No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
Differentiation between true mangroves and mangrove associates based on leaf traits and salt contents
Abstract
Aims
Mangrove species are classified as true mangroves and mangrove associates. However, as for some fringe species found mainly on the landward transitional zones of mangroves, no consensus among scientists could be reached in favor of this classification and much debate arises. We hypothesized that true mangroves differ from mangrove associates physiologically and ecologically in their ability to survive in mangrove environment.
Methods
To test this hypothesis, leaf structural traits and osmotic properties were used to describe variation in 33 mangrove species (17 true mangroves, 6 mangrove associates and 10 controversial species).
Important Findings
Specific leaf area (SLA) of true mangroves as well as leaf nitrogen concentration on a leaf mass (Nmass) were lower than that of mangrove associates; leaf succulence was, in general, twice as high in true mangroves compared to mangrove associates; true mangroves accumulated 8–9 times more Na and Cl than mangrove associates and the former had K/Na ratios <0.5, but the latter had K/Na ratios >0.5. These results indicated that true mangroves differed reliably from mangrove associates in leaf traits and osmotic properties. True mangroves are true halophytes and mangrove associates are glycophytes with certain salt tolerance. Combining distribution pattern information, the 10 controversial species were reclassified.
... However, mangroves have been largely overlooked in these global trait analyses 9,10 , leaving a critical gap in our understanding of coastal ecosystems. Despite growing interest in examining individual traits, a comprehensive understanding of trait coordination and its ecological implications is lacking 9,[11][12][13] . To fill this knowledge gap, further investigation into trait coordination of mangrove species and its relevance to resource-investment strategies is necessary. ...
... Mangrove species grow mainly in coastal saline or brackish water. They are often categorized into true mangroves and mangrove associates 11,[14][15][16] , although the assignation of some species to these categories is still under debate 11 . True mangroves thrive in the intertidal zone, constantly exposed to tidal fluctuations, while mangrove associates tend to occupy landward areas, experiencing less frequent tidal influence [16][17][18][19] . ...
... Mangrove species grow mainly in coastal saline or brackish water. They are often categorized into true mangroves and mangrove associates 11,[14][15][16] , although the assignation of some species to these categories is still under debate 11 . True mangroves thrive in the intertidal zone, constantly exposed to tidal fluctuations, while mangrove associates tend to occupy landward areas, experiencing less frequent tidal influence [16][17][18][19] . ...
The leaf economics spectrum (LES) has been proposed as a framework for understanding leaf resource-investment and plant growth strategies, but it is scarcely examined in mangrove communities. This study investigates LES patterns in mangrove communities to examine whether the trait coordination spectrum, if it exists, is associated with plant growth strategies. By conducting a comprehensive sampling across a wide range of mangrove species in China, we confirmed the presence of LES across mangrove species, and found that true mangroves generally exhibit a more conservative strategy characterized by higher leaf mass per area (LMA) and lower leaf nutrient concentrations compared to mangrove associates. We also observed considerable intraspecific variation in traits, particularly in LMA. In some cases, fast-growing species exhibited higher LMA and lower leaf nutrient concentrations than slow-growing species. Fast-growing species also showed higher leaf thickness than slow-growing species, but no difference in leaf density between them, suggesting that LMA composition is important in understanding trait coordination and its link with plant growth strategies in mangrove communities. Our findings highlight a complex link between trait coordination and plant growth strategies in mangrove species.
... Together with associated microbes, fungi, other plants, and animals, they form a mangrove forest community also called mangal [2]. Altogether, about 75 true mangrove species from 11 families are recognized [3][4][5]. Lumnitzera racemosa Willd. belongs to the mostly (sub)tropical family Combretaceae. ...
... The crude product was suspended in DCM and then stored overnight in the refrigerator. Subsequently, the supernatant was removed, and the precipitation step was repeated, yielding 0.79 g of an orange amorphous solid (5) which was used without further chromatographic purification. ...
... Mar. Drugs 2023, 21, x FOR PEER REVIEW 9 of 19 Scheme 1. Two-step chemical synthesis of lumnitzeralactone (1b) from EA (2) via formation of a stable intermediate(5). ...
The previously undescribed natural product lumnitzeralactone (1), which represents a derivative of ellagic acid, was isolated from the anti-bacterial extract of the Indonesian mangrove species Lumnitzera racemosa Willd. The structure of lumnitzeralactone (1), a proton-deficient and highly challenging condensed aromatic ring system, was unambiguously elucidated by extensive spectroscopic analyses involving high-resolution mass spectrometry (HRMS), 1D ¹H and ¹³C nuclear magnetic resonance spectroscopy (NMR), and 2D NMR (including 1,1-ADEQUATE and 1,n-ADEQUATE). Determination of the structure was supported by computer-assisted structure elucidation (CASE system applying ACD-SE), density functional theory (DFT) calculations, and a two-step chemical synthesis. Possible biosynthetic pathways involving mangrove-associated fungi have been suggested.
... Compared to terrestrial plants, mangroves have evolved several morphological and physiological features to adapt to saline environments, such as salt glands, leaf succulence, salt sequestration in leaf vacuoles and ultrafiltration mechanisms for salt exclusion [1,11]. However, different mangrove species have various adaptations to salinity [12]. Unlike true mangroves, which achieve the maximum growth in saline environments, mangrove associates are generally facultative halophytes and grow better with fresh water [11,13]. ...
... Accordingly, when exposed to 700 mM salt stress for 7 d, the leakage of leaf plasma membrane was significantly increased, and the water content in leaves was substantially decreased (Fig. 1C and D). Compared to true mangrove plants, mangrove associates like H. nymphaeifolia in general have lower osmolality [12], and thus are prone to lose water under salt stress. As a response, the genes associated with osmosensory signaling pathway were differentially expressed in stressed individuals ( Fig. 2D and E). ...
Background
Hernandia nymphaeifolia is a typical mangrove associate with high ecological, ornamental, and medicinal values, but in China, it has become endangered in recent years, and an urgent protection is needed. Salinity is a key factor for growth and survival of mangrove seedlings, and thus a comprehensive understanding of salt tolerance in mangroves is important for their conservation and afforestation. However, little is known regarding salt-responsive mechanisms in H. nymphaeifolia.
Results
In this study, we posed gradient salt treatments on H. nymphaeifolia seedlings and investigated their physiological and transcriptional reprogramming in response to salinity stress. The results revealed that hyper-salinity stress adversely impacted on leaf growth, cell integrity and photosynthetic performance of H. nymphaeifolia seedlings than those growing in fresh water or low salt conditions, mirroring its moderate salinity tolerance as a mangrove associate. Genes involved in osmotic sensing and regulation, reactive oxygen species (ROS) scavenging and ion homeostasis were differentially expressed to alleviate the destructive effects. Furthermore, our results identified some kinase-encoding genes as hub genes in co-expression networks, which may play a key role in regulating the synergistic expression of salt-responsive genes upon stress conditions.
Conclusion
This research enriches our knowledge of the molecular mechanisms underlying the salinity tolerance of mangrove associates, which can theoretically assist the conservation and restoration of H. nymphaeifolia. Our findings also provide valuable genetic resources for future potential bioengineering applications in the fields of agriculture and forestry.
... True mangroves are a type of plant that truly grows in salty intertidal habitats (Djamaluddin, 2018), the habitat of coastal ecosystems that experience ebb and flow, high salinity changes, unstable substrates and low oxygen (Wang et al., 2011). In the study, 24 species were found to be true mangroves, consisting of Acanthus ilicifolius Bush habit, up to 2 m high. ...
... Associated mangroves are mangroves that grow behind the true mangrove zone, are tolerant of salinity, are transitional vegetation to land or sea, and can interact with true mangroves (Wang et al., 2011). In the study, 14 species were found to be associated mangroves, consisting of: Morinda citrifolia. ...
Karimunjawa National Park (TNK) area is ± 111,625 hectares covering 27 islands located in Jepara Regency, Central Java at the northern tip of Java Island. Karimunjawa became Karimunjawa National Park (TNK) based on the Decree of the Minister of Forestry and Plantation No.78/Kpts-II/1999 because it has high diversity. The complexity of ecosystems in TNK is interesting to study, such as coral reef ecosystems, mangrove forests, lowland tropical rainforests, seagrass meadows, seaweed, and coastal forests. The mangrove forest in Karimunjawa National Park is a unique ecosystem because it consists of many mangrove species. However, data on the diversity of mangrove species on this island has not been widely described. This study aims to reveal mangrove diversity in Karimunjawa National Park as a rescue strategy and explore the potential of mangrove biodiversity. This research is a descriptive study using the cruising method to explore mangrove species diversity. The location of mangrove diversity exploration is mangrove forest in Karimunjawa National Park. The results found 14 families consisting of 38 mangrove species. Among the 38 species, 24 species are true mangroves, while the other 14 species are associated with mangroves.
... Examples of minor mangrove species include Bruguiera ciliandra, Nypa fruticans, Intsia bijuga, Xylocarpus moluccensis, and others (Tomlinson 2016). Meanwhile, mangrove associates are a type of plants that have a lower ecological and physiological ability to survive in the mangrove ecosystem than true mangroves, characterized by the lower leaf succulence (two times lower than true mangroves), as well as the lower accumulation of Na and Cl (8-9 times lower than true mangroves) (Wang et al. 2011). The following plants are included in this classification: Acrostichum spp., Excoecaria agallocha, Heritiera littoralis, and Hernandia nymphaeifolia (Wang et al. 2011). ...
... Meanwhile, mangrove associates are a type of plants that have a lower ecological and physiological ability to survive in the mangrove ecosystem than true mangroves, characterized by the lower leaf succulence (two times lower than true mangroves), as well as the lower accumulation of Na and Cl (8-9 times lower than true mangroves) (Wang et al. 2011). The following plants are included in this classification: Acrostichum spp., Excoecaria agallocha, Heritiera littoralis, and Hernandia nymphaeifolia (Wang et al. 2011). ...
As a country with the widest mangrove forest area in the world, Indonesia has potential and challenges in preserving the mangrove ecosystem. Bekasi Regency is an area with a mangrove ecosystem that has experienced degradation, so research needs to be conducted to monitor the mangrove area and uncover land use by coastal communities. This research uses field data (including agricultural and fishing activities) in mangrove forest area in Bekasi Coastline Buffer Area, and remote sensing data from Sentinel-2 MultiSpectral Instrument (MSI) satellite data. In process analysis, using machine learning (ML) algorithm is the Support Vector Machine (SVM) and through in the advanced GEE computing platform. The analysis involves 11 indices consisting of vegetation indices, namely NDI, MNDVI, SAVI, SLAVI, and ARVI; water indices, namely NDWI, LSWI, and ANDWI; and building indices, namely IBI. The results of mangrove mapping obtained an area of 836.91 ha or equivalent to 6.57% of the area of Bekasi Regency and the Overall Accuracy (OA) results reached 90%, and Kappa Statistics (KS) were 0.8. The mapped mangrove areas have great potential in various aspects, especially playing a role in controlling land erosion, protecting against atmospheric disasters, and also contributing to controlling climate change. The silvofishery area which is a balance between mangroves and ponds, has great potential in sustainable land use and coastal ecosystem restoration.This research is expected to encourage policymakers to become one of the strategic policy supports that can quickly restore the mangrove ecosystem, thus controlling the threat of sea-level inundation that adds to the vulnerability area every year.
... This occurs due to the osmotic effect of the salt around the roots, which deters plant water uptake and causes leaf cells to lose water. However, this loss of cell volume and turgor is transient and reductions in cell elongation and also cell division lead to slower leaf appearance and smaller final size over the longer term (Munns and Tester 2008 (Dagar and Singh, 2007) [9] C. inerme has the characteristics of both true mangroves and mangrove associates (Wang et al., 2010) [52] . Irrigation water salinity has been reported to cause a quadratic reduction of the dry biomass of shoots, dry biomass of stems and height of plants (Fraga et al., 2010). ...
... This occurs due to the osmotic effect of the salt around the roots, which deters plant water uptake and causes leaf cells to lose water. However, this loss of cell volume and turgor is transient and reductions in cell elongation and also cell division lead to slower leaf appearance and smaller final size over the longer term (Munns and Tester 2008 (Dagar and Singh, 2007) [9] C. inerme has the characteristics of both true mangroves and mangrove associates (Wang et al., 2010) [52] . Irrigation water salinity has been reported to cause a quadratic reduction of the dry biomass of shoots, dry biomass of stems and height of plants (Fraga et al., 2010). ...
In the Floriculture industry apart from cultivation of loose flowers and cut flowers, the landscape gardening industry is a fast emerging and an innovative industry. In landscaping, plant components play a major role to make it more creative. Of these plants, ornamental shrubs play a key role in landscaping. Shrubs are the most diverse group of ornamentals grown in gardens. It may be defined as a perennial plant having many woody branches arising from the base of the plant while their upper shoots are soft. The growth habit of the shrubs is generally erect and bushy, attaining a height of 0.5 to 4 meters, while some shrubs grow prostrate in habit. They vary widely in stature and include dwarf bushes to those attaining the stature of small trees. It forms an integral and major part in landscaping. Any indoor or outdoor garden is incomplete without a shrub. Hence, ornamental landscaping is a commercially important element of the floriculture industry.
... However, for some species, a consensus among scientists was not found, and the classification remains debatable. Wang et al. (2010) defined these as 'controversial' species and differentiated them on the basis of leaf traits and osmotic properties. They categorised as 'controversial' those species for which there is, as yet, no acceptable classification consensus whether to include them in the group of true mangroves or in the group of mangrove associate species. ...
... Acrostichum auerum, Derris heterophylla and Xylocarpus rumphii are not considered mangrove species according to Kandasamy and Bingham (2001); Xylocarpus rumphii is a rare non-mangrove plant (Guo et al. 2018) and Acrostichum aureum and Derris heterophylla are mangrove associate species (Das et al. 2002;Mukherjee et al. 2006;Wang et al. 2010). On the basis of the above articles, we suggest that in the Maldives there are 14 mangrove species: A. marina, B. cylindrica, B. gymnorrhiza, B. hainesii, B. sexangula, C. tagal, E. agallocha, H. littoralis, L. racemosa, P. acidula, R. apiculata, R. mucronata, S. caseolaris and X. moluccensis, of which 3 are considered as controversial species, (E. ...
