Mangrove Restoration Programs Research Articles

Stuck in the mangrove mud: The risk of trace element exposure to shore crabs in restored urban mangroves

The restoration of mangroves in urban environments can increase the risk of contaminant exposure and subsequent health effects to resident biota, yet this risk is rarely considered in mangrove restoration programs. Here we assessed the influence of sediment chemistry on contaminant bioaccumulation in shore crabs from restored and natural mangroves in urban environments compared to a reference site. The concentrations of some trace elements were several-fold higher in the sediment and crab tissues of the urban restored site compared to the natural reference site (Cd = 6×, Co = 7×, Cr = 4×, Mn = 30×, and Ni = 18× greater in sediments, while Cd = 4×, Co = 2×, Cr = 2×, Mn = 6×, and Ni = 3× greater in crab tissues). NMR-based metabolomics on crabs revealed higher abundances of proline and glutamate at urban sites, which may be indicative of physiological stress from trace element contamination. Choice experiments were used to test habitat selectivity by crabs from each population, and showed that crabs avoided sediments from the contaminated urban sites. Our results suggest that restoring mangroves in contaminated environments could create ecological sinks, where animals take residence in the new habitat but are exposed to sediment-based contaminants, with potential implications for organism and population health.

Community Participation in Mangrove Conservation: the Evidence from Blang Sebel, Simeulue

Abstract Yayasan Konservasi Pesisir Indonesia (Yakopi) is one of the non-profit organizations that focuses on mangrove conservation in Indonesia. The mangrove restoration program that has been carried out by Yakopi for the Simeulue Regency Region, especially Blang Sebel Village, is planting mangroves covering 19.19 hectares. Therefore, other tools are needed to complement the planting program through mangrove zoning mapping and making village regulations for mangrove protection. This research approach is qualitative using the Participatory Rural Appraisal (PRA) method. The data collection techniques used are Focus Group Discussion (FGD), Participatory Mapping, and documentation with the data analysis technique used is descriptive analysis. The results of the study show that mangrove zoning mapping is applied with three zones, namely the utilization zone, buffer zone, and core zone. Based on community deliberation, an agreement was reached on village regulations No. 04 of 2023 for mangrove protection in Blang Sebel. Based on the results of the research, it is hoped that community-based mangrove management can take place in a sustainable manner to realize the balance of coastal ecosystems at local level and minimize the impact of climate change at global level.

Improving soil carbon estimates of Philippine mangroves using localized organic matter to organic carbon equations

BackgroundSoutheast Asian (SEA) mangroves are globally recognized as blue carbon hotspots. Methodologies that measure mangrove soil carbon stock (SCS) are either accurate but costly (i.e., elemental analyzers), or economical but less accurate (i.e., loss-on-ignition [LOI]). Most SEA countries estimate SCS by measuring soil organic matter (OM) through the LOI method then converting it into organic carbon (OC) using a conventional conversion equation (%Corg = 0.415 * % LOI + 2.89, R2 = 0.59, n = 78) developed from Palau mangroves. The local site conditions in Palau does not reflect the wide range of environmental settings and disturbances in the Philippines. Consequently, the conventional conversion equation possibly compounds the inaccuracies of converting OM to OC causing over- or under-estimated SCS. Here, we generated a localized OM-OC conversion equation and tested its accuracy in computing SCS against the conventional equation. The localized equation was generated by plotting % OC (from elemental analyzer) against the % OM (from LOI). The study was conducted in different mangrove stands (natural, restored, and mangrove-recolonized fishponds) in Oriental Mindoro and Sorsogon, Philippines from the West and North Philippine Sea biogeographic regions, respectively. The OM:OC ratios were also statistically tested based on (a) stand types, (b) among natural stands, and (c) across different ages of the restored and recolonized stands. Increasing the accuracy of OM-OC conversion equations will improve SCS estimates that will yield reasonable C emission reduction targets for the country’s commitments on Nationally Determined Contributions (NDC) under the Paris Agreement.ResultsThe localized conversion equation is %OC = 0.36 * % LOI + 2.40 (R2 = 0.67; n = 458). The SOM:OC ratios showed significant differences based on stand types (x2 = 19.24; P = 6.63 × 10–05), among natural stands (F = 23.22; p = 1.17 × 10–08), and among ages of restored (F = 5.14; P = 0.03) and recolonized stands (F = 3.4; P = 0.02). SCS estimates using the localized (5%) and stand-specific equations (7%) were similar with the values derived from an elemental analyzer. In contrast, the conventional equation overestimates SCS by 20%.ConclusionsThe calculated SCS improves as the conversion equation becomes more reflective of localized site conditions. Both localized and stand-specific conversion equations yielded more accurate SCS compared to the conventional equation. While our study explored only two out of the six marine biogeographic regions in the Philippines, we proved that having a localized conversion equation leads to improved SCS measurements. Using our proposed equations will make more realistic SCS targets (and therefore GHG reductions) in designing mangrove restoration programs to achieve the country’s NDC commitments.

