In their search to learn more about the impact of humans and climate change on grasses in the Drakensberg Mountain Centre (DMC), one of the most studied mountain systems in the region, a group of scientists found a new grass species, which they named Festuca drakensbergensis (common name unknown; herein could be designated the ‘Drakensberg Alpine Fescue’).
The team who is working on the project includes Dr Vincent R. Clark, Head of the Afromontane Research Unit at the University of the Free State (UFS), Prof Steven P. Sylvester from the Nanjing Forestry University in Nanjing, Jiangsu, China, and Dr Robert J. Soreng, working in the Department of Botany at the Smithsonian Institution in Washington DC.
The discovery
The species, that was discovered in March 2020, was found during extensive fieldwork and herbarium research across the 40 000 km2 Maloti-Drakensberg area. The DMC has a very high endemic plant diversity, says Dr Clark.
He goes on to say that the DMC has a Montane Sub-Centre (below 2800 m) and an alpine sub-centre (above 2800 m). “It is the only mountain system in Africa south of Mt Kilimanjaro with an alpine component,” he adds.
ProfSylvester says the species was easily recognisable during their fieldwork, being found fairly common throughout the Afro-alpine landscape. Although at that point they only knew it to be a distinct taxon, they realised that the species was new to science when they tried to identify it and compared it with other closely related Festuca taxa.
Besides this discovery, the team also reinstated two varieties of Festuca caprina and rediscovered the overlooked F. exaristata, all of them endemic to the DMC. Prof Sylvester believes that this discovery highlights the importance of these high-elevation ecosystems as harbours of unique biodiversity that require focused conservation efforts.
Although grasses are a dominant species that control the ecosystem function in the Afro-alpine grasslands, they are the least known of all plant species found in these ecosystems. Up until now there has been a lack of focused research on Afro-alpine grasses.
“We provide a taxonomic reappraisal of the Festuca caprina complex that will aid future ecological and biogeographical research in the DMC and allow us to better understand the complexities of these ecosystems and how to conserve and manage them,” says Prof Sylvester.
This discovery highlights the importance of these high-elevation ecosystems as harbours of unique biodiversity that require focused conservation efforts. - Prof Steven Sylvester
Adding value
According to Dr Clark, the species contributes to the grazing and rangeland value of the Maloti-Drakensberg. “It also has functional value in terms of maintaining ecosystem integrity and associated water production landscape value in the area,” he says.
“The species seems fairly robust to pressures from grazing and burning, being found in both heavily grazed areas and semi-pristine areas, and may prove a useful species as part of a seed mix of native grasses for reseeding degraded Afro-alpine slopes and ski slopes,” mentions Prof Sylvester regarding the benefits of this indigenous species to the region.
The species is very common in Lesotho in Bokong Nature Reserve, Sehlabathebe National Park, and Sani Pass, and at Tiffendell and AfriSki ski resorts. Dr Soreng believes the species is likely to have a wider distribution range across the Maloti-Drakensberg, than what was documented before research was cut short due to the COVID-19 pandemic.
Next steps
According to Prof Sylvester, this taxonomic research feeds into a large-scale ecological study looking at the response of Afro-alpine ecosystems to different grazing and burning regimes that is being run in collaboration with Dr Clark at the ARU and Dr Soreng of the Smithsonian Institute, Washington DC.
“While our research has uncovered interesting novelties and provided a greater understanding of the taxonomy of grasses from high elevation Maloti-Drakensberg, there is still much to be done with regards taxonomic research of cool-season grasses in southern Africa,” says Prof Sylvester.
Dr Clark supports this notion and states that there is a major need for a better holistic understanding of the alpine zone in the Maloti-Drakensberg, given immediate pressures from over-grazing, land-use transformation, invasive species, and climate change.
“This is because the Maloti-Drakensberg is the most important water tower in southern Africa, providing water for some 30 million people in three countries. As the Maloti-Drakensberg is dominated by natural grasslands, understanding grass diversity and ecological behaviour is a primary need in the face of immediate human impacts and global change,” he says.