Postfire grazing management effects on mesic sagebrush-steppe vegetation: Spring grazing

• Vegetation responses to fire-grazing interactions are poorly understood.
• Cover, density, and frequency responses were investigated in sagebrush-steppe.
• Fire-grazing interactions had very few effects on vegetation except litter cover.
• Findings will aid in the formulating postfire livestock grazing management.

The influence of fire-grazing interactions on ecological pattern and process has been fairly well studied in some rangeland ecosystems (e.g., tallgrass prairie) but is only poorly understood in others. On sagebrush-steppe rangelands of the western US, there has been a long-standing concern that fire followed by grazing can cause substantial mortality in sensitive plant species. Vegetation responses to fire-grazing interactions, however, have never been studied in the higher elevation, more mesic portions of the sagebrush-steppe. We investigated whether graminoid, forb, and litter cover; bare ground; and species density and frequency responses differed among burned areas which were grazed at a very light stocking rate (33 ha AUM−1) during spring (May) without postfire deferment, burned areas where 1–2 growing seasons of grazing deferment were applied, and burned areas completely excluded from postfire grazing. Fire-grazing interactions had very few effects on vegetation but did reduce litter cover and bare ground compared to burning alone. This was a case study; consequently, caution should be taken in applying these results beyond their limited scope of inference. In some situations, however, postfire grazing can likely be employed without deferment or after deferring for only one growing season, and not cause substantial adverse impacts on vegetation.