A serious disease (top dying) of H. fomes in Sundarbans is affecting millions of the trees. An inventory by Chaffey et al., (1985) revealed that there were about 45.2 million top dying trees in the Sundarbans of which 20 million had more than 50% of their crown affected by top dying. The loss of H. fomes will have a major impact on the Sundarbans mangrove ecosystem, as well as lead to economic losses. Despite various hypotheses as to the causes of this top-dying, the underlying causes are still not well understood. The present work has explored some of the possible factors involved, focussing particularly on the relationship between the amount of top-dying in different places and the concentrations of a number of chemical elements present in the soil and water, in order to test the hypothesis that chemical pollution might be responsible. Other factors such as the pH, salinity and nutrient status were also assessed. Nine plots were selected for sampling of soil, water, and vegetation in order to categorise different areas in terms of their intensity of top-dying. 63 soil samples and 9 water samples were tested, mainly by ICPMS, to investigate certain parameters of the soil and water, such as Sn, Exchangeable K, Soil pH, Pb, Zn, Ni, soil pH, CEC, soil nutrients, soil moisture content, and elemental concentrations of 32 other elements. Most of the elements studied had no significant correlation with the top dying of Heritiera fomes. However, Sn, Exchangeable K, and soil pH were significantly related, and three elements, namely Pb, Zn, Sr, were also close to significance. Of the hypotheses previously put forward to explain top-dying, the present results do not support enhanced salinity as the cause. It is likely that several of the above-mentioned environmental factors interact with each other to induce top dying in Sundri. But, the present results have showed that Sn, Exchangeable K, Pb , Sr and Zn could be directly linked with top-dying of Heritiera fomes (Sundri) in Sundarbans ( Awal, 2007; 2009; 2014), particularly by weakening the vigour of the trees and allowing other factors such as pathological agents to attack the plants.
Awal, Mohd. Abdul,
Analysis of Causes of Disease in Sundarbans Natural Mangrove, American Journal of Bioscience and Bioengineering.
Vol. 2, No. 2,
2014, pp. 18-32.
Awal, M.A. (2007). Analysis of possible environmental factors causing top-dying in mangrove forest trees in the Sundarbans in Bangladesh. PhD thesis, University of Bradford.
Awal, M.A., Hale, W.H.G. & Stern, B. (2009). Trace element concentrations in mangrove sediments in the Sundarbans, Bangladesh. Marine Pollution Bulletin, 58(12), 1944-1948.
Awal, M.A. (2014). “Correlation between the chemical composition of the surface sediment and water in the mangrove forest of the Sundarbans, Bangladesh, and the regeneration, growth and dieback of the forest trees and people health”..Journal of Science Innovation; 2014. 2(2): pp.11-21.Science Publishing Group, USA; May 20th, 2014(2):11-21;doi: 10.11648/j/si.20140202.11.
ADB, 1992. Non-Wood forests Products. Project 372001/9; forest master Plan, Bangladesh. Asian development Bank, Manila, Philippines: 46-50.
Asian Development Bank, 1993-95. Main Plan-1993/2012. Vol.1. Forestry Master Plan. Asian Development Bank, Manila, Philippines.
Ahmed, K.J. 1957. Tidal forests of East Pakistan, their growth and regeneration. The Pakistan Journal of Forestry, Volume, Deradun, Pakistan.
Bakshi, B. K. 1954. Wilt disease of Dalbergia sissoo Roxb due to Fusarium solani Sensu Snyder and Hensen. Natural Nature 174: 278-291.
Balmforth, E. B. 1985. Observation on Sundri top dying-descriptive Sampling. In the Sundarbans reserved forest. Draft Working Paper, UNDP/FAO Project BGD/77/017, and Dhaka.32 pp.
Banik, H. 2000. Bangladesh Sundarbans. Hitutumi Book House and Publishers.TalpukurPar, Comilla, (in Bangla), Bangladesh.
Blasco, F. (1977). Outlines of Ecology, Botany and Forestry of the Mangals of the Indian sub-continent. In: Wet coastal ecosystem (ed. V.J. Chapman), Elsevier, Amsterdam 13(1), 19(2).
Chaffey, D. R; Miller, F.R; Sandom, J. H. 1985. A forest inventory of the Sundarbans, Bangladesh, Main report, Project Report No.140, 196 pp; Overseas Development Administration, London, U.K:195-196.
Chaudhury, A.M. 1968. Working Plan of Sundarbans Forest Division for the period from 1960-61 to 1979-80, 82: East Pakistan Government Press, Dacca.
Chowdhury, J. H. 1973. Preliminary report of the investigation of the top dying of Sundri in the Sundarbans. BFRI, Chittagong, Bangladesh, 2 p.
Chowdhury, J. H. and Baksha, M.W. 1983. Studies on the role of Chrysocroa sp. in the initiation of top dying of Sundry. Bano-Biggyan Patrika, 12 (1&2): 30-34.
