Moderate Grazer Density Stabilizes Forage Availability More Than Patch Burning in Low-Stature Grassland

Spatially patchy fire creates landscape-level diversity that in turn stabilizes several rangeland ecosystem services, including forage production and habitat availability. To enhance biodiversity livestock production, efforts are underway to restore regimes rangelands throughout the Great Plains. However, invasive species such as tall fescue Schedonorus arundinaceus syn. Festuca arundinacea, initially introduced for hamper prescribed use. Grazer density, or stocking rate, modulates effect of on ecological patterns invaded, semi-natural pastures. We compare three diversity–stability responses—temporal variability aboveground plant biomass, portfolio effects among functional groups, beta group composition—in pastures managed with two different through periods heavy, light, moderate rate southern Iowa, USA. Pastures were either burned patches, one-third pasture each year, completely every third year. The period grazer density had least temporal regardless regime. also found statistical evidence a under stocking, where diversification communities varying cover groups can stabilize by reducing year-to-year variability. Beta was greatest during well. short stature prevented patch-burning regime create contrast vegetation structure there no difference any mechanism response across burning. Although longitudinal, these data suggest biomass declines mechanisms underlie function. Our results support decades-old principle range management: grazing intensity enhances stability, which has been shown buffer shortfalls drought.