Species Avicennia Research Articles

Analyzing the effects of afforestation on estuarine environment of river Subarnarekha, India using geospatial technologies and participatory appraisals.

In the Subarnarekha estuary of eastern India, deforestation remained a perpetual menace throughout the last century, thereby considerably augmenting the regional environmental vulnerability, especially in the wake of climate change-induced rise of sea levels. Like other similar areas, coastal afforestation had been widely implemented here as a prime measure of integrated coastal zone management. This study highlighted the impacts of such afforestation initiatives conducted in this area during the last 40years by integrating geospatial information and community feedbacks. It was also a pioneering one in evaluating the level of sustainability achieved by these initiatives chiefly by analyzing their ability to attain the dual aims of environmental conservation and livelihood generation for the coastal communities. Results indicated that the detrimental effects of the continual removal of healthy mangrove and Pandanus tectorius stands could overwhelmingly be traced along the backshore areas and riverbanks. However, the scenario became better since 2008-2009 as both the dense mangroves and Casuarina plantations had experienced considerable areal increases primarily due to the renewed impetus on the Joint Forest Management and Social Forestry programs as well as regulation on shrimp aquaculture practices. Conversely, overall status of biodiversity and ecological composure remained alarmingly poor as many areas exhibited monospecific stands of Avicennia species. Accordingly, the study suggested establishment of appropriate zonal plantations based on species assemblage and utilities, bio-stabilization of coastal dunes, regulated grazing, enhanced community emancipation regarding usufruct sharing, and conflict resolution as the imperative measures for sustainable ecological restoration of this estuary.

Population genetic structure, introgression, and hybridization in the genus Rhizophora along the Brazilian coast.

Mangrove plants comprise plants with similar ecological features that have enabled them to adapt to life between the sea and the land. Within a geographic region, different mangrove species share not only similar adaptations but also similar genetic structure patterns. Along the eastern coast of South America, there is a subdivision between the populations north and south of the continent's northeastern extremity. Here, we aimed to test for this north‐south genetic structure in Rhizophora mangle, a dominant mangrove plant in the Western Hemisphere. Additionally, we aimed to study the relationships between R. mangle, R. racemosa, and R. × harrisonii and to test for evidence of hybridization and introgression. Our results confirmed the north‐south genetic structure pattern in R. mangle and revealed a less abrupt genetic break in the northern population than those observed in Avicennia species, another dominant and widespread mangrove genus in the Western Hemisphere. These results are consistent with the role of oceanic currents influencing sea‐dispersed plants and differences between Avicennia and Rhizophora propagules in longevity and establishment time. We also observed that introgression and hybridization are relevant biological processes in the northeastern coast of South America and that they are likely asymmetric toward R. mangle, suggesting that adaptation might be a process maintaining this hybrid zone.

Geographical Distance and Large Rivers Shape Genetic Structure of Avicennia officinalis in the Highly Dynamic Sundarbans Mangrove Forest and Ganges Delta Region

The Ganges Delta and Sundarbans comprise the largest continuous mangrove area in the world. These mangroves are subjected to high riverine and tidal dynamics, and the coastline irregularity is characterized by many north-to-south oriented rivers that may hamper dispersal of mangrove propagules. Whereas connectivity levels and resulting population genetic structure often can be explained by ocean currents, other factors may control estuarine-scale mangrove genetic patterns and limit gene flow even between sites in close geographic proximity. We investigated whether the complex estuarine coastline in the Ganges Delta and Sundarbans shaped the genetic structure of Avicennia officinalis populations across regions and rivers at various distances (ca. 1 to 265 km). Using nine microsatellite loci, 433 individuals from 14 populations revealed predominant outcrossing and a high level of genetic variation when compared to other Avicennia species. A moderate but significant level of differentiation was detected among populations (F ST = 0.09), and a principal coordinate analysis clearly separated populations of the Chittagong coastline from the Sundarbans. An individual-based Bayesian analysis also indicated those two gene pools. Genetic distances across the whole region could best be explained by cumulative river width and geographical distance separating the populations. Within the Sundarban region, the low genetic differentiation of A. officinalis populations indicated a continuous distribution model with a smooth isolation-by-distance that gradually increased across large rivers shaping the genetic structure of A. officinalis in the Ganges Delta. These findings indicated that in addition to geographical distance, rivers might act as physical barriers, affect gene flow and shape genetic connectivity. This and detailed population genetic information should be incorporated into the ongoing afforestation or restoration strategies in and outside of the Sundarbans mangrove forest.

