Conservation efforts help an endangered dipterocarp spread roots in Bangladesh
Conservation efforts help an endangered dipterocarp spread roots in Bangladesh
Sadiqur Rahman
14 Apr 2026<br>Asia
Comments<br>Share article
Share this article
If you liked this story, share it with other people.
Threads
Page link
Cite article
Conservation of the endangered boilam tree (Anisoptera scaphula) — Bangladesh’s tallest tree species — has reached a milestone after a 34-year-old man planted saplings across all the districts of the country.<br>A Bangladeshi forestry professor’s dedicated work offers fresh hope for science-based conservation of the rare species.<br>With no established conservation approach in Southeast Asia, where the species is also endangered, the Bangladeshi model could serve as a replicable solution.
See All Key Ideas
On Jan. 23, 2026, Mahbubul Islam Polash, a 34-year-old man from Bangladesh’s northern district of Sirajganj, traveled to Teknaf area in the southeastern coastal district of Cox’s Bazar, around 600 kilometers (373 miles) south of his hometown. Here, he planted a sapling of Anisoptera scaphula, a dipterocarp tree commonly known as boilam in Bangladesh.
That day marked the 64th planting of the endangered tree species, completing the plantation campaign in all the districts of the country. The campaign was launched on June 5, 2024, coinciding with World Environment Day, in the northwestern Rajshahi district.
When Polash learned that the towering tree species was on the verge of extinction and birds like kites and vultures were losing nesting habitats, he pinned his focus on planting boilams.
“Even if it was just one species, I wanted to spread it countrywide,” Polash tells Mongabay.
In 2019, he says, he planned to collect its seeds or saplings from the Chittagong Hill Tracts (CHT) and distribute them across the country. But his initial attempts to germinate boilam seeds failed.
Undeterred he continued to try and, in 2023, he succeeded in the germination of 74 seeds from the 2,000 sourced from mother trees in the hilly Bandarban and Khagrachhari districts. The saplings were nurtured on a piece of land adjacent to Polash’s home in Sirajganj for a year until they reached a height of about 30-45 centimeters (12-18 inches).
Finally, the boilam saplings were planted in 64 districts of Bangladesh. Polash spent 597 days and self-financed around 246,000 takas (about $2,000) to complete this remarkable campaign.
A. scaphula is a large perennial tree species, reaching heights between 30-45 meters (98-148 feet). It grows in semi-evergreen and evergreen forests on undulating land and the lower parts of valleys and can tolerate high humidities.
This particular dipterocarp species is considered a flagship tree in Bangladesh as it hosts large birds for nesting and many orchid species. Besides, its timber is hard, rigid and durable.
A young boilam tree at Mahbubul Islam Polash’s garden. Image courtesy of Mahbubul Islam Polash.<br>Mahbubul Islam Polash curates a garden with more than 300 rare flora species. Image courtesy of Mahbubul Islam Polash.<br>Citing deforestation and over-exploitation for timber as major threats, the Bangladesh National Herbarium (BNH), a research organization and museum under the Ministry of Environment, Forest and Climate Change, declared A. scaphula as one of the 446 threatened plants in the country.
BNH’s principal scientific officer, Sarder Nasir Uddin, says that the conservation of the endangered boilam is important on ethical grounds, as every species has the right to survive.
“Moreover, boilam plays a vital role in shaping the hilly forests. Also, it has high timber value,” he adds.
Vital contributions by botanists
Boilam typically occurs in small patches in the forested areas of the hilly Chattogram district, the CHT and Cox’s Bazar.
However, Polash says he has found evidence that boilam could grow in the plains as well.
Applying local knowledge, he has chosen the plantation sites where jackfruit trees — highly sensitive to salinity and waterlogging — survive.
Back in 1994, a couple of years after Polash’s birth, a professor at the Institute of Forestry and Environmental Sciences (IFES) under Chittagong University, M. Kamaluddin, warned his students that Boilam would go extinct.
Eventually, Kamaluddin collected boilam seeds from Chattogram’s Hazarikhil area (now a wildlife sanctuary), germinated them and planted saplings in the institute’s premises, planning for the species’ last resort to survive in the country.
“He was the one who first took initiatives for conserving the boilam and two other species,” says Md Aktar Hossain, a professor at the same institute, who accompanied Kamaluddin through the whole process.
Kamaluddin died in an accident in China in 2005. Three of the boilam trees he planted at IFES campus have survived, and one of them fruits once a year.
In 2011, after completion of higher degrees at a...