By Ferdinand Theo Preller
In the streets of Stellenbosch, a small-scale apocalypse is occurring. Disease and death are running rampant. Corpses line the streets. And as it stands, we have no solution, no cure. We stand to lose the very individuals that made this town the “Eikestad”. In short, the trees are dying.
While the picture I painted is very dramatic, it is also accurate. Walking down Dorp Street will confirm my story: the oaks lining the pavement have bare branches sticking out amongst the greenery, and some trees are already completely brown or leafless. This slow dying has been going on under our noses for years, largely unknown to the general public. And the culprit of this tree-killing spree? Polyphagous Shot Hole Borer beetles, or PSHB for short. PSHB comes from South-East Asia, and invaded South Africa through infested pallets delivered to the Port of Durban. From there, they have been spreading from one province to the next, aided by people transporting firewood infested with PSHB.
These beetles tunnel into trees, infect them with the Fusarium fungus and then feed on the fungus as it slowly begins choking the tree to death. The Fusarium fungus targets the trees’ xylem tissue, the cells that are responsible for transporting water from the roots to the rest of the tree. This causes a condition known as Fusarium dieback, where branches progressively lose their leaves, then die and dry out, and eventually fall off the tree due to strong winds or other disturbances. Remember all those oak trees around Stellenbosch? Now remember all the cars parked underneath them, as well as the sidewalks that enjoy the trees’ shade in the summer. PSHB is a real, relevant problem in our town. Many of the iconic trees of Stellies, including the oaks, will have to be removed for safety reasons in the coming years.
PSHB was first recorded in Stellenbosch in 2022 by Stellenbosch University (SU) researcher Francois Roets, who had been monitoring their presence in Somerset West and the greater Cape Town area. The researchers who first identified the PSHB in Stellenbosch predicted that we would begin seeing the first signs of dying in three to four years, which is what is happening now. Another bleak prediction they made was that, without major intervention, most of the at-risk alien trees in Stellenbosch, such as the oaks, would be dead in 10 years.
We are now living through a critical point of Stellenbosch’s history. Will we have to relinquish our oak trees to the past? Maybe, but this also presents us with an opportunity. While the oaks of Stellenbosch are a part of our cultural heritage, they are still aliens, trees that are not adapted to our climate or soil. Though it may not have looked like it, most oak trees in Stellenbosch have been struggling for as long as they have been standing. The PSHB simply acted as the straw hammer that bashed in the camel’s back. Replanting the oaks, especially while the beetle infestation is in full swing, will likely just lead to more tree deaths. There is currently no way to stop the beetles from boring into trees, nor can we stop the Fusarium fungus from killing them.
A possible way forward is to leave the oaks in the past, at least for now. There are lists of trees that are susceptible to PSHB, as well as trees that are not. Perhaps it is time to move on and replant using indigenous tree species that the beetles cannot effectively survive in. This could be good for Stellenbosch, celebrating our natural heritage within our town by incorporating local trees into our urban spaces. This would also be good for the birds, reptiles and insects of Stellenbosch, as native tree species provide ecosystem services, primarily food, which oaks and other aliens do not.
Increasing biodiversity and potentially stopping the tree apocalypse? That sounds like a win-win situation. However, it will require active participation from the students and permanent residents of Stellenbosch, interacting with the municipality and calling for action. Something will have to happen, and soon. Hopefully, if we inspire action early enough, we may come out of this situation with a greener town than before.