Re-Evaluation of Phylogenetic Relationships among Species of the Mangrove Genus Avicennia from Indo-West Pacific Based on Multilocus Analyses.

Avicennia L. (Avicenniaceae), one of the most diverse mangrove genera, is distributed widely in tropical and subtropical intertidal zones worldwide. Five species of Avicennia in the Indo-West Pacific region have been previously described. However, their phylogenetic relationships were determined based on morphological and allozyme data. To enhance our understanding of evolutionary patterns in the clade, we carried out a molecular phylogenetic study using wide sampling and multiple loci. Our results support two monophyletic clades across all species worldwide in Avicennia: an Atlantic-East Pacific (AEP) lineage and an Indo-West Pacific (IWP) lineage. This split is in line with biogeographic distribution of the clade. Focusing on the IWP branch, we reconstructed a detailed phylogenetic tree based on sequences from 25 nuclear genes. The results identified three distinct subclades, (1) A. rumphiana and A. alba, (2) A. officinalis and A. integra, and (3) the A. marina complex, with high bootstrap support. The results strongly corresponded to two morphological traits in floral structure: stigma position in relation to the anthers and style length. Using Bayesian dating methods we estimated diversification of the IWP lineage was dated to late Miocene (c. 6.0 million years ago) and may have been driven largely by the fluctuating sea levels since that time.

The genus Avicennia, a pioneer group of dominant mangrove plant species with potential medicinal values: a review

ABSTRACTThe genus Avicennia comprises eight species of mangrove trees that occur in intertidal zones of estuaries and seabeds found in tropical and temperate regions spanning throughout the world. The plants belonging to the genus have both ecological and economic benefits. Different parts of the plants have ethnomedicinal applications for treatment of various diseases such as cancer, diabetes, malaria, rheumatism, asthma, small pox and ulcer. Pharmacological investigations have revealed antimicrobial, antioxidant, anticancer, antidiabetic, anti-inflammatory activities and so on in these plants. The genus possesses some unique metabolites of varied chemicals classes, which are responsible for their wide range of pharmacological activities. The presence of different bioactive compounds such as alkaloids, flavonoids, phenols, saponins, tannins, glycosides and terpenoids has been detected. Hence, there is a great scope to discover new biological active phytochemicals from different mangrove species of genus Avicennia. Although many research articles have been published on various pharmacological aspects of different plants of the genus, no comprehensive review is yet available pertaining to their ethnomedicinal uses, chemical constituents and pharmacological activities. The present article discusses the diversity as well as distribution of different species of genus Avicennia along with an in-depth coverage of their ethnomedicinal uses, phytochemical and pharmacological profiles.

Species distribution and introgressive hybridization of two Avicennia species from the Western Hemisphere unveiled by phylogeographic patterns.

BackgroundMangrove plants grow in the intertidal zone in tropical and subtropical regions worldwide. The global latitudinal distribution of the mangrove is mainly influenced by climatic and oceanographic features. Because of current climate changes, poleward range expansions have been reported for the major biogeographic regions of mangrove forests in the Western and Eastern Hemispheres. There is evidence that mangrove forests also responded similarly after the last glaciation by expanding their ranges. In this context, the use of genetic tools is an informative approach for understanding how historical processes and factors impact the distribution of mangrove species. We investigated the phylogeographic patterns of two Avicennia species, A. germinans and A. schaueriana, from the Western Hemisphere using nuclear and chloroplast DNA markers.ResultsOur results indicate that, although Avicennia bicolor, A. germinans and A. schaueriana are independent lineages, hybridization between A. schaueriana and A. germinans is a relevant evolutionary process. Our findings also reinforce the role of long-distance dispersal in widespread mangrove species such as A. germinans, for which we observed signs of transatlantic dispersal, a process that has, most likely, contributed to the breadth of the distribution of A. germinans. However, along the southern coast of South America, A. schaueriana is the only representative of the genus. The distribution patterns of A. germinans and A. schaueriana are explained by their different responses to past climate changes and by the unequal historical effectiveness of relative gene flow by propagules and pollen.ConclusionsWe observed that A. bicolor, A. germinans and A. schaueriana are three evolutionary lineages that present historical and ongoing hybridization on the American continent. We also inferred a new evidence of transatlantic dispersal for A. germinans, which may have contributed to its widespread distribution. Despite the generally wider distribution of A. germinans, only A. schaueriana is found in southern South America, which may be explained by the different demographic histories of these two species and the larger proportion of gene flow produced by propagules rather than pollen in A. schaueriana. These results highlight that these species responded in different ways to past events, indicating that such differences may also occur in the currently changing world.Electronic supplementary materialThe online version of this article (doi:10.1186/s12862-015-0343-z) contains supplementary material, which is available to authorized users.

