The impact of livestock grazing on the persistence of a perennial forb in a temperate Australian grassland

Abstract

The presence of perennial plant species in grazed habitats may be an imperfect predictor of their long-term ability to persist under grazing by livestock. This is particularly the case in landscapes where grazing by livestock is a relatively recent occurrence or where management practices are leading to intensification of grazing. This paper investigates the impacts of grazing on the native perennial inter-tussock forb Leptorhynchos elongatus (Asteraceae) in grasslands on the Monaro Tablelands of New South Wales. Although the species persists in grazed habitats, exclosures indicate that current grazing management can lead to severe depletion of seed, largely due to selective removal of flowers and seed heads by livestock. A population model suggests that under current grazing management, population growth rates may be negative. Removal of livestock during flowering and seed set may assist long-term persistence of this species in grazed habitats. Despite almost 200 years of livestock grazing on the Monaro Tablelands, recent intensification of grazing management could result in the future loss of some plant species in grazed habitats.