Impact of Plant Species on Dibru-Saikhowa National Park
Native and invasive plant species are contributing to changes in the riverine ecosystem of the Dibru-Saikhowa National Park (DSNP) in eastern Assam. This park is the exclusive habitat for feral horses in India.
Key Findings of the Study
- The study identified two native plants, Bombax ceiba and Lagerstroemia speciosa, as "grassland invaders" contributing significantly to ecosystem changes.
- Invasive species include:
- Shrubs: Chromolaena odorata and Ageratum conyzoides
- Herb: Parthenium hysterophorous
- Climber: Mikania micrantha
- The study, titled Grasslands in Flux, was published in the journal Earth and analyzed land use and land cover (LULC) changes from 1999 to 2024 using remote sensing and GIS.
Changes in Land Use and Vegetation
- In 2000, grasslands covered 28.78% of DSNP's 425 sq. km area.
- By 2013, shrubland became dominant, covering 81.31 sq. km, while degraded forest expanded to 75.56 sq. km.
- In 2024, degraded forest further increased to cover 80.52 sq. km (23.47%).
- Significant declines in grasslands, semi-evergreen forests, and bare land were observed.
Implications for Biodiversity
- Changes in DSNP's landscape pose threats to grassland-obligate faunal species, many of which are globally threatened.
- Species impacted include the Bengal florican, hog deer, and swamp grass babbler.
- Home to around 200 feral horses, descendants of those abandoned during World War 2.
Recommended Conservation Measures
- Implement a targeted grassland recovery project.
- Control invasive species and enhance surveillance.
- Increase staffing and consider relocating forest villages to reduce human impact.
- Promote community-based conservation efforts.
The study concludes that informed LULC-based management is essential for maintaining critical habitat patches, mitigating anthropogenic degradation, and enhancing the survival of native floral and faunal assemblages in DSNP.
