Indigenous and Alien Flora Alter Assam’s Dibru-Saikhowa Ecosystem

The characteristic grassland of Dibru-Saikhowa National Park (DSNP) in Assam is experiencing a quick change due to proliferation of both native and invasive flora, posing a grave threat to its diverse fauna.

A Critical Habitat at Risk

DSNP is an essential biodiversity area, and is the only extant natural habitat for feral horses in India. It is a Biosphere reserve that consists mainly of grasslands, wetlands and forests, which are habitats to a huge number of endemic species and those, which are threatened.

Key Findings: Vanishing Grasslands

Recent remote-sensing analysis (1999-2024) shows a significant decrease in grasslands which decreased from 28.78% of the park in 2000. This deficiency is mostly the result of the increase of:

Degraded forest, which envelops more than 23% of the park.

BUSHES -Encroachment of bush into open habitats.

The Unusual Culprits

The change is being forced not only by known invasive species such as Chromolaena odorata and Mikania micrantha, but also by native trees like Bombax ceiba (Simalu) and Lagerstroemia speciosa (Ajar). These indigenous are forcefully invading the grasslands and altering the vegetation pattern, similar to the nonnative species.

Impact on Wildlife

The disappearing open grassland poses an immediate threat to species that rely on them, such as:

• The Bengal florican that is critically endangered
• Hog deer
• Swamp mirosi babbler
• The herd of feral horses to the tune of ~200 is emblematic of this park.

Such degradation of the habitat symmetrically decreases biodiversity and the capacity of ecosystems to store carbon.

Underlying Pressures

Human-induced factors emanating from the park-based villages and repetitive floods baking and flooding the Brahmaputra River further complicate conservation measures.

Conservation Recommendations

The study suggests that immediate actions are required – such as:

• A targeted grassland recovery project.
• Management of invasive species in spread.
• More surveillance in parks, more staff.
• Translating forest villages to reduce human pressure.
• Bottom-up conservation and science-led land management to protect what habitat remains.