This synthesis relied on ground based research work including selected interviews and information collected from different research findings, some of which was gray literature, while others were publications from different peer-reviewed journals or periodicals etc. Information was also gathered by attending workshops, seminars conferences and visiting research institutions and meteorological stations. Some information was collected directly from the stakeholders, rural and urban administrative bodies, farmers and NGOs. The impacts of floods on plantations and their bearing on climate change were studied and the traditional coping practices have been investigated; their efficacy is highlighted and compared with present practices to find out the mistakes as well as to integrate the scientific basis of the traditional knowledge regarding natural and artificial mechanism followed by the people of the most vulnerable region of the earth for thousands of years. The synthesis also benefitted from research work that was conducted in 2001 and focused on linking floods and water-logging to the death of Dalbergia sissoo, a native tree species of India, Nepal, and Pakistan (Basak, 2006. Fifteen districts of Bangladesh that have a large numbers of Dalbergia sissoo plantations that were severely affected by recent flooding were surveyed between February and June 2001. The study considered the health condition of each tree and trees were grouped into four categories such as slightly affected by flooding and waterlogging (0–25%), moderate (26–50%), severe (51–75%) and dead (76–100%)(Basak, 2006).
3. Causes and impacts of floods on plantations causes of floods in Bangladesh are related to multiple factors including climate change-induced erratic and frequent rainfall, cloud outburst, monsoon downpour, synchronization of flood peaks, sea-level rise (SLR), accumulation of sediments, river bed aggradation, deforestation in the upstream regions, soil erosion due to tillage, river dams, rapid urbanization, seismic and neo-tectonic activities and greenhouse effects (Khalequzzaman, 1991; Emery and Aubrey, 1989). The GBM has hundreds of tributaries and distributaries flowing from the Himalayan and Burmese ranges pouring trillions of cubic liters of water with 17,000 million tons of silt every year onto the floodplain and finally to the Bay of Bengal. Due to unplanned construction of road transportation systems, agriculture, urbanization and industrial expansion across the flood plains in recent years, the basins of the wet-bodies raised substantially, thus the water-holding capacity has been decreased significantly and floods have become a regular phenomenon every year. Millions of people lose their homes, livestock and crops. Trees and homestead vegetation are also severely affected and people lose their means of income, find no work and are forced to starve. Trees of 1–32 years old had been found affected by floods. It shows the extent of damage caused by floods in various districts of Bangladesh. In general, the severity of death had been found higher in the western districts of Bangladesh in comparison to the eastern regions (Banglapedia, 2006). The highest incidence was noted in Chuadanga (64.4%) and the lowest in Mymensingh(21.7%). Other districts suffering more than 50% death were Comilla, Meherpur, Kushtia and Rangpur. With the advance of time, healthy trees near the dead ones also died. Signs of damage show data on age-related death of Dalbergia sissoo trees; among the for Dalbergia sissoo classes, the age-class 17–24years suffered the highest rate of loss followed by the age-class 9–16 years. The lowest rate was found in the age class of 1–8 years. It was found that due to the severe floods of 1987–1988, the long period of inundation and also water-logging caused root rotting, permanent wilting, defoliation of the trees; and absence of air in the root system constrained respiration. It is recognized that in some plants there are two types of wilting, one is physiological due to either water-stress or water-logging and the second one is pathogenic which happens by the infection of fungus. In the inundated areas of Bangladesh, most of the Dalbergia sissoo plants died of susceptibility to conditions resulting from the long duration of floods. In addition,Fusarium solanif. Dalbergia being an opportunistic fungus created disease in some of the flood-affected Dalbergia sissoo plants.