Mangrove forests are one of the most important biological, ecological and economic ecosystems in the world. In the Maldives, they play a crucial role in maintaining coastal biodiversity, providing ecosystem services, such as coastal protection, and supporting livelihoods by providing income and food. Overall, 23 Maldivian islands have at least 1 protected mangrove area. However, knowledge of the mangroves of the Maldives is scarce, scattered and sometimes conflicting. There is a lack of information on a national scale regarding their distribution, diversity, ecological importance and associated biodiversity. The aim of this review is to analyse scientific publications, reports, and online documents on mangroves for the entire Maldivian archipelago to provide the first comprehensive summary of the current state of knowledge of mangroves from a national perspective. This includes the geographical location of mangrove forests, the identity and distribution of mangrove species, ecosystem services, ecological importance and diversity of mangrove-associated flora and fauna. We analysed available information from both the grey literature and scientific publications and found that 14 mangrove species have been documented on 108 islands (9% of all Maldivian islands). Mangroves are mainly concentrated in northern atolls and are associated with diverse flora and fauna. Furthermore, we identified inconsistencies and gaps in the literature and proposed future directions for research. This is crucial for informed decision-making, developing effective conservation strategies and long-term sustainability of mangrove ecosystems.
... , 2016;Naidoo et al., 1997). However, it's difficult to quantify the response of GPP to tide cycles at present. The regulation of photosynthesis by tides in mangroves should be investigated in more detail in future studies (Cui et al., 2018). Besides, the temperature and salinity tolerance are different between mangrove species (X. Li et al., 2022;L. Wang et al., 2010), which should be parametrized for global scale simulation. The model uses satellite-based LAI products as input, which may induce uncertainties. In addition, the satellite-based LAI constrains the ability of future projections by the model. In the future, the model will focus on developing a module to simulate the LAI dynamics of mangro ...
... f LWP min :Leng and Cao (2020). g N: L.Wang et al., 2010. ...
Mangrove ecosystems are becoming increasingly important in global climate mitigation. However, large gaps still exist in evaluating mangroves' gross primary productivity (GPP) due to reasons such as the specific influences, for example, temperature and salt stresses are poorly described in Earth System Models (ESMs). This study developed a process‐based biogeochemical model (Mango‐GPP) to improve the GPP simulation in natural and restored mangroves. The model integrates mangrove‐specific physiological processes, including the response to salt and temperature stresses, as well as the light‐use efficiency at different growing stages. Eddy covariance flux measurements at two natural sites and one restored site in China were used to calibrate and validate Mango‐GPP. The model was calibrated by inverse analysis approach based on two cases and independently validated against the other cases. The validation results showed that it was generally capable of simulating the seasonal and interannual GPP variations at different sites. The simulated daily and annual GPPs agreed well with the observations and yielded R² of 0.67 and 0.96, with model efficiency of 0.64 and 0.93, respectively. In comparison, Mango‐GPP showed better performances than many current satellite‐based GPP products and ESMs. The model was more sensitive to solar radiation, carbon dioxide concentration, and leaf traits. Future improvements should focus on enhancing Mango‐GPP's descriptive power of key processes, and further simulating other carbon fluxes at regional scales. This work provides a model foundation for further simulating carbon exchanges between the atmosphere, mangrove, and ocean for studying the coastal wetland restoration on regional carbon neutrality.
... The mangrove vegetation contains the true mangroves and mangrove associates, whereas some studies in Bintuni focused more on the true mangroves. However, in the mangrove forest, plenty of vegetation was classified as mangrove associates that are part of vegetation diversity in the mangrove ecosystem (Wang et al. 2011;Chanda et al. 2016). The mangrove forest is more dynamic regarding substrates and sediments resulting from tidal activity. ...
... The protection forest is an undisturbed area, but the geographical position in this gulf is because mostly the protection forests are located in the outlier of the gulf. Thus, the seed dispersal process of whether true mangroves or mangrove associates counts on the hydrochory since the true mangrove provides the viviparous seeds as propagules (Kathiresan and Bingham 2001;Wang et al. 2011;Islam et al. 2022). The nature reserve is mainly located in the corner of the gulf, and the areas are shaped by the deposition of rivers creating many tide-dominated deltas in which vegetation, particularly true mangroves, grew (Fagherazzi 2008). ...
Kasihiw P, Bawole R, Marwa J, Murdjoko A, Wihyawari A, Heipon Y, Cabuy RL, Benu NMH, Hematang F. 2023. Floristic richness and diversity of Bintuni mangrove, Bird's Head Peninsula, West Papua, Indonesia. Biodiversitas 24: 2887-2897. Mangrove ecosystems play an important role in the functions of coastal protection, fish and other living-organism habitats, carbon storage, and the livelihood of local people. Yet, mangrove forests generally face ecological threats like anthropogenic pressures. However, fewer studies were carried out in this area, so this research aimed to reveal the vegetation diversity and richness in Bintuni, not only the true mangroves but also the mangroves associates with three different conditions, namely sandy areas called protection forests, disturbed forests called production forests, and delta called nature reserve. The results showed that species vegetation in the Bintuni Mangrove could be differentiated as true mangroves (29.82%) and mangrove associates (70.18%) of the total species richness of mangrove vegetation where in terms of taxonomic composition, the three forests encompassed 25 families, 47 genera, and 57 species clustered into 9 lifeforms. Then, the vegetation diversity and richness were highest in the nature reserve, and 34 (59.65% of total species number) species of vegetation in common share in three forest types. Consequently, frequent checking of vegetation richness is important since the Bintuni mangrove does not seem to have a significant threat like massive conversion of mangrove.
... These halophytic plants are categorized into two types which are true mangroves and mangrove associates. Wang et al. (2011) and Tomlinson (1986) established criteria to differentiate between them and their criteria for true mangroves are composed of these features: (i) strictly distributed to the mangrove environment which does not go beyond the terrestrial areas; (ii) specialized adaptations of their morphology like the root system and type of reproduction; (iii) osmoregulation or salt excretion as a physiological mechanism; and (iv) being taxonomically separated from other plant relatives in the terrestrial environment. ...
... This reciprocal learning approach facilitated the exchange of expertise between parties. During this interaction, the space scientists were introduced to Pemphis acidula, locally known as Bantigi (Figure 9), a mangrove species typically found in landward zones of mangrove forests and sheltered beaches (Wang et al., 2011). Notably, this species is classified as rare and threatened by the Department of Environment and Natural Resources (DENR) due to its exploitation for bonsai purposes (Evangelista, 2018). ...
Mangroves are crucial coastal ecosystems. They provide numerous ecological and socio-economic benefits – shoreline protection, carbon sequestration, food security, and biodiversity conservation. The Philippine Mangrove Map 2023, generated through Machine Learning, improves understanding, accounting, and conserving these vital habitats. However, ensuring the accuracy and reliability of maps is imperative for informed decision-making and effective conservation efforts. Various validation methods were reviewed to develop a nationwide approach integrating practicality and statistical rigor, incorporating multiple data sources such as satellite and airborne imagery and GPS points from the government, civil society, and citizens. Capacity building enabled large-scale citizen science collaboration to gather quality datasets and foster reciprocal learning between scientists and local citizens. This collaborative effort aims to improve the quality of datasets and ultimately enhance the accuracy of the Philippine Mangrove Map 2023 and succeeding mangrove extents maps.
... The floral species in mangrove ecosystem can be categorized into true mangroves and mangrove associates (Selvam, 2007;Wang et al., 2011). The species which are adapted to mangrove habitat and do not extend into other terrestrial plant communities are referred to as true mangrove species. ...
The mangrove ecosystem of Indian Sundarbans in the lower Gangetic delta region sustains a number of mangrove associate floral species whose ecosystem services have not been properly evaluated. We present here few ecosystem services of Porteresia coarctata and Ipomoea pes-caprae in the sphere of environment upgradation and alternative livelihood. Recent advancements in these two sectors have opened up a new horizon, which has high potential to improve the economic profile of the people living in this mangrove dominated lower Gangetic delta region. Life Sciences International Standard Serial Number (ISSN): 2249-6807
... According to Harun-or-Rashid et al. [69], if a cyclone occurs near the fruiting season of mangrove species, the disturbed area can be quickly recolonized and regenerated by these species. In contrast, cyclones occurring outside the seeding season may favor the establishment of non-mangroves and mangrove associates, which are more tolerant to salinity and disturbances [70]. Additionally, disturbance-and saline-tolerant species like E. agallocha, which are fast-growing, can quickly occupy degraded regions [69]. ...
The Sundarbans is the world’s largest contiguous mangrove forest with an area of about 10,000 square kilometers and shared between Bangladesh and India. This world-renowned mangrove forest, located on the lower Ganges floodplain and facing the Bay of Bengal, has long served as a crucial barrier, shielding southern coastal Bangladesh from cyclone hazards. However, the Sundarbans
mangrove ecosystem is now increasingly threatened by climate-induced hazards, particularly tropical cyclones originating from the Indian Ocean. To assess the cyclone vulnerability of this unique ecosystem, using geospatial techniques, we analyzed the damage caused by past cyclones and the subsequent recovery across three salinity zones, i.e., Oligohaline, Mesohaline, and Polyhaline. Our study also
examined the relationship between cyclone intensity with the extent of damage and forest recovery. The
findings of our study indicate that the Polyhaline zone, the largest in terms of area and with the lowest elevation, suffered the most significant damage from cyclones in the Sundarbans region, likely due to its proximity to the most cyclone paths. A correlation analysis revealed that cyclone damage positively correlated with wind speed and negatively correlated with the distance of landfall from the center of the
Sundarbans. With the expectation of more extreme weather events in the near future, the Sundarbans mangrove forest faces a potentially devastating outlook unless both natural protection processes and human interventions are undertaken to safeguard this critical ecosystem.
... Mangroves are exclusive plant species that are adapted to the tidal mangrove habitat, and do not extend into other coastal habitats such as sandy beaches and rocky shores. Plants that occur in all coastal habitats including mangroves are known as mangrove associates or nonexclusive species [1,2]. Mangroves are exclusive species, which are adapted to the mangrove habitat, and do not extend into other terrestrial plant communities. ...
In this article, the diversity of mangrove and associate species with anticancer properties are reviewed. Information included their scientific names, synonyms, common names, families and life-forms. Their anticancer properties are documented with description on cancer cell types, effects and mechanisms. Mangroves are exclusive species confined to the mangrove habitat. Plants that occur in the coastal environment and also in mangroves are associates or non-exclusive species. In this article, species with anticancer properties are 25 mangrove species belonging to 17 genera and 11 families, and 31 associate species belonging to 28 genera and 20 families possess. Most reported mangrove species are Avicennia marina and Ceriops tagal with five and four studies, respectively. Associate species most reported are Talipariti tiliaceum or Hibiscus tiliaceus with five studies, followed by Anacardium occidentale, Artocarpus altilis, Ceriops manghas, Pluchea indica and Pongamia pinnata with four studies each. In the conservation of mangrove and associate species with anticancer properties, in in-situ conservation, species are protected in their natural surroundings as ecosystems (e.g., virgin jungle reserves and Ramsar sites) while in ex-situ conservation, species are protected outside their natural habitats (e.g., arboreta and botanical gardens).
... Mangroves are exclusive plant species that are adapted to the tidal mangrove habitat, and do not extend into other coastal habitats such as sandy beaches and rocky shores. Plants that occur in all coastal habitats including mangroves are known as mangrove associates or nonexclusive species [1,2]. Mangroves are exclusive species, which are adapted to the mangrove habitat, and do not extend into other terrestrial plant communities. ...
In this article, the diversity of mangrove and associate species with anticancer properties are reviewed. Information included their scientific names, synonyms, common names, families and life-forms. Their anticancer properties are documented with description on cancer cell types, effects and mechanisms. Mangroves are exclusive species confined to the mangrove habitat. Plants that occur in the coastal environment and also in mangroves are associates or non-exclusive species. In this article, species with anticancer properties are 20 mangrove species belonging to 13 genera and 11 families, and 26 associate species belonging to 24 genera and 17 families possess. Most reported mangrove species are Avicennia marina and Ceriops tagal with five and four studies, respectively. Associate species most reported are Talipariti tiliaceum or Hibiscus tiliaceus with five studies, followed by Anacardium occidentale, Artocarpus altilis, Ceriops manghas, Pluchea indica and Pongamia pinnata with four studies each. In the conservation of mangrove and associate species with anticancer properties, in in-situ conservation, species are protected in their natural surroundings as ecosystems (e.g., virgin jungle reserves and Ramsar sites) while in ex-situ conservation, species are protected outside their natural habitats (e.g., arboreta and botanical gardens).
... According to Harun-or-Rashid et al. [69], if a cyclone occurs near the fruiting season of mangrove species, the disturbed area can be quickly recolonized and regenerated by these species. In contrast, cyclones occurring outside the seeding season may favor the establishment of non-mangroves and mangrove associates, which are more tolerant to salinity and disturbances [70]. Additionally, disturbance-and saline-tolerant species like E. agallocha, which are fast-growing, can quickly occupy degraded regions [69]. ...
