Review of the invasive forage grass, guinea grass (Megathyrsus maximus): Ecology and potential impacts in arid and semi-arid regions

Several introduced African grasses are known to present recurring patterns of invasiveness and cause a severe impact on the diversity and functioning of ecosystems worldwide. Megathyrsus maximus (Guinea grass), a forage grass species native to South Africa, is reported to be highly invasive and pose a serious threat to native biodiversity in the introduced range. Despite the severe ecological threats posed by M. maximus worldwide, there is a dearth of information on the ecological and agroecological impact of M. maximus when growing in unintended areas. In this review, we present general information on M. maximus, its distribution and ecological threats it poses, particularly in arid and semi-arid regions. We highlight the gaps in current knowledge on the impact on recipient communities, challenges in effective management, and potential impacts due to climate change, particularly changes in rainfall patterns. We also stress the need for public awareness about the threats posed by M. maximus to prevent its invasion in unintended areas.