Succession and livestock grazing in a northeastern Oregon riparian ecosystem

Livestock grazed the study area from late August until mid September. Utilization varied from >70% in dry meadows to <3% in cheatgrass dominated stands. Ungrazed dry and moist meadow communities had significantly lower species richness and diversity when compared to grazed counterparts. In the most heavily grazed communities, ruderal and competitive ruderal species were favored by grazing disturbance. In enclosures of the same communities, competitive or competitive stress tolerant species were favored. Results indicate that influences of herbivory on species diversity and eveness varies from one community to another. -from Authors