The Sundarbans is the world’s largest contiguous mangrove forest with an area of about 10,000 square kilometers and shared between Bangladesh and India. This world-renowned mangrove forest, located on the lower Ganges floodplain and facing the Bay of Bengal, has long served as a crucial barrier, shielding southern coastal Bangladesh from cyclone hazards. However, the Sundarbans mangrove ecosystem is now increasingly threatened by climate-induced hazards, particularly tropical cyclones originating from the Indian Ocean. To assess the cyclone vulnerability of this unique ecosystem, using geospatial techniques, we analyzed the damage caused by past cyclones and the subsequent recovery across three salinity zones, i.e., Oligohaline, Mesohaline, and Polyhaline. Our study also examined the relationship between cyclone intensity with the extent of damage and forest recovery. The findings of our study indicate that the Polyhaline zone, the largest in terms of area and with the lowest elevation, suffered the most significant damage from cyclones in the Sundarbans region, likely due to its proximity to the most cyclone paths. A correlation analysis revealed that cyclone damage positively correlated with wind speed and negatively correlated with the distance of landfall from the center of the Sundarbans. With the expectation of more extreme weather events in the near future, the Sundarbans mangrove forest faces a potentially devastating outlook unless both natural protection processes and human interventions are undertaken to safeguard this critical ecosystem.
... Furthermore, this genus exhibits higher adaptability to changes in sporulation patterns under diverse environmental conditions, leading to their dominance (Stutz and Morton, 1996). A previous study revealed that the basic nature of mangrove soil might assured Glomus presence (Wang et al., 2011). The presence of a high AMF species diversity in Henry Island gives a clear indication of the site's diversity. ...
Mangroves, despite thriving at the fringes of habitat tolerance in coastal regions, stand out as one of the world's most highly productive ecosystems. This study delves into the remarkable symbiotic relationship between mangroves and arbuscular mycorrhizal fungi (AMF). Specifically, it assesses seasonal diversity in six true mangrove species and four associated species, situated in Henry's Island, Bakkhali, India. Spore density and root colonization were examined across different seasons. The highest spore density was observed in Heritiera fomes (a timber-producing mangrove) during the post-monsoon season, followed by pre-monsoon and monsoon periods. Root colonization was notably prominent in Ceriops tagal (Indian mangrove), Bruguira gymnorrhiza (Oriental mangrove), and Sonneratia alba (flowering evergreen mangrove) during both pre-and post-monsoon seasons. This study unveiled a rich fungal diversity, with a total of 60 AMF species belonging to 13 genera. Among these, the genus Glomus emerged as the dominant group, with species such as G. deserticola along with another genus Rhizophagus intraradics displaying widespread distribution. Notably, Glomus consistently ranked as the most prevalent genus throughout the year, indicating its remarkable adaptability and strong dispersal capacity in both true and associate mangrove plant species. This research sheds light on the seasonal dynamics of AMF associations in mangrove ecosystems, emphasizing the significance of Glomus as a key player in this symbiotic relationship. These findings contribute to our understanding of the ecological intricacies within mangrove habitats and highlight the adaptability of certain AMF genera to varying environmental conditions.
... Plant identity significantly affected both the diversity and community structure of phyllosphere epiphytic and endophytic bacteria, as previous studies have shown 44,57,58 . Various plant species possess various functional traits, such as specific leaf area, nutrient content, osmotic properties, respiration rate, and dust retention efficiency which are significantly correlated with the surface bacteria community of leaf and stem [59][60][61] . In various samples of UGS's type, microbial communities exhibited inherent differences, possibly due to their inherent adaptability. ...
The benefits of urban green space are socially widely recognized as a direct link between plant–microbe interactions and the maintenance of biodiversity, community stability, and ecosystem functioning. Nevertheless, there is a lack of knowledge about the factors influencing microbial communities in urban green spaces, especially those related to phyllosphere epiphytes and stem epiphytes. In this study, we analyzed the microbial community assembly in leaf and stem bark samples collected from Square, Road, Campus, and Park. Illumina sequecing of 16S amplicons was performed to characterize microbial diversity and composition. The α-diversity was significantly higher in the bark epiphytic community, compared to the phyllosphere. Moreover, urban greenspaces'type altered the way communities gathered. The main soil and air properties factors of the urban greenhouse (e.g. soil temperature, atmospheric moisture, air temperature) were shaping the characteristics of bacterial communities on the leaf surface and bark epiphytic. In addition, in the co-occurrence network analysis, keystone taxa were not mostly observed in abundant species, which may be necessary to maintain ecosystem functions. Finally, our findings provide a deeper understanding of the ecological dynamics and microbial interactions within plant phyllosphere and stem epiphytes microbiomes.
... In the true mangrove plant, Avicennia marina, the expression level of the SOS1 gene is up-regulated by NaCl and nitric oxide (NO) (Chen et al. 2010). Pongamia is a semimangrove (also called mangrove associate) because it can grow in either freshwater or moderate salinity water (Wang et al. 2010). Pongamia grows well at 500 mM NaCl stress for 15 days without visible stress symptoms (Marriboina et al. 2017). ...
A high concentration of sodium (Na⁺) is the primary stressor for plants in high salinity environments. The Salt Overly Sensitive (SOS) pathway is one of the best-studied signal transduction pathways, which confers plants the ability to export too much Na⁺ out of the cells or translocate the cytoplasmic Na⁺ into the vacuole. In this study, the Salt Overly Sensitive3 (MpSOS3) gene from Pongamia (Millettia pinnata Syn. Pongamia pinnata), a semi-mangrove, was isolated and characterized. The MpSOS3 protein has canonical EF-hand motifs conserved in other calcium-binding proteins and an N-myristoylation signature sequence. The MpSOS3 gene was significantly induced by salt stress, especially in Pongamia roots. Expression of the wild-type MpSOS3 but not the mutated nonmyristoylated MpSOS3-G2A could rescue the salt-hypersensitive phenotype of the Arabidopsis sos3-1 mutant, which suggested the N-myristoylation signature sequence of MpSOS3 was required for MpSOS3 function in plant salt tolerance. Heterologous expression of MpSOS3 in Arabidopsis accumulated less H2O2, superoxide anion radical (O2⁻), and malondialdehyde (MDA) than wild-type plants, which enhanced the salt tolerance of transgenic Arabidopsis plants. Under salt stress, MpSOS3 transgenic plants accumulated a lower content of Na⁺ and a higher content of K⁺ than wild-type plants, which maintained a better K⁺/Na⁺ ratio in transgenic plants. Moreover, no development and growth discrepancies were observed in the MpSOS3 heterologous overexpression plants compared to wild-type plants. Our results demonstrated that the MpSOS3 pathway confers a conservative salt-tolerant role and provided a foundation for further study of the SOS pathway in Pongamia.
... They consist of around 73 species of trees and shrubs (Sandilyan & Kathiresan, 2012). They are classified as true mangroves(which have stilt roots for breathing or viviparous germination) and mangrove associates (Wang et al., 2011). They are one of the world's most productive ecosystems with average gross and net primary production rates of 4.6 kg C/ha and 1.9 kg C/ha respectively (Alongi, 2009). ...
Mangroves are woody halophytes that live in salt or brackish water. They act as habitats for terrestrial and marine flora and fauna, as ecosystem engineers shaping and maintaining the intertidal zone, as a renewable resource of wood and fuel, and as key accumulation sites for soils, sediment particles, and associated elements. They consist of around 73 species of trees and shrubs. They are classified as true mangroves (which have stilt roots for breathing or viviparous germination) and mangrove associates. They are one of the world's most productive ecosystems with average gross and net primary production rates of 4.6 kg C/ha and 1.9 kg C/ha respectively. The estimated total mangrove forest area of the world in 2000 was 137,760 km² in 118 countries and territories. The total mangrove area accounts for 0.7% of the total tropical forests of the world. The largest extent of mangroves is found in Asia (42%) followed by Africa (20%), North and Central America (15%), Oceania (12%) and South America (11%). Approximately 75% of mangroves are concentrated in just 15 countries.
The internship was based on various methods and techniques used to understand the salt stress tolerance of mangroves on a genetic level.
... Some studies have revealed the floristic aspect concerning species richness and diversity where the species number was 57 consisting of true mangroves (29.82%) and mangrove associates (70.18%) (Sillanpää et al. 2017;Kasihiw et al. 2023). Mangrove forest is a habitat of not only true mangroves, but also mangrove associates which are important in coastal ecosystems (Wang et al. 2011;Sarker et al. 2019b;Otero et al. 2020). The mangrove forest in Teluk Bintuni also contains species with conservation status of Near Threatened and Vulnerable (Kasihiw et al. 2023). ...
Kasihiw P, Bawole R, Marwa J, Murdjoko A, Wihyawari A, Heipon Y, Cabuy RL, Benu NMH, Hematang F, Leftungun NY. 2024. Mangrove distribution to support biodiversity management in Teluk Bintuni District, West Papua, Indonesia. Biodiversitas 25: 644-653. Mangroves play an important role in coastal ecosystems, but the areas of mangroves are decreasing globally. Understanding the ecological and geographical distribution of mangroves will be useful to develop sustainable management and policy. Thus, this study aimed to analyze the ecological and geographical distribution of mangroves in Teluk Bintuni, West Papua, Indonesia. The distribution of mangroves was investigated to see the relationships between elevation and the number of individual mangroves at the family level. Vegetation data were collected by setting 180 circular plots and geographical data were obtained from secondary sources. Our study revealed that Rhizophoraceae family was found in all plots with 97.78% presence, whereas Acanthaceae and Meliaceae families were found in half of the plots with 65% and 60.56% presence, respectively. Lythraceae, Primulaceae, Malvaceae, and Arecaceae were only found in 15% of the plots. Elevation affected significantly the presence of mangroves which there mainly occurred in elevation between 10-30 m asl, while they were lower in below 10 m asl and above 30 m asl. Species belonging to Acanthaceae and Lythraceae, such as those from the genera of Avicennia and Sonneratia, were found more abundant in the low elevation (seaward zone) than in the higher elevation (landward zone). In contrast, species belonging to Meliaceae and Rhizophoraceae were more abundant in the landward zone with the presence of genera Xylocarpus, Bruguiera, Ceriops, and Rhizophora. The distribution of Arecaceae, Malvaceae, and Primulaceae did not show a significant pattern where they appeared randomly in mangrove forests. Geographically, 12.43% area of Teluk Bintuni District was mangroves which mainly occurred in the eastern and southern parts. Based on forest status, 2.23%, 35.60%, 10.46%, and 51.71% of mangroves in Teluk Bintuni occur in non-forestry use areas (Area Penggunaan Lain/APL), conservation forest (Hutan Konservasi) in the form of nature reserve, protected forest (Hutan Lindung), and production forest (Hutan Produksi), respectively. As the mangrove ecosystem has been part of local people, the specific management to support biodiversity in mangrove forests must be put officially in the development program.
... There are 587 halophytes in China, including three species of ferns, two of which are Acrostichum species [71]. In addition, since the sister clade Ceratopteris occupies freshwater habitats, Acrostichum species may have evolved a suite of traits and molecular mechanisms to thrive under high-salinity conditions [72][73][74]. Thus, the Acrostichum genus is an excellent sample for understanding high salinity adaptation in ferns. ...
As the only aquatic lineage of Pteridaceae, Parkerioideae is distinct from many xeric-adapted species of the family and consists of the freshwater Ceratopteris species and the only mangrove ferns from the genus Acrostichum. Previous studies have shown that whole genome duplication (WGD) has occurred in Parkerioideae at least once and may have played a role in their adaptive evolution; however, more in-depth research regarding this is still required. In this study, comparative and evolutionary transcriptomics analyses were carried out to identify WGDs and explore their roles in the environmental adaptation of Parkerioideae. Three putative WGD events were identified within Parkerioideae, two of which were specific to Ceratopteris and Acrostichum, respectively. The functional enrichment analysis indicated that the lineage-specific WGD events have played a role in the adaptation of Parkerioideae to the low oxygen concentrations of aquatic habitats, as well as different aquatic environments of Ceratopteris and Acrostichum, such as the adaptation of Ceratopteris to reduced light levels and the adaptation of Acrostichum to high salinity. Positive selection analysis further provided evidence that the putative WGD events may have facilitated the adaptation of Parkerioideae to changes in habitat. Moreover, the gene family analysis indicated that the plasma membrane H⁺-ATPase (AHA), vacuolar H⁺-ATPase (VHA), and suppressor of K⁺ transport growth defect 1 (SKD1) may have been involved in the high salinity adaptation of Acrostichum. Our study provides new insights into the evolution and adaptations of Parkerioideae in different aquatic environments.
... Information about mangrove types in each literature was presented in the distribution table in each region and classified based on criteria (true or associate mangrove) and flora habitus (tree, shrubs, herbs, palm, epiphyte, lianas, fern, and parasites). According to Wang et al. (2010), true mangrove comprises halophytes (tolerant of high salt levels), while associates include glycophytes (only tolerates certain salt concentration levels). ...
This study was conducted to analyze the biodiversity of mangrove species and fauna in Indonesia as well as the management strategies for its preservation. The results showed that the total number of mangrove species was 240, consisting of 48 true and 192 associated mangrove. This number also comprised 74 trees, 36 shrubs, 52 herbs, six palms, 43 epiphytes, 23 lianas, three ferns, and three parasite species. Aglaia mackiana was identified as a new record in the Papua region attributed to the New Guinea Coastal Current (NGCC), while Ceriops australis was newly found in regions of Papua, Bali—Nusa Tenggara (Timor, Flores, Sumbawa), Java, and Sumatra (Pulau Bilinton). The diversity of marine fauna in the mangrove area consisted of 125 fish species from 47 families and 169 macrozoobenthos from 52 families. In addition, there were 161 terrestrial faunas, consisting of 80 birds, 38 squamata, four crocodiles, six amphibians, 11 testudinate, and 21 mammal species. This high level of biodiversity was influenced by the commitment of the Indonesian government to managing mangrove ecosystems through conservation. These efforts were carried out to preserve and improve ecosystem services such as mangrove biodiversity, carbon stock potential, coastal protection, and the unique biodiversity of marine and terrestrial fauna. Based on the results, incredibly unique fauna included Crocodilus found in Papua, Kalimantan, Java, and Sumatra region, Halcyon sp. in Papua and Java region, Anhinga sp. in Kalimantan and Java region, as well as Nasalis larvatus in Kalimantan.
... The floral species in mangrove ecosystem can be categorized into true mangroves and mangrove associates (Selvam, 2007;Wang et al., 2011). The species which are adapted to mangrove habitat and do not extend into other terrestrial plant communities are referred to as true mangrove species. ...
