Relationships among spectral vegetation indices and grassland biophysical parameters including the effects of varying levels of standing dead vegetation, range sites, and range plant communities were examined. Range plant communities consisting of northern mixed grass prairie and a smooth brome field as well as range sites and management in a Sand Hills bluestem prairie were sampled with a ground radiometer and for LAI, biomass, chlorophy]] and nitrogen amounts. Live above ground (herbaceous and shrub leaf) biomass quadrat estimates in early June, 1994, ranged from a mean value of 35,9 g/m2 in the burned area to 128.0 g/m2 in the mixed grass prairie. Shrubs, when present, had a stronger effect on the ground radiometer NDVI and MSAVI relationships with live biomass than either standing dead vegetation or plant community composition. Predictive relationships for live biomass from ground radiometer spectral data allowed rapid nondestructive estimation of live biomass for eleven 30 m by 30 m plots. Strong (r2 ‐ 0.81 to 0.87) predictive relationships for live biomass and SPOT vegetation indices at the 30 m by 30 m scale were developed and applied to estimate live biomass for entire site areas.