Community perception toward mangrove restoration program in Kampung Nelayan Seberang, Medan

Indonesia has the largest mangrove forests in the world. However, Indonesia is also listed as the largest contributor to loss of the world's mangrove forests. Good mangroves will support the lives of coastal communities and vice versa. Mangrove forests in the area of Kampung Nelayan Seberang, Medan Belawan and its surroundings were also degraded. Therefore, degraded mangrove forests need to be restored through mangrove restoration activities with the involvement of the surrounding community. This community service activity through the Assisted Village Program will carry out mangrove restoration activities with the people of Kampung Nelayan Seberang. The success of restoration activities is determined by good understanding of the mangrove ecosystem and the commitment of the community to be involved in restoring it. The objective of this study was to identify understanding related to mangrove ecosystems and community perceptions of its restoration efforts. Collecting data was carried out by interviewing respondents who represented the population. Descriptive analysis is used to describe the socio-economic conditions, understanding and perceptions of the community regarding ecosystems and mangrove restoration. Generally, respondents understand the role of mangrove forests and agree that mangrove restoration must be done together. Amount of 53 - 83% of respondents agreed and understood that mangrove restoration is important for life and has an impact on income, social and cultural life. The results showed that 60 - 90% of respondents around the restoration area need a rehabilitation program and are willing to be involved in a mangrove restoration program with the parties.

Mangrove ecosystems as fundamental habitats for fish from the Mexican Caribbean: An evaluation between a conserved and restoration zone

Mangrove ecosystems can function as a habitat for many juvenile marine fish species, with provisions of food and refuge. Seemingly, these ecosystems have been extensively reduced due to anthropogenic activity, as is widespread land use and road construction along the coastline. Nonetheless, much needed restoration efforts have increased tremendously over time. This study analyzes fish community, and the manner in which habitats in the mangrove ecosystem are used, comparing two mangrove zones, a conserved zone (healthier state) and one undergoing restoration. Hydrologically, no significant differences were registered (KW p>0.05). Of the 24 species registered, marine species were dominant in the conserved zone and estuarine species dominant in the restoration zone. Juvenile fishes were more abundant in the conserved mangrove zone, with a higher proportion of adults found in the restoration zone. According to Hutcheson’s t test, fish diversity showed significant statistical differences between sites combined with distinct climatic seasons. The Canonical Correspondence Analysis (CCA) indicated a relationship between secondary freshwater species Floridichthys polyommus and Cyprinodon artifrons and greater salinity and temperature, whereas marine species had a higher relationship with well oxygenated sites. A high number of marine fish species in juvenile stage in the conserved area may relate to mangroves functioning as nurseries. This can serve as a useful indicator by managers taking an integral approach to evaluate and monitor present and future mangrove restoration programs and pathways.

