Showing papers on "Heritiera fomes published in 2013"

Cyclone Sidr Impacts on the Sundarbans Floristic Diversity

Abstract: The Sundarbans - the world’s largest single block of tidal halophytic mangrove forest situated at the southwest of Bangladesh, plays a vital role in maintaining environmental sustainability of the country and the world in general. This study identified and quantified the extent and degree of damage caused to the floristic diversity of the Sundarbans by the tropical cyclone Sidr in 15 November 2007. It also quantified the extent and rate of the post-cyclone regeneration in the damaged flora. Unsupervised classification - ISODATA and the normalized difference vegetation index (NDVI) were carried out over a temporal series of 2007-2010 on four Landsat 7 Enhanced Thematic Mapper Plus (ETM +) images for the months of February. Land change analysis from the classification results show that three important floristic taxa - Heritiera fomes (Sundari), Excoecaria agallocha (Gewa) and Sonneratia apetala (Kewra) have been significantly affected by the cyclone. NDVI analysis indicates that 45% area of the Bangladesh’s part of the Sundarbans (approximately 2500 sq.km) was affected due to the cyclone action. Results further indicated that the average rate of post-cyclone floristic growth in 2009-2010 is four times higher than the average rate in 2008-2009. Thus the study identified a temporary loss of the diversity (in terms of relative abundance) in the affected three floristic taxa of the Sundarbans after that severe exogenous perturbation; which took three years to regenerate. Moreover, it showed the higher efficiency and promptness of remote sensing techniques in similar cases than the ground data based studies.

Climate change impacts on the Sundarbans mangrove ecosystem services and dependent livelihoods in Bangladesh

Abstract: The Sundarbans mangrove forest of Bangladesh provides ecosystem services having great importance for local livelihoods, national economy and global environment. Nevertheless, the Sundarbans is threatened by various natural and anthropogenic pressures including climate change. This paper presents the potential impacts of climate change on the ecosystem services of the Sundarbans and the forest dependent livelihoods. Both secondary information on climate change impacts and primary data on forest dependent livelihoods were used for the analysis. Recent study revealed that the suitable area of two dominant tree species ofthe Sundarbans - Sundri (Heritiera fomes) and Gewa (Excoecaria agallocha) may be decreased significantly by the year 2100 due to sea level rise (88 cm) in the Sundarbans compared to the year 2001, which may be reduce the timber stock of those trees. This indicates the potential loss of economic value of the key provisioning services of Sundarbans. Similarly, the other ecosystem services (e.g. fisheries, tourism, biodiversity, carbon sequestration, etc.) maybe affected by climate change. Consequently, the forest dependent livelihoods would be affected by the degraded ecosystem services of the forest. Further studies should quantify the impacts of climate change on all the ecosystem services and explore the potential loss and opportunities in future. A new paradigm of management should look forward considering climate change, ecological integrity, sustainable harvesting and ensuring continuity of the ecosystem services of the Sundarbans.

