Restoring Bangladesh’s forests: Why 250m tree initiative must prioritise indigenous species

The new Bangladesh government, led by the BNP, has announced an ambitious "National Green Mission" to plant 250 million trees over the next five years to combat climate change and environmental degradation. 

The announcement by the new Government of Bangladesh to plant 250 million trees in the shortest possible time is undoubtedly encouraging. In a country where forest cover is limited and biodiversity is under increasing pressure from population growth, infrastructure development, and climate change, such an initiative has the potential to bring substantial ecological benefits (FAO, 2020; Hughes, 2017; Bangladesh Forest Department, 2022). If implemented wisely, it could help restore degraded landscapes, stabiliae soils, enhance carbon sequestration, and revive wildlife habitats across the country (Lamb, 2018).

However, experience from previous nationwide plantation programmes raises an important concern. In the past, large-scale tree planting in Bangladesh has frequently relied on fast-growing exotic species, particularly Acacia and Eucalyptus. These species have often been introduced into natural forest ecosystems such as the Sal (Shorea robusta) forests of central and northwestern Bangladesh and the mixed evergreen forests of Greater Sylhet and the Chittagong region (Rahman, 2011; Gain, 2002).

While such plantations may quickly create a “green cover,” they rarely restore the ecological functions and biodiversity of natural forests (Lindenmayer & Hobbs, 2004; Chazdon, 2014).

The success of the new national tree-planting campaign will therefore depend not only on the number of trees planted but on what species are planted and how they are arranged to recreate functioning ecosystems (Lamb, 2018).

A plantation of a single or a few fast-growing tree species may appear green and dense from a distance, but it does not necessarily function as a true forest ecosystem.

Natural forests are complex ecological systems composed of multiple layers of vegetation—tall canopy trees, mid-story trees, shrubs, climbers, herbs, epiphytes, mosses, fungi, and microorganisms (Chazdon, 2014).

These components interact with each other and with wildlife to create a self-sustaining ecological community. The biodiversity within such forests provides food, shelter, breeding sites, and migration pathways for thousands of species of insects, birds, mammals, reptiles, and amphibians (Hughes, 2017).

Monoculture plantations, especially of exotic species, typically lack this structural complexity. Their simplified architecture supports far fewer species of wildlife and provides limited ecological services beyond timber or fuelwood production (Lindenmayer & Hobbs, 2004).

In contrast, multi-species indigenous forests can gradually recreate ecological processes that have been lost due to deforestation and habitat degradation (Chazdon, 2014; Lamb, 2018).

Since the 1970s, Bangladesh has undertaken numerous afforestation and social forestry programmes. These initiatives have helped increase tree cover in some areas, particularly along roadsides, embankments, and marginal lands (Bangladesh Forest Department, 2022).

However, many plantation programmes in natural forest areas have relied heavily on exotic species such as Acacia auriculiformis, Acacia mangium, and Eucalyptus camaldulensis (Gain, 2002).

These species were introduced because they grow quickly, tolerate poor soils, and produce timber or fuelwood within relatively short rotations (Lamb, 2018).

While economically attractive, their ecological impacts have raised serious concerns (Lindenmayer & Hobbs, 2004).

The ecological limitations of exotic plantations are particularly evident in Bangladesh’s Sal forests and evergreen hill forests.

Historically, the Sal forests of the central region—stretching across Madhupur, Bhawal, Tangail, and parts of northern districts—were dominated by Shorea robusta and associated indigenous species. Over the past several decades, large portions of these forests have been degraded or converted into plantations dominated by exotic species (Gain, 2002; Rahman, 2011).

Similarly, parts of the Chittagong and Sylhet hill forests, including areas around Lawachara National Park and Chunati Wildlife Sanctuary, have experienced habitat degradation and fragmentation (Nishorgo Support Project, 2006; Bangladesh Forest Department, 2017).

These forests once supported rich biodiversity including:

• Hoolock gibbons

• Langurs

• Hornbills

• Numerous forest birds and reptiles

In many degraded areas, replacing native forest with monoculture plantations has reduced habitat quality for wildlife.

