Restoring Bangladesh’s forests: Why indigenous trees must replace exotic plantations
Planting 250 million trees is possible. But planting 250 million right trees — native, diverse, and ecologically meaningful — would truly help secure the future of Bangladesh’s forests and biodiversity
Bangladesh is among the tropical countries with the lowest per-capita forest cover, yet it is also one of the most densely populated landscapes on Earth. In such a setting, every hectare of natural forest is precious. Any large-scale tree-planting programme must therefore be guided not simply by numbers, but by ecological wisdom.
Planting millions of trees is commendable only if those trees help rebuild functioning ecosystems. Otherwise, large-scale planting can create little more than plantations that provide timber but fail to support wildlife, biodiversity, or long-term environmental stability.
Recent proposals and public discussions sometimes refer to ambitious targets such as planting 250 million trees. While such numbers may sound impressive, the real question is: what kinds of trees will be planted, and where? If exotic or fast-growing plantation species replace natural forest vegetation, the result may actually degrade ecosystems rather than restore them.
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The scale of a 250-million-tree programme
A programme aiming to plant 250 million trees would require substantial land and logistical planning. With a common forestry spacing of about 3 metres by 3 metres, roughly 1,100 trees can be planted per hectare.
At that density, planting 250 million trees would require approximately 225,000 hectares, or about 2,250 square kilometres of land. This area is roughly equivalent to the size of an average district in Bangladesh or about seven to eight upazilas combined.
To achieve such a programme, nurseries would need to produce more than 300 million seedlings to compensate for normal mortality during planting and early growth. Thousands of nurseries, large quantities of seed, and hundreds of thousands of worker-days would be needed. Clearly, such an undertaking represents not only a forestry programme but also a national ecological commitment.
Given this scale, it becomes even more important that the species selected truly contribute to forest restoration and biodiversity conservation.
Why exotic trees cannot replace native forests
For decades, forestry programmes in Bangladesh and elsewhere in South Asia have relied heavily on exotic species such as acacias, eucalyptus, and other fast-growing trees. These species were often introduced because they grow quickly and can produce timber or fuelwood in relatively short rotations.
However, exotic plantation trees generally fail to replicate the ecological functions of native forests. Many of them produce poor wildlife habitat, limited fruit or nectar resources, and simplified canopy structures. Their leaf litter and root systems may also alter soil chemistry and water balance.
Natural forests in Bangladesh evolved over thousands of years with indigenous plant communities and wildlife species that depend on each other. Birds, bats, primates, squirrels, insects, reptiles, and countless other organisms rely on specific native trees for food, shelter, nesting, and breeding. When these trees disappear, entire ecological networks collapse.
Therefore, large-scale planting programmes should focus primarily on restoring native forests and removing exotic plantations from natural forest landscapes wherever feasible.
Rebuilding forest structure: More than just trees
A true forest is not simply a collection of trees. It is a multi-layered ecosystem consisting of several vegetation strata that together support wildlife and maintain ecological stability.
A scientifically planned restoration programme should therefore include:
- Upper canopy trees
- Medium-height trees
- Sub-canopy species
- Shrubs and understory vegetation
- Climbers and lianas
- Ground-cover grasses and herbs
Such structural diversity creates habitats for a wide range of species—from canopy-dwelling primates and birds to ground-living mammals, reptiles, and insects.
The importance of tall native trees
One of the most important components of tropical forests is the presence of large, tall trees that dominate the upper canopy. These trees provide shade, regulate the microclimate, and produce fruits and seeds essential for wildlife.
Restoration programmes should therefore include indigenous species across different height classes.
Small to medium trees (5–7 metres):
These trees often form the lower canopy and sub-canopy layers. Many produce berries, nectar, or small fruits that sustain birds and small mammals.
Medium-height trees (8–15 metres):
These species form important feeding and nesting resources and often produce edible fruits, flowers, or medicinal products.
Large trees (16–35 metres):
These trees form the main forest canopy and provide extensive branching systems for arboreal wildlife such as monkeys, squirrels, civets, and many bird species.
Very tall emergent trees (over 35 metres):
These giants tower above the canopy and play a critical ecological role. Examples of such species include Garjan, Civit, Boilam, Chambal, Telshur, Buddha Narikel, and Lohakath. These trees provide massive trunks and branches suitable for nesting raptors, hornbills, and other large birds, as well as shelter for numerous arboreal animals.
The loss of such towering species from forests dramatically reduces habitat quality for wildlife.
Fruit-bearing trees and wildlife food sources
Natural forests are also rich in fruit-bearing trees, which provide essential nutrition for animals. A restoration programme should include a wide variety of fruit types:
- Large fleshy fruits such as Jackfruit, Dewa or Lakooch and Chapalish, consumed by Ulluk or Hoolock Gibbon, monkeys, civets, bats, and large birds
- Juicy fruits, e.g. Mango, Uriam, Kadamba, Amra, Badaam, are attractive to hornbills, barbets, and bulbuls
- Small berries, e.g. Kalo Jam, Dhaki Jam, Golap Jam, Boro or Kul. Anoi or Bonkhoi are important for insectivorous and frugivorous birds
- Tiny fruits, e.g. Titi Jam, Datranga, are eaten by small mammals and reptiles
Particularly important are Fig trees (Ficus species, 6 to 10 species). Figs are often referred to as keystone species because they produce fruit at different times of the year when other food sources are scarce. Numerous birds, bats, and mammals depend on figs during lean seasons.
