystems. We therefore studied the mechanisms of reciprocal facilitative interactions between native annual plants, Suaeda salsa, and burrowing crabs, Helice tientsinensis, in a middle‐elevation saltmarsh (with generally high plant density and moderate tides) in the Yellow River Delta of China. We investigated the relationship between the densities of the plants and crab burrows in different seasons. Then, we tested whether and how saltmarsh plants and crabs indeed facilitate each other in a series of field and laboratory experiments. Finally, we applied the results by creating a field‐scale artificial approach for microtopographic modification to restore a degraded saltmarsh. We found that the density of plant seedlings in spring was positively correlated with the density of crab burrows in the previous autumn; moreover, the density of crab burrows was correlated with the density of plants in summer. The concave–convex surface microtopography created by crabs promoted seed retention and seedling establishment of saltmarsh plants in winter and spring. These plants in turn facilitated crabs by inhibiting predators, providing food and reducing physical stresses for crabs in summer and autumn. The experimental removal of saltmarsh plants decreased crab burrow density, while both transplanting and simulating plants in bare patches promoted crabs. The microtopographic modification, inspired by our new understanding of the interactions between saltmarsh plants and crabs, showed that these degraded saltmarsh ecosystems can be restored by a single ploughing intervention. Synthesis. Our results suggest a reciprocal facilitation between annual plants and burrowing crabs in a middle‐elevation saltmarsh ecosystem. This knowledge yielded new restoration options for degraded coastal saltmarshes through the one‐time ploughing initiation of microtopographic variation, which could promote the re‐establishment of ecosystem engineers and lead to the efficient recovery of pioneer coastal vegetation and associated fauna.

Flume Experiments on Flow Analysis and Energy Reduction through a Compound Tsunami Mitigation System with a Seaward Embankment and Landward Vegetation over a Mound

As a countermeasure against tsunami inundation, the present study conducted a series of laboratory experiments using a compound mitigation system in which a seaward embankment (E) followed by landward coastal vegetation (V) over a mound (M) (EMV) was investigated in supercritical flow conditions. The changes of flow around the mitigation system and energy reduction were clarified under varying conditions of mound height and vegetation density. Cases of an embankment followed by only a mound (EMNV) were also considered for comparison. Experimental results showed that three basic types of flow structures were observed within the mitigation system in EMV cases. A water cushion was created within the mitigation system mainly due to the combined effects of the mound and vegetation. It significantly reduced the maximum total energy in EMV cases by approximately 41–66%, whereas in EMNV cases, the maximum energy reduction was found to be 23–65%. Increments in both mound height and vegetation density increased the intensity of the water cushion within the mitigation system by offering more drag and reflecting the flow, and hence, significantly reduced the energy of the flow.

Concentration Effect of Leaf Extract from Kekara Laut (Canavalia Maritima Thou.) in inhibiting of Staphylococcus Epidermidis Bacteria with a Statistical Science Approach

Importantly to study the coastal vegetation from Kekara Laut (Canavalia maritima Thou.) to observe the antibacterial agents towards Staphylococcus epidermidis. The purpose of this study to examine the variation concentration effect of an ethanol leaf extract from Canavalia maritima Thou. in inhibiting the growth of S. epiderimidis bacteria. The leaf of Canavalia maritima Thou. was prepared using a physicochemical method to obtain ethanol extract, then varied in several concentrations, namely 5% w/v; 10% w/v; 15% w/v; and 20% w/v. Based on these results, we obtain the ethanol leaf extract can inhibit the growth of S. epidermidis with a concentration of 15% w/v for 24 hours having an inhibition zone of 17.17 mm. The statistical analysis test was very significantly different from all antibacterial tests, the value of F count was 682.1 with F table (3.48), at the level of α = 0.05 (3.48) and α = 0.01 (5.99), which indicates that H0 is rejected, but using the Variance method in the Newman-Keuls range approach shows that each concentration has a good inhibitory ability. The use of Canavalia maritima Thou. leaf extract in low concentrations can significantly inhibit bacterial growth (bacteriostatic).

Concentration Effect of Leaf Extract from Kekara Laut (Canavalia Maritima Thou.) in inhibiting of Staphylococcus Epidermidis Bacteria with a Statistical Science Approach

Importantly to study the coastal vegetation from Kekara Laut (Canavalia maritima Thou.) to observe the antibacterial agents towards Staphylococcus epidermidis. The purpose of this study to examine the variation concentration effect of an ethanol leaf extract from Canavalia maritima Thou. in inhibiting the growth of S. epiderimidis bacteria. The leaf of Canavalia maritima Thou. was prepared using a physicochemical method to obtain ethanol extract, then varied in several concentrations, namely 5% w/v; 10% w/v; 15% w/v; and 20% w/v. Based on these results, we obtain the ethanol leaf extract can inhibit the growth of S. epidermidis with a concentration of 15% w/v for 24 hours having an inhibition zone of 17.17 mm. The statistical analysis test was very significantly different from all antibacterial tests, the value of F count was 682.1 with F table (3.48), at the level of α = 0.05 (3.48) and α = 0.01 (5.99), which indicates that H0 is rejected, but using the Variance method in the Newman-Keuls range approach shows that each concentration has a good inhibitory ability. The use of Canavalia maritima Thou. leaf extract in low concentrations can significantly inhibit bacterial growth (bacteriostatic).

Study of Mangrove Forest Existing Condition using Remote Sensing Image in The Karawang Coast of 2018

ABSTRACTThe northern part of Karawang is a coastal area with mostly mud-sand substrates. This substrate tends to be unstable, so that naturally, this kind of sediment is supported by coastal vegetation that forms coastal ecosystems, such as mangroves; therefore, the importance of mangroves in Karawang coast is definite. Unfotunately the data regarding the condition of mangroves in Karawang Regency is quite insufficient. This information, especially about its existence, is needed as a database for further research and as basis to support government policies on coastal area management. The aim of this research is to provide information about the existence of mangrove in Karawang Regency. The method is by using Normalized Different Vegetation Index (NDVI) calculations on Landsat 8 2018 satellite imagery of Karawang to get the data that reveal the information. We have discovered that the existing of mangroves in Karawang Regency in 2018 is 305,14 Ha. Border coast that is vegetated is only 33.75 km of 77 km long coastline of Karawang. Only less than 5% of the total mangrove protected area in Karawang Regency is detected as mangrove from the total 9.055 Ha of the area.