The mangrove ecosystem of Indian Sundarbans in the lower Gangetic delta region sustains a number of mangrove associate floral species whose ecosystem services have not been properly evaluated. We present here few ecosystem services of Porteresia coarctata and Ipomoea pes-caprae in the sphere of environment upgradation and alternative livelihood. Recent advancements in these two sectors have opened up a new horizon, which has high potential to improve the economic profile of the people living in this mangrove dominated lower Gangetic delta region.
... Mangrove associates are different from the true mangroves. Mangrove associates are found in the land region of the mudflat rather than shoreline region where true mangroves are found (Wang et al., 2010). They lack physiologically adaptation as compared to true mangroves. ...
The chapter is about the mangrove diversity in Indian Subcontinent
... Mangroves are trees growing in the intertidal zone of the tropical ocean and are classified into true mangroves and semi-mangroves (also called mangrove associates) (Duke, 2017;Huang et al., 2012;Nizam et al., 2022). Semi-mangroves are glycophytes, but they can also grow in both fresh water and high-salinity water (Kazakoff et al., 2010;Wang et al., 2010). Pongamia (Millettia pinnata syn. ...
Abiotic stress, such as salt and drought stress, seriously limits plant growth and crop yield. Abscisic acid (ABA) is essential in regulating plant responses to abiotic stress via signal perception, transduction, and transcriptional regulation. Pongamia (Millettia pinnata) is a kind of semi-mangrove plant with strong stress tolerance and can grow in fresh and sea water. However, the molecular mechanism of the ABA signaling pathway mediating the environmental tolerance of Pongamia is still scarce so far. AITR (ABA-Induced Transcription Repressor) was a recently identified small conserved family of transcription factor in angiosperms, which played controversial roles in response to abiotic stresses in different species. Here, we identified an ABA-induced gene, MpAITR1, which encoded a nucleus localization transcriptional factor in Pongamia. MpAITR1 was highly induced by ABA and salt treatments in roots and leaves. Heterologous expression of MpAITR1 in Arabidopsis increased sensitivity to ABA, moreover, enhanced tolerance to salt and drought stress. The expression levels of some ABA-responsive and stress-responsive genes were altered in transgenic plants compared to wild-type plants under the ABA, salt, and drought stress, which was consistent with the stress-tolerant phenotype of transgenic plants. These results reveal that MpAITR1 positively modulates ABA signaling pathways and enhances the tolerance to salt and drought stress by regulating downstream target genes. Taken together, MpAITR1 from the semi-mangrove plant Pongamia serves as a potential candidate for stress-tolerant crop breeding.
... The floral species in mangrove ecosystem can be categorized into true mangroves and mangrove associates (Selvam, 2007;Wang et al., 2011). The species which are adapted to mangrove habitat and do not extend into other terrestrial plant communities are referred to as true mangrove species. ...
The mangrove ecosystem of Indian Sundarbans in the lower Gangetic delta region sustains a number of mangrove associate floral species whose ecosystem services have not been properly evaluated. We present here few ecosystem services of Porteresia coarctata and Ipomoea pes-caprae in the sphere of environment upgradation and alternative livelihood. Recent advancements in these two sectors have opened up a new horizon, which has high potential to improve the economic profile of the people living in this mangrove dominated lower Gangetic delta region. Life Sciences International Standard Serial Number (ISSN): 2249-6807
... The total mangrove area in China is approximately 27,100 ha, and species account for approximately one-third of the total mangrove species worldwide (Chen et al., 2009). The latitudinal span, and the transition of salinity from seaward to landward, would affect tree height and phenology for mangrove species (Li and Lee, 1997;Wang et al., 2010). Furthermore, anthropogenic activities (e. g., coastal farming and coastal development) have resulted in the fragmentation of mangroves, as well as various vegetation near water having a similar appearance to mangroves in RS imagery (Gao, 1998;Hu et al., 2018;Vo et al., 2013). ...
... The higher number of listings was due to the inclusion of a few mangrove hybrids, Intsia bijuga and Finlaysonia obovata, as exclusive mangroves, and these were reported as mangrove associates by Giesen et al. (2006) and Tomlinson (1986). Mangrove associates are mostly found in terrestrial or aquatic habitats but are also commonly found in mangrove ecosystems (Tomlinson, 1986;Wang et al., 2011). ...
Mangroves in wetland ecosystems are diverse and play significant role in the adjacent communities on which they are dependent for their livelihoods. It is also important for fishery resources and nutrient inputs in marine and brackish water ecosystems. However, little is known about the tropical wetland lagoon ecosystems, particularly mangrove diversity and assemblages. Therefore, this present study was initiated to observe the mangrove species diversity and assemblages together with the conservation status in an important tropical wetland ecosystem in Setiu, Terengganu, Malaysia. In a variety of landward and small fringe island areas, three zones of square plots were selected (zones 1, 2 and 3) to address the objectives of this study. As a result, a total of 20 true mangrove species belonging to 11 genera from nine families were documented, of which, Avicennia rumphiana was listed as vulnerable (VU) by the IUCN. Twelve species of mangrove associates from 11 genera and nine families were also found in the investigated zones at Setiu. One of the mangrove associates, Intsia bijuga, was designated as vulnerable (VU) by the IUCN. The Shannon diversity index (H') of mangroves was found to be 1.08 at Setiu Wetland. Rhizophora mucronata was found to be well-expanded (H' = 1.05) followed by A. rumphiana, A. officinalis, Heritiera littoralis, A. corniculatum. Excoecaria agallocha, Lumnitzera racemosa, and A. ebracteatus (H' = 0.0) as the lowest. The findings of the present study revealed that mangroves in the Setiu Wetland are diverse and healthy compared to other mangrove ecosystems in the region. To maintain the health and function of the mangrove ecosystem in Setiu Wetland, proper monitoring is required.
... Mangroves are a polyphyletic group of halophytic woody plants restricted to tropical and subtropical intertidal zones [1]. They are further classified into true mangroves and mangrove associates based on salt-tolerant traits and ecological adaptations [2]. Kandelia candel (L.) Druce and Rhizophora mucronata Lam. are true viviparous mangroves that belong to the Rhizophoraceae family [3,4]. ...
Secondary metabolites in mangroves often interfere with RNA extraction yielding poor concentration and quality, which is unsuitable for downstream applications. As existing protocols yielded low-quality RNA from root tissues of Kandelia candel (L.) Druce and Rhizophora mucronata Lam., an optimized method was developed for improving the quality and yield of RNA. Compared with three other methods, this optimized protocol gave better RNA yield and purity for both species. The absorbance ratios were ≥1.9 for A260/280 and A260/230, while RNA integrity number values ranged from 7.5 to 9.6. Results show that our modified method is efficient in obtaining high-quality RNA from mangrove roots and is suitable for downstream experiments such as cDNA synthesis, real-time quantitative PCR and next-generation sequencing.
... Meanwhile, Wang et al., (2011) utilized leaf structural characteristics and osmotic properties to characterize variation among 33 mangrove species (17 true mangroves, 6 mangrove associates and 10 controversial species) in China. Results showed that the specific leaf area and leaf nitrogen concentration on a leaf mass of true mangroves were lower than those of mangrove associates; leaf succulence was, on average, twice as high in true mangroves compared to mangrove associates; true mangroves accumulated 8-9 times more Na and Cl than mangrove associates; and the former had K/Na ratios 0.5, whereas the latter had K/Na ratios >0.5. ...
This laboratory work used maturase K (matK) protein sequences to conduct a molecular phylogenetic analysis of several Philippine mangrove species. It looked specifically at the relationship between true mangrove species and mangrove associates. The analysis included twenty (23) different true mangrove species from twelve (12) different families species as listed by Primavera et al., (2004) and one (1) outgroup species, Talipariti tiliaceum. The matK reference coding sequences (RefSeq) of the different mangrove species were obtained from the National Center for Biotechnology Information (NCBI) and aligned with the Molecular Evolutionary Genetics Analysis (MEGA) software via the Multiple Sequence Comparison by Log-Expectation (MUSCLE) program. MEGA was also used to determine the phylogeny of the mangrove species using the aligned sequence and the maximum parsimony (MP) method with the subtree-Pruning-Regrafting algorithm. The evolutionary history of the mangrove species was deduced using the MP method, with the most parsimonious tree among the top five (length = 1703). The consistency index is 0.671169 (0.626418) for all sites and parsimony-informative sites, the retention index is 0.800357 (0.800357), and the composite index is 0.537174. (0.501357). The generated phylogenetic tree was unrooted, confirming the hypothesis that true mangrove species will be clustered into clades with clear distinctions at the family and genus levels. However, the ingroup Heritiera and Xylocarpus species that were initially identified as true mangrove species were discovered to be closest relatives of T. tiliaceum, an outgroup mangrove associate. This study extended the understanding that Heritiera and Xylocarpus are mangrove associates together with T. tiliaceum as evidenced by their characteristics that set them apart from the true mangrove species. Moreover, H. littoralis was inferred to be the first taxon to evolve from the root. Altogether, this bioinformatics analysis indicates that matK protein is a useful molecular marker for identifying and inferring relationships of mangrove species. The high bootstrap values observed in the phylogenetic tree suggest the high internal consistency of the inferred relationships between mangrove species.
... Microbial communities inhabiting mangroves have received increasing attention because mangroves have important ecological roles and provide a wide range of services in environment and economy (Taylor et al., 2003). In mangrove forests, different microbial communities in the phyllosphere of true mangroves and mangrove associates (two categories of mangrove species) are anticipated due to that they have significantly different leaf physiological and ecological traits (Wang et al., 2011). However, only community structure and network properties of phyllosphere fungi on true mangroves have been investigated and reported (Yao et al., 2019). ...
Microorganisms can influence plant growth and health, ecosystem functioning, and stability. Community and network structures of mangrove phyllosphere fungi have rarely been studied although mangroves have very important ecological and economical values. Here, we used high throughput sequencing of the internal transcribed spacer 2 (ITS2) to assess epiphytic and endophytic phyllosphere fungal communities of six true mangrove species and five mangrove associates. Totally, we obtained 1,391 fungal operational taxonomic units (OTUs), including 596 specific epiphytic fungi, 600 specific endophytic fungi, and 195 shared fungi. The richness and community composition differed significantly for epiphytes and endophytes. Phylogeny of the host plant had a significant constraint on epiphytes but not endophytes. Network analyses showed that plant–epiphyte and plant–endophyte networks exhibited strong specialization and modularity but low connectance and anti-nestedness. Compared to plant–endophyte network, plant–epiphyte network showed stronger specialization, modularity, and robustness but lower connectance and anti-nestedness. These differences in community and network structures of epiphytes and endophytes may be caused by spatial niche partitioning, indicating their underlying ecological and environmental drivers are inconsistent. We highlight the important role of plant phylogeny in the assembly of epiphytic but not endophytic fungal communities in mangrove ecosystems.
... The floral species in mangrove ecosystem can be categorized into true mangroves and mangrove associates (Selvam, 2007;Wang et al., 2011). The species which are adapted to mangrove habitat and do not extend into other terrestrial plant communities are referred to as true mangrove species. ...
The mangrove ecosystem of Indian Sundarbans in the lower Gangetic delta region sustains a number of mangrove associate floral species whose ecosystem services have not been properly evaluated. We present here few ecosystem services of Porteresia coarctata and Ipomoea pes-caprae in the sphere of environment upgradation and alternative livelihood. Recent advancements in these two sectors have opened up a new horizon, which has high potential to improve the economic profile of the people living in this mangrove dominated lower Gangetic delta region. Life Sciences International Standard Serial Number (ISSN): 2249-6807
Mangroves are the only species that survive in harsh conditions where no other species can survive. They mainly found at intertidal zones of tropical and subtropical regions of all over the world. They form a bridge between terrestrial and aquatic ecosystem and enables flow of energy between them. These woody species consist various adaptation in anatomy, physiology and morphology to survive in harsh environment conditions. This forest provides important and unique ecosystem good and services to human society as well as to coastal and marine ecosystem. Biotic pressure and natural calamities are the enemies of these ecosystems. Urbanisation and industrialization are the main cause of deforestation of the mangal. Due to pollution and over extraction caused by aquaculture, agriculture and urban development, large scale deforestation of these ecosystem has been recorded in past few decades. Intensive conservation efforts are needed to conserve these sensitive ecosystems. The ecology, diversity and distribution of mangroves in Glob, in India and particular in Gujarat has been reviewed in this paper. The data obtained from various literature of the authors had been analysed. Also, the importance, threats and conservation strategies to protect these ecosystems were also reviewed in briefly.
Climate change and global warming continue to occur up to the present. One of the gases significantly influencing climate change is carbon dioxide (CO2). The increase in CO2 can be mitigated by capturing carbon from the atmosphere and storing it in biomass in a process known as carbon sequestration. Forests play a crucial role as a mitigator in reducing global warming and climate change, acting as both a carbon sink and absorber. Mangrove forests, in particular have a high capacity for carbon storage, approximately three times more than terrestrial forests. This research aims to (1) assess the health condition of the mangrove forests in Pesawaran Regency and (2) estimate the CO2 absorption produced by Pesawaran Regency. The study utilizes Sentinel-2 satellite imagery and field data collection. Sentinel-2 images undergo Normalized Difference Vegetation Index (NDVI) transformation. The research results indicate that the mangrove forests in Pesawaran Regency in 2023 are predominantly in good condition, covering an area of 562,31 hectares (99%), while 6,12 hectares (1%) are in a degraded condition. The CO2 absorption by the mangrove forests pesawaran regency is estimated to be 336.367,47 tons CO2 and 591,75 tons CO2/ha.
