The Sundarbans, the largest mangrove forest in the world. Photo: Wikipedia

By Md Aynal Haque

KHULNA, Jan 28, 2025 (BSS) - Invasive plants are proving detrimental to the ecosystem and biodiversity of the Sundarbans, the largest mangrove forest in the world, where flora is dominated by mangrove species and their associated species.

The Sundarbans' mangrove forests, wetlands, and plant species, both native and invasive, lie within the coastal region, which is rich in natural resources such as deltas, tidal flats, mangrove forests, lagoons, sandbars, estuaries, and a coastal ecological environment.

Conservation experts have expressed concern that a few foreign plants have become invasive, causing significant losses to local flora and fauna over the past few decades and reducing the forested area.

Native plant species in protected areas like the Sundarbans are under threat as numerous invasive foreign plants have been detected within local flora reserves, they said.

Experts fear these invasive plants may lead to the extinction of native plant species and disrupt the forest's ecology and ecosystem.

Of the 23 identified invasive species, 19 are native or naturalized to the Sundarbans' mangrove regions. The abundance, diversity, and rate of invasion of these species are highest along the riverbanks.

The flora of the Sundarbans is characterized by 26 true mangrove species and 29 mangrove-associated species, including garjan, kankra, goran, and baen.

Prof. Mahmud Hossain of the Forestry and Wood Technology Discipline at Khulna University told BSS that the Bangladesh National Herbarium has identified 17 foreign invasive plant species harmful to the Sundarbans' ecosystem.

He emphasized that these invasive plants can be controlled by preventing their marketing and trade, which negatively impact the environment, economy, and society. Additionally, eliminating them from the ecosystem and halting their spread are necessary steps.

"Preventive measures such as early detection, screening of imported plant species, and implementing quarantine procedures are relatively easy to adopt," he added. However, he also acknowledged, "The introduction of foreign plants is an old practice, and not all foreign plants are harmful."

"It is crucial to conserve indigenous plant species and forest areas by fully identifying alien invasive plant species in the protected Sundarbans areas," he further stated.

Ecology and biodiversity conservation researcher Pavel Partha told BSS that alien species compete with native species in protected forest areas, alter ecosystems, and disrupt food chains.

He recommended advanced measures, including early detection and screening of invasive plants.

Additionally, the flora of the Sundarbans is decreasing as local residents collect fruits for fuel, hindering the natural regeneration of plants. As a result, the mangrove forest is shrinking day by day.

Prof. Abdullah Harun Chowdhury of the Environmental Science Discipline at Khulna University said thousands of fruits from various plant species drift into the Shyamnagar area daily, carried by river water from the Sundarbans.

"Instead of planting the seeds, people use them as fuel, which not only reduces plant species but also negatively impacts the natural balance," he said.

It is noteworthy that the Sundarbans and its surrounding areas are home to 334 plant species belonging to 245 genera of angiosperms and ferns.

Forest expert Pijush Bawali, who works on the Sundarbans, said the local population lacks awareness about the potential use of fruits for reforestation.

"If these fruits were used as seeds, the Sundarbans' area could be expanded," he said.

Iqbal Hossain Chowdhury, assistant forest conservator of the Satkhira Range, said the use of fruits as fuel has decreased recently due to awareness programmes.