Native Plants in Assam’s Dibru-Saikhowa are now at the centre of ecological studies, as researchers warn of significant changes in the park’s riverine ecosystem. A recent study highlights how native plants, alongside invasive species, are transforming the grasslands of Dibru-Saikhowa National Park (DSNP) in eastern Assam. These changes pose risks to the survival of many endemic and endangered species, including the Bengal florican and the park’s unique population of feral horses.
Dibru-Saikhowa National Park: A Biodiversity Hotspot
Dibru-Saikhowa National Park was formed by merging the Dibru and Saikhowa Reserve Forests. It was declared a wildlife sanctuary in 1995 and upgraded to a national park in 1999. Spread across 425 square kilometres, the park lies between the Brahmaputra and Dibru rivers. In 1997, UNESCO recognised the region as a Biosphere Reserve, underlining its global ecological importance.
The park is home to a mosaic of grasslands, semi-evergreen forests, and wetlands, making it a haven for rare plants and animals. It is the only habitat in India for feral horses, which are descendants of World War II cavalry animals. DSNP also supports a rich diversity of birds, reptiles, and aquatic life, making it a priority site for conservation.
Key Findings on Vegetation Changes
The study used land use and land cover (LULC) analysis with remote sensing and GIS technology to track vegetation shifts between 1999 and 2024. The findings reveal a sharp decline in grassland cover—from 28.78% in 2000 to much lower levels today. In contrast, shrublands and degraded forests expanded significantly, replacing both grasslands and semi-evergreen forests.
By 2024, degraded forests covered 23.47% of the park, a sharp increase from just 10.87 sq km in 2013. This loss of open habitats is alarming because many threatened species rely on grasslands for breeding, feeding, and survival.
Native Plants in Assam’s Dibru-Saikhowa and Their Role
While invasive species are often blamed for habitat degradation, researchers stress that native plants in Assam’s Dibru-Saikhowa are also playing a role in altering the park’s ecology. Native trees such as Bombax ceiba (Simalu) and Lagerstroemia speciosa (Ajar) have begun encroaching on grassland areas.
These native invaders modify the ecosystem in ways similar to invasive plants like Chromolaena odorata, Ageratum conyzoides, Parthenium hysterophorus, and Mikania micrantha. Together, they reduce grassland coverage, alter vegetation structure, and disrupt the delicate balance of the ecosystem.
Impact on Wildlife and Biodiversity
The shrinking grasslands directly threaten species dependent on open habitats. The Bengal florican, a critically endangered bird, is one of the most affected. Similarly, the hog deer and the swamp grass babbler face severe risks as their breeding grounds diminish.
The park’s famed feral horses, numbering around 200, also rely heavily on open grasslands for grazing. With habitats being taken over by shrubs and forests, their survival may be at stake.
Beyond animals, these changes impact the park’s ability to store carbon and regulate climate. Forest degradation reduces biodiversity resilience, making the ecosystem more vulnerable to natural disasters.
Anthropogenic Pressures and Flooding
Human activities add further strain to the park. Several forest villages within DSNP contribute to grazing, firewood collection, and encroachment. Recurring floods from the Brahmaputra River worsen the situation by destabilising landscapes and accelerating vegetation change.
The combination of human activity, flooding, and the spread of both invasive and native encroaching species creates a complex conservation challenge that requires urgent attention.
Recommendations for Conservation
The study calls for a grassland recovery programme tailored to the specific needs of DSNP. Recommendations include:
- Control of invasive species through scientific methods.
- Management of native encroaching plants to restore grassland balance.
- Enhanced surveillance and staffing to prevent illegal activities.
- Relocation of forest villages to reduce human pressure.
- Community-based conservation initiatives that involve locals in protecting the park.
- Use of scientific data for land-use planning to preserve habitat patches and ensure species survival.
Experts emphasise that without targeted action, the park’s unique biodiversity—its feral horses, Bengal florican, and countless other species—could face irreversible decline.
Conclusion
Native Plants in Assam’s Dibru-Saikhowa are reshaping the park’s fragile ecosystem alongside invasive species. While their spread is a natural process, unchecked expansion threatens grasslands vital to rare wildlife. With climate change, human pressures, and natural flooding intensifying the situation, proactive conservation is no longer optional but essential.
Protecting DSNP requires a balance between ecological preservation and sustainable human use. Through targeted conservation efforts and community participation, it is still possible to restore grasslands, safeguard biodiversity, and ensure that Dibru-Saikhowa remains a jewel of Assam’s ecological heritage.