Multiple-geographic-scale genetic structure of two mangrove tree species: the roles of mating system, hybridization, limited dispersal and extrinsic factors.

Mangrove plants comprise a unique group of organisms that grow within the intertidal zones of tropical and subtropical regions and whose distributions are influenced by both biotic and abiotic factors. To understand how these extrinsic and intrinsic processes influence a more fundamental level of the biological hierarchy of mangroves, we studied the genetic diversity of two Neotropical mangrove trees, Avicenniagerminans and A. schaueriana, using microsatellites markers. As reported for other sea-dispersed species, there was a strong differentiation between A. germinans and A. schaueriana populations sampled north and south of the northeastern extremity of South America, likely due to the influence of marine superficial currents. Moreover, we observed fine-scale genetic structures even when no obvious physical barriers were present, indicating pollen and propagule dispersal limitation, which could be explained by isolation-by-distance coupled with mating system differences. We report the first evidence of ongoing hybridization between Avicennia species and that these hybrids are fertile, although this interspecific crossing has not contributed to an increase in the genetic diversity the populations where A. germinans and A. schaueriana hybridize. These findings highlight the complex interplay between intrinsic and extrinsic factors that shape the distribution of the genetic diversity in these sea-dispersed colonizer species.

Proteomic analysis of plasma membrane and tonoplast from the leaves of mangrove plantAvicennia officinalis

In order to understand the salt tolerance and secretion in mangrove plant species, gel electrophoresis coupled with LC-MS-based proteomics was used to identify key transport proteins in the plasma membrane (PM) and tonoplast fractions of Avicennia officinalis leaves. PM and tonoplast proteins were purified using two-aqueous-phase partitioning and density gradient centrifugation, respectively. Forty of the 254 PM proteins and 31 of the 165 tonoplast proteins identified were predicted to have transmembrane domains. About 95% of the identified proteins could be classified based on their functions. The major classes of proteins were predicted to be involved in transport, metabolic processes, defense/stress response, and signal transduction, while a few of the proteins were predicted to be involved in other functions such as membrane trafficking. The main classes of transporter proteins identified included H(+) -ATPases, ATP-binding cassette transporters, and aquaporins, all of which could play a role in salt secretion. These data will serve as the baseline membrane proteomic dataset for Avicennia species. Further, this information can contribute to future studies on understanding the mechanism of salt tolerance in halophytes in addition to salt secretion in mangroves. All MS data have been deposited in the ProteomeXchange with identifier PXD000837 (http://proteomecentral.proteomexchange.org/dataset/PXD000837).

Post-Glacial Expansion and Population Genetic Divergence of Mangrove Species Avicennia germinans (L.) Stearn and Rhizophora mangle L. along the Mexican Coast

Mangrove forests in the Gulf of California, Mexico represent the northernmost populations along the Pacific coast and thus they are likely to be source populations for colonization at higher latitudes as climate becomes more favorable. Today, these populations are relatively small and fragmented and prior research has indicated that they are poor in genetic diversity. Here we set out to investigate whether the low diversity in this region was a result of recent colonization, or fragmentation and genetic drift of once more extensive mangroves due to climatic changes in the recent past. By sampling the two major mangrove species, Rhizophora mangle and Avicennia germinans, along the Pacific and Atlantic coasts of Mexico, we set out to test whether concordant genetic signals could elucidate recent evolution of the ecosystem. Genetic diversity of both mangrove species showed a decreasing trend toward northern latitudes along the Pacific coast. The lowest levels of genetic diversity were found at the range limits around the Gulf of California and the outer Baja California peninsula. Lack of a strong spatial genetic structure in this area and recent northern gene flow in A. germinans suggest recent colonization by this species. On the other hand, lack of a signal of recent northern dispersal in R. mangle, despite the higher dispersal capability of this species, indicates a longer presence of populations, at least in the southern Gulf of California. We suggest that the longer history, together with higher genetic diversity of R. mangle at the range limits, likely provides a gene pool better able to colonize northwards under climate change than A. germinans.

