Mangrove Diversity Research Articles

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

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

KEANEKARAGAMAN TUMBUHAN MANGROVE DI TAMAN NASIONAL BALI BARAT

The diversity of mangrove at West Bali National Park has not been reported completely. The exploration was conducted from 12 - 16 June, 2011 from Banyuwedang to Gilimanuk and from Gilimanuk to Sumbersari-Melaya mangrove forests. The result showed that 18 families consist of 21 genera and 28 mangrove species were recorded at West Bali National Park, these are 11,5% of the Indonesian mangroves.

Mangrove and coral reef sponge faunas: untold stories about shallow water Porifera in the Caribbean

Sponge faunas from coral reefs and mangrove ecosystems in the Caribbean have mostly been studied from an ecological perspective, with researchers considering the effects of physical and biological factors on their species distribution. To discern evolutionary patterns, this study analyzed the systematic composition, taxonomic diversity, and ecological properties (reproductive strategies, size, shape, endosymbiosis) of mangrove and reef sponge assemblages from seven distant Caribbean localities. Species composition was compared by use of cluster analysis (Sorensen’s), and taxonomic diversity by use of the biodiversity index average taxonomic distinctness (AvTD). Mangrove and reef-associated sponge faunas were found to be statistically dissimilar, with the AvTD values suggesting stronger taxonomic bias toward specific groups in mangroves, irrespective of geographic distance. Most Demospongiae orders have 30–50% more species in coral reefs than in mangroves. The richest reef genera (Agelas, Aplysina, Callyspongia, Petrosia, and Xestospongia) rarely colonize contiguous mangrove formations. The distribution and diversity of suprageneric taxa suggest that coral reef sponge assemblages might represent an older fauna. This historical interpretation would place mangrove subtidal habitats as the youngest marine ecosystem, rather than a below-optimum ecosystem. Life history traits support a biological split discussed here from the perspective of distinct evolutionary histories and different environmental conditions.

KOMPOSISI KEBERADAAN KRUSTASEA DI MANGROVE DELTA MAHAKAM KALIMANTAN TIMUR

Normal 0 false false false IN X-NONE X-NONE MicrosoftInternetExplorer4 Mangrove area, Mahakam Delta, East Kalimantan . The aim of this research was to analyze the diversity and the richness of crustacean. The research was done in the locations where dense area (Muara Ilu I), moderate area (Muara Ilu II, P. Tunu) and rare area of mangroves Muara Pantuan (P. Lagenting Luar). The transect research method was used stand upright line of the seashore for mangrove and crustacean. The result of environment parameter shows relative in good condition for living mangrove and crustacean organisms. Total founded crustacean were 40 species and 9 families. The 38 species were non economic values and 2 species were economic values: Varuna yui and Scylla olivacea , also founded 2 new species: Metaplax sp. nov. (Grapsidae) and Macrophthalmus sp. nov. (Sesarmidae). The highest crustacean density varies depend on the environment characteristic of the research station. The highest density was 1456 ind/m 2 (station 6) and the lowest density was 27 ind/m 2 (station 8). Diversity Index was lower category (H’ = 3.0700), while Similarity Index (E = 2.0180) was high enough, so the distribution of crustacean relatively similar. Dominancy Index was low (C =   1.6270). While the highest mangrove diversity Index was at Muara Ilu I (H = 2.14) and following by Muara Ilu II (H = 1.40) and Mauara Pantuan (H = 2.03). Over all the three locations of mangrove vegetation (tree, belta and seed) are in the lower categories diversity index, similarity index and dominance index. Keywords: crustacean, mangrove ecosystem, Mahakam delta, East Kalimantan, diversity, density

The Loss of Species: Mangrove Extinction Risk and Geographic Areas of Global Concern

Mangrove species are uniquely adapted to tropical and subtropical coasts, and although relatively low in number of species, mangrove forests provide at least US $1.6 billion each year in ecosystem services and support coastal livelihoods worldwide. Globally, mangrove areas are declining rapidly as they are cleared for coastal development and aquaculture and logged for timber and fuel production. Little is known about the effects of mangrove area loss on individual mangrove species and local or regional populations. To address this gap, species-specific information on global distribution, population status, life history traits, and major threats were compiled for each of the 70 known species of mangroves. Each species' probability of extinction was assessed under the Categories and Criteria of the IUCN Red List of Threatened Species. Eleven of the 70 mangrove species (16%) are at elevated threat of extinction. Particular areas of geographical concern include the Atlantic and Pacific coasts of Central America, where as many as 40% of mangroves species present are threatened with extinction. Across the globe, mangrove species found primarily in the high intertidal and upstream estuarine zones, which often have specific freshwater requirements and patchy distributions, are the most threatened because they are often the first cleared for development of aquaculture and agriculture. The loss of mangrove species will have devastating economic and environmental consequences for coastal communities, especially in those areas with low mangrove diversity and high mangrove area or species loss. Several species at high risk of extinction may disappear well before the next decade if existing protective measures are not enforced.