Chowdhury, A.M. 1984. Integrated Development of the Sundarbans, Bangladesh: Silvicultural Aspects of the Sundarbans. FAO Report No / TCP/ BGD/ 2309 (Mf), W / R003.
Chowdhury, M. I. 1984. Morphological, hydrological and ecological aspects of the Sundarbans. FAO report N0. FO: TCP/BGD/2309(Mf) W /R0027, 32 P.
Curtis, S.J. 1933. Working Plan for the forests of the Sundarbans Division, for the period from 1st April 1931 to 31st March, 1951, Vol.1, 175 p. Bengal government press, Calcutta, India.
Ellison, J. C. 1998. Impacts of sediment burial on mangroves. Marine Pollution Bulletin 37: 420-426.
Ellison, J. C. 2000. Mangrove restoration: Do we know enough? Restoration Ecology. 8: 219-229.
Faizuddin, M. 2003. Research on the Top Dying of Sundri in Bangladesh: 43, Mangrove Silviculture Division, Bangladesh Forest Research Institute, Khulna, Bangladesh.
Faizuddin, M. and Islam, S.A. 2003. Generated Technology and Usable Information of the Mangrove Silviculture. Mangrove Silviculture Division, Bangladesh Forest Research Institute, Khulna, p. 17.
FAO, 1994. Review of the state of world marine fisheries resources. FAO Fisheries resources. FAO Fisheries Technical Approach Paper 335:143.
Forestal, 1960. Forest inventory 1958-59, Sundarban Forests. Forestal International Incorporated, Oregon, Canada.
Fujimoto, K; Miyagi, T; Kikuchi, T; and kawana, T. (1996). Mangrove habitat formation and response to Holocene sea-level changes on kosrae Island, Micronesia. Mangrove and salt marshes, 1:47-57.
Gibson, I.A.S. 1975. Reports on a visit to the People’s Republic of Bangladesh, 28 February to 1 April 1975.Unpublished Report, ODA, London, 28pp.
Government of India, 1990. Conservation of Mangroves in India, Ministry of Environment and Forests, New Delhi, August, 1990.
Gupta, D.P. (1982). The control of Resources. Cambridge, M.A: Harvard University Press.
Hassan, M. M. 1984. Soil formation in the recent deltaic region of Bangladesh. Bangladesh Journal of Soil Science 20:37-45.
Hassan, M. M. 1988. Soil and Salinity of the Sundarbans in relation to top dying, regeneration and survival of Sundri. UPR of Bangladesh Forest Research Institute, Chittagong: 9.
Hassan, M. M.; Mazumder, A. H.; Islam, A. T. M. N. and Hossain, A.T. M. E. 1990. Soil, hydrology and salinity of Sundarbans in relation to top dying, regeneration and survival of Sundri (Heritiera fomes) trees. In: Rahaman, M. A.; Khandakar, K.; Ahmed, F.U. and Ali, M.O. (Eds.). Proceedings of the Seminar on Top Dying of Sundri (Heritiera fomes) Trees. Bangladesh Agricultural Research Council, Dhaka: 1- 11.
Hoffman J. A. Katz, J. And Bertness, M. D 1986. Mangrove ecosystem. Journal of Ecology, 72 (2): 621-625.
Howlader, A. S. 1973. Report on the Preliminary investigation of Probable causes of Top-Dying, Regeneration and Survival of Sundri. Unpublished Report, BFRI, Chittagong, 9 pp.
Islam, A. K. M. N. 1982. Physico-chemical properties of Sundarbans mangrove forest. Proceedings of the Second Bangladesh national Conference on Forestry 50-54 p. Dhaka, Bangladesh.
Islam, M. A. 1992. Some relevant information about the Sundarbans Forest Division, Khulna, Bangladesh.
Jimenez, C. Y. 1993. Soil compaction as a constraint to tree growth in tropical and subtropical urban habitats. Environmental Conservation. 20: 35-49.
Jones, G; Battershill, C; and Cole, R. (1992). Marine reserves: do they work? In: C. Battershill (ed.) Proceedings of the International Temperate Reef Symposium, Aucland, New Zealand, p.29-45.
Khan, J. A. 1997. Estimation of unregulated densities by line transects method in Gir forest, India. Tropical Ecology. 38(1): 65-72.
Macnae, W. 1968. A general account of the fauna and flora of mangrove swamps and forests in the Indo-West Pacific region. Advance Marine Biology, 6: 73-270.
Naskar, K. and Mandal, R. 1999. Ecology and Biodiversity of Indian Mangroves, Publishing House, New Delhi, India, Volume, I & II, p.21.
Paul, S.P; and Hossain, A. T. M. E. 1997. Final report on the SDC-VFFP and SSD-BFRI collaborative studies on soil fertility status under cropland agroforestry systems. SDC-VFFP, Dhaka, Bangladesh.
Peters, R.L; and Darling, J. D. (1985). The greenhouse effect and nature reserves. Biological Science, 35 (11): 707- 717.