Discrimination of mangrove species and mudflat classes using in situ hyperspectral data: a case study of Indian Sundarbans

This study attempts to assess whether canopy spectra of mangrove species and mudflat spectra recorded under field conditions contain adequate spectral information for discerning mangroves at species rank and mudflats at the class level. This article highlights the hyperspectral characteristics of canopies of 17 tropical mangrove species, belonging to nine families, creek water and four mudflat classes found in the tidal forests of Indian Sundarbans. Hyperspectral observations were recorded using a field spectroradiometer, and pre-processed and averaged reflectance values of samples were subjected to various statistically tests such as k-means cluster analysis, one-way analysis of variance (ANOVA), stepwise linear discrimination and factor analysis. k-means cluster analysis showed highest Euclidean distance between Rhizophoraceae and Myrsinaceae/Plumbaginaceae. ANOVA results indicated that all the canopy spectra were statistically different at all the spectral locations except one with majority of the bands exhibiting 99% confidence level, and for the mudflat classes and creek water, all bands showed p < 0.01. Discriminant analysis was performed in different combinations/cases to identify the bands for maximum separability. Optimal Wilks' Lambda (L) were achieved with two, six, four, eight, one, four, two and three for differentiating canopies of the species of Avicennia, Sonneratia, Xylocarpus, Bruguiera, Ceriops, Bruguiera and Rhizophora, all species of Rhizophoraceae, two species of Arecaceae, respectively. For mudflat classes and creek water, the best possible Wilks' Lambda were attained with four, five and two for discriminating upper, intermediate and mud lower, mud lower and water, mud upper with and without roots, correspondingly. Factor analysis was the tool used to identify the wavelengths that were uncorrelated and contained maximum information in the combination of selected wavelengths. The most significant bands for canopy discrimination were 960, 970, 1000, 1070, 1120, 1160, 2070, 2080, 2150, 2200, 2240 and 2340 nm; for discrimination amongst mudflat classes and creek water, the bands were 540, 550, 730, 740, 770, 780, 880, 1190, 1290, 2010 and 2150 nm. Overall, hyperspectral data showed potential for discriminating between mangrove canopies of different species and for discerning mudflat classes. The outcomes of the study also indicated the efficacy of the applied statistical tools for discrimination.

Geostatistical Approach for Site Suitability Mapping of Degraded Mangrove Forest in the Mahakam Delta, Indonesia

As part of operational guidance of mangrove forest rehabilitation in the Mahakam delta, Indonesia, site suitability mapping for 14 species of mangrove was modelled by combining 4 underlying factors—clay, sand, salinity and tidal inundation. Semivariogram analysis and a geographic information system (GIS) were used to apply a site-suitability model, while kriging interpolation generated surface layers, based on sample point data collection. The tidal inundation map was derived from a tide table and a digital elevation model from topographic maps. The final site-suitability maps were produced using spatial analysis technique, by overlaying all surface layers. We used a Gaussian model to adjust a semivariogram graph in order to help to understand the variation of sample data values, and create a natural surface layer of data distribution over the area of study. By examining the statistical value and the visual inspection of surface layers, we saw that the models were consistent with the expected data behavior; therefore, we assumed that interpolation has been carried out appropriately. Our site-suitability map showed that Avicennia species was the most suitable species and matched with 50% of the study area, followed by Nypa fruticans, which occupied about 42%. These results were actually consistent with the mangrove zoning pattern in the region prior to deforestation and conversion.

The Mechanism of Mangrove Tree in Wave Energy Propagation

The role of mangrove trees in reducing the tsunami waves during the tragedy of Andaman tsunami occurred on December 26, 2004, has been credited and these indirectly raise awareness about the role of mangroves forest as a natural breakwater on the beach. This paper will focus on the mangrove trees from Avicennia and Rhizophora species in order to identify the methods of breaking wave energy that has been carried out by the mangrove roots and stems. Analysis of the mangrove roots coordination pattern had been conducted by gathering data at study site located at Kemaman, Terengganu and the data had been plotted in Gambit software for simulation purpose in Fluent Inc software. Hence, the simulation result showed that the ratio of wave height and velocity reduction may vary depending on factors such as the species of the mangrove trees and density of the roots that grow around the tree. Consequently, the study will be examining the waveform that is mitigated by the both species Avicennia and Rhizophora using turbulent flow and experiment will be conducted to validate the data obtained by the simulation.