Conservation initiatives in areas such as Lawachara and Chunati have shown that restoring indigenous vegetation significantly improves habitat conditions for wildlife and promotes natural regeneration of forest ecosystems (Nishorgo Support Project, 2006).

1. Low biodiversity value

Exotic monocultures provide limited food and nesting sites for native wildlife. Many insects, birds, and mammals have evolved with indigenous plants and cannot utilize unfamiliar species effectively (Lindenmayer & Hobbs, 2004).

2. Poor undergrowth development

Some exotic species produce dense shade or chemical compounds that inhibit the growth of understory plants (Chazdon, 2014).

3. Reduced soil biodiversity

Natural forests support diverse communities of fungi, bacteria, and soil invertebrates that help recycle nutrients (Lamb, 2018).

4. Water and soil impacts

Species such as eucalyptus are known for high water consumption and can alter soil moisture regimes (FAO, 2020).

5. Fragmentation of wildlife habitats

Exotic plantations do not effectively replace the ecological role of native forests (Hughes, 2017).

Indigenous species evolved naturally within a particular region and developed ecological relationships with local wildlife and soil organisms (Rahman, 2011).

Restoring native vegetation supports wildlife, pollination networks, seed dispersal by birds and mammals, and long-term forest regeneration (Chazdon, 2014; Lamb, 2018).

Fruit-bearing and flowering trees are particularly important because they provide essential food resources for birds, bats, and primates.

Figs (Ficus spp.) are widely recognized as keystone species in tropical forests because they produce fruit during periods when other food sources are scarce (Chazdon, 2014).

If Bangladesh aims to plant 250 million trees while restoring ecological integrity, the programme should adopt a scientifically guided ecosystem restoration approach (IUCN, 2019; Lamb, 2018).

Rather than focusing only on tree numbers, plantations should be designed to recreate multi-layered forest structures resembling natural ecosystems.

A restoration plantation should ideally include 30 or more indigenous plant species representing different ecological roles.

The inclusion of pteridophytes, bryophytes, fungi, mosses, and algae may at first appear unusual; however, these groups are integral components of forest ecosystems and play a critical role in nutrient cycling and microhabitat formation (Chazdon, 2014).

Much of the nutrient recycling in tropical forests occurs at a microscopic scale through fungi, mosses, and microbes breaking down organic matter and returning nutrients to the soil (Lamb, 2018).

Restoring multi-species indigenous forests would produce major benefits for wildlife across Bangladesh (Hughes, 2017).

Habitat restoration can reconnect fragmented landscapes and support movement of species such as Asian elephants, arboreal primates, and forest birds (IUCN, 2019).

Native flowering plants also support bees, butterflies, and other pollinators essential for both forest ecosystems and agriculture.

Tree-planting campaigns often emphasize impressive numbers—millions of seedlings planted within a short period.

However, ecological success depends more on species diversity, survival rates, and habitat restoration than on the number of trees planted (Lamb, 2018).

If properly designed, the 250 million tree initiative could become one of the most significant ecological restoration efforts in South Asia (IUCN, 2019).

Bangladesh Forest Department. (2017). Management Plan for Chunati Wildlife Sanctuary.

Bangladesh Forest Department. (2022). Bangladesh Forest Statistics.

Chazdon, R. (2014). Second Growth: The Promise of Tropical Forest Regeneration. University of Chicago Press.

FAO. (2020). Global Forest Resources Assessment. Food and Agriculture Organization.

Gain, P. (2002). The Last Forests of Bangladesh. Society for Environment and Human Development (SEHD).

Hughes, A.C. (2017). Understanding the drivers of Southeast Asian biodiversity loss. Biological Conservation.

IUCN. (2019). Forest Landscape Restoration Opportunities in Asia.

Lamb, D. (2018). Large-Scale Forest Restoration. Routledge.

Lindenmayer, D., & Hobbs, R. (2004). Fauna conservation in plantation forests. Biological Conservation.

Nishorgo Support Project. (2006). Co-management of Protected Areas in Bangladesh.

Rahman, M.A. (2011). Plant Diversity in Bangladesh. University of Dhaka.

Reza Khan is a Wildlife, Zoo and Safari Park Specialist