Diversity of true mangroves and their associates in the Pondicherry region of South India and development of a mangrove knowledgebase

Mangroves are salt–tolerant forest ecosystems of tropical and subtropical intertidal regions of the world. There may be no other group of plants with such highly developed morphological and physiological adaptations to extreme conditions. They are a rich source of steroids, triterpenes, saponins, flavonoids, alkaloids and tannins. The Pondicherry region in South India has no forest, but has scattered patches of mangroves and remnants of tropical dry evergreen forest in the form of sacred groves. The present study documents the directly observed diversity of true mangroves and their associates, in four geographical regions of Pondicherry in South India; namely Pondicherry, Karaikal, Mahe and Yanam. These places are far from one another and the mangrove species diversity varies from one place to another, due to factors such as climate, tidal factors and anthropogenic pressures. In addition, we have also developed a knowledgebase entitled “Mangroves of Pondicherry”, which contains information including botanical name, English name, local name (Tamil language), Family, description, images and common uses of true mangroves and their associates. This knowledge resource is available for open access at http://web.iitd.ac.in/~sundar/mangroves/. Key words: Mangroves, knowledgebase, sacred groves, tropical dry evergreen forest, Pondicherry, South India

Biological and environmental characteristics of mangrove habitats from Manori creek, West Coast, India

Mumbai, a megacity of India, and its adjacent marine environment, though heavily stressed from various anthropogenic interferences, harbor approximatley 146 km(2) of mangrove cover. Manori creek, in the close vicinity of Mumbai, sustains relatively better mangrove formations. A creek habitat had been evaluated for its biological and environmental characteristics, and is compared with similar but relatively lesser stressed Mandovi estuary (approximately 475 km south of Mumbai). Several evidences of deteriorating environment of Manori creek have been described with respect to Water quality index and various biotic community structures. Water quality index of <55 indicated unacceptable aquatic conditions of Manori creek. Dominance of Avicennia marina and poor abundance and diversity of mangrove and associated biological features indicate highly stressed environment. Dominance of stress-tolerant phytoplankton spp. such as Skeletonema costatum and benthic fauna such as Polychaeta further supported the view. The data presented in the present document would help in developing rational approach towards conservation, protection, and sustainable development of mangrove-dominated creek and estuarine wetlands.

Diversity and spatial heterogeneity of mangrove associated sponges of Curaçao and Aruba

Sponges are major epibionts of mangrove roots in the Caribbean. Mangrove sponge communities in the Caribbean mainly consist of species that are typical to this habitat and community compositions often differ from those found on coral reefs nearby. Heterogeneity in species distributions between locations and within locations between roots is often reported. This study quantifies the diversity and abundance of mangrove associated sponges in the inner bays of Curaçao and Aruba and correlates variability of regional sponge diversity with environmental variables measured along the surveyed sites. Tannin concentrations vary between mangrove roots, and were correlated to sponge cover as a possible cause for habitat heterogeneity on a smaller scale. A total of 22 species was observed. Heterogeneity in species richness and abundance was apparent, and several sponge species were restricted in their depth of occurrence. Statistical data reduction suggests that sponge diversity may be partly explained by the distance towards adjacent reefs and to the degree of eutrophication, in which the latter is comprised of rate of planktonic respiration, total carbon and turbidity. Tannin concentrations did not determine within locality species heterogeneity as a priori postulated, but were positively related to sponge cover for reasons not yet elucidated.

Assessment of Mangrove Diversity in Sunderban Tiger Reserve, India

Assessment of Mangrove Diversity in Sunderban Tiger Reserve, India

Genetic diversity of black mangrove (Avicennia germinans) in natural and reforested areas of Salamanca Island Parkway, Colombian Caribbean

The species Avicennia germinans in natural and reforested areas was analyzed to obtain information about its genetic diversity in a highly disturbed mangrove ecosystem and to generate a useful tool for determining the donor and receptor populations of propagules. Tissue of 149 individuals was collected in the protected areas of the Tayrona National Natural Park (Tayrona-NNP) and the Salamanca Island Parkway (Salamanca-IP). A total of 38 alleles were found in seven microsatellite loci, leading to the detection of high levels of heterozygosity in the two protected areas. The impact of the highway on the Salamanca-IP-south population was shown when the inbreeding coefficient from younger individuals was compared with older ones; inbreeding increased 4.2 times. The inbreeding coefficient in the reforested area was 2.2 times higher than that in the Salamanca-IP-south zone. Thus, for future reforestations in this area, the collecting of propagules should come from two sectors—one to the north of the highway including Tayrona-NNP and the other to the south. Finally, we consider that the viability of the reforested population in the short and medium term would be improved if good reforestation practices are implemented for A. germinans.

