The impact of a novel invasive species,Orbea variegata(African carrion flower), on the chenopod shrublands of South Australia

This study measured the impact of an introduced plant species,Orbea variegata(African carrion flower), upon the dominant shrubAtriplex vesicaria(bladder saltbush) and the annual plant community in chenopod shrublands of South Australia. Shrubs withOrbeagrowing underneath were likely to be less healthy than shrubs withoutOrbea. Pre-dawn water potential and growth of saltbush decreased in the presence ofOrbea.Orbeaappears to limit water availability to saltbush either by direct competition, a decrease in rainfall penetration through the soil, or a combination of both.Orbeaalso reduced both the germinable soil seed bank and the biomass of annual plants. Our data suggest thatOrbeahas a severe detrimental effect on the native vegetation. We speculate that Orbea has the potential to spread further into the chenopod shrublands during years of particularly high summer rainfall.