Remote sensing technologies offer significant potential for monitoring mangrove ecosystems, which serve as invaluable hubs of biodiversity and providers of crucial ecosystem services (ESs). In the face of mounting threats from human activities and climate change, effective monitoring becomes paramount to safeguarding their health and the services they offer. Remote sensing and Earth observation techniques present exceptional opportunities for monitoring mangrove ecosystems and their ESs. Despite the successful use of remote sensing and Earth observation-based technologies in mapping and monitoring mangrove ecosystems, few studies have been undertaken to utilize them for assessing mangrove ESs. This paper explores the vast potential of remote sensing and Earth observation in monitoring mangrove ecosystems and assessing their ESs. Through a comprehensive review and discussion of relevant scientific literature, researchers also have employed various sensors to study carbon stocks, species diversity, biomass, and related topics. These findings provide a set of values data essential for protecting, preserving, and conserving these ecosystems and their resources, thereby facilitating better management, planning, and policymaking. By leveraging these technologies, policymakers, scientists, and conservationists can make informed decisions to conserve mangrove ecosystems and ensure their long-term viability.
This study aimed at assessing the concentrations and perturbations of the physicochemical properties and heavy metals in the soil of the coastal regions of Akwa Ibom State, Nigeria. Sampling was carried out across three mangrove locations (Iko Town, Okoroutip and Uta Ewa) in Eastern Obolo, Ibeno and Ikot Abasi Local Government Areas respectively. Four vegetation plots were randomly selected, and within each plot, three belt transects were established. Physicochemical properties [Sand, Clay, Silt, organic carbon (OC), total nitrogen, sulphate and chlorine content] and heavy metals (Arsenic, Silver, Chromium, Copper, Nickel, Lead, Mercury, Cadmium, Titanium, Vanadium and Zinc) were analyzed using standardized methods. Results from this study revealed considerable variations in the physicochemical properties of soil in the study area. The aforementioned heavy metals were present in both wet and dry seasons in considerable concentrations in the soil samples within the study areas. However, were within and below WHO limits. The variations in the physicochemical properties and the presence of these heavy metals in the samples are indicative of an impacted environment unsuitable for the growth and survival of the endemic flora and fauna species of this unique ecosystem. In view of the current knowledge of the role of mangrove ecosystems in blue-economy of the nation and mitigation of ongoing climate change, we advocate a tripartite alliance between the government, multinational companies operating within the area and the various impacted communities that leads to a concerted efforts of constant monitoring and remediation in the reduction of current and future pollutant levels.
A taxonomic revision of Rhizophora L. (Rhizophoraceae) in Thailand is presented. Two species, R. apiculata Blume and R. mucronata Poir., are enumerated with updated morphological descriptions, illustrations and a taxonomic identification key, together with notes on distributions, habitats and ecology, phenology, conservation assessments, etymology, vernacular names, uses, and specimens examined. Three names in Rhizophora , are lectotypified: R. apiculata and two associated synonyms of R. mucronata ( i.e ., R. latifolia Miq. and R. macrorrhiza Griff.). R. longissima Blanco, a synonym of R. mucronata , is neotypified. All two Rhizophora species have a conservation assessment of Least Concern (LC). Based on the morphological identification, these two species can be distinguished from one another by the shape and width of the leaf laminae and the length of a terminal stiff point of the leaf laminae; the type and position of the inflorescences and the number of flowers per inflorescence; the character and color of the bracteoles; the presence or absence of the flower pedicels; the shape of the mature flower buds; the shape, color, and texture of the sepals; the shape, character, and the presence or absence of hairs of the petals; the number of stamens per flower; the size of the fruits; the color and size of the hypocotyls; the color and diameter of the cotyledonous cylindrical tubes; and the color of the colleters and exudate. The thick cuticles, sunken stomata, large hypodermal cells, and cork warts are adaptive anatomical features of leaves in Rhizophora that live in the mangrove environments. The pollen grains of Thai Rhizophora species are tricolporate, prolate spheroidal or oblate spheroidal shapes, small-sized, and reticulate exine sculpturing.
True mangroves and mangrove associates are salt-tolerant trees and shrubs that serve a critical role in preserving the ecological balance of tropical and subtropical estuarine environments. However, they are not immune to the damage caused by fungal pathogens. In this study, leaves exhibiting leaf spot symptoms were gathered from mangrove estuary and forests in Prachuap Khiri Khan, Thailand. Through morphological and multilocus phylogenetic analyses (LSU, ITS, RPB2 and TUB2) along with genealogical concordance phylogenetic species recognition, we identified Allophoma acanthi sp. nov. from Acanthus ilicifolius. Additionally, A. minor was identified as the causative agent of leaf spots in true mangrove and mangrove associate species, namely, Acanthus ilicifolius, Combretum sp., Hibiscus tiliaceus, Intsia bijuga, Lumnitzera racemosa and Sonneratia alba. We also provide evidence to support the synonymization of A. thunbergiae with A. minor. All eight isolates of Allophoma species in this study demonstrated pathogenicity to their original hosts with varied virulence, confirming Koch's postulates. Our findings contribute to the understanding of fungal pathogens affecting true mangroves and mangrove associates.
The benefits of urban green space (UGS) for society are widely recognized, as a direct link between plant-microbe interactions and the maintenance of biodiversity, community stability, and ecosystem functioning. There is, however, a lack of knowledge about the factors influencing the microbial communities in urban green spaces, especially those related to phyllosphere epiphytes and stem epiphytes. In this study, we analyzed the microbial community assembly in leaf and stem bark samples collected from Square, Road, Campus, and Park. The α-diversity was higher in the bark epiphytic community, compared to the phyllosphere. Moreover, the types of urban greenspaces altered the way communities gathered. The main factors of the urban greenhouse (soil and air properties) were shaping the characteristics of bacterial communities on the leaf surface and bark epiphytic. In the co-occurrence network analysis, keystone taxa were not mostly observed in abundant species, which may be necessary to maintain ecosystem functions. Our findings provide a deeper understanding of the ecological dynamics and microbial interactions within plant phyllosphere and stem epiphytes microbiomes.
Marine Biopharmaceuticals: Scope and Prospects is a collaboration of experts in pharmacology, biology and biochemistry with a focus on Marine Bioprospecting. The book provides an in-depth exploration of promising pharmaceutical compounds found in various marine biota and their therapeutic applications. The comprehensive contents cover marine ecosystems, marine biopharmaceutical, and delve into the chemistry and therapeutic applications of compounds from diverse marine organisms such as seaweeds, sponges, cnidarians, bryozoans, worms, shellfish, tunicates, and fishes.
The chapters also highlight approved and marketed marine biota-derived drugs and marine biota-derived drug candidates currently under clinical trials. Marine biopharmaceutical compounds targeting SARS-CoV-2 are also covered, reflecting the latest developments in the field. The editors conclude the book by advocating for the establishment of professional grade Marine Biopharmacy courses at university level to contribute to this emerging field.
This reference serves as a guide for researchers and instructors in disciplines such as Pharmaceutical Sciences, Marine Biology, Marine Microbiology, Marine Biochemistry, and Marine Biotechnology. Moreover, it is positioned as a standard reference for libraries in colleges and universities, offering critical insights for drug companies engaged in the development of new drugs from marine biopharmaceuticals.
Mangroves are widely recognized as one of the most carbon-rich ecosystems. However, the impact of different species, especially slow- and fast-growing ones, on carbon stocks can vary significantly ¹ . These findings have generated a strong interest in understanding the diversity of resource-investment strategies among mangrove species. The global leaf economic spectrum holds the potential for identifying these strategies in mangroves 2,3 . Nevertheless, it remains unclear whether leaf economic traits of mangrove species exhibit expected coordination patterns. Through the analysis of 36 widely distributed mangrove species, we demonstrate that the cross-species trait spectrums of mangroves encompassing both true mangroves and mangrove associates align with findings from global vegetation analysis ² . The distinct strategies between mangrove groups indicated by trait spectrums are consistent with previous observations ⁴ . However, the cross-species trait spectrums are not consistently valid in identifying strategies within or between mangrove species. Through conducting a case study, we provide empirical evidence that a fast-growing species (having a greater photosynthetic capacity and tree height) could be positioned towards the slower end of trait spectrums compared with slow-growing species when living in hyper-saline soils. Contrary to the common assumption 5,6 , the greater mass per leaf area of the fast-growing species is primarily derived from thicker leaves and a higher phosphorus content per leaf area compared with the slow-growing species. These findings suggest that the cross-species trait spectrum may have limitations in accurately identifying resource-investment strategies in plants with thick leaves.
This thesis examines the biodiversity and evolutionary ecology of Lumnitzera mangroves in the Indonesian Archipelago. Using a combination of genomics and metabolomics, the study arrived at several key findings: (1) Investigation into 14 populations of L. littorea and 21 populations of L. racemosa revealed low genetic variation, with significant barriers like Sulawesi and the Java Sea influencing genetic differentiation. (2) Specifically for L. littorea, Wallace's line was identified as a key biogeographical separator, marking divergent evolutionary pathways and separating phylogroups, whereas L. racemosa showed a mixing population in the Wallacea region. (3) Uniquely, the research discovered a diversity in sulfated constituents, including previously unknown compounds like Lumnitzeralactone. (4) Further emphasizing the mangroves' medicinal importance, antibacterial potential was uncovered in the species. (5) The study innovatively linked phylogenetic data with chemical analyses, offering a comprehensive view of mangrove evolution and ecology. (6) Finally, the findings highlighted the need for specific conservation strategies, considering the genetic differentiation within populations, to protect the mangroves' ecological significance and medicinal value across Indonesia.
Metabolomic and genomic markers in plants have helped diagnose evolutionary pressures and resulting modern-day floristic diversification. Here we use a different set of metrics, 17 biochemical measures made at the whole tissue or bulk tissue level, to study diversification in resource use and productivity among Pacific mangroves. Three mangrove species Bruguiera gynmorhiza (BRGY), Rhizphora apiculata (RHAP), and Sonneratia alba (SOAL) were studied across 5 sites on the island of Kosrae, Federated States of Micronesia with measurements of the following chemical metrics: C, N, P, K, Na, Mg, Ca, B, S, Mn, Fe, Cu, Zn elements and isotope values δ ² H, δ ¹³ C, δ ¹⁵ N, and δ ³⁴ S. Species were remarkably distinct in chemical profiles, showing significant differences across all metrics. This indicated long-term resource use partitioning and optimization, with metrics showing physiology and patch-related differences. The patch-related differences meant that metrics were not really fixed in species, but represented flexible traits (“flexitraits”) in fingerprinting mangrove ecology. Effects of tree harvesting could be fingerprinted with the metrics at one of the Kosrae sites. Modeling showed two results. (1) Conservation efforts to preserve low-nutrient specialists like BRGY probably should involve removal of competing SOAL and RHAP rather than nutrient reductions. (2) Although mangrove growth rates were most limited by P, water was a strongly co-limiting factor. This study introduces a new physiological parameter to plant ecology, a water-to-phosphorus ratio, “normalized δ ¹³ C/P” or “f 13C /P”, that should generally help diagnose how plant N and P nutrient use can be co-limited by water.
Karyotype analysis and cytophotometric estimation of 4C nuclear DNA were carried out in Acanthus ebracteatus, A. ilicifolius and A. volubilis found in the mangrove forests of Orissa, India. The somatic chromosome numbers, except in A. ilicifolius (2n = 44), are reported for the first time in A. ebracteatus (2n = 44) and A. volubilis (2n = 44). Karyotype analysis revealed species-specific chromosomal characteristics, numerical and minute structural alterations of chromosomes. Critical analysis showed significant variations in the 4C DNA amount between the species. The correlation coefficient among the various chromosomal and nuclear parameters were interdependent suggesting a compromise between structural and molecular changes of the genome in speciation.
Seeds of the mangrove Avicennia marina were germinated and grown for up to 11 months on nutrient solution or nutrient solution containing 10, 25, 50, 75 or 100% natural seawater (500 mM sodium; 580 mM chloride). Early seedling development was most rapid in the absence of sodium chloride, but soon declined. As a result, biomass production in this treatment was poorest. The response was associated with the appearance of necrotic lesions. The growth optimum based on fresh or dry weight occurred on 10, 25 or 50% seawater. Plants receiving higher salinities, particularly full strength seawater, were slow to develop, and low in biomass, but healthy in appearance. Seeds taken from parent trees growing on tidal mudflats had osmotic potentials more negative than seawater, but contained little sodium or chloride, potassium being the most abundant inorganic ion. The osmotic potentials of the seedlings were more negative than those of the external watering solutions by at least 2 MPa in all of the treatments. Turgor pressures of approximately 0.8 MPa were evident for the salt-treated plants, but were much lower (0.2-0.3 MPa) for plants receiving only nutrient. Seedlings grown on nutrient alone accumulated mainly potassium (sodium and chloride being unavailable) and probably depended upon organic substances, in particular organic anions, to generate internal osmotic potential. Plants on 10-100% seawater treatments behaved as typical halophytes accumulating increasing levels of sodium and chloride as external salinity increased, even though the leaves can regulate steady-state ionic concentrations by means of salt glands. Sodium replaced potassium, but preferential potassium uptake was maintained over a wide range of external sodium concentrations. Chloride accumulation balanced approximately half of the cations present. The calculated osmotic contribution made by the cations (assuming complete charge balance by chloride) in the leaf extracts corresponded closely to measured osmotic potential.
This book begins with an introductory chapter, with consideration of the importance of geography, geology, floristic relationships and climate and vegetation patterns. Nine chapters follow, dealing with specific geographical areas: western Melanesia; eastern Melanesia; the subtropical islands in the New Zealand region; Micronesia; central Polynesia; western Polynesia; eastern Polynesia; northern Polynesia - the Hawaiian Islands; and the oceanic islands in the eastern Pacific. Each of the geographical chapters includes introductory remarks on the regional geography/geology and climate before detailed descriptions of the vegetation. A final chapter looks at the future of island vegetation.