The Impact of Mangrove Prop-Root Epibionts on Juvenile Reef Fishes: A Field Experiment Using Artificial Roots and Epifauna

A field experiment was established in Bocas Del Toro, Panama to examine the relationship between sessile organisms living on mangrove prop roots and fish communities. Artificial mangrove roots (AMR) with different sets of artificial (AE) or real epibionts were established in five different locations in two separate years. Fish species in each plot were identified, counted, and their size estimated by visual census for 15 days in each replicate. In the artificial mangrove plots, the treatments with the most heterogeneous structure had significantly greater abundance of most families and species richness of fish in both years of the experiment. AMR plots with AEs attracted a more abundant and diverse fish assemblage than those with live epibionts, which had lower three-dimensional structure. All of the AMR plots had significantly greater fish abundance than comparable plots of sea grass alone. The location of the replicate also made a significant difference to fish abundance. The data indicate that prop-root epibionts can enhance fish abundance and diversity in mangroves, although the relationship may depend on the specific nature of the epibionts and fishes present.

Rate of Lineage Origin Explains the Diversity Anomaly in the World’s Mangrove Vegetation

The contribution of nonecological factors to global patterns in diversity is evident when species richness differs between regions with similar habitats and geographic area. Mangrove environments in the Eastern Hemisphere harbor six times as many species of trees and shrubs as similar environments in the New World. Genetic divergence of mangrove lineages from terrestrial relatives, in combination with fossil evidence, suggests that mangrove diversity is limited by evolutionary transition into the stressful marine environment, the number of mangrove lineages has increased steadily over the Tertiary with little global extinction, and the diversity anomaly in mangrove vegetation reflects regional differences in the rate of origin of new mangrove lineages.

A study of salt secretion by mangroves of Rekawa Lagoon, Sri Lanka

A method to measure the salt secretion by mangroves which are open to the sea spray was developed and used to measure the salt secretion by mangrove species of Rekawa lagoon, an ecosystem with the highest diversity of true mangroves in southern Sri Lanka. Out of the twelve species of mangroves, only four species i.e. Acanthus ilicifolius, Aegiceras corniculatum, Avicennia marina, and Avicennia officinalis proved to be able to secrete salts. Under the salinity regime (26.2 ± 4.41 ppt) existed during the experimental period, the salt secretion by leaves of these four species were 47.2 ± 18.3, 35.1 ± 16.0, 149.3 ± 45.9, and 81.6 ± 30.5 mg salt cm−2 day−1 respectively. This result corroborates the published records and, hence validates the technique used in this study to measure the salt secretion. These four species exhibited increases in salt secretion with increases in soil salinity, consistent with previous reports. Results of this study also shows that the capacity to secrete salts at any given salinity was different between four species, following an order of Av. marina > Av. officinalis > Ac. ilicifolius, and Ae. corniculatum. The salt secretion by these species immediately after reducing the soil salinity was increased significantly implying an opportunistic removal of salt, which was accumulated in the plant body under high saline condition. Capacity for salt secretion by the four species as well as the magnitude of the increase of salt secretion as a response to increasing soil salinity, vary in parallel to the variations in salt tolerance given in published reports for the same species.

Floral Diversity Of Mangrove Forest In The Kaliuntu Bay- Rembang Based On Palynological Evidences

Palynological evidences (polen and spores) have been used to study mangrove diversity of coastal zone sites at Kaliuntu bay (Rembang), province of Central Java. Data was collected in April 2nd to April 17th 2005, following transect method. In this research for sediments sampling used surface-subsurface sampling method (depth in 10cm). The result showed that mangrove forest in the coastal zone of Kaliuntu bay (Rembang) was dominated by Rhizophoarceae polen type (included Rhizophora genera)© 2006 Jurusan Biologi FMIPA UNS SurakartaKey words: palynological evidences; diversity; polen type

Rate of Lineage Origin Explains the Diversity Anomaly in the World's Mangrove Vegetation

The contribution of nonecological factors to global patterns in diversity is evident when species richness differs between regions with similar habitats and geographic area. Mangrove environments in the Eastern Hemisphere harbor six times as many species of trees and shrubs as similar environments in the New World. Genetic divergence of mangrove lineages from terrestrial relatives, in combination with fossil evidence, suggests that mangrove diversity is limited by evolutionary transition into the stressful marine environment, the number of mangrove lineages has increased steadily over the Tertiary with little global extinction, and the diversity anomaly in mangrove vegetation reflects regional differences in the rate of origin of new mangrove lineages.

