Can native grass species outcompete invasive goldenrods?
Invasive goldenrods (Euthamia graminifolia, Solidago altissima, Solidago canadensis and Solidago gigantea: Asteraceae) have similar competitive abilities and can outcompete native plant species when they invade natural and semi-natural habitats. Often invasive plant species can produce substantially more biomass than native species of similar form and function. As a result, these invasive species can suppress the regeneration of native plant communities. In the present study, the interactions between the alien goldenrods and native grass species (Festuca pratensis, Lolium perenne: Poaceae) were studied to test the hypothesis that native grasses are able to outcompete invasive goldenrods. Two types of L. perenne were used in the study, a forage variety (Temprano) and a turf variety (Talgo). Seeds from invasive goldenrods were collected from near Wroclaw, Poland and stored over winter. The seeds of the grasses were obtained from the Plant Breeding and Acclimatization Institute (PL). The species were grown in pots and each goldenrod species was grown with one grass species and a control where the grass and goldenrod species were grown individually. Total plant biomass was higher when the species were grown in combination compared to individually. When grown in combination, both grass species and goldenrods generally produced more above-ground biomass compared to when grown individually. The higher biomass of the goldenrod species when grown in combination with the grasses could be attributed to reduced intraspecific competition as the grass species are relatively small and there is more free space for the goldenrods to occupy. Therefore, the results of the experiment suggest that the two-grass species used in this study do not appear to be able to outcompete invasive goldenrods.
Szymura M, Szymura TH, Wolski K, Swierszcz S (2018) Can native grass species outcompete invasive goldenrods? Results of a replacement series experiment. Weed Research 58, 304-317.