Mangrove restoration in Vietnamese Mekong Delta during 2015-2020: Achievements and challenges

Mangrove forest in the Mekong Delta plays important roles in protecting coasts from soil erosion and strong waves, supplying seafood, and accumulating carbon. Despite these benefits, mangroves have been and continue to be severely damaged by the impacts of natural and socioeconomic activities. In recent years, large areas of mangrove forest have been restored through planting and other various management actions. In this study, we analyzed high-resolution WorldView-2 images to quantify changes in the mangrove forest in seven coastal provinces (Tien Giang, Ben Tre, Tra Vinh, Soc Trang, Bac Lieu, Ca Mau, and Kien Giang) of the Mekong Delta from 2015 to 2020. Our study is one of the first to analyze mangrove forest change at the commune scale, the smallest official administrative unit in Vietnam, to determine the area of restored mangroves. The potentials and challenges in future mangrove restoration were also assessed by analyzing satellite imagery and field survey data. In the study area, mangrove forest area increased by 11,184 ha (approximately 2,237 ha per year) from 79,593 ha in 2015 to 90,777 ha in 2020. A total area of 16,138 ha (approximately 20.3%) was lost due to mangrove conversion to other land uses, aquaculture activities and coastal erosion, etc., while 27,322 ha (approximately 34.1%) was restored or newly planted during state- and NGO-funded mangrove restoration projects and programs. These results confirmed that mangrove restoration projects and programs have played a significant role in maintaining and increasing mangrove forest cover in Mekong Delta. The results can also assist managers and decision makers in mangrove restoration evaluation, and suggest analyzing WorldView-2 images to monitor mangrove restoration over time in Vietnam.

Mapping Multi-Decadal Mangrove Extent in the Northern Coast of Vietnam Using Landsat Time-Series Data on Google Earth Engine Platform

A pixel-based algorithm for multi-temporal Landsat (TM/ETM+/OLI/OLI-2) imagery between 1990 and 2022 monitored mangrove dynamics and detected their changes in the three provinces (i.e., Thai Binh, Nam Dinh and Hai Phong), which are located on the Northern coast of Vietnam, through the Google Earth Engine (GEE) cloud computing platform. Results showed that the mangrove area in the study area decreased from 2960 ha in 1990 to 2408 ha in 1995 and then significantly increased to 4435 ha in 2000 but later declined to 3502 ha in 2005. The mangrove areas experienced an increase from 4706 ha in 2010 to 10,125 ha in 2020 and reached a highest peak of 10,630 ha in 2022. In 2022, Hai Phong province had the largest area of mangrove (3934 ha), followed by Nam Dinh (3501 ha) and Thai Binh (3195 ha) provinces. The overall accuracies for 2020 and 2022 were 94.94% and 91.98%, while the Kappa coefficients were 0.90 and 0.84, respectively. The mangrove restoration programs and policies by the Vietnamese government and local governments are the key drivers of this increase in mangroves in the three provinces from 1990 to 2022. The results also demonstrated that the combination of Landsat time series images, a pixel-based algorithm, and the GEE platform has a high potential for monitoring long-term change of mangrove forests during 32 years in the tropics. Moreover, the obtained mangrove forest maps at a 30-m spatial resolution can serve as a useful and up-to-date dataset for sustainable management and conservation of these mangrove forests in the Red River Delta, Vietnam.

Characteristics of Avicennia lanata (Ridley) Species for mangrove restoration on the coast of North Gorontalo

Research on the rare mangrove Avicennia lanata (Ridley) is based on the habitat affinity of this species on the coast of North Gorontalo observed during 2017-2019. The current search was carried out in geographically isolated areas (land and islands) using a combination of tracking and Point Centered Quarter (PCQ) techniques to observe the substrate condition and elevation of the mangrove patch habitat, as well as to observe the morpho-anatomical character of the stand. The results showed that the habitat affinity of A. lanata species in North Gorontalo covers a wide range of substrate types, including mud, sandy mud, sand, muddy sand, and sandy and muddy soil on land with an elevation of 5.11–6.57 MDPL. The morpho-anatomical character as a distinguishing feature of A. lanata species from other Avicennia species found in leaves, stems, and fruit, could only be observed clearly in individual stands and trees. This study recommends restoration/monitoring of mangrove species A. lanata (Ridley) with a mixed-species restoration approach and community-based co-planting in a long-term mangrove restoration program in the coastal area of North Gorontalo.

