Ecosystem Disruption in Dibru-Saikhowa National Park: The Role of Native and Invasive Plant Species

A recent study published in the journal *Earth* underscores significant ecological changes occurring in eastern Assam's Dibru-Saikhowa National Park (DSNP), which is the only habitat for feral horses in India. The research identifies two native plant species, Bombax ceiba (Simalu) and Lagerstroemia speciosa (Ajar), that are exacerbating the environmental challenges posed by invasive species such as Chromolaena odorata and Ageratum conyzoides. These alterations are largely attributed to recurring floods from the Brahmaputra River and increased human activity from surrounding forest villages.

The study, titled "Grasslands in Flux," employs remote sensing and geographic information systems to analyze land use and land cover (LULC) changes within DSNP from its establishment as a national park in 1999 to projected conditions in 2024. The park, spanning 425 square kilometers across the Dibrugarh and Tinsukia districts, has seen a notable decline in grassland areas, decreasing from 28.78% coverage in 2000 to significant shrubland expansion by 2013.

The degradation of forest ecosystems threatens local biodiversity, particularly for species dependent on grasslands, such as the Bengal florican, hog deer, and swamp grass babbler, which are already experiencing population declines. The park is also home to approximately 200 feral horses, descendants of military horses left behind post-World War II, whose survival is increasingly jeopardized by habitat changes.

In response to these findings, the authors advocate for a comprehensive grassland recovery initiative aimed at controlling invasive species, enhancing conservation resources, and potentially relocating human settlements to mitigate ecological impacts. Proactive and informed land management strategies are essential for preserving the unique biodiversity of the Dibru-Saikhowa National Park and its critical habitats.