Can native grass species outcompete invasive goldenrods? Results of a replacement series experiment

Abstract

Summary Invasion by alien species is a serious threat to the biodiversity and function of semi‐natural grasslands and may impede restoration efforts in degraded meadows due to high competitiveness. Goldenrods ( Solidago and Euthamia species) are considered among the most injurious invaders of grasslands in Central Europe. We tested the hypothesis that native grass species are able to outcompete the invasive goldenrods. A replacement series experiment was established to determine levels of interference between native grass taxa and goldenrods. In the experiment, four alien goldenrod species ( Solidago altissima , Solidago canadensis , Solidago gigantea and Euthamia graminifolia ) and one native species ( Solidago virgaurea ) were studied. The native grasses were represented by Lolium perenne (forage and turf varieties) and Festuca pratensis (forage variety). Total biomass was higher in the mixture of species compared with that in monoculture. The higher total biomass was due to higher productivity of the goldenrod species, whereas that of the grasses was reduced. These results demonstrated the high competitiveness of alien goldenrods compared with native grass species.