Showing papers on "Heritiera fomes published in 2011"

Status Of The Mammal Fauna In Sundarban Tiger Reserve, West Bengal - India

Abstract: Sundarban Tiger Reserve (2,584.89 km 2 ) in West Bengal is a part of the world’s largest estuarine wetland and the only mangrove tigerland, spread over India and Bangladesh. Its plant associations exhibit a great generic/species diversity and offers habitats of many rare and endangered mammals. The dense thickets of Heritiera fomes , Nypa fruticans and Phoenix paludosa form the prime habitat of Panthera tigris tigris . This tigerland is also the abode of a good number of its prey and other associated mammal species. A one-year (January-December 2010) study was conducted with the frontline forest department staff to investigate the distribution and status of the mammalian species found in this thirty-eight years’ old tiger conservation area, involving literature review, questionnaire and ground surveys. This has revealed shrinkage of the mangrove swamp habitat and a number of mammal species in decline due to extensive anthropogenic and natural threats. Out of forty nine extant species recorded (eight orders: twenty three families), four are globally endangered, four vulnerable and two near threatened as per IUCN Red List. Alarmingly, fifteen mammal species were found on only rare occasions. In addition, six species (two orders: three families) had become extinct during the last two centuries. Though distributed over all forest block areas, the frequency of tigersighting was recorded more from Sajnekhali Wildlife Sanctuary and the buffer areas than Sundarban National Park or the core area. High-priority wildlife conservation, proper implementation of the tiger action plan, further infrastructural development and effective joint forest management are essential for saving this tigerland. Key words : Tigerland; world heritage; wetland; distribution; threats; conservation DOI: http://dx.doi.org/10.4038/tapro.v3i2.3961 TAPROBANICA 2011; 3(2): 52-68

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

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

Photosynthesis and antioxidative enzyme activities in five Indian mangroves with respect to their adaptability

Abstract: Five typical mangroves were taken (Bruguiera gymnorrhiza, Excoecaria agallocha, Heritiera fomes, Phoenix paludosa and Xylocarpus granatum) both from Sundarbans (in situ) and grown in a mesophytic environment (ex situ, in the Institute’s premises) for 12–15 years. A comparative account of PAR utilization for maximum photosynthesis, stomatal conductance and production of two antioxidant enzymes (peroxidase and Superoxide dismutase) were done between the in situ and ex situ habitats. The present work revealed that the average net photosynthesis was slightly higher in mangroves from non-saline habitats than that of the native ones. At the same time, stomatal conductances were remarkably reduced under salinity-stressed habitats when compared with those of the mesophytic counterparts, by 25–52%. Salinity imposed increase of antioxidant enzymes was observed. Both the investigated antioxidant enzymes showed considerable increase in saline-grown individuals and proved their efficient scavenging ability to evolve reactive oxygen species (ROS), but these increases were relatively lower in Heritiera and Xylocarpus even though the net photosynthesis was higher. This might be related to their lower adaptability under increased salinity stress than those of the other three species investigated.

Chemical characterization of six mangrove species in Bangladesh

Abstract: Lack of data especially pertaining to the chemistry of mangrove wood species makes it difficult to prepare successful plans for their conservation and to use mangroves as a source of wood fiber. In this paper, chemical characterizations of the six main mangrove species of Bangladesh [namely Keora (Sonneratia apetala), Geoa (Excoecaria agallocha), Bine (Avicennia alba), Sundari (Heritiera fomes) Pashur (Xyloccarpous mekongests), and Kakra (Bruguiera gymnorhiza)] were investigated. The chemical results revealed that these species contain high percentages of dichloromethane followed by methanol extractives. Methanol extracts in Pashur, Sundari, and Bine were higher than 10%, which indicates high percentage of tannin material. The total lignin content in these species was higher than 25%, except for Gewa (23.6%) and Pashur (21.3%), which is higher than that of the normal range of hardwood. The pentosan content in these six species was within the range of 19.4–22.8%. The α-cellulose content in Keora and Gewa was acceptable for pulp production, but the others were lower than the normal range of hardwood. Alkaline nitrobenzene oxidation showed that all these species had a very high syringaldehyde to vanillin (2.6–5.0) ratio except Keora (1.6). Surprisingly, rhamnose is the main constituent with xylose of hemicelluloses of these six mangrove species. The ash content in these six mangrove wood species was also higher than that in normal hardwood.

Damage and Post-cyclone Regeneration Assessment of the Sundarbans Botanic Biodiversity caused by the Cyclone Sidr

Abstract: The Sundarbans is the largest single block of tidal halophytic mangrove forest in the World. The versatile biodiversity of this forest, situated at the southwest of Bangladesh, plays a vital role in maintaining environmental sustainability of the country. This study identifies and quantifies the damage caused by the tropical cyclone Sidr in 15 November 2007 and the post-cyclone regeneration of the botanic biodiversity of the Sundarbans. Unsupervised classification and the normalised difference vegetation index (NDVI) were carried out over a temporal series of four Landsat 7 Enhanced Thematic Mapper Plus (ETM +) images for the month of February in the period between years 2007 and 2010. The obtained overall accuracies for the classification of the images of years 2007 and 2010 (the ones\' for which there were ground-truth data available) were, respectively, 76% and 88%. Classification results and land change analysis show that three important botanic species - Heritiera fomes (Sundari), Excoecaria agallocha (Gewa) and Sonneratia mangrove (Kewra) have been significantly affected by the cyclone. On the other hand NDVI analysis indicated that 45% area of the Sundarbans (approximately 2500 sq.km) has been damaged due to the cyclone action. Results further indicate that the rate of post-cyclone regeneration in 2009-2010 is four times higher than the regeneration rate of 2008-2009. Although cyclone Sidr has done significant damage to the diversity of the mangrove forest, it has regenerated to a satisfactory condition despite the effects of climate change and man-made encroachment.