Phillips, O. L; Gentry, A.H: 1994. Increasing turnover through time in tropical forests. Science, 263: 954-958.
Plice, M.J. 1949. Some effects of salt water on soil fertility. Proceedings of the Soil Science Society of America, 24: 275-279.
Rahman, M.A.; Khisa, S.K. and Basak, A.C. 1983. Top dying of Sundri in Sundarbans, Bono Biggyan Patrica 12 (1& 2): 69-71.
Rahman, M. A. 1986. Present understanding of top dying of Sundri in the Sundarbans. Paper presented at the 5th Biennial Botanical Conference held at the Department of Botany, Dhaka University: 3.
Rahman, M. A. 1995. Mangrove plant pathology of the Sundarbans reserved forest in Bangladesh, field document No.3 of FAO/UNDP Project BGD/84/056-Integrated Resources Development of the Sundarbans Reserved Forest, Khulna, Bangladesh, p.83.
Rahman, M.A. 2001. Diseases and disorders of tree species in the Sundarbans and their management. In: Siddiqi, N.A. and Baksa, M.W.(eds.). Mangrove research and Development, Bangladesh Forest Research institute, Chittagong: 1986-1997, 3(1 and 2):86-93.
Rahman, M.A. 2003. Genetic Approach to mitigate the top Dying Problem of Heritiera fomes in the Mangrove Forests, Khulna University, Bangladesh, 87pp.
Rahman, M.A. 2003. Mid-term Report on Top Dying of Sundri (Heritiera fomes) and Its Management in the Sundarbans Biodiversity Conservation Project, Khulna.109pp.
Ross and Shell, 1987. Na and K level in Sundri tissue, Cambridge University press, London. Seidensticker, J. Hai; A. 1983. The Sundarbans wildlife managemen
plan: conservation in the Bangladesh (cited in Chaffey et al., 1985), Bangladesh.
Seidensticker, J. 1986. Large Carnivores and the consequences of habitat insularization, Ecology and conservation of tigers in Indonesia and Bangladesh. In: Cats of the World: Biology, Conservation & management. (Eds. S. D. Miller & D.D. Eveutt). Wetidal Wildlife Federation, Washington DC, p. 1-41.
Seidensticker, J. & Hai, M.A. 1983. The Sundarbans Wildlife Management. Bangladesh coastal zone. International Union for Conservation of Nature. Gland, Switzerland.
Seidensticker, J.; Christie, S. & Jackson, P.1999. Introducing the tiger. Cambridge University press, London, p.1-3.
Shahidullah, M.1980. Salinity penetration on the south-west of Bangladesh: Impact of reduced low flow of the major rivers of Bangladesh (Seminar).Mimeographed report.10 pp.
Siddiqi, N. A; Islam, M. R; Khan, M.A.S. and Shahidullah, M. (1993). Mangrove nurseries in Bangladesh. Mangrove ecosystems occasio-nal papers. International Society for Mangrove Ecosystems, Japan: 1-14.
Singh, V.P; Garge, A; Mail, L.P; and Pathak, S.M. (1986). Some ecological aspects of mangrove forest of Andaman Islands. Journal of Bombay Natural History Society. 83:525-537.
Smith et al., 2000.Heavy Metals in Nigerian crude Oils. AJEAM-RAGEE, Volume 9 October 2004: 78-87.
Snedakar, S .C. 1984. General Ecology: Resource Utilization Potential for the Bangladesh, Dhaka, Bangladesh: 31.
Snedaker, S.C. 1977. General Ecology and Resource Utilization Potential of the Sundarbans, FAO Report No.Fo:TCP/BGD/2309 (MF) W/R, 28 prepared for the Government of Bangladesh, Dhaka: 31.
Sobhan, A.1973. Report on the preliminary investigation of potable causes of top dying of Sundri trees in the Sundarbans. Unpublished report, Soil Science Division, Bangladesh Forest Research Institute, Chittagong.7 pp.
Tamang, K. M. 1993. Wildlife Management Plan for the Sundarbans Reserved Forest. Integrated Resource Development of the Sundarbans Reserve Forest. UNDP /FAO, BGD/84/056, Khulna, Bangladesh.
Thom, B.G.1982. Mangrove ecology- a geo-morphological perspective. 1982, p.3-17.
Tiner, R. W; J R. (1984). Wetlands of the United States: Current Status and Recent Trends. Newton Corner, Massachusetts: U.S. Fish and Wildlife Service, Habitat Resources.
Troup, R.S. 1921. The Silviculture of Indian Trees—Volume 1. Clarendon Press, Oxford: 153-544.
UN-ESCAP, 1987. Final Report: Volume 2. Coastal environment management plan for Bangladesh. Bangkok, Thailand.
UN-ESCAP, 1988. Coastal environment management plan for Bangladesh. Bangkok, Thailand: 7-34.
UNESCO, 1997. Convention Concerning the Protection of the World Cultural and Natural Heritage, France, Paris.
WHO, 1981. Resistance of Disease vectors to pesticides. World Health.