The scientific community accept marram grass to AUTHORS: be non-invasive in dune stabilisation in the Cape

Abstract

Significance:
For more than three decades, botanists and dune ecologists in the Department of Botany at Rhodes University have spent over 20 000 people-hours researching marram grass. Because of the invasive nature of the plant in Australasia and North America, the plant was long thought to be invasive in the Cape. It has been concluded that the species is non-invasive so long as the variety present in the Cape is used and no new material is introduced. Despite this evidence, the authorities list marram grass as a Category 2 species of weed which may only be grown under permitted conditions in demarcated areas. In order to obtain a permit to use the grass in a large stabilisation project at Hout Bay, a detailed study was reinitiated on the distribution of marram grass 20 years after the original studies on its distribution had been completed. These results confirmed results of the previous studies that the grass was non-invasive. These findings were ratified in a peer-reviewed research paper published recently in a special issue on ‘Dynamics and Stability of Plant Communities in Coastal Sand Dunes’ of the open access journal Plants (Lubke; Plants 2022;11(17), Art. #2260). Finally, marram grass, as it occurs on our Cape dunes, may be accepted as a useful pioneer and dune stabiliser. No indigenous species are capable of performing the same process.