‘Top-dying disease’ has killed 15% trees in the Sundarbans since the 80s
Sundari tree, one of the most common mangrove species in the Sundarbans, is disappearing from the forest because of various diseases.
The diseases include “top-dying disease” which has killed 15% of the trees since the 80s.
In the last 30 years, 1.44 million cubic meters of Sundari trees, worth Tk2,000 crore, have been lost to “top-dying disease,” experts said.
Climate change has lead to an increase in the salinity of the water and soil of the Sundarbans— which is another reason for the rapid decline in the number of Sundari, Passur, and Keora trees.
Gewa and Goran are being planted in the forest in place of the Sundari trees. Gewa and Goran are now grown in 50% of new places.
There are 334 species of trees and plants in 4,143-sqkm area out of 6,017 sqkm.[J1]
According to experts, the change in the quantities of saline and sweet water causes harm to mangrove forests. Increases of saline water are fatal to Sundari trees; and thish is happening in the Sundarbans.
Top-dying disease among the Sundari, heart-rot disease among the Pashur, and die-back disease in the Kewara, are behind the trees’ rapid decline.
Top-dying and heart-rot disease attacked the tress in the forest’s following compartments: 6, 14, 19, 20, 21, 25, 26, 27, 28, 32, 33, 36, 37, 38, and 39.
Noted water expert Ainun Nishat said Sundari trees have been dying due to the adverse effects of the Farakka and a lack of sweet water. "There are now 85.67crore Sundari trees in the forest which are on the verge of extinction."
Md Bashirul-Al-Mamun, West Divisional Forest officer of the Sundarbans, said they found 30ppm of salinity in the water—which decreases the disease-prevention capacity of the trees.
Dr Swapan Sarker, an associate professor at the Forest Environment Science of Shahjalal University of Science and Technology (SUST), in his research, mentioned that diversity within the Sundarbans decreased between 1986-2014.
In the report, he said the number of: Sundari, Passur, Shingra, Amur, Dhundal, and Kakra trees, is on the decline.