Showing papers on "Heritiera fomes published in 2006"
01 Jan 2006
TL;DR: In this article, both field survey (primary data) and historical (secondary) data were used to assess the present status of salinity rise in Sundarbans area as well as the effect of saliencyrise on species destruction like Sundari (Heritiera fomes) which is the climax species of Sundarbants.
Abstract: The world largest mangrove forest, Sundarbans is situated at the western coastal zone of Bangladesh that covers about 40% of the total forest and gives good feedback to the national economy. But for last few years, salinity increasing drastically in this particular region due to sea water intrusion, reduction of fresh water flow and human activities like shrimp farming. In this study both field survey (primary data) and historical (secondary) data were used to assess the present status of salinity rise in Sundarbans area as well as the effect of salinityrise on species destruction like Sundari (Heritiera fomes) which is the climax species of Sundarbans. It was observed that sea level is rising in the Sundarbans coast at the rate of 4 mm/year that is much higher than global trend of 2 mm/year and results more areas to inundate by tidal water. Besides, the water diversion and withdrawal of fresh water in the upstream significantly hampering salt balance system in Sundarbans that leads to permanent and high level of salinity. The soil salinity rise increases with the increase of depth of soil and high level of salinity in the root zone of the plants results a high concentration of sodium salts within the plants body that causes to the reduction of the forest production, restricting the growth of the species like Sundari (Heritiera fomes) and even causes to die.
30 citations
TL;DR: The findings indicate that low survival rate and poor growth of the trees can be attributed to both ground level and biotic disturbances.
Abstract: The aim of this study is to clarify the survival and growth performances of six native mangrove species (Avicennia officinalis, Avicennia marina, Bruguiera sexangula, Heritiera fomes, Rhizophora apiculata and Sonneratia apetala) that were replanted on abandoned paddy fields in the Ayeyarwady (AYWD) Delta of Myanmar where natural mangroves once existed. The findings indicate that low survival rate and poor growth of the trees can be attributed to both ground level and biotic disturbances. The growth of trees at low ground was obviously better than that of trees at high ground. At low ground, S. apetala demonstrated the best growth and R. apiculata had the highest survival rate. At high ground, the survival and growth rates of A. officinalis were the best. All the species replanted showed the highest increments of tree height from the middle of rainy season to the beginning of winter.
3 citations
13 Dec 2006
TL;DR: On the verge of its extinction, these observations can help to chase up suitable strategies to restore the environment for H. fomes instead of unplanned plantation and wasting the propagules of this rare species.
Abstract: Nandy(Datta), P., M. Ghose, R. Spooner-Hart and S. Das. 2006. Is Heritiera fomes Buch. Ham. less adapted to the present conditions of the Indian Sundarbans compared to other mangrove species?Ann. Trop. Res. 28(2):76-91. The Sundarbans forest forms one of the largest mangrove vegetation in the Bengal Basin. The name indicates dominance of the tree species Heritiera fomes Buch. Ham., locally known as 'Sundari' because of its elegance. Explosive demographic pressure and indiscriminate exploitation of natural resources caused imbalance in this ecosystem. Moreover, reduced fresh water influx and increased sedimentation appeared to be an increasing problem for navigation that in turn, led to elevated soil salinity. In the Indian part of this forest, scarcity of Heritiera fomes can be attributed to these manual and environmental adversities. In comparison to the other predominating species in Sundarbans, H. fomes is less equipped in its leaf anatomical adaptations and water-use management. Considerably thin cuticle and high stomatal frequency encourage water efflux; whereas, poorly developed water storage tissue and low frequency of terminal tracheioids weaken the water retention mechanism. This inefficiency is reflected well by the transpiration rate and stomatal conductance that continuously increase even beyond 1600 μmol m-2s-1. In H. fomes, assimilation potential declines beyond 1250 μmol m-2s-1 PAR, which unlike the other taxa, can be attributed to the poorly developed palisade tissue and low nitrogen content in leaf. The optimum leaf temperature for photosynthesis is 30oC that is considerably lower than that in the others. Osmotic potential (O) of root and leaf is not low enough to facilitate water uptake from the extremely saline substrate; absence of free proline coupled with low Na+ content explains the loss of turgidity in Heritiera fomes Buch. Ham. of the Indian Sundarbans 77 leaf cells. Reduced leaf N+ may interfere the metabolic processes and hinder synthesis of the compatible solutes to some extent thus renders the species incompatible to the soil and microclimate of western Sundarbans. On the verge of its extinction, these observations can help to chase up suitable strategies to restore the environment for H. fomes instead of unplanned plantation and wasting the propagules of this rare species. Correspondence:S. Das Present Address: Agricultural and Ecological Research Unit, Indian Statistical Institute, 203, B.T.Road, Calcutta 700 108, India Email:sauren@isical.ac.in
3 citations