Floral composition and vegetation structure of Nara Mangrove Reserve, Kadolkele, Sri Lanka and guidelines for conservation

This study was conducted to understand vegetation structure and floral composition to develop suitable protocols for the conservation of NARA mangrove reserve, Kadolkele which is 10 ha in extent and located on the right bank of the northern part of Negombo Estuary (7011’ N, 79050’ E). The ecological value of mangroves is the least concern of people in the surrounding area and this mangrove patch is frequently under threat due to high land demand and its high economic value. Therefore,it is essential to understand ecological and other relevant features in order to determine strategies to conserve this mangrove forest. Knowledge of the vegetation structure and plant composition of this mangrove reserve is an important prerequisite, not only to understand all the aspects of structure and function of this reserve, but also to formulate guidelines for their conservation and management.Vegetation data were collected in 100 m2 (10 m x 10 m) plots along three transects. Each transects extended inland from the shoreline. A quantitative study of the vegetation (true mangroves, mangrove associates, other trees and shrubs, seedlings and saplings) was conducted and species identified. The anthropogenic activities carried out in the area were also noted.In total, 29 mangrove species were recorded, out of which 18 were considered true mangroves. Thirty three other types of vegetation were noted. Families with highest abundance of mangroves were Rhizophoraceae, Avicenniaceae and Combretaceae with identical zonal distribution towards the inland, respectively. Lumnitzera racemosa andAvicennia marina were most prominent among the families of Combretaceae and Avicenniaceae, respectively. Rhizophora apiculata and R. mucronata were the most abundant in family Rhizophoraceae while other members included Bruguiera gymnorhiza,B. sexangula and Ceriops tagal. Mangrove associates were found towards landside with high abundance of Premna integrifolia, Derris scandens and Acanthus ilicifolius. Out of the 20 species of true mangroves along the Sri Lankan south-western coast, present study recorded 17 species and an additional species Avicennia alba, which was recently introduced to the reserve from Thailand.The results of the study indicate Kadolkele Mangrove Reserve consists of high biological diversity of mangroves and therefore it is extremely valuable as a living mangrove forest site readily accessible for education and research, being only 40 km north from Colombo. Destructive activities of the surrounding low income population, increasing of invasive alien floral species and deposition of the garbage such as polythene and plastics due to tidal activities of the lagoon were found to be the severe threats. In order to conserve this reserve, it is necessary to develop a management plan and detail studies should be carried out to improve the knowledge on the faunal diversity of mangrove reserve to provide information required to declare the mangrove reserve of Kadolkele as a conservation zone. Action should be taken to enhance the awareness of the surrounding community on mangroves to achieve sustainable conservation including utilization. The preliminary results of this study can be used as baseline data to monitor environmental change if further development activities continue at Negombo, and for comparison with other more degraded or rehabilitated habitats in western coast of Sri Lanka.

Struktur dan Komposisi Vegetasi Mangrove di Kawasan Pesisir Pulau Sebatik, Kabupaten Nunukan, Kalimantan Timur

