Effects of Soil Disturbance on Success of a Rare Savanna Forb, Liatris scariosa var. nieuwlandii in Habitats Dominated by Early and Late Successional Grasses

Abstract

Abstract In tallgrass prairie restoration, dominance by competitive late succession prairie grasses may cause loss of species that are poor competitors. In a field experiment we tested whether disturbance could reverse this process for Liatris scariosa var. nieuwlandii, a threatened savanna species thought to be a poor competitor. At our study site, this species appears to be stable in vegetation dominated by Danthonia spicata, an early successional grass, but declining in the presence of Andropogon gerardii, a dominant prairie grass restored to the study area. We used correlation analysis to test whether cover of grasses affected L. s. nieuwlandii abundance and experimental disturbance to test whether competition could be reduced. We disturbed soil at small (<100 cm2) and large (2.25 m2) scales within vegetation dominated by D. spicata or A. gerardii. We measured the response of L. s. nieuwlandii to disturbance by planting seeds within undisturbed and disturbed patches. In undisturbed patches, cover of D...