Ecoregions of the sanctuary comprise mostly grassland and wet grasslands vegetation and some South Western Ghats montane rain forests and high shola at the higher western elevations. South Western Ghats moist deciduous forests at mid elevations give way to dry deciduous forests and thorny scrub forests in the lower dryer eastern edges of the valley. The major xerophyticspecies in the thorny scrub forests are Acacia arabica, Acacia leucofolia, Acacia concinna, Prosporis juliflora, and Opuntia stricta.