Ecology of Sundarban, Bangladesh

Abstract: Sundarban is the largest mangrove wetland in the world. It covers an area of about 1mha, of which 60% is located in Bangladesh and the remaining western portion, comprising 40%, lies in India. Mangrove ecosystems are of great ecological significance in the tropical and sub-tropical coast. They protect our coast from heavy wind, tidal waves, coastal erosion and sea water intrusion, generate substantial quantities of fishery resources and provide many useful forestry products. The Sundarban ecosystem supports rich fisheries diversity. This ecosystem support 27 families and 53 species of pelagic fish, 49 families 124 species of demersal fish, 5 families and 24 species of shrimps, 3 families and 7 species of crabs, 8 species of lobster. A total 334 plants, 165 algal, 13 special orchids, 17 fern, 87 monocotyledon and 230 dicotyledon belonging to 245 genera and 75 families from the sundarbans and adjacent area are found available. The principal tree species is Sundry ( Heritiera fomes ) which covers about 73% to total landmass and the second species is Gewa ( Excoecaria agallocha ) which covers about 16% of total forest area. The plant species include 35 legumes, 29 grasses, 19 sedges, and 18 euphorbias. Of the 50 true mangrove plant species recorded throughout the globe, the Sundarbans alone contain 35 species. The magnificent among the animals on land is Royal Bengal Tiger, Spotted deer, barking deer and wild boars are there in plenty. Besides those jungle cats, fishing cat, civet cat, monkey, bengal fox, jackle, water monitor, monitor lizard and snakes are important faunal spp . Moreover, abundant of the Sundarbans are purple heron, pond heron, cattle egret, little egret, open billed stork, smaller adjutant stork, brahmini kite, spotted dove, rose ringed parakeet, crow pheasant, wood pecker, bee eater, drongo, pide myna, jungle myna, bulbul, tailor bird, magpie robin, sparrow etc., Otherwise, recorded that wild Buffalo, 2 species of deer, javan rhinoceros extinct and presently 2 species of amphibians, 14 species of reptiles 25 species of birds and 5 species of mammals are considered as endangered species. This paper is to produce a new assessment of the mangroves ecology of Sundarbans. DOI: http://dx.doi.org/10.3329/jsf.v8i1-2.14618 J. Sci. Foundation, 8(1&2): 35-47, June-December 2010

Classification of floristic composition of mangrove forests using hyperspectral data: case study of Bhitarkanika National Park, India

Abstract: The aim of the present work is to unveil the potential of some of the unexplored remote sensing techniques for mangrove studies. The paper deals with the classification of an Earth Observing–1 Hyperion image of the mangrove area of Bhitarkanika National Park, Odisha, India into mangrove floristic composition classes. Out of 196 calibrated bands of the image, 56 were found to be highly uncorrelated and contained maximum information; therefore, these 56 bands were used for classification. Amongst the three full–pixel classifiers tested in the investigation, Support Vector Machine produced the best results in terms of training pixel accuracy with overall precision of 96.85 %, in comparison to about 70–72.0 % for the other two classifiers. A total of five mangrove classes were obtained – pure or dominant class of Heritiera fomes, mixed class of H. fomes, mixed Excoecaria agallocha with Avicennia officinalis, mixed class of fringing Sonneratia apetala and class comprising of mangrove associates with salt resistant grasses. Post–classification field data also established the same. Pure or dominant classes of H. fomes occupied more than 50 % of the total mangrove vegetation in the forest blocks of the National Park. Spectral profile matching of image pixels with that of in–situ collected canopy reflectance profile revealed good match for H. fomes (pure or dominant stands). Red–edge index, which was a preferred criterion for matching was notably correlated in case of H. fomes and E. agallocha. The outcomes indicated the efficacy of hyperspectral canopy reflectance library for such kind of work. It is hoped that the methodology presented in this paper will prove to be useful and may be followed for producing mangrove floristic maps at finer levels.

Anticancer activity and chromatography characterization of methanol extract of Heritiera fomes Buch. Ham., a mangrove plant from Bhitarkanika, India

Abstract: Heritiera fomes Buch. Ham., a dominant mangrove tree species occurring in Bhitarkanika mangrove forest, Odisha, India has been known for its ethnomedicinal uses for the treatment of gastrointestinal disorders, hepatic disorders, skin diseases, diabetes and goiter. Scientific evidence in support ethnomedicinal uses of this plant is lacking. Hence the study is aimed to determine the anticancer activity along with the partial characterization of methanol extract of H. fomes in both in vitro and in vivo by using animal model. The methanol extract of both leaf and stem powder showed anticancer properties with 40 % inhibition against B16 mouse melanoma (in vitro system) and Ehrlich Ascites Carcinoma (EAC) in Swiss albino mice (in vivo system). The partial characterizations of the methanol extract by TLC, HPLC, 1H NMR and FTIR spectral analysis revealed phenolic as the lead compounds. Overall results showed that both the leaf and stem extracts of H. fomes possess strong anticancer properties along with the presence of most of the phytochemicals which supports previous claims of the traditional use for various diseases.