Review: Causes and impacts of anthropogenic activities on mangrove deforestation and degradation in Indonesia

Abstract. Cahyaningsih AP, Deanova AK, Pristiawati CM, Ulumuddin YI, Kusumawati L, Setyawan AD. 2022. Review: Causes and impacts of anthropogenic activities on mangrove deforestation and degradation in Indonesia. Intl J Bonorowo Wetlands 12: 12-22. Indonesia is a country with the largest extent of mangroves in the world. However, as the human population increases, the extent and quality of the mangroves decrease. The increasing population is in line with the increase in human activities, leading to deforestation and degradation of the mangrove forests. This paper aimed to review anthropogenic activities that cause mangrove deforestation and degradation in Indonesia and the impacts of such anthropogenic activities on the mangrove ecosystems and formulate the efforts to overcome mangrove deforestation and degradation in the country. Various human activities are the primary drivers of deforestation and degradation of mangroves, including land conversion from mangrove forests into other land uses (e.g., agricultural lands, ponds, infrastructure developments, and human settlements), extractive activities (e.g., mining and logging), and household and industrial activities (e.g., plastic debris, heavy metals pollutants). These anthropogenic factors reduce mangrove forest area, changes in mangrove composition, uneven species abundance, and pollution. Combined with sea-level rise caused by global climate changes, such activities pose devastating threats to Indonesian mangroves. Efforts to overcome these problems include increasing awareness of communities regarding mangrove conservation, conducting mangrove restoration programs, and promoting sustainable management of mangrove, for example, through ecotourism. On top of that, community participation plays an essential role in Indonesia's sustainable management and conservation of mangrove forests.

GENETIC DIVERSITY OF NATURAL AND RESTORED API-API PUTIH (AVICENNIA ALBA) POPULATIONS IN THE WEST COAST OF PENINSULAR MALAYSIA

A large tract of mangrove forest in Malaysia has been lost due to increased anthropogenic activities. Restorative practices of mangrove forest have been adopted nationwide to re-establish ecosystem services in combating coastal erosion. However, genetic considerations in local mangrove restoration practices are still far lacking despite the vast literature on their genetic diversity. To understand whether the restored mangroves can impact the genetic diversity distribution among natural populations, we used eight microsatellite markers to assess the genetic diversity of the Api-api putih (Avicennia alba) between the natural and restored populations along the west coast of Peninsular Malaysia. We found no difference in terms of genetic diversity between these populations. Two genetic clusters were detected among A. alba along the west coast based on Bayesian clustering and discriminant analysis of principal components (DAPC). The southwest monsoon current circulation that coincides the timing of seed dispersal of A. alba may explain such pattern of genetic differentiation. Despite the minimal genetic structure, our results suggest that seed sourcing from either population is viable for the local mangrove restoration programs in the future.

Active restoration leads to rapid recovery of aboveground biomass but limited recovery of fish diversity in planted mangrove forests of the North Brazil Shelf

Coastal degradation has spurred active restoration of mangrove ecosystems, from local initiatives to global commitments to increase mangrove forest area by 20% over the next decade. Mangrove restoration projects typically have multiple objectives, including carbon storage, coastal resilience, and fisheries recovery. How planting seedlings, the most common form of active restoration, can promote recovery of mangrove ecosystem functions remains an urgent research need. We quantified multiple ecosystem outcomes of Guyana's national mangrove restoration program, approximately a decade after seedling planting, and compared restoration outcomes with conditions in intact and degraded mangrove forests. Multivariate analyses indicate that intact and restored sites' environmental conditions were similar to each other but different from degraded sites. Aboveground biomass in restored sites (103 Mg ha−1) was 13 and 99% greater than intact (89.4 Mg ha−1) and degraded (0.12 Mg ha−1) sites, respectively. Active restoration successfully increased seedling abundance of both planted and unplanted species, with similar abundance between intact and restored sites. In contrast, fish communities in restored sites remained similar to degraded sites. Restored sites were dominated by a single algivorous fish species, with lower species diversity and commercially valuable fisheries than intact sites. Our results demonstrate that active restoration is a viable option to restore mangrove forest tree biomass and tree species composition in this region. However, even under a best‐case scenario for mangrove forest restoration, fisheries did not recover during our study's timespan. Long‐term monitoring and controlled experiments will be essential to further understand restoration outcomes for multiple ecosystem services in mangrove forests.

