Disturbed grasslands, once intact grasslands, have a mixture of native bunchgrasses and forbs, and 20-50% invasive weeds including diffuse knapweed (Centaurea diffusa) and sulphur cinquefoil (Potentilla recta). In the study area, some grassland ecosystems have been invaded by noxious weeds that cover more than 50% of the plant community. These ecosystems would be extremely challenging to restore and were excluded from the disturbed grasslands category.