Sebatik Island is one of the main habitat of mangrove ecosystems in Indonesia. Based on the function, one of the mangrove forest resources with huge potential. Mangrove communities occupy the area between land and sea that have environmental conditions differ from one another. This is interesting because the management is still encountered some problems such as the conversion of mangrove forest as an area of fishpond, housing and other interests. The purpose of this study to determine the structure and composition of mangrove vegetation in Coastal Areas of Sebatik Island, Nunukan regency, East Kalimantan. The study was conducted at five locations on the island of Sebatik, the River Stake, Cape Coral, Balansiku, Setabu and Bambangan, each site is divided into 9 transects. Vegetation data retrieval done by the method of sampling survey. Each transect sampling plot made. Each individual tree (plot 10 m x 10 m) and Sapling (subplot 5 m x 5 m) were identified and measured diameter at breast height (± 1.3 m). While the calculated number of seedlings of each species and the percentage of closure (plots 1 mx 1 m). Mangrove area. The results indicate the presence of 19 species of mangrove species that fall into 14 families were found at the sites. In general, vegetation of mangrove tree is dominated by Sonneratia alba in Sebatik Island with Importance Value (IV) range from 86.83 - 171.43 % and density 500 ind/ha - 2000 ind/ha, except Bambangan which dominated by Rhizophora apiculata 86.52% and density 100 ind/ha. Sapling category, dominated by species of Sonneratia alba in Balansiku and Setabu with IV 136.65 % and 67.65 % with a density 3200 ind/ha and 1600 ind/ha. Sungai Pancang is dominated by species Avicennia alba with IV 81.64 % and density 2000 ind/ha, Tanjung Karang dominated by species Rhizopohora mucronata with IV 59.24% and density 1200 ind/ha, and Bambangan dominated by species Rhizopohora apiculata with IV 82.76% and density 2000 ind/ha. Seedling category, dominated by species of Sonneratia alba in the Sungai Pancang and Setabu with IV 107.15% and 72.79% with a density 30 000 ind/ha and 60 000 ind/ha, Tanjung Karang and Bambangan dominated by species of Rhizophora apiculata with IV 115.55 % and 136.53% and density 50 000 ind/ha and 150 000 ind/ha. species diversity and evenness was average.

DNA Base Composition Heterogeneity in Two Avicennia Species in Response to Nitrogen Limitation in the Sundarban Mangrove Forest, India

DNA Base Composition Heterogeneity in Two Avicennia Species in Response to Nitrogen Limitation in the Sundarban Mangrove Forest, India

VALUASI EKONOMI SUMBERDAYA HUTAN MANGROVE DI DESA PALAES KECAMATAN LIKUPANG BARAT KABUPATEN MINAHASA UTARA

The purpose of this study to determine the economics value of mangrove forest ecosystems, as well asits contribution to society in the region of mangrove research sites in the Palaes Village, District of WestLikupang, North Minahasa regency. In this research, using primary and secondary data. The variablesmeasured were the direct benefit of the value generated from direct utilization of mangrove forests such asthe potential for wood (timber and firewood), palm leaves craftsmen , catching fish, shrimp and crab(Rp/year). The value of benefits Indirect value resulting from the utilization of mangrove forest indirectlynamed as breaking waves (break water) (Rp/year). Value of benefit options, namely the economic valuederived from potential direct or indirect utilization of a resource / ecosystem in the future the value ofBiodiversity (Rp/year).Based on INP calculation to determine the existence of a species in a community under study, obtainedPalaes Village mangrove forest dominated by Rhizophora at 109,499. INP data from other speciesin a row on the kind of Brugiera of 58,088, amounting to 57,492 Ceriops species, Xilocarpus of 41,491,20,860 species of Sonneratia and Avicennia species amounted to 12,860.Based on the calculations found that the benefits obtained if mangrove forests are maintained atRp10,888,218,123,/year, calculated from the sum of the direct benefits other than timber potential, indirectbenefits and benefits options. Meanwhile, if the potential for exploitation of timber obtained a profit ofRp273,617,273/year. It can be concluded that if the mangrove forest is maintained, then the benefits will39.8 times greater than exploiting the natural resources of mangrove forests Palaes Village.By considering the total economic value derived from the mangrove forest ecosystem in Palaes Village,it has the benefits of mangrove forest and an important functions as economic resources and ecologicalresources for the life of the people who are around him. Therefore, the presence of (physical condition)of mangrove forest ecosystems must be maintained as an asset development, be it by local communitiesand other parties such as government, private sector, researchers and LSM, so that development activitiescan work well and the availability of mangrove forest resources remain secure.