Mangrove restoration in Colombia: Trends and lessons learned

Loss and degradation of mangroves in Colombia has motivated the development of restoration efforts since the 1990s. Many experiences have been accumulated; however, there is no general balance to evaluate approaches, techniques, and results from which best practices and public policy, and a long-term national mangrove restoration plan can be proposed. To fill this gap, a review of the scientific literature and unpublished reports was complemented with surveys to build a database “MANRESCO v. 1.0” released with paper. Analysis made it possible to describe the historical and geographical trends and to identify the relative success of the many actions, according to restoration types, mangroves types and specific techniques we documented. 163 actions between 1995 and 2018 on six biophysical typologies of mangroves, four restoration types and ten techniques to face deforestation, hydrological alteration, and oil spills were recorded. A Chi-square test was used to found relationship between relative succeed and some variables. No relationship was found between biophysical mangrove types and the relative success (p-value = 0.11), but success largely depended on the type of restoration and the technique used. Most effective type of restoration was the Community Based Ecological Mangrove Restoration. Techniques involving hydrological restoration had more highly successful cases than others (15%). The most widely used and common technique was the sowing of seedlings and propagules, which have been commonly used regardless of anthropic threat, but with a low level of success. According to the results of the largest mangrove restoration program in Latin America (Ciénaga Grande de Santa Marta), the techniques can be complemented in scale and time, resulting in a 69% of mangrove cover at a cost of 4115US $/ha. However, techniques need to be chosen on proper knowledge of socioecological systems to improve the cost-benefit estimation. Lesson learned and gaps identified can be useful to other countries carrying on mangrove restoration programs.

Dampak Pemulihan Mangrove Terhadap Bahan Baku, Kesempatan Kerja dan Pendapatan Keluarga Pesisir

This study which was conducted in the coastal area of Rugemuk Village, Pantai Labu Subdistrict, Deli Serdang Regency aims to 1) analyze the impact of mangrove forest recovery program on mangrove cover area; 2) analyze the impact of mangrove recovery program on availability of raw materials of coastal agroindustry; 3) analyze the impact of mangrove forest recovery program on employment opportunities;Â 4) analyze the impact of mangrove recovery program on coastal household income. Data analysis method used in this research is comparative method that is Wilcoxon Match Pairs Test and Test-t. Sampling method used is simple random sampling method with the number of samples of 79 samples. The results showed that 1) There is increasing mangrove forest cover area after mangrove restoration program; 2) There is significant difference availability of raw materials of coastal agroindustry; 3) There is significant difference employment opportunities before and after mangrove restoration program; 4) There is significant difference in coastal household income before and after mangrove restoration program

Determining hydrological flow paths to enhance restoration in impaired mangrove wetlands.

The restoration of mangroves has gained prominence in recent decades. Hydrological rehabilitation has been undertaken to connect impaired mangroves with the sea, lagoons or estuaries. Because mangrove hydrodynamics occurs on the surface and interstitial spaces in the sediment, we propose to determine the hydrological flow paths to restore the hydrological regimes of the impaired mangroves. The hydrological flow paths were determined through a micro basin analysis based on microtopographic data to generate a digital elevation model. Applying this methodological approach, the hydrology of an impaired area on a barrier island in the Gulf of Mexico was restored by excavating, desilting or clearing the channels on the identified hydrological flow paths. This area was compared to one in which impaired mangroves were reconnected to the marine lagoon but disregarding the flow paths. Data collected in both areas were evaluated by flood level analysis, using two methods: (i) a simple linear regression model (SLRM) and (ii) spectral analysis (SA), also known as dominant frequency analysis. The results suggest that restoration based on the hydrological flow paths was more effective than the direct opening to the nearest main water body without accounting for the microtopography. In both areas, soil salinity and sulfides decreased after hydrological reconnection. However, a greater efficiency in the investment of time and human resources was achieved when preferential flow paths were identified and taken into account. The methodological procedures described in this study are of universal application to other mangrove restoration programs.

