Grasslands represent an important habitat in the Royal Manas National Park, occupying 1191.18 hectares of its geographical area. The condition of most of the grasslands has degraded over the years due to the invasion of woody perennials. A biodiversity assessment of Specialthang grassland, covering 240 acres under Manas Range, was conducted to assess the status of the grasslands and to provide insights for developing scientific grassland management regimes. The quadrat sampling method, point count, and modified pollard walk methods were used for vegetation, avifauna, and butterfly surveys respectively. Encounter rate from line transects and photographic capture rate index from camera traps were used for mammal survey.
A total of 71 plant species, 14 butterfly species, 61 bird species, and 13 mammal species were recorded from the study area.
The study showed a high dominance of Chromolaena odoratum (24084.3 per hectare) followed by Clerodendrum viscosum (1270), Leea asiatica (1232.8), and Urena lobata (1232.3).
Species such as cogon grass (Imperata cylindrica), lemongrass (Cymbopogon pendulus), elephant grass (Saccharum narenga), Penicum auritum and Arundinella bengalensis had high important value index (IVI).
The mean encounter rate and photographic capture rate for large and medium mammals such as Elephant (Elephus maximus), Sambar
(Rusa unicolor), Wild Pig (Sus scrofa), and Barking Deer (Muntiacus muntjak) were high. Conversely, small mammal encounter rate was recorded significantly low. Long-term assessment of biodiversity of grasslands shall be pivotal in planning, development, and adaptive management of grasslands. We recommend the use of patch mosaic burning technique, based on sound knowledge of grassland ecology, for the protection and restoration of grasslands in the Royal Manas National Park.