Abstract: Based on the observation data obtained from five representative steppes, i . e . , temperate meadow steppe, temperate steppe, temperate desert steppe, temperate steppe-desert and temperate desert in Inner Mongolia, regression models were established to express the relations between each grassland biomass and four vegetation indices, with the information about grassland utilization status considered. The qualitative variable utilization status was introduced into remote sensing estimation models as a dummy variable, and the optimal mixed estimation models and vegetation indices for three types of utilization status were selected. The results showed that EVI was the best index reflecting grassland yield variation, and the average estimation precision of the models was 80%. The precision of the mixed models introduced with utilization status (mixed model Ⅱ) arrived to 79%, being higher than that of the models without the information of utilization status. Comparing with the models established for different utilization status, mixed model Ⅱ had the advantages of concision and convenience.

Key words: River continuum concept, Ecosystem services, Ecosystem health, Ecosystem management, Watershed ecology