Despite raid erection of buildings and new structures fills up Dhaka city, trees still remain in certain areas. According to a tree survey conducted by the Bangladesh Forest Department and the US Forest Service, around 1.3 million large and small trees still survive in 306 square kilometers of within Dhaka city.
This is Dhaka’s first-ever comprehensive tree survey, titled ‘Urban Tree Inventory of Dhaka City’. The findings show that tree density is higher in the Dhaka South City Corporation (DSCC) area, with an average of 15 trees per hectare, compared to about 7 in the Dhaka North City Corporation (DNCC) area.
Tree cover makes up 10.8 per cent of DSCC and 10.5 per cent of DNCC. The report compares this with other global cities: Toronto has about 27 per cent tree cover, Atlanta 37 per cent, and New York nearly 21 per cent.
Dhaka has one tree for every seven residents. These trees absorb around 538 tons of pollutants annually, including particulate matter, nitrogen oxide, and carbon dioxide, while producing about 53,500 tons of oxygen each year. The total estimated financial value of Dhaka's trees is about Tk 1.06 billion (approximately USD 10 million).
Md Zahir Iqbal, Deputy Conservator of Forests, who was involved in the research, told Prothom Alo, “Until now, data on tree cover in Dhaka varied greatly. This research gives us a complete picture of the city’s trees—their type, species, density, and distribution.”
He added that full knowledge about urban greenery is essential if policymakers are to prioritise it in urban planning. This study will help guide green-conscious decisions.
Survey method
The survey began in November 2022, with data collection completed by 8 August, 2023. A book was published upon analysis of data. The study received funding from the US Agency for International Development (USAID).
Researchers selected 755 total plots—370 in the south and 385 in the north—and used the US Northern Research Center’s “I-Tree Eco Tool” to calculate tree numbers. The plots were selected through a random sampling method.
Sahadev Chandra Majumder, a former program coordinator at the US Forest Service who was involved with the study, told Prothom Alo, “We used globally recognised methods to determine the tree population.”
Most prevalent trees
In total, 110 species from 33 families of trees were identified in Dhaka. The most common are mango, mahogany, and coconut. Others include banyan, koroi, akashmoni, eucalyptus, aswattha, mandhar, gamar, rain tree, jarul, sinduri, debdaru, kathgolap, black plum, tamarind, arjun, teak, bahera, almond, babla, jujube, Burmese silk cotton, crotons, barun, camphor, palmyra, star fruit, jackfruit, hijal, neem, bakul, drumstick, kamini, kadam, shiuli, and others.
Professor Kamal Hossain from the Institute of Forestry and Environmental Science at Chittagong University, also involved in the study, noted that 62 per cent of Dhaka’s trees area non-native species. For future greening projects, he recommends prioritising native species like mango, mahogany, black plum, white koroi, jackfruit, and konokchura over purely ornamental trees.
Of the 1.3 million total trees, 682,600 are in DNCC and around 616,900 in DSCC. Among the 538 tons of pollutants absorbed annually, trees in DNCC account for 319 tons, and those in DSCC for 219 tons. If these pollutants had to be removed artificially, it would cost nearly Tk 350 million.
Sahadev Chandra Majumder, former Programme Coordinator of the US Forest Service, further explained that trees help purify the air through a process called evapotranspiration, where harmful particles are trapped on the bark, leaves, and stems. According to him, mahogany is the most effective air purifier, followed by black koroi, mango, and black plum.
How much green has disappeared?
Since this is the first tree survey conducted in Dhaka, it cannot be learnt whether tree-covered areas have increased or decreased. However, other studies have explored this issue and provide insight into the decline of green spaces.
For instance, a 2022 study published in the US-based Environmental Journal, titled Present Status and Historical Changes of Urban Green Space in Dhaka City, states that in 1989, 17 per cent of Dhaka’s area was covered in greenery. By 2020, that number had dropped drastically to just 2 per cent.
According to guidelines from the United Nations Environment Programme (UNEP), a city should have at least 25 per cent of its total area covered in green spaces.
Professor Adil Muhammad Khan from the Department of Urban and Regional Planning at Jahangirnagar University told Prothom Alo that areas designated as green zones in urban plans have been encroached upon and replaced by infrastructure, often with both government and private backing.
As trees disappear, the heat rises
Environmentalists warn that decreasing trees and wetlands are contributing to rising temperatures in Dhaka. Research shows that areas with more trees and wetlands tend to feel cooler, while places lacking them are significantly hotter. Compared to surrounding districts, Dhaka has a higher average temperature.
Professor Ahmad Kamruzzaman Majumdar, Dean of the Faculty of Science at Stamford University, said, “Dhaka currently hosts nearly three times the population it was designed to accommodate. Green areas should have expanded in proportion to the population—but instead, the opposite has occurred.”
“Dhaka once had three layers of greenery-- grass, shrubs, and trees. Now, only some trees remain—and many of those are being cut down in the name of beautification.”
Professor Majumdar emphasised that grass and shrubs play a critical role in reducing surface temperature. Without a concrete, targeted plan to expand greenery, city dwellers will face increasing hardship due to extreme heat.
To combat the rising heat and promote biodiversity, DNCC and the Forest Department have recently signed a Memorandum of Understanding (MoU). As part of this initiative, DNCC will plant trees in road medians, sidewalks, canal banks, and other plantable open areas.
Speaking to Prothom Alo, the Chief Conservator of Forests, Md Amir Hossain Chowdhury, said, “If DNCC seeks our support in greening their open spaces and medians, we’ll provide technical assistance. If they hand over land, we’ll establish ‘mini urban forests’ in those locations.”
Previously, in 2023, DNCC undertook a project to plant 100,000 trees. Many were successfully planted and some have survived, though others have died.
“Walking under shade brings joy”
In summer, walking along Dhaka’s sidewalks can become unbearable due to the lack of trees and shade.
A few years ago, large trees stood in the median of the Mohakhali–Gulshan Link Road, providing shade on both sides of the street. In 2023, however, these trees were cut down under the banner of beautification.
On 1 June, at the Amtoli part of that same road, vegetable vendor Gani Mia told Prothom Alo, “There used to be big trees here. We’d get shade and feel relief from the heat. A few years back, city corporation workers came and cut them all down.”
He added, “People used to stand in the shade, waiting for buses. Now, that shade is gone, and people are really suffering.”
The situation is quite different in the Ramna area, where shaded sidewalks offer a peaceful walking experience. Shahadat Hossain, a government employee who often walks to work along those tree-lined paths, said, “Walking under the shade is a joy.”