SA’s poorly-documented mountains are vital water towers for millions of people

As a youngster growing up on Gauteng’s West Rand, Ralph Clark had plenty of open spaces he could disappear into and explore: waterfalls, open protea savanna, old mine workings and caves.  

Now, as the director of the Afromontane Research Unit at the University of the Free State, Clark jokes that although he gets paid to climb mountains, the reality is that he does a lot of desk work “to enable others in our team to climb mountains”.

Still, the Maloti-Drakensberg is only 40 minutes from campus and an hour from home. “I do have the privilege of getting into the mountain much more regularly than someone based further afield, for both work and recreation.” 

His unit seeks to become the continental leader in African mountain research and to facilitate a stronger community of practice for poorly-represented Southern African mountains — of which biodiversity is a strong component — in the global mountain arena. 

Earlier this year, together with the African Mountain Research Foundation and the Global Mountain Safeguard Research Programme, it hosted the first ever Southern African Mountain Conference 2022, focused on their value and vulnerabilities. 

Making a case for southern Africa’s remote, fragile mountains 

The region’s biodiversity-rich mountains matter. “Southern African mountains provide most of our freshwater in the semi-arid, drought-prone region. Without them, we would be as dry and hot and flat as Australia,” he said. “Our mountains are our water towers — very abused water towers but towers nevertheless. The Maloti-Drakensberg alone supports 30 million people, sending water as far as Upington.” 

According to the foundation, which describes Southern African mountains as a “data black hole”, they provide vital water catchment services for the world’s fastest growing population.  “But climate change and invasive species are degrading these mountains and making it harder for them to act as ‘water towers’ for lowland agriculture, towns and cities. If we don’t do something about it, the consequences in 10 to 20 years could be catastrophic for hundreds of millions of people.”

Clark pointed out how certain types of agriculture can only occur in these mountains — tea and coffee in the cool eastern highlands of Zimbabwe, cherries in the eastern Free State, deciduous fruit in the Koue Bokkeveld mountain range near Ceres and wild-growing honeybush from the Cape mountains. 

Much of the region’s commercial timber is grown in the mountainous areas in the south and east, among the few places that can support the industry. Mountain biodiversity, too, plays a vital role in carbon storage, as a source of medicinal plants, safeguarding soil stability and in culture, spirituality, tourism and recreation.

Diversity approaches Greater Cape Floristic Region

Southern African mountains host extraordinary diversity “making them doubly valuable as biodiversity repositories and field laboratories”, Clark said. As mountains have relatively small surface areas in the total region, the distribution ranges of most mountain species is very narrow, with a high proportion being confined to small sections of mountains.

Yet, at a regional level, they rank among the most poorly documented in the world in terms of biodiversity knowledge. “We’re still at a point in South Africa where we don’t really know comprehensively what biodiversity many of our mountains have.”

But what early research is revealing is fascinating — the grasslands of the eastern Great Escarpment nears the Cape Floristic Region in terms of absolute numbers of species and proportionate richness. 

“The verdict is not fully in yet, and it is unlikely that anything can outcompete the diversity in the core of the Greater Cape Floristic Region, but our preliminary data so far suggests that diversity in the eastern Great Escarpment (Sneeuberg to Nyanga) could be around 5 000 species of plant, with endemism [species found nowhere else] of around 77%.” 

This is compared to 9 000 species of plant in the core Greater Cape Floristic Region and endemism of 70%. “As the surface areas of the eastern Great Escarpment and the core Greater Cape Floristic Region are similar — 90 000 km2 — the richness in endemism is similar.” 

The challenge with this approach is that they are not a comparable unit: the eastern Great Escarpment is a “mountain-delimited idea” and the core Greater Cape Floristic Region is a “climatically-delimited idea”, he said.

“To compare mountain with mountain we need to compare the diversity of the mountain in the core Greater Cape Floristic Region with the eastern Great Escarpment to see which wins. But the fact is that our summer rainfall mountain diversity is under-appreciated, with a very significant local endemism and strong mountain-focused regional endemism along the eastern Great Escarpment that has figures approaching the celebrated Cape Floristic Region, and should be taken note of.”

Obstacles to research 

There are a combination of reasons for the diversity of Southern African mountains not being well known. “There are not that many people working on this topic. It really is a love for the job, and not very sexy in terms of ‘cutting edge’ science.” 

Mountain fieldwork is hard work; finding students who love being in the field for long periods without a mall nearby and no wi-fi is becoming scarce. “Mountains are usually far from main centres — out of sight and out of mind — so don’t feature highly on national research agendas, plus it takes effort to get there.”

War, too, has hindered research. “For example, Mt Gorongosa was the Renamo base, and much of Mozambique and Angola were off-limits for 20 to 30 years. The Angolan Highlands are probably some of the least studied and explored mountains in the world,” but this is being worked on.

“The northern inselbergs of Mozambique have only recently been explored in detail. Much of the Malagasy Highlands are still poorly explored, and there are few comprehensive biodiversity studies for much of the Maloti-Drakensberg outside the KwaZulu-Natal side. Even there, there are blank spots.”

Crossing boundaries

Mountains show no respect for human borders. Provincial and national permit regulations have become “tedious” and “unhelpful” for bona fide non-commercial biodiversity prospecting, Clark said. “It’s impossible to send a team in the field without at least a year lead-in to get permits. It’s also virtually impossible to comply with the letter of the law, as much of the law is either impractical, or the capacity in government does not exist to assist honest academics comply.” 

And, as most of the region’s mountains are transboundary systems, researchers need two or more sets of permits to work on the same mountain, which can become “very problematic”.

Southern Africa has limited taxonomic capacity. “The hiatus between a new species discovery and its official description and publication can take 50 years. This is because there are so many new discoveries and so few people to process and publish them.” The region “is just so biologically rich that it will still take generations to explore and document it all”.

Threats facing mountain biodiversity

The immediate threats are landscape transformation through overgrazing, large-scale afforestation for commercial forestry, woody alien invasive species expansion and poaching. Clark said that seven of nine cycad species found only in the Mpumalanga-Limpopo escarpment area “are mostly gone from the wild”. Other threats include a rapid increase in native woody vegetation, mines and large dams, while climate change is a “background factor”.

The decades-long acknowledged problem of mass rangeland overgrazing across much of the Maloti-Drakensberg, is still not solved and is “a problem much much bigger than climate change”, he said. “We are slowly growing a team that links science, practitioners and government as a partnership in the northern Maloti-Drakensberg, where we hope to see interventions that reverse the trend.”

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