Terrestrial animals such as deer, sambar, rodents, monkeys, mongoose, civets, partridges, Mathura, peacock-pheasant, and quail eat berries and fruits as well as seeds and grains. Many small passerine birds are dependent on tiny grains and seeds for their food.
Without such species, restored forests may look green but remain ecologically impoverished.
Trees suitable for nesting and shelter
Wildlife requires not only food but also safe nesting and shelter sites. Certain native trees with soft wood or large cavities are especially valuable for nesting birds, owls, parrots, and small mammals.
Large trees with expansive canopies also provide movement pathways for arboreal animals such as primates, especially Ulluk, Binturong, Leaf monkeys and squirrels. Continuous canopy cover allows these animals to travel without descending to the ground, reducing exposure to predators and human disturbance.
Therefore, forest restoration must prioritise species that develop broad crowns and strong branching structures.
Understory shrubs, climbers, and ground cover
Healthy forests also contain dense understory vegetation. Shrubs and small plants provide hiding places and feeding areas for many animals. They also help protect soil from erosion and maintain moisture.
Restoration programmes should include:
- Native shrubs producing berries and nectar
- Climbers and lianas that link tree canopies and provide fruit for wildlife. Many animals use these for climbing and moving from one canopy to the next without going down to the ground.
- Ground-cover grasses and herbs that stabilise soil and provide major food not only to small birds but also to all herbivores, including our land giant, Hati or Elephant. These are a staple diet for the grazing animals.
- Wild cucumbers and climbing vines are used by insects and birds
These layers together create the complex habitat structure that defines natural forests.
Medicinal and traditional plants
Bangladesh possesses a rich heritage of medicinal and aromatic plants, many of which are integral to traditional Ayurvedic and folk medicine. Forest restoration programmes offer an opportunity to reintroduce these valuable species into suitable habitats.
Such plants not only support biodiversity but also preserve traditional knowledge and rural livelihoods. They may include trees, shrubs, and herbs used for herbal remedies, essential oils, and traditional healing systems.
Incorporating these plants into forest landscapes also contributes to the broader goals of health, culture, and ecological sustainability.
Carbon sequestration and climate benefits
Indigenous forests are also important for carbon sequestration, helping mitigate climate change. Large native trees with long lifespans store substantial amounts of carbon in their trunks, roots, and surrounding soils.
While fast-growing plantation species may initially absorb carbon quickly, natural forests often store far more carbon over the long term because of their greater biomass and longevity.
Restoring native forests, therefore, represents not only a biodiversity strategy but also an effective climate mitigation measure.
Firewood and community plantations
While natural forests should focus on indigenous biodiversity, fuelwood and community needs must also be addressed. Planting fast-growing trees for firewood or timber can be appropriate in certain locations, provided they do not replace natural forests.
Such plantations could be established on:
- Barren or degraded land
- Unused government khas land
- Roadside and embankment areas
- Village commons
These areas can provide sustainable supplies of fuelwood and construction materials without damaging natural forest ecosystems.
Greening homesteads and institutions
Tree planting should also extend beyond forests into human settlements and institutions. Homestead gardens, office compounds, schools, colleges, madrasas, and religious establishments offer valuable opportunities for planting indigenous trees.
Such efforts can create urban and rural green networks, providing shade, fruit, and habitat for birds and insects. They also help reconnect people with nature and encourage environmental stewardship.
Religious and community compounds, in particular, can become centres of ecological awareness, where traditional respect for nature aligns with modern conservation goals.
Toward a national restoration vision
If Bangladesh undertakes a programme to plant hundreds of millions of trees, it should aim not merely to increase tree numbers but to restore functioning forest ecosystems. This requires careful planning, scientific guidance, and long-term commitment.
Key principles should include:
- Prioritising indigenous tree species
- Gradually replacing exotic plantations in natural forest areas
- Restoring multi-layered forest structure
- Supporting wildlife habitat and food resources
- Integrating medicinal and culturally important plants
- Planting fuelwood species in appropriate non-forest areas
- Engaging local communities and institutions
By following these principles, Bangladesh can transform large-scale planting initiatives into genuine ecological restoration programmes.
Conclusion
Tree planting campaigns often focus on numbers — millions or even billions of seedlings planted each year. Yet the true measure of success lies not in how many trees are planted but in what kinds of forests emerge decades later.
Bangladesh cannot afford to replace its remaining natural forests with exotic plantations that support little wildlife and provide limited ecological value. Instead, the country must prioritise the restoration of diverse indigenous forests, rich in fruit-bearing trees, towering canopy species, medicinal plants, shrubs, and climbers.
Such forests will provide habitat for wildlife, store carbon, protect soil and water, and preserve the natural heritage of the nation.
Planting 250 million trees is possible. But planting 250 million right trees — native, diverse, and ecologically meaningful — would truly help secure the future of Bangladesh's forests and biodiversity.
Dr Reza Khan is a wildlife, zoo and safari park management and conservation specialist.
Disclaimer: The views and opinions expressed in this article are those of the author and do not necessarily reflect the opinions and views of The Business Standard.
