Rare plant experts from the University of Pretoria are spearheading the re-introduction of thousands of critically endangered Magaliesberg aloe (Aloe peglerae) seedlings into the wild.
Rare plant experts from the University of Pretoria are spearheading the re-introduction of thousands of critically endangered Magaliesberg aloe (Aloe peglerae) seedlings into the wild.
The project, which is supported by the Botanical Society of South Africa, is the first major reintroduction effort involving an endemic South African aloe species.
The Magaliesberg aloe is a slow-growing species, known for its spectacular red flowers. It only grows on north-facing slopes of the Magaliesberg, to the north of Pretoria.
The plant has a very narrow distribution range — the Magaliesberg from Gauteng into North West — and is particularly well adapted to the very hot, dry conditions experienced on top of the mountain range, said Richard Hay, the curator of the Future Africa Campus gardens and the Future Africa Indigenous and Orphan Crops Collection of the Manie van der Schijff Botanical Garden at the University of Pretoria.
The aloe was listed as critically endangered after a survey in 2016 found its overall population numbers to have dropped by an estimated 43% in a decade. The biggest culprit has been illegal harvesting by plant collectors and gardeners.
“It’s just because it grows in such a small area, and is fairly slow growing and slow to recruit the next generation, there has been a steady decline over time,” said Hay.
Parts of its limited range have been threatened with habitat loss, particularly in the Witwatersberg.
“It’s a very striking plant; when it flowers it really stands out in the veld so it looks really good. It’s usually novice gardeners and people who don’t know very much about the plant who take it and think it will look good in their garden and then, within a year or two, it just rots,” he said.
“This is because they’re so well adapted to these very harsh conditions and only grow on the tops of the ridges on the north facing side.”
Since November last year, more than 1 500 seedlings have been planted at intervals along the foothills of the Magaliesberg above Mamelodi. The idea is to continuously reintroduce young plants only into areas where the aloe once grew naturally, noted Hay, who is also the Botanical Society’s conservation project coordinator for the northern region.
Giving back to nature
“From historical records we know that this aloe used to grow on the mountain above Mamelodi. We therefore know that by reintroducing seedlings into the area there is no risk of interfering with the genetics of existing wild populations.”
The area is managed by the Mothong African Heritage Trust, which was founded by traditional health practitioner Ephraim Cebisa Mabena to protect the natural vegetation of the mountain, including working with the wider community, educating people about preserving the natural environment.
“In our particular collaboration between the botanical gardens and the Botanical Society [of South Africa], we specifically chose the Mamelodi end of the ridge because it has historically been neglected in terms of conservation or formal conversation,” Hay said.
“Dr Mabena has spent the last 20 years acting as a steward of this section of the Magaliesberg, preserving the ecosystem, setting up an indigenous plant nursery and working with the community to educate people about the importance of intact ecosystems.
“We specifically wanted to start with him to support his work and to get this species back on that side of the range and because he and his family now have legal custodianship of this area of land and have done exceptional work working with the community and establishing an informal nature reserve,” Hay said.
The project is only possible because of the 20-odd years that Mabena “spent preserving this space in and among all the other development around him”, he added.
Mabena said that without flora and fauna, he couldn’t be a traditional healer, adding that it’s humanity’s duty to take care of and protect these natural resources.
“Imagine that we harvest almost everything in the mountain? Definitely we’re going to be making nature angry and … nature will remain with nothing. That’s why today we have red-listed plants that are over harvested. Nature gives us and we must plough back.”
Replanting process
Hay said the heavy rainfall over the northern parts of South Africa over December did not cause rot or in other ways damage the seedlings that had already been planted. It would take about a decade before these seedlings flower for the first time.
The replanting is guided by best practices developed through the research of Arnold Frisby, a PhD candidate in botany at the University of Pretoria and curator of its cycad and indigenous plant nursery.
“Planting seedlings within their natural distribution range in sheltered spots, for instance next to or under grasses, greatly improves their [chances of] survival,” Frisby said.
The idea behind the reintroduction project was sparked through initial informal conversations about plant conservation between Hay, Jason Sampson — the head curator of the Manie van der Schijff Botanical Garden — as well as Quinton Bean and Andy de Wet, who are the owners of the specialist nursery The Aloe Farm near Hartbeespoort, north of Johannesburg.
The Aloe Farm donated 8 000 one-year-old Magaliesberg aloe seedlings in July 2023.
These were nursed over many months in the greenhouses at the Manie van der Schiff Botanical Garden on the university’s Hatfield Campus by the university staff, volunteers from the Botanical Society and the Johannesburg Succulent Society, and interns from the Tshwane University of Technology.
Many of these team members later helped to replant the seedlings above Mamelodi.
The team is inspired by the example set by other reintroduction projects in support of the survival and persistence of critically endangered species, such as the Clanwilliam cedar tree and Cape Town’s Erica verticillata, said Martina Treurnicht, the Botanical Society’s national conservation project manager.
Citizen science and volunteers are crucial to the success of programmes aimed at ensuring the survival and persistence of species, she said. “Volunteers play a key role in hands-on conservation, from planting initiatives to raising awareness in local communities — and it is great to see people working together for this purpose.”
On The Aloe Farm’s involvement in the project, Bean said, “We strongly believe in conservation through propagation. Preserving species diversity is important. It’s the right thing to do.”
Hay added that, from a conservation perspective, the plants are important sources of food for animals of the Magaliesberg during winter, when not much else flowers. “Added to this, when adult plants are removed from the already small existing populations, it completely disrupts the generational recruitment of the species.”
Bigger plants that Frisby raised as part of his PhD research will be planted in the Future Africa gardens. These could flower within eight years. “Seeds collected from this new satellite population will sustain efforts to continuously reintroduce the species into areas where the species is wiped out to help establish populations of varying ages.”
Hay said a small, isolated population of Magaliesberg aloe occurs on the Witwatersberg near Krugersdorp on Gauteng’s West Rand.
“We do suspect it’s completely extinct in the wild now but there’s a lot of illegal mining activity around there. My colleague, Arnold Frisby, said he hasn’t been able to go back to check but he does have seeds, so we have a little satellite population, potentially.”
Protecting Gauteng’s grasslands
Very few fragments of intact habitat are left in Gauteng because of urban sprawl. But Gauteng’s vanishing grasslands boast rich biodiversity, Hay said, adding that many people regard grasslands as empty wasteland and barren veld.
“A lot of South Africans are aware of the fynbos and the species richness down there [in the Western Cape]; there’s a lot more interest recently in the Succulent Karoo and into the desert biome up in the North West but Gauteng’s grasslands are just as species diverse and just as important,” he said.
He encourages more people to get involved in their local green spaces. “It’s very easy to get caught up in blaming municipalities and the provincial and national government for failing to look after these spaces but, ultimately, they belong to residents.”
