The landscape level plant diversity was measured in Terai grassland of north-eastern Uttar Pradesh. The field assessment, based on random quadrats, was undertaken at 11 sites, sampling an area of 333.75 ha. The grassland vegetation was comprised of a greater species richness compared to old-field vegetation. The grassy landscape as a mosaic of grassland patches contained 287 species in the sampled quadrats, which represented 177 genera from 53 families. The species composition of sites varied significantly with an increase in species richness corresponding with landscape heterogeneity. The species richness of a few sites was significantly high due to mesic condition and topographic heterogeneity. The fully exposed sites had average moisture with moderate disturbance and showed greater diversity and lower dominance. However, the partially shaded locations had high moisture and low disturbance resulting in minimum diversity and maximum dominance. The presence of high levels of disturbance in the form of severe grazing, trampling and/or cutting favoured prostrate, perennial, herbaceous-grasses such as Cynodon dactylon and Imperata cylindrica as well as the forbs such as Desmodium triflorum, Evolvulus nummularis, and Rungia repens. The marked differences among grassland habitats and the intensity of various biotic processes within the grassy landscape of the adjoining forest result in an array of grassland patches with marked differences in their diversity. Due to changes in agricultural practices and grazing intensification, the Terai grassland has been significantly reduced and highly fragmented resulting into the rarefaction  of species that were once common and widespread. The shrinkage of specialized habitat owing to intense cultural activities, severe grazing and recurrent trampling has pushed several medicinally important and other rare plant species towards local extinction. Therefore, we suggest that appropriate management guidelines be implemented in order to conserve at risk species from extinction on the Terai grassland. 

 

Key words: Grassy landscape, Disturbance, Habitat fragmentation, Patch size, Species diversity.