Populations of Acrostichum aureum growing under contrasting conditions of soil salinity and sunlight exposure were studied in two sites in the north coast of Puerto Rico. Plant size and density of clumps under full sun exposure are larger in sites with lower soil salinity. In shady habitats with relatively high soil salinity (understory of Laguncularia forests), plants grow larger but occur at lower densities as compared with nonshaded sites. Apparently salt stress in shady habitats is reduced due to lower evaporative demands. Osmotic concentration of leaf cell sap increases markedly with soil salinity (except in shade plants), a process accompanied by corresponding increases in leaf water content per unit leaf area, and reductions in leaflet size and specific leaf area. The major solutes responsible for increases in cell sap osmotic pressure are Na+, Mg2+, and sucrose. However, the largest relative response to salinity is shown by the cyclitol D-1-0-methyl-muco-inositol, a cytoplasmic compatible solute. Thus, this cyclitol can be considered as an accurate indicator of salt stress in A. aureum. The Cl-/Na+ molar ratios in the cell sap are consistently higher in A. aureum compared to L. racemosa and R. mangle (2.5 against 1.2 and 1.5, respectively). The K/Na molar ratio based on total content per unit tissue dry weight is also higher in the fern (2.6) compared to typical mangroves (less than 0.5). These results indicate a difference in ion selectivity at the root level.
Growth, ionic and water relations of three mangrove species viz. Avicennia marina, Ceriops tagal and Rhizophora mucronata were studied in different seawater concentrations (0, 25, 50, 75 and 100%). All mangrove species showed optimal growth at 50% seawater. Relatively more biomass was accumulated by R. mucronata while C. tagal had the tallest individuals. Tissue water potential became more negative with the increase in salinity and stomatal conductance was decreased in all plants. Higher stomatal conductance was noted in R. mucronata, followed by A. marina and C. tagal. Sodium and chloride ions increased with the increase in salinity and this accumulation was much higher in A. marina.
Bringing together leaf trait data spanning 2,548 species and 175 sites we describe, for the first time at global scale, a universal spectrum of leaf economics consisting of key chemical, structural and physiological properties. The spectrum runs from quick to slow return on investments of nutrients and dry mass in leaves, and operates largely independently of growth form, plant functional type or biome. Categories along the spectrum would, in general, describe leaf economic variation at the global scale better than plant functional types, because functional types overlap substantially in their leaf traits. Overall, modulation of leaf traits and trait relationships by climate is surprisingly modest, although some striking and significant patterns can be seen. Reliable quantification of the leaf economics spectrum and its interaction with climate will prove valuable for modelling nutrient fluxes and vegetation boundaries under changing land-use and climate.
Questions
How do forest types differ in their distinctiveness among islands in relation to environmental and anthropogenic disturbance gradients? Are biogeographic factors also involved?
Location
Tonga, ca. 170 oceanic islands totalling 700 km ² spread across 8° of latitude in Western Polynesia.
Method
Relative basal area was analysed for 134 species of woody plants in 187 plots. We used clustering, indirect gradient analysis, and indicator species analysis to identify continuous and discontinuous variation in species composition across geographical, environmental and disturbance gradients. Partial DCA related environmental to compositional gradients for each major forest type after accounting for locality. CCA and partial CCA partitioned observed compositional variation into components explained by environment/disturbance, locality and covariation between them.
Results
Differences among forest types are related to environment and degree of anthropogenic disturbance. After accounting for inter‐island differences, compositional variation (1) in coastal forest types is related to substrate, steepness and proximity to coast; (2) in early‐successional, lowland rain forest to proximity to the coast, steepness and cultivation disturbance; (3) in late‐successional, lowland forest types to elevation. For coastal/littoral forests, most of the compositional variation (71%) is explained by disturbance and environmental variables that do not covary with island while for both early and late‐successional forests there is a higher degree of compositional variation reflecting covariation between disturbance/environment and island.
Conclusions
There are regional similarities, across islands, among littoral/coastal forest types dominated by widespread seawater‐dispersed species. The early‐successional species that dominate secondary forests are distributed broadly across islands and environmental gradients, consistent with the gradient‐in‐time model of succession. Among‐island differences in early‐successional forest may reflect differences in land‐use practices rather than environmental differences or biogeographical history. In late‐successional forests, variation in composition among islands can be partly explained by differences among islands and hypothesized tight links between species and environment. Disentangling the effects of anthropogenic disturbance history versus biogeographic history on late‐successional forest in this region awaits further study.
Studies (1996–'99) on the community structure of a mangrove forest in Coringa Wildlife Sanctuary in the Godavari estuarine system on the East Coast of India revealed altogether 15 species of mangroves represented by 8 families and 10 genera besides, 6 associate plant species and 6 of marshgrass. Description of forest structure (PCQM method) included measures of species composition, tree density, basal area and spatial distribution patterns of component vegetation at 75 GPS fixed locations. Avicennia marina, A. officinalis, Excoecaria agallocha, Aegiceras corniculatum, Sonneratia apetala, Ceriops decandra, Rhizophora apiculata and R. mucronata were the important mangrove species. Tree density varied between 47 and 1731 stems/0.1 ha and basal area 0.1 and 10.9 m2/0.01 ha. With the help of multivariate analysis (PRIMER) and based on species composition and tree density, it was possible to subdivide the sites into five groups that showed characteristic zonation patterns. For example, E. agallocha was typical of landward locations. A. marina (along with A. officinalis and A. alba) represented sites at the bed level and neap high tide level. There was a large group of sites inhabited by diverse species (14) indicative of spring high tide level conditions. Tidal elevation and ambient salinity appeared important in determining the observed zonation.
Photosynthetic responses of two mangroves and a mangrove associate were investigated in a low salinity site at Beachwood (<12) and a high salinity site at Durban Bay (35). Measurements were made of CO2 exchange, chlorophyll fluorescence, ion and water relations of Avicennia marina, Bruguiera gymnorrhiza and Hibiscus tiliaceus at the two sites. At Beachwood, CO2 exchange was highest in H. tiliaceus (9.12 mol m-2s-1) and least in A. marina (3.27 mol m-2s-1). At the Durban Bay site, CO2 exchange in A. marina was greater than that at Beachwood by 79%, that in H. tiliaceus decreased by 59% while that in B. gymnorrhiza remained unchanged. In all species, photosystem II (PSII) quantum yield decreased with increase in photon flux density (PFD) up to 2,000 mol m-2s-1. Electron transport rate (ETR) through PSII increased with increase in PFD, reaching saturation at 1000 mol m-2s-1. At saturating PFD, PSII quantum yield and ETR were higher in the mangroves but lower in H. tiliaceus at the high salinity site. Photochemical and non-photochemical quenching were, however, lower in the mangroves but higher in H. tiliaceus at the high salinity site. Predawn and midday leaf water potential were higher at Beachwood and significantly reduced at Durban Bay, values being highest in H. tiliaceus (-0.4 and -1.8 MPa) and least in A. marina (-2.5 and -3.8 MPa). Leaf concentrations of Na+, Cl-, Ca2+ and Mg2+ in mangroves were significantly higher at Durban Bay than at Beachwood. In H. tiliaceus there were no differences in ion concentrations between sites except for K+, which was significantly higher at Durban Bay.
In the present study three species of Heritiera Aiton (Sterculiaceae) were characterized using 9 amplified fragment length polymorphism (AFLP) primer combinations and the genetic relationship
among these three species was assessed, Nine AFLP primer combinations yielded 445 bands out of which 210 were monomorphic
and 235 were polymorphic. Out of the 235 polymorphic bands 79 were present only in a single species. Among the total amplified
bands 255 were shared between H. fomes and H. littoralis, 225 were shared between H. fomes and H. macrophylla and 306 bands were shared between H. littoralis and H. macrophylla. The cluster analysis showed H. littoralis is closer to H. macrophylla than H. fomes. The similarity between H. fomes and H. littoralis was higher than that of H. fomes and H. macrophylla. The present study indicates that H. littoralis is better classified as mangrove associate or back mangal than a true mangrove.
The effects of a range of salinity (0, 100, 200 and 400mM NaCl) on growth, ion accumulation, photosynthesis and anatomical changes of leaves were studied in the mangrove, Bruguiera parviflora of the family Rhizophoraceae under hydroponically cultured conditions. The growth rates measured in terms of plant height, fresh and dry weight and leaf area were maximal in culture treated with 100mM NaCl and decreased at higher concentrations. A significant increase of Na+ content of leaves from 46.01mmolm-2 in the absence of NaCl to 140.55mmolm-2 in plants treated with 400mM NaCl was recorded. The corresponding Cl- contents were 26.92mmolm-2 and 97.89mmolm-2. There was no significant alteration of the endogenous level of K+ and Fe2+ in leaves. A drop of Ca2+ and Mg2+ content of leaves upon salt accumulation suggests increasing membrane stability and decreased chlorophyll content respectively. Total chlorophyll content decreased from 83.44gcm-2 in untreated plants to 46.56gcm-2 in plants treated with 400mM NaCl, suggesting that NaCl has a limiting effect on photochemistry that ultimately affects photosynthesis by inhibiting chlorophyll synthesis (ca. 50% loss in chlorophyll). Light-saturated rates of photosynthesis decreased by 22% in plants treated with 400mM NaCl compared with untreated plants. Both mesophyll and stomatal conductance by CO2 diffusion decreased linearly in leaves with increasing salt concentration. Stomatal and mesophyll conductance decreased by 49% and 52% respectively after 45days in 400mM NaCl compared with conductance in the absence of NaCl. Scanning electron microscope study revealed a decreased stomatal pore area (63%) in plants treated with 400mM NaCl compared with untreated plants, which might be responsible for decreased stomatal conductance. Epidermal and mesophyll thickness and intercellular spaces decreased significantly in leaves after treatment with 400mM NaCl compared with untreated leaves. These changes in mesophyll anatomy might have accounted for the decreased mesophyll conductance. We conclude that high salinity reduces photosynthesis in leaves of B. parviflora, primarily by reducing diffusion of CO2 to the chloroplast, both by stomatal closure and by changes in mesophyll structure, which decreased the conductance to CO2 within the leaf, as well as by affecting the photochemistry of the leaves.
Genetic diversity within and among 10 mangrove and non-mangrove populations of Heritiera littoralis from three sites in China and one site in Australia was determined using inter-simple sequence repeats (ISSR). Eleven primers produced 173 bands across a total of 166 individuals. At the species level, genetic diversity was high (P=93.1%, He=0.24, and I=0.37). Higher genetic diversity was observed in Australian populations compared to Chinese populations, which can be explained by either ecogeographic variation or evolutionary history. A significant correlation between genetic and geographic distances was detected among the 10 populations, but no such correlation was found among either Chinese or Australian populations. AMOVA indicated that 41.7% of the total genetic variation was explained by differences between China and Australia. As for Chinese populations, 22.5% of the genetic variation was accounted for by geographical effects with 5.3% for differentiation between habitats. We suggest that geographic distance is the primary cause of genetic differentiation between China and Australia at the regional scale, whereas, the strongly divergent habitats (marine versus terrestrial) also play an important role in within region differentiation at the local scale. An understanding of the genetic structure of H. littoralis provides insight for the conservation and the management of these species.
Mangroves are woody plants that grow at the interface between land and sea in tropical and sub-tropical latitudes where they exist in conditions of high salinity, extreme tides, strong winds, high temperatures and muddy, anaerobic soils. There may be no other group of plants with such highly developed morphological and physiological adaptations to extreme conditions.Because of their environment, mangroves are necessarily tolerant of high salt levels and have mechanisms to take up water despite strong osmotic potentials. Some also take up salts, but excrete them through specialized glands in the leaves. Others transfer salts into senescent leaves or store them in the bark or the wood. Still others simply become increasingly conservative in their water use as water salinity increases Morphological specializations include profuse lateral roots that anchor the trees in the loose sediments, exposed aerial roots for gas exchange and viviparous waterdispersed propagules.Mangroves create unique ecological environments that host rich assemblages of species. The muddy or sandy sediments of the mangal are home to a variety of epibenthic, infaunal, and meiofaunal invertebrates Channels within the mangal support communities of phytoplankton, zooplankton and fish. The mangal may play a special role as nursery habitat for juveniles of fish whose adults occupy other habitats (e.g. coral reefs and seagrass beds).Because they are surrounded by loose sediments, the submerged mangroves' roots, trunks and branches are islands of habitat that may attract rich epifaunal communities including bacteria, fungi, macroalgae and invertebrates. The aerial roots, trunks, leaves and branches host other groups of organisms. A number of crab species live among the roots, on the trunks or even forage in the canopy. Insects, reptiles, amphibians, birds and mammals thrive in the habitat and contribute to its unique character.Living at the interface between land and sea, mangroves are well adapted to deal with natural stressors (e.g. temperature, salinity, anoxia, UV). However, because they live close to their tolerance limits, they may be particularly sensitive to disturbances like those created by human activities. Because of their proximity to population centers, mangals have historically been favored sites for sewage disposal. Industrial effluents have contributed to heavy metal contamination in the sediments. Oil from spills and from petroleum production has flowed into many mangals. These insults have had significant negative effects on the mangroves.Habitat destruction through human encroachment has been the primary cause of mangrove loss. Diversion of freshwater for irrigation and land reclamation has destroyed extensive mangrove forests. In the past several decades, numerous tracts of mangrove have been converted for aquaculture, fundamentally altering the nature of the habitat. Measurements reveal alarming levels of mangrove destruction. Some estimates put global loss rates at one million ha y−1, with mangroves in some regions in danger of complete collapse. Heavy historical exploitation of mangroves has left many remaining habitats severely damaged.These impacts are likely to continue, and worsen, as human populations expand further into the mangals. In regions where mangrove removal has produced significant environmental problems, efforts are underway to launch mangrove agroforestry and agriculture projects. Mangrove systems require intensive care to save threatened areas. So far, conservation and management efforts lag behind the destruction; there is still much to learn about proper management and sustainable harvesting of mangrove forests.Mangroves have enormous ecological value. They protect and stabilize coastlines, enrich coastal waters, yield commercial forest products and support coastal fisheries. Mangrove forests are among the world's most productive ecosystems, producing organic carbon well in excess of the ecosystem requirements and contributing significantly to the global carbon cycle. Extracts from mangroves and mangrove-dependent species have proven activity against human, animal and plant pathogens. Mangroves may be further developed as sources of high-value commercial products and fishery resources and as sites for a burgeoning ecotourism industry. Their unique features also make them ideal sites for experimental studies of biodiversity and ecosystem function. Where degraded areas are being revegetated, continued monitoring and thorough assessment must be done to help understand the recovery process. This knowledge will help develop strategies to promote better rehabilitation of degraded mangrove habitats the world over and ensure that these unique ecosystems survive and flourish.
