Negative impacts of Osteospermum moniliferum in Chile
Osteospermum moniliferum (synonym: Chrysanthemoides monilifera) (Asteraceae) is a shrub native to South Africa. It is considered an invasive alien species in Australia and New Zealand, and in the EPPO region it has been introduced to Italy (Sicily) and Southern France. In Chile, O. moniliferum has invaded the Central Valparaíso region. This region is a port area where a number of invasive alien plant species are recorded. To evaluate the potential impact of O. moniliferum on local biodiversity, sites were sampled with and without O. moniliferum. At each site, plant species were identified, and the abundance of each species was estimated. Leaves of O. moniliferum were collected in the field for experiments of potential allelopathic impact of O. moniliferum on seedling development. Seedlings of a native shrub (Baccharis linearis: Asteraceae) and an invasive tree (Genista monspessulana: Fabaceae) were grown and an aqueous solution of different concentrations (0, 25, 50 and 100%) of the leaf extract was added to developing seedlings. The field study showed that O. moniliferum negatively impacts plant diversity and the highest negative effect was seen on endemic species. The leaf extract inhibited the germination of the native shrub, especially at higher concentrations (50 and 100%), but did not inhibit the germination of the invasive shrub. The results suggest that O. moniliferum has allelopathic impacts on native species in Chile which can act to rapidly change the plant community, decreasing native species and promoting non-native invasive species.
Sources
Atala C, Reyes SA, Osses J, Jeldes-Cajas O, Vargas R (2023) The invasive shrub Chrysanthemoides monilifera (boneseed) negatively impacts native plant communities in a Mediterranean zone in Central Chile. Brazilian Journal of Botany, https://doi.org/10.1007/s40415-023-00905-9