Invasive alien species and rapid urban development are among the biggest threats to biodiversity in Stellenbosch, and major interventions are needed to get them under control.
These were the key insights given by local environmental experts when quizzed about the town’s ecological welfare, in light of the United Nations (UN) International Day of Biological Diversity that took place on 22 May.
“Many alien trees and shrubs are causing havoc in fynbos and in other vegetation such as the strips of forest vegetation along our rivers,” says Prof. Dave Richardson, the Director of the Centre of Excellence for Invasion Biology (CIB) at Stellenbosch University (SU).
A bonsai stands tall at the SU Botanical Garden. Not only is it the oldest university botanical garden in the South Africa, but it also houses the country’s largest bonsai collection. PHOTO: Nell Hofmeyr
He describes how rivers and streams around the town are “choked” with foreign acacias, poplars and pines – to name a few of the culprits. These invaders have negatively transformed the vegetation by reducing streamflow and disrupting natural ecological processes.
Another big danger is the steady rise of urban development. This is according to both Peter Kruger, the interim Curator at the SU Botanical Garden, and Macelline Kotze, the municipal Eco-Officer at the Jan Marais Nature Reserve.
The Jan Marais Nature Reserve, located just across from Irene Ladies’ Residence, is maintained by the Stellenbosch Municipality. It is home to over 150 different plant species. PHOTO: Nell Hofmeyr
“Just look at the way Stellenbosch and Cape Town are expanding. Housing and development are certainly major threats to both plants and animals,” says Kruger.
Kotze says the effects of infrastructure on the environment are especially evident at the Jan Marais Nature Reserve. “We’re situated right in the middle of a residential area. New buildings are constantly being built and it is causing major strain on biodiversity in the area.”
With the Botanical Garden and Jan Marais Nature Reserve situated on campus, Jonkershoek Nature Reserve just around the corner, and hectares of winelands spanning every direction – Stellenbosch is abundant with flora and fauna.
But is enough being done to conserve biodiversity in the area?
Dave Pepler, an environmentalist and presenter of KykNet’s nature programme Groen, reckons that local government has “failed spectacularly” in their efforts.
“In the early 70s I poached trout in the middle of town – now the Eerste River is ecologically dead. The municipal grounds are invaded and eroded. Everything is about the surface look of the town with no ecological underpinning. My dictum: You simply cannot build a thriving economy on a bankrupt ecology.”
One of the roses in bloom at the SU Botanical Garden. PHOTO: Nell Hofmeyr
Kotze insists the environment is a priority for the municipality but identifies a lack of manpower as the main reason why change is not happening fast enough. “There are never enough hands to do the work,” she says.
According to Richardson, regional government are trying to fight the alien invasion problem, noting that support has been given to the national Working for Water programme as well as for research on biological control.
As for local government, “[they] are also doing something, by clearing some streams of alien plants,” he says. “However, such inputs are nowhere near enough – almost everywhere in South Africa, including around Stellenbosch, the situation is rapidly getting worse. This is a huge challenge and radical new interventions are urgently needed.”