An account of mangrove plant species worldwide and the factors influencing their distributions.
Definition of mangroves.
Typically trees or shrubs, exceeding 0.5m in height, growing above mean sea level on unconsolidated sediments of the intertidal zone in marine coastal environments, or along estuarine margins. Mangroves are an ecological entity, comprised of several genetically unrelated taxa.
The Australian coastline is 18% occupied by a very special and beneficial habitat of extraordinary trees and larger shrubs bathed regularly by seawater flooding tides and washing waves. Published in 2006, this practical guide describes each of these highly adapted intertidal plants known in Australian waters at the time.
This is the 2006 AUTHORITATIVE GUIDE TO AUSTRALIA’S MANGROVE PLANTS with:
- descriptions of 41 Australian species, 57% of the world’s
- illustrated keys assist identification
- more than 500 colour photographs
- feature artworks by Fran Davies
- State & Territory sections with local specialist contributions
- a manual for community awareness & knowledge
This book is an educational resource to inform research, teaching and the eco-minded.
Some difficulties attendant upon attempts to define a mangrove are discussed in the light of recently acquired Knowledge of the floristic diversity of some tropical tidal swamps. Inconsistencies in the use of the term ‘mangrove’ are pointed out. It is suggested that in future, either a very broad definition of ‘mangrove’ be accepted or the use of the term be abandoned in favour of less equivocal terms. Lists of over 900 species which occur in tidal swamps in the Indo-West Pacific are appended. These exclude epiphytes.
The species composition and characteristics of mangrove flora in the world were reviewed and discussed. The results suggested that the world's mangrove plants have 84 species (including 12 varieties) in 24 genera and 16 families. Of which, true mangrove plants have 70 species (including 12 varieties) in 16 genera and 11 families, and semi-mangrove plants 14 species in eight genera and five families. The Eastern Group has 74 species (including 12 varieties) in 18 genera and 14 families, characterized by the genera Aegiceras, Osbornia, Aegialitis, Bruguiera, Ceriops, Kandelia, Scyphiphora and Nypa etc. The Western Group has only 10 species in six genera and five families, characterized by the endemic one-species family, Pelliceraceae, and the genus Laguncularia. The mangrove flora of China is composed of 26 species (including one variety) in 15 genera and 12 families, four of which are endemic. Hainan is most rich in mangrove species, making up about 96.2% of the Chinese total; Guangdong ranks second, making up about 42.3%. It has been demonstrated that Rhizophora stylosa was mistaken for R. mucronata in Taiwan by previous authors.
Mangroves are trees or bushes growing between the level of high water of spring tides and a level close to but above mean sea-level. Very few species of mangrove are deep rooted, or have persistent tap roots. Almost all are shallow rooted but the root systems are often extensive and may cover a wide area. Rhizophoraceous trees have seedlings with a long radicle which would seem well suited to develop into a tap root, but as soon as the seedling becomes established in the mud the radicle develops little further. Trees of Avicennia and of Sonneratia develop several different kinds of roots. The main rooting system consists of large cable roots which give off anchoring roots downwards and aerial roots or pneumatophores upwards. These pneumatophores in their turn produce a large number of nutritive roots which penetrate the mineral-rich subsurface layers of the soil. The land animals found in mangrove forests include roosting flocks of fruit bats, fishing and insectivorous birds, and many insects are conspicuous. Of the marine animals, crabs and molluscs live permanently in the forest, and prawns and fishes come in on the tide to feed on the apparently abundant nutriment provided by the mangrove soils. In South East Asia man uses mangrove areas for the establishment of ponds for the culture of fish and prawns, and for timber.
Distribution of mangroves has been mapped on twenty-one reefs of the northern Great Barrier Reef, Queensland. The mangrove flora consists of fifteen species, together with associated sea-grasses and succulents. Two species form unusual dwarf-scrub communities on the seaward sides of windward shingle ridges, others form distinctive high-level woodland on or in the lee of the ridges themselves. The most extensive woodland is dominated by Rhizophora stylosa on the reef-top. The area and rate of spread of this is mainly a function of reef-top morphology, itself the result of reef upgrowth from older foundations in the Holocene. The cessation of vertical growth is marked on these reefs by microatoll formation, and fossil microatolls up to nearly 6000 years old are found beneath mangrove swamps. Growth may, however, be interrupted by catastrophic cyclone damage. The extent and rate of spread of reef-top mangroves thus varies markedly between different reefs, and cannot be used directly to calibrate reef-top development. Reef mangroves in Queensland are thus opportunistic colonizers of available habitats, in the same manner as argued by B. G. Thom for deltaic environments.
Neotropical species of the genera Rhizophora, Lagunculariaand
Avicenniagrow in environments of variable salinity and flooding stress.
Species of Rhizophorapredominate in riverine and low-energy coastal
fringe environments with continuous water movement, while Laguncularia
racemosa, and particularly Avicennia germinans, grow in areas with
stagnating water. Avicennia germinansappears to have the largest range
of salinity tolerance. The osmotic characteristics of Rhizophoraspp., L.
racemosaand A. germinansin riverine and coastal environments of
north-eastern Venezuela are described and correlated with edaphic and
climatic factors. Mature, fully-exposed leaves were collected in humid
riverine sites (San Juan River Estuary, Monagas and Sucre States), and
seasonally dry coastal fringe habitats (the Unare Coastal Lagoon, and
the Chimana Islands off-shore Puerto de La Cruz, Anzoátegui
State). Cleaned leaf samples were frozen until measurement of leaf
dimensions, chlorophyll, phosphorus and nitrogen contents, δ
13C, osmolality of cell sap, and cell sap content of Na, K
and Cl. Results indicate: (1) in all species, leaf sap osmolality is
highly and positively correlated with interstitial water salinity, and
negatively correlated with leaf area; (2) nitrogen and phosphorus
contents of leaves are generally lower in dry areas, but average values
are not significantly different. Therefore, it appears that nutrient
deficiency is not a main factor determining variations in community
structure. Nitrogen content per unit dry weight is, in general, twice as
high in A. germinanscompared to Rhizophoraspecies and L. racemosa; (3)
cell sap osmolality is mostly explained by the concentration of Na and
Cl; (4) osmolality of riverine plants (957-1253 mmol kg -1)
is lower than that of coastal plants (1558-1761 mmol kg -1);
and (5) δ 13C values are more negative in riverine
(-27·4 to -28·1‰) than in coastal plants
(-25·4 to -27·2‰), indicating a higher water-use
efficiency in the latter. Coastal plants have a higher water-use
efficiency but their growth is inhibited by salinity stress.
Young and old leaves from 22 mangrove species of Northern Queensland (Australia) were investigated for inorganic ions and organic acids. Na+ and Cl− concentrations expressed on plant water basis were close to sea water with the exception of Heritiera littoralis and Hibiscus tiliaceus, which are both regarded as brackish water species. Leaf age did not appear to effect Na+ and Cl− storage much. SO42− and Mg2+ increased markedly in old leaves of salt-secreting species such as Avicennia marina, Avicennia eucalyptifolia, Aegialitis annulata, Aegiceras corniculatum and Acanthus ilicifolius as well as in the members of the Rhizophoraceae.
Free oxalate was found in all salt-secreting species and young leaves of Lumnitzera racemosa. Malate and citrate were present in all species, while quinate and shikimate occurred frequently. The contribution of organic acids to the anion content was important in only a few cases.
Mechanisms of salt-regulation and problems in the classification of mangroves are discussed.
This report is by the Working Group on Mangrove Ecosystems of the IUCN Commission on Ecology in cooperation with the United Nations Environment Programme and the World Wildlife Fund. The review describes the mangrove resource and its value; factors which maintain the ecological processes in mangroves; and the causes and consequences of mangrove destruction. There is a section on management of the mangrove resource and 2 chapters on recommendations for those concerned with mangrove management and applied research needs. Appendices describe the mangrove reserves of the world. -K.Clayton
An analysis has been made in the Sundarbans mangroves to relate the community structure and distribution of species with soil salinity and pH gradients. Soil salinity (13.0 to 31.2 ppt) decreased with increasing distance from the tidal coast but no such trend was noticed in soil pH (7.0 to 7.9). Frequency of tidal inundation seemed to affect soil salinity. Acanthus ilicifolius, Avicennia alba and A. marina dominate the sites having regular diurnal tidal inundation. Maximum complexity index was noted on the least saline zone. Ecological group classification indicates that Avicennia marina and A. officinalis can tolerate wide range of soil salinity while Aegiceras corniculatum, Ceriops decandra, Dalbergia spinosa, Derris trifoliata and Excoecaria agallocha are restricted to low salinity areas. Most species had an optimum pH range except Avicennia marina, which occurred in varied pH conditions. Acanthus ilicifolius was relatively insensitive to pH and salinity gradient due to its wide ecological amplitudes.
The effects of salinity on water relations and ion concentrations were investigated in seedlings of the mangroves Avicennia alba, Bruguiera gymnorrhiza, Heritiera littoralis and Xylocarpus granatum grown at salinities of 0, 10, 20, 30, 40 and 60‰. All four species survived and grew at salinities ranging from 0 to 40‰, but none survived at a salinity of 60‰. The concentration of sodium and chloride in the xylem sap increased with increasing salinity in both A. alba and B. gymnorrhiza. Sodium and chloride concentrations in the xylem sap of A. alba grown at 40‰ salinity both reached 114molm−3, about 15% of the external concentration around the roots. The xylem sap of B. gymnorrhiza grown at 40‰ salinity, by contrast, contained only 7.0molm−3 sodium and 4.1molm−3 chloride, about 1% of their concentrations in the external solution around the roots. The results indicated that B. gymnorrhiza, which does not have salt-secreting glands, was more effective at excluding salt than A. alba, which has salt-secreting glands.Analysis of pressure–volume curves showed that the bulk modulus of elasticity increased with increasing salinity. This was accompanied by a decrease in shoot water potential, mainly associated with a reduction in shoot osmotic potentials with increasing salinity. The decrease in osmotic potential was attributed to increasing solute concentrations, particularly sodium and chloride, in the leaves of all species except H. littoralis, which had little sodium and chloride in the leaves.
Two sympatric subspecies of the xerohalophyte Atriplex canescens Pursh. (Nutt.) were compared for 84 d in outdoor salinity trials in their native coastal desert environment in Sonora, Mexico. Subspecies linearis grows naturally on sea water in the high intertidal zone of estuaries while subspecies canescens grows on dunes. In lysimeter pot experiments, ssp. linearis exhibited 50% growth reduction when the mean root zone salinity reached 1160 mol m−3 NaCl compared to just 760 mol m−3 for ssp. canescens. When irrigated with sea water in a flood plot, ssp. linearis had 50% higher growth rates than ssp. canescens. The specialization of ssp. linearis for a saline environment was associated with greater net transport of Na+ from root to shoot, greater Na+ accumulation in the leaves and a higher Na:K ratio in the leaves compared to ssp. canescens. On the other hand, the two subspecies achieved approximately the same degree of osmotic adjustment in the leaves, equal to two to three times the external salinity, and had similar water use efficiencies. Even at relatively low salinities, both subspecies accumulated larger quantities of Na+ for osmotic adjustment than K+. The results suggest that breeding for Na+ accumulation rather than exclusion might be the more effective strategy for improving salt tolerance of conventional crop plants.
Growth rates and levels of minerals, Na+, K+, Mg++, Ca++, and water were measured in dicotyledonous halophytes grown along a salinity gradient from fresh water to 720 mol m−3 NaCl in a controlled environment greenhouse. Ten test species from the families Chenopodiaceae, Aizoaceae, and Batidaceae exhibited growth stimulation by 180 mol m−3 NaCl and were classified as euhalophytes. Ten others from the families Chenopodiaceae, Aizoaceae, Asteraceae, Brassicaceae, Polygonaceae, Boraginaceae, Malvaceae, and Plumbaginaceae showed their best growth on fresh water and were classified miohalophytes. Salt, and particularly sodium, accumulated in all halophytes but to a significantly greater extent among euhalophytes than miohalophytes. The water content of most species increased when grown on 180 mol m−3 NaCl compared to fresh water; but at higher salinities some of the species underwent dehydration. Dehydration of the succulent S. europaca was not coupled to a proportional decrease in growth. Water content and cation accumulation in euhalophytes appeared to be coordinated to produce a constant osmotic potential gradient within the shoot tissues relative to the external salinity. In contrast, miohalophytes did not appear to regulate osmotic potential as closely as euhalophytes.
Growth and metabolic responses to salt stress were studied in gametophytes of Acrostichum aureum L. (a mangrove fern). Gametophytes were cultured in 0–170 mM NaCl solutions. The growth of gametophytes was best in low NaCl concentrations (35 and 85 mM), and was retarded at higher NaCl concentrations. Photosynthetic rate of gametophytes was also significantly reduced when grown in high NaCl concentrations. Severe salt stress (>120 mM NaCl) led to a preferential accumulation of d-pinitol in gametophytes, whereas the sporophyte accumulated d-1-O-methyl-muco-inositol. The content of d-pinitol reached up to 50% of the soluble carbohydrate pool of gametophytes under 155 and 170 mM NaCl. The accumulation of d-pinitol and other cyclitols in gametophytes was correlated with the retention of photochemical efficiency of photosystem II and the survival of gametophytes after transfer to solutions containing 340 and 600 mM NaCl, respectively.