Species diversity and composition of mangroves in Tacloban City, Philippines

This study reflects the present status of Tacloban City mangrove vegetation and would be useful for mangrove restoration program. Surveys of mangrove forests in Tacloban City were conducted from October to November 2017 in 12 selected sites. Quadrat method was used to assess the species composition and stand structure of the canopy layer, representing seaward, middle and landward zones. The mangrove forests in Tacloban City contain 23 mangrove species belonging to 12 families and 15 genera. Rhizophoraceae and Acanthaceae are the most dominating families. As per IUCN report, among the 23 species, 4 were recognized as threatened. These include the Endangered Camptostemon philippinensis, the Vulnerable Avicennia rumpiana and the Near Threatened Aegiceras floridum and Ceriops decandra. Rhizophora Apiculata is the most abundant species, followed by Sonneratia alba. Other abundant species are Avicennia officinalis, Avicennia marina and Rhizophora mucronata. The least abundant are Bruguiera gymnorrhiza, Camptostemon philippinensis and Xylocarpus granatum. The canopy layer is composed of small-sized trees with an average tree density of 1,678 per ha and stem density of 3,133 per ha. The average height and diameter are 6.15m and 8.95cm, respectively. Mangrove diversity is generally low. Shannon index of diversity value ranges from 0.762 to 1.132, with an average value of 0.914. Understory is characterized by few species of regenerants, low density and low species diversity.

Loss and recovery of carbon and nitrogen after mangrove clearing

Offsetting carbon (C) emissions and reducing nitrogen (N) pollution have been goals of mangrove restoration programs around the world. There is a common, yet dubious expectation that mangrove restoration will result in immediate and perpetual delivery of ecosystem services. There are expected time lags between mangrove clearing and C and N losses, and between restoration and C and N gains. Obtaining accurate rates of losses and gains requires frequent and long-term sampling, which is expensive and time consuming. To address this knowledge gap, we used a chronosequence of mangrove forests in mangroves in Matang Mangrove Forest Reserve (MMFR) in Malaysia, a region with one of the most C dense forests in the world. In this site, we assessed the ecosystem C and N stocks, including soil, downed wood, downed litter, and trees. The objective was to measure C and N changes through time. After mangrove clearing, C and N losses in soil and downed wood were rapid, with stocks halved after just one year. In the first 10 years after replantation, the forest recovered quickly, with rates of C accumulation of 9.5 Mg C ha−1 yr−1. After ten years, the rate of accumulation decreased to 2.8 Mg C ha−1 yr−1. However, 40 years after replantation, mangroves were still about 26% lower in C and 15% lower in N compared to our reference forest. The trajectory of recovery of C and N stocks in these forests was different among mangrove components: forest litter recovered rapidly, but downed wood and soil recovered much slower. Programs aimed at reducing C emissions and N pollution should consider that there are temporal lags and ecosystem trade-offs when assessing the effectiveness of mangrove protection and restoration as climate change mitigation strategies.