Comparative Floral Development and Structure of the Black Mangrove GenusAvicenniaL. and Related Taxa in the Acanthaceae

Phylogenetic relationships of Avicennia have been difficult to trace because of the presence of convergent characters related to the mangrove environment. Recent molecular data suggest a close relationship to Thunbergioideae, a subfamily within Acanthaceae (Lamiales), but morphological support for the new findings has been equivocal. Floral structure and development are comparatively studied here in three species of Avicennia, with special attention given to the ovary and the ovules, which are also studied in Thunbergioideae. The suggested sister group relationship of Avicennia and Thunbergioideae is supported by three synapomorphies: (1) collateral ovule arrangement, (2) vertical orientation of ovule curvature, and (3) an exposed nucellus that is contiguous with the ovary wall, at least during early stages of ovule development. We interpret the latter character as a neotenic feature that is retained in the anthetic ovules of Avicennia. We confirm that the apparently tetramerous flowers of Avicennia have a basically pentamerous floral ground plan. Additional floral characters shared between Avicennia and Thunbergioideae include left contort corolla aestivation, thickened filament bases with glandular hairs, presence of pollen sac placentoids, and various aspects of fruit morphology and embryology. However, these features are either symplesiomorphic or are not known well enough to allow for unequivocal conclusion on character evolution in Acanthaceae.

Assessing the status of three mangrove species restored by the local community in the cyclone-affected area of the Ayeyarwady Delta, Myanmar

This paper assesses the extent of success and failure of mangrove plantations in Myanmar, restored by local people with the help of foresters under a community forestry program initiated in 1995. The species of these restored plantations are Avicennia officinalis, Avicennia marina and Heritiera fomes, each of which was restored on two plots, one on low and one on high ground, yielding a total of six plots. These plots have been continuously monitored in order to investigate survival and growth rates. The plots were established on abandoned land that had been previously used for paddy cultivation. Cyclone Nargis hit these plantations during the monitoring period, at the beginning of May, 2008. As a consequence, the survival rates of A. officinalis on low ground and A. marina on high ground declined slightly, but the overall affect was not severe. Excluding individuals affected by the cyclone, height and diameter growth of A. officinalis and A. marina were significantly higher on low ground than on high ground, i.e. on sites thought to be consistently similar to the natural habitats of these species. Contrary to these two Avicennia species, the height growth of H. fomes was higher on high ground than on low ground; the diameter growth was not significantly different. As the growth of H. fomes was very slow, however, it is still not possible to describe the differences clearly. This study may provide useful guidelines for foresters and local people to establish successful mangrove restorations and to predict production from community-owned mangrove forests.

Stimulatory effects of sea salts on cell growth in liquid culture of Avicenniaceae mangrove

The effects of salts on cell proliferation in suspension cultures of Avicennia alba and on callus induction from the leaf-tissue of A. marina were investigated using a small-scale liquid culture method. The effects of the seawater components, NaCl, KCl, CaCl2, MgCl2, and MgSO4 were examined separately. In both Avicennia species, the cell growth was increased in the presence of a low concentration, 10 mM, of MgCl2. Even in the presence of 100 mM NaCl, growth was stimulated in A. marina and there was no inhibition of growth in A. alba. CaCl2 was the most inhibitory and completely inhibited growth at 100 mM in both species. Similarities and differences in the effects of sea salts among Avicennia species and Sonneratia alba and Bruguiera sexangula of different mangrove families are discussed. This is the first report on establishing cell suspension culture of the mangrove plant A. alba belonging to the Avicenniaceae.

Chemical and Biogeophysical Impact of Four‐Dimensional (4D) Seismic Exploration in Sub‐Saharan Africa, and Restoration of Dysfunctionalized Mangrove Forests in the Prospect Areas

Four-dimensional (4D) seismic exploration, an improved geophysical technique for hydrocarbon-data acquisition, was applied for the first time in the Nembe Creek prospect area of Nigeria. The affected soils were slightly alkaline in situ when wet (pH 7.2), but extremely acidic when dry (pH 3.0). The organic carbon content (4.6-26.8%) and other physicochemical properties of soils and water (N, P, and heavy-metal contents, etc.) were higher than the baseline values obtained in 2001 before seismic profiling. Most values also exceeded the baseline compliance standards of the Department of Petroleum Resources (DPR), the World Health Organization (WHO), and the Federal Environmental Protection Agency (FEPA). Rehabilitation of the affected areas was achieved by stabilizing the mangrove floor by liming and appropriate application of nutrients, followed by replanting the cut seismic lines over a distance of 1,372 km with different mangrove species, including juvenile Rhizophora racemosa, R. mangle, and Avicennia species, which were transferred from nursery points. Quicker post-operational intervention is recommended for future 4D surveys, because the time lag between the end of seismic activity and post-impact investigation is critical in determining the relationship between activity and impact: the longer the intervening period, the more mooted the interaction.