An Assessment of Metrics to Measure Seasonal Variation in and Grazing Effects on Riparian Plant Communities

Abstract

Abstract. Several riparian plant community and streambank metrics were evaluated in 5 streams subject to grazing on public lands in central eastern Idaho. In this study, we evaluated 3 attributes associated with the ground cover on streambanks: percent cover of live vegetation, litter, and bare ground; and we evaluated 4 attributes that describe the vegetation community: plant species richness, wetland index value, percent cover of forbs, and percent cover of graminoids. We were particularly interested in how these attributes differed between grazed and ungrazed sites, how the attributes changed through time, and ultimately how the attributes were able to discriminate the effects of livestock grazing. We found that 2 metrics, percent live vegetation and bare ground, consistently reflected a seasonal effect of grazing. Litter cover also consistently reflected overall seasonal differences, but results often were not significant. Results for species richness suggested this metric may be most applicable when ...