Traits allowing Avicennia marina propagules to overcome seawater salinity

The present study investigated the mechanism by which propagules of Avicennia marina overcome the high surrounding salinity and how they withstand and establish in such a stressful environment. Mature propagules were collected from mother trees at two sites along the Saudi Read Sea shoreline. Based on their sizes, they were divided into small, medium and large propagules. Their morphological characterization and sodium, potassium, chloride and total sugar concentrations (TSC) in embryonic axis, cotyledons and coat were assessed. Toxic ions (Na+ and Cl−) were mainly accumulated in the propagule coat by which they were trapped away from the embryo. The high total sugar accumulation in cotyledons might help in embryonic axis growth. The early development of the embryonic axis inside the propagule before dispersing from the mother plant might help in overcoming high salinity during germination stage and seedling establishment. The large propagules from ‘Al Birk’ site which exhibited the highest TSC and K+/Na+ ratio in cotyledons and well-developed embryonic axis appeared promising for mangrove restoration programs along the Red Sea Shorelines.

Valuation Economy Restoration Program of Mangrove Forest Pasarbanggi Village District of Rembang

This study aims to identify the problems and find the economic value of mangrove forest restoration program utilization of village Pasarbanggi Rembang. The research of using the DPSIR analysis and cost-benefit analysis methods which include Net Present Value (NPV), Interest Rate of Return (IRR), Net B/C Ratio, and Payback Period. DPSIR analysis results known that human activity is divided into two types, namely constructive and destructive. constructive activity derives from the awareness of local people who have had a positive outlook towards the sustainability of mangrove resources and desire to contribute to conservation. More destructive activity resulting from external factor. The results of the cost-benefit analysis method shows that the NPV is obtained by using the discount factor of 9% amounting to IDR 4.990.339.459- with an IRR of 16.73%, Net B/C Ratio of 1.77 with the returns can be achieved after 8 years 9 the moon. The value of mangrove forest to reviewed by value to the option with the highest biodiversity of mangrove forests is IDR 12.328.200- per year.

Molecular markers assisted DNA polymorphism: Implications in mangrove research

Mangroves are defined as woody, evergreen group of plant community; grow on the swampy substrate at tropical and sub-tropical habitatsadjusted to high salinity, periodical tidal influence, strong winds, high temperatures, high precipitation and anaerobic soils. They possessunique morphological and physiological adaptive features to cope with these extreme conditions. Mangrove vegetation is the cradle of several marine fauna and provides first line of defense against devastating sea surges, typhoon, tsunami, etc. However, since industrial era, many of the mangrove members were affected by several environmental constrains and anthropogenic activities that raised the sea level, lowered sweet water influx from the adjacent rivers and encroachment for the new settlement formation, increasing salinity. Hence, mangrove restoration program is the front line topic of interest to the plant biologists across the tropical and subtropical world since it has a productive and protective role for the inhabitants. Sound knowledge of molecular characteristic of the individual taxa will be provide an advantage for this initiative.Recent advancement in molecular markers based on the PCR technique techniqueswill enhance the knowledge about genetic background of each individual taxon, ultimately leading to valid guided references towards the understanding the inherent nature of the plant itself and beneficial to proper restoration program.

Native salt-tolerant grass species for habitat restoration, their acclimation and contribution to improving edaphic conditions: a study from a degraded mangrove in the Indian Sundarbans

The Sundarbans is the largest continuous block of mangrove distributed over both India and Bangladesh and is threatened with pronounced erosion and mudflat degradation in its western reaches. Since 2013, considerable progress has been achieved through the restoration of highly degraded mudflats by the extensive utilization of four native grass species plantings, Porteresia coarctata, Myriostachya wightiana, Paspalum vaginatum, and Sporobolus virginicus. These grasses proved to exhibit the highest survival (80–90%) in the lower and middle intertidal zone and during the last three years (2013–2016) almost 6000 m2 area have been restored by the growth of these grasses. Increased osmolyte synthesis under degraded conditions in these native grasses offered osmotic protection and helped to expand and restore the mudflat to an elevation suitable for mangrove establishment. The rhizosphere of the four grasses was engaged in the decomposition cycle, releasing more nutrients, more nutrient cycling soil microbial enzymes, and encouraged high densities of nutrient cycling bacteria. The study demonstrates that stabilization and reclamation of the denuded mudflat by halotolerant grasses is an essential prerequisite for any successful mangrove restoration program. The facilitative role of the salt marsh is crucial to aid colonization by mangrove propagules.