Benthic bacterial diversity and nutrient processes in mangroves: impact of deforestation

The bacterial diversity and nutrient dynamics of mangrove sediments in Kisakasaka, Tanzania, was investigated in order to evaluate potential changes associated with deforestation of mangroves. Study sites included relatively undisturbed, recently protected mangroves and clear-cut mangrove areas that were sampled during both the wet and dry seasons. Physicochemical parameters, nitrogenase activity, pore water nutrient concentrations and bacterial diversity were measured in sediment depth profiles using both molecular and chemical techniques. Results show that there are significant differences in sediment pore water nutrient concentrations and bacterial diversity in sediments of mangrove areas which have been deforested compared to those which have been protected. Average measured values for protected and deforested areas, respectively, were: sulphide (S 2−), <42±10 μM and >1.9±0.5 mM at 30 cm depth; ammonium (NH 4 +), 58±2 μM and 113±12 μM at 4–5 cm depth; soluble reactive phosphate, 40.2±11 μM and 18.4±1.2 at 4–5 cm depth. Nitrogen fixation rates were lower in deforested areas during day and night, organic content was higher in protected areas (20±5%) compared to deforested areas (12±3%). The bacterial diversity was lower in deforested areas as determined by Shannon index using 16S rRNA gene analysis with terminal restriction fragment length polymorphism.

Mangrove history since 1,500 years B.P. at Dangmal, Baitarni-Brahmani Delta, Orissa, India

The paper embodies the results of fine resolution palynostratigraphy of a sediment profile dated 1,500 years B.P. from Dangmal, an area within Bhitarkanika wildlife sanctuary in Cuttack District, Orissa. It is second largest mangrove swamp in India covering an area of 142 sq. km with thickets of mangrove forest. Bhitarkanika is famous for beautiful repository of mangrove constituents wherein 61 species out of the total 67 Indian species exist signifying the mangrove diversity. The bottom samples of profile exhibited rich occurrence of palynodebris such as pollen, spores, diatoms, dinoflagellate cysts, microforaminifera, Pseudoschizaea, etc. The core mangrove taxa encountered are Rhizophora, Heritiera, Sonneratia, Avicennia, Excoecaria, Aegialitis, etc. indicating conducive environment for growth and development of mangroves. However, the frequency of both core and peripheral mangroves declined in the middle and further reduced in the upper part of the profile. It has been found that there was comparatively low degree of mangal exploitation at Dangmal as compared to other investigated areas of Mahanadi Delta, Orissa.

Molecular phylogeny of mangroves V. Analysis of genome relationships in mangrove species using RAPD and RFLP markers

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.

Issues of Spatial, Taxonomic and Temporal Scale in Delineating Links between Mangrove Diversity and Ecosystem Function

Issues of Spatial, Taxonomic and Temporal Scale in Delineating Links between Mangrove Diversity and Ecosystem Function

Do mangrove diversity and leaf litter decay promote meiofaunal diversity?

The effects of mangrove diversity and the process of leaf litter decay on the diversity and community structure of meiofauna inhabiting leaf litter were investigated in a simple field experiment in a wet, tropical, soft sediment, mangrove forest in north-eastern Malaysia. Strings of freshly fallen leaves of Rhizophora apiculata and Bruguiera parviflora were placed on the mud surface in two adjacent subplots, each dominated by one of these tree species. The leaf strings were sampled weekly over five weeks and the nematodes and copepods found on the leaves were identified to species and enumerated. It is shown that, under similar conditions of sediment composition, salinity and tidal inundation, the species of mangrove tree or their leaves have little influence on leaf litter meiofaunal climax communities. Such differences as are apparent in the early part of the experiment are probably the result of differences in tree root structure, associated macrofauna and the initial chemical composition of the leaves. It is also shown that there are significant differences in the litter meiofaunal communities during the process of leaf litter decay. For the copepods, a distinct leaf litter community is characterized by the presence of members of the family Darcythompsoniidae and it is the completion of their lifecycle which is the principal feature of the community changes. Development of the nematode community is characterized by subtle shifts in the composition of species inhabiting the leaf litter. It is suggested that changes in the meiofauna community may be more intimately linked to successional changes in the chemistry and/or microflora of the leaf litter than to the physical breakdown of the substratum.