Salt Stress: A Biochemical and Physiological Adaptation of Some Indian Halophytes of Sundarbans

Abstract: Experiment was conducted with five typical mangroves (Bruguiera gymnorrhiza, Excoecaria agallocha, Heritiera fomes, Phoenix paludosa, and Xylocarpus granatum) both from Sundarbans (in-situ) and grown in mesophytic condition (ex-situ, in the Indian Statistical Institute’s premises) since 15–17 years. A comparative account on PAR utilization for maximum photosynthesis, stomatal conductance, total leaf proteins, and polymorphic expression of two antioxidative enzymes (peroxidase and superoxide dismutase) and two hydrolyzing enzymes (esterase and acid phosphatase) were estimated both qualitatively and quantitatively. The present work revealed that the net photosynthesis was higher in mangroves from mesophytic habitats than those of the native plants, but the PAR acquisitions for maximum photosynthesis were greater in most of the Sundarbans species, except H. fomes and X. granatum. At the same time, the stomatal conductance was remarkably depleted under salinity stressed habitats than those of the nonsaline counterparts and ranged between nearly 25 and 52%. Total leaf protein content form the above said taxa revealed that the increment of total protein occurred in mesophytic habitat and it was ranged between 156% (in P. paludosa) and 5.7% (in X. granatum). PAGE analysis revealed that in most of the cases there were extra numbers of protein bands expressed with relatively low molecular weight in saline habitat plants. In all salinity imposed plants, there were sharp increase in band intensity and number of isoforms of each enzyme. Peroxidase increment in saline plants was ranged between 257% (in Bruguiera) and 139% (in Excoecaria). Similarly, superoxide dismutase (SOD) was estimated as 247% (in Heritiera) to 147% (in Excoecaria) in saline habitats. Increments of esterase and acid phosphatase were varied from 287% (in Phoenix) to 154% (in Excoecaria) and 293% (in Bruguiera) to 139% (in Excoecaria), respectively. Salinity imposed increment of antioxidant enzymes proved their efficient scavenging ability to evolved reactive oxygen species (ROS), but these increments were relatively lower in Heritiera and Xylocarpus even though the net photosynthesis was higher. This might be related to their less adaptability in elevated salinity stress than those of the other three species investigated from the same regime. Among the plants grown in in situ condition, some taxa have the better ability of enzyme production, which might be correlated with the efficient stress management practice. A statistical relationship was observed between the total protein content and the investigated enzyme concentration, dependent on the habitat and discussed accordingly.

How Mangroves Respond to Hypersaline Condition? Preparedness for Predicted Sea Level Rise

Abstract: Climate change has several components of varied nature and scale that influences the coastal vegetation. For mangroves, however, the most relevant components include changes in sea level, high water events, stormi- ness, precipitation, temperature, atmospheric CO2 concentration, ocean circulation patterns, health of functionally linked neighbour- ing ecosystems, as well as human responses to climate change. Of all the outcomes from changes in the atmosphere's composition and alterations to land surfaces, relative sea level rise is the greatest threat to mangroves. The adverse effect gets much more magnified if the mangrove flora is freshwater loving in nature like Heritiera fomes, Sonneratia apetala or Nypa fruticans. The rising sea level in- creases the salinity of the ambient water and soil, which poses a negative impact on the growth and physiological set-up of mangroves. The present paper highlights a case study of adaptation of five different mangrove species to increasing salinity in the tiger dominated Indian Sundarbans of lower Gangetic region. Along with the growth rate of the species in natural conditions, their pigment systems have also been analysed with respect to changing salinity levels. The results of the present study can be extrapolated to predict the effect of climate change induced sea level rise in Indian Sundarbans region on mangrove vegetation. The ecological value of the system in terms of carbon sequestration has also been highlighted since salt marshes, mangroves, and seagrasses store ten times more car- bon in their soils per hectare than temperate forests and fifty times more than tropical forests. Some management action plans (like regular dredging of the accumulated silt, interlinking of rivers etc.) have also been discussed to restore the mangrove system from the adverse impact of hypersalinization.