Recently published reports list numbers and distributions of Sri Lankan mangrove species that outnumber the actual species present in the field. The present study serves to review this literature and highlight the causes of such apparently large species numbers, while providing an objective and realistic review of the mangrove species actually present in Sri Lanka today. This study is based on standardized fieldwork over a 4-year period using well-established diagnostic identification keys. The study indicates that there are at present 20 identified ‘mangrove species’ (major and minor components) and at least 18 ‘mangrove associates’ along the south-western coast of the island, and addresses the importance of clearly defining these terms. Incorrect identifications in the past have adversely affected interpretation of species composition in the framework of biogeography, remote sensing and biological conservation and management. © 2002 The Linnean Society of London, Botanical Journal of the Linnean Society, 138, 29–43.
An annotated list of indigenous Fijian seed plant genera is presented and comprises 484 genera and 1315 species in 137 families. The relative diversity of the largest families and genera in Fiji is indicated and compared with floras in New Caledonia and the Upper Watut Valley, Papua New Guinea. Differences and similarities appear to be due to biogeographical/phylogenetic factors rather than ecological differences or means of dispersal. Generic diversity for the seed plants as a whole is greatest between 0–100 m and decreases monotonically with altitude. However, in the largest family, Orchidaceae, maximum diversity occurs between 200–400 m. Fifty percent of the families are recorded from shore habitat. Twenty-seven percent of the families and 80 species occur in or around mangrove, where the most diverse families are Orchidaceae, Rubiaceae, and the legumes. Some of the mangrove-associate species are pantropical or Indo-Pacific but most are locally or regionally endemic. Fifty-six percent of the Fijian families are recorded on limestone. Twenty-nine species are restricted to limestone and 12 species usually occur on limestone. The importance of calcium in reducing the effects of salinity is emphasized and 39 species are recorded from both mangrove and limestone. A plagiotropic habit occurs in 38 species which occur on limestone or around beaches, and 20 of these are Pacific endemics. Genera restricted to higher altitudes include many present elsewhere in Melanesia but absent from Australia despite suitable habitat there, again indicating the importance of biogeographical and historical factors. Altitudinal anomalies in Fiji taxa are cited and include 7 anomalously high records from northern Viti Levu, a site of major uplift, and 22 anomalously low altitudinal records in the Lau Group, a site of subsidence. It is suggested that the Fijian flora has not been derived from immigrants from Asia, but has evolved more or less in situ. Taxa would have survived as metapopulations on the individually ephemeral volcanic islands always found at oceanic subduction zones and hot spots, and the atolls which characterize areas of subsidence. The complex geology of Fiji is determined by its position between two subduction zones of opposite polarity, the Vanuatu and Tonga Trenches, in what is currently a region of transform faulting. The large islands comprise fragments of island arcs that have amalgamated and welded together. There has been considerable uplift as well as subsidence in the islands and it is suggested that both these processes have had drastic effects on the altitudinal range of the taxa. Limestone and mangrove floras could have provided a widespread, diverse ancestral species pool from which freshwater swamp forest, lowland rainforest, dry forest, secondary forest, thickets, and montane forest have been derived during phases of uplift. © 2006 The Linnean Society of London, Biological Journal of the Linnean Society, 2006, 89, 407–431.
Early growth of Ceriops australis and C. decandra was studied in response to salinity and irradiance under laboratory conditions. These results provided a basis for interpretation of growth patterns during seedling establishment by seven species of Rhizophoraceae with variation in irradiance under natural low and high salinity regimes in a tropical mangrove forest. Survival declined with decrease in irradiance, except where very low salinities apparently induced sensitivity to high irradiance in vulnerable species. Survival in understorey shade was lower in the high than low salinity environment. However, these apparent effects of salinity were eliminated by reducing below-ground interactions with adult trees. Interspecific differences in initial propagule mass had no effect on survival, but were correlated with differences in average shoot mass after 1 year, emphasising the importance of juvenile reserves to early growth. There were interspecific differences in the salinity regime in which seedlings grew best, but shoot growth declined with decreasing irradiance. In most species, shoot mass of plants grown under natural canopy shade was less than initial propagule mass and was little affected by salinity. Salinity had greater effects on shoot growth under high irradiance than under natural canopy shade, implying effects of salinity on the capacity to use resources in growth. Each species exhibited a different pattern of shoot growth relative to initial propagule mass in response to salinity and irradiance. These patterns were consistent with, but do not fully explain, the distribution of the Rhizophoraceae along a natural salinity gradient in the Adelaide River system.
Tolerance of gametophytes of Acrostichum aureum to NaCl and dehydration was investigated under controlled conditions following
the changes in chlorophyll fluorescence parameters (Fv/Fm, qP, qN). Salt tolerance was increased by growing gametophytes in
low concentrations of NaCl. However, such treatment could not increase the tolerance of gametophytes to dehydration. Under
water stress, a decrease in photochemical quenching (qP) was accompanied by an increase in non-photochemical quenching (qN).
Under salt stress, qP also decreased, but qN did not change significantly in salt-hardened gametophytes.
chlorophyll fluorescence–dehydration–fern–NaCl–osmotic potential–salt stress
DNA from pooled leaf samples of 11 true major mangrove, three true minor mangrove, two mangrove associate, two mangrove parasite,
three terrestrial and one cultivated species were isolated for the present study. In total, 198 random amplified polymorphic
DNAs (RAPDs) and 180 restriction fragment length polymorphism (RFLP) loci were scored by using ten primers and 14 enzyme-probe
combinations respectively. The polymorphism observed for these markers revealed a high degree of genetic diversity in mangroves
at both inter-specific or inter-generic levels. A dendrogram, constructed after pooling both RAPD and RFLP data, using a similarity
index was analysed for genome relationships among these species. The dendrogram showed clustering of all the major mangroves,
except for Nypa fruticans (Arecaceae), into one group. All species under the tribe Rhizophorae formed a sub-cluster, to which Xylocarpus granatum was found to be the most closesly related species. The clustering pattern implied that Excoecaria agallocha and Acanthus ilicifolius should be considered as true minor mangroves. The present study also provided molecular data favouring the separation of
Avicennia spp. from the Verbenaceae to create a monotypic family the Avicenniaceae. The separation of Viscum orientale into the Viscaceae was also favoured.
Young and old leaves of twenty-three mangrove species from northern Queensland (Australia) were investigated for their mineral ion and organic solute content. With a few exceptions, the Na+ and the Cl-concentrations calculated on the basis of plant water (p.w.) were close to that of seawater and showed little age-induced changes. In some species, especially in Ceriops tagal, SO4
2- accumulated with increasing leaf age. The most widely distributed organic solutes were pinitol and mannitol, which were stored up to 280 mM plant water. A negative correlation between pinitol and SO4
2- was found in the case of Ceriops tagal. Other compatible solutes known for halophytes, such as proline and methylated quaternary ammonium compounds (MQAC), were present only in a few mangrove species. Proline occurred in two Xylocarpus species, while MQAC were accumulated by Avicennia eucalyptifolia, A. marina, Acanthus ilicifolius, Heritiera littoralis and Hibiscus tiliaceus. In all other species, low molecular weight carbohydrates (LMWC) were the main organic solutes.
The concentrations of nitrogen (N), phosphorus (P), potassium (K), sodium (Na), calcium (Ca), magnesium (Mg) and chlorine (Cl) were followed monthly in pre-senescence leaves and post-abscission leaves of Kandelia candel (L.) Druce at the Jiulongjiang estuary, and Fujian, China. The element retranslocation efficiency (RE) was studied during leaf senescence. The element RE''s evaluated using different methods were compared and a new method was put forward to evaluate element RE during leaf senescence in evergreen trees without concentrated leaf fall. The results showed that during leaf senescence, 77.22% N, 57.53% P, and 44.51% K were translocated out of senescing leaves. Translocation of nutrients out of senescing leaves back into shoots was an important nutnent-conservation mechanism for N and P, was less important for K, and did not occur for Ca, Mg, Na, or Cl. One of the reasons for the high primary productivity of mangroves in nutrient poor sites (especially with low N) is the high nutrient use efficiency.
The ionic relations in halophytes from the region east of Neusiedler Lake in Austria have been investigated. The study encompasses the following compounds: Na, K, Mg, Ca; Cl, SO4, phosphate, nitrate, and organic acids.The ionic composition varies substantially among the species investigated. Frequently a specific pattern of ion content can be found within a specific taxon.a)
Dicotyledons: Extraordinary accumulation of sodium, high intake of inorganic ions (mainly Cl, less SO4), and regular occurrence of free oxalate, causing low Ca-concentrations, are typical for Chenopodiaceae and Caryophyllaceae (Spergularia media). Lepidium crassifolium shows similar sodium preponderance accompanied by high levels of SO4, Cl, and organic anions other than oxalate (mainly citrate and malate). The remaining dicotyledons show rather moderate salt content; Asteraceae and Cichoriaceae prefer Cl, and Plantago maritima accumulates high amounts of SO4 as well as Cl. Malate and citrate are, without exception, the main organic anions. The K:Na ratios in dicotyledons (esp. Chenopodiaceae and Lepidium-Brassicaceae) lie far below unity.
b)
Monocotyledons: In marked contrast, Poaceae, Cyperaceae, and Juncaceae are characterized by a general low salt status. With few exceptions, Cl is stored as the main inorganic anion, phosphate reaches higher levels than in dicotyledons and in many cases lies in nearly the same concentration range as SO4. The pattern of organic anions with malate and citrate as the main acids, does not basically differ from nonhalophilous species. In any case, K:Na ratio exceeds unity. Triglochin maritimum is the only monocotyle species exhibiting as high salt content and low K:Na ratios as dicotyledons.
Nitrate and phosphate are of minor quantitative importance with regard to their osmotic efficiency; their mEq percentage of the total anion concentration range between 0.03 to 2.6 (NO3) and 0.5 to 13.6 (phosphate), respectively.The results are discussed from different points of view: on the one hand, the general problems of salt tolerance, on the other hand, the taxonomical and ecological aspects. beneficial to plant growth in view of salt sensitivity of enzymatic reactions. However, low osmotic potential of cell sap, and consequently, the acquisition of water is guaranteed by storing high amounts of sugars: according to our data (Albert and Popp, in preparation) total sugar concentration in halophilous Poaceae, Cyperaceae, and Juncaceae amounts to up to 200 mmoll-1 fresh water, whereas in salt rich dicotyle species the sugar content is comparatively low (up to 50 mmol).
The effect of salinity on leaf area and the relative accumulation of Na+ and K+ in leaves of the mangrove associate Hibiscus tiliaceus were investigated. Photosynthetic gas exchange characteristics were also examined under arid and non-arid leaf conditions at 0, 10, 20 and 30‰ substrate salinity. At salinities ≥ 40‰, plants showed complete defoliation followed by 100% mortality within 1 week. Salinities ≤ 30‰ were negatively correlated with the total leaf area per plant (r2 = 0.94). The reduction in the total plant leaf area is attributed to the reduction in the area of individual leaves (r2 = 0.94). Selective uptake of K+ over Na+ declined sharply with increasing salinity, where K+/Na+ ratio was reduced from 6.37 to 0.69 in plants treated with 0 and 30‰, respectively. Under non-arid leaf condition, increasing salinity from 0 to 30‰ has significantly reduced the values of the intrinsic components of photosynthesis Vc,max (from 50.4 to 18.4 μmol m−2 s-1), Jmax (from 118.0 to 33.8 μmol photons m−2 s−1), and VTPU (from 6.90 to 2.30 μmol m−2 s−1), while stomatal limitation to gas phase conductance (SL) increased from 14.6 to 38.4%. Water use efficiency (WUE) has subsequently doubled from 3.20 for the control plants to 8.93 for 30‰ treatment. Under arid leaf conditions, the stomatal factor (SL) was more limiting to photosynthesis than its biochemical components (73.4 to 26.6%, respectively, at 30‰). It is concluded that salinity causes a drastic decline in photosynthetic gas exchange in H. tiliaceus leaves through its intrinsic and stomatal components, and that the apparent phenotypic plasticity represented by the leaf area modulation is unlikely to be the mechanism by which H. tiliaceus avoids salt stress.
It is quite difficult to conclusively pinpoint the dates when mangroves first appeared and diversified in the Neotropics, thus a number of hypotheses have transpired, and the topic is still a matter of debate. These explanations can be classified into two categories: those that propose a unique centre of origin followed by radiate dispersal (through three routes), and those based on the fragmentation of a common widespread ancestral population or biota. As an alternative to those all-inclusive schemes and given the wide taxonomic variety of mangroves, ad hoc explanations should be implemented for each species, as essayed by Duke (1995) with the genus Avicennia. This author has also cautioned that the present-day co-occurrence of mangrove species should not be interpreted as a measure of common origin.
Leaf structural and chemical characteristics were compared in pairs of species that were phylogenetically independently constrasted along rainfall gradients(10 pairs) or soil nutrient gradients(9 pairs), using perennial plants in New South Wales, Australia. The objective was to test the hypothesis regarding leaf attributes that should be successful in sustaining populations in vegetation at lower vs. higher rainfall or lower vs. higher soil nutrients, and especially to assess the proposition that lower rainfall and lower soil nutrients favour similar shifts, and in this sense can be grouped together as sources of 'stress'. Some evolutionary divergences in leaf structure recur repeatedly toward the lower end of both rainfall and soil nutrient gradients. These include narrower leaves, lower specific leaf area(SLA), thicker lamina, and denser leaf tissue. In other respects, the different resource gradients appeared to favour different leaf attributes. In 8 of 10 contrasts, plants of low water environments had more sclerified vasculature than their relatives on higher rainfall sites. This may be an adaptation to resist wilting and so mitigate cell damage. In 9 of 10 contrasts plants of low water environments had more nitrogen per unit leaf area than their relatives in high rainfall sites. This may be to exploit higher light availability in arid communities. In 7 of 9 contrasts, plants from low soil nutient environments had thicker epidermis than their relatives on higher nutrient soils, and consequently, the ratios of phenol/N and tannnin/N were higher. Thicker epidermis and increased defense/N may reduce herbivory and thereby reduce demand on soil nutrients.