GRAAFF-REINET NEWS — A number of factors can cause new vegetation to sprout in abundance, from runaway fires to floods after good rainfall.
In the Camdeboo National Park, however, it was not floods or fire that encouraged vegetation to sprout.
Here, the low water levels of the park’s central feature, the Nqweba Dam, have exposed more fertile soil, creating the ideal growing conditions in areas around the dam. Unfortunately, the new life came in the form of invasive pink tamarisk (Tamarix romosissima), a problem species in the Northern, Eastern and Western Cape. Tamarisk is easily recognised by its pink flowers.
These thirsty trees, originating from Eastern Europe and Asia, spread via waterways and the wind.
Camdeboo park manager Nick de Goede says the dam’s level at the start of winter was so low that one could walk from one side of the dam to the other. The park is in a summer-rainfall region, but the past couple of years have seen below average records.
“Areas that were previously underwater and now exposed, are a problem,” says Biodiversity and Social Projects (BSP) manager Karen Jacobs. BSP teams have made good headway to clear other populations in the area. The new saplings can have a detrimental effect on areas that were already cleared, says Jacobs.
Once good rainfall hits the park and its catchment areas, dam levels will rise again. But for now, affected areas will have to be mapped and addressed to prevent further spread and depletion of water sources.
The problem is also not a new one. “Tamarisk has been in the area for a while, but only occurs around the dam,” says Jacobs. She says the tamarisk infestation originated from higher up in the Sundays River, outside the park. From the Nqweba Dam, the Sundays River meanders all the way down to the Addo Elephant National Park, where it drains into the Darlington Dam. This area now also faces problems.
Removing tamarisk is also not easy, as established trees can grow up to 6m tall. Because of the multi-stemmed nature of the trees, the eradication process is slow. “For big trees, we use brush cutters and chainsaws to make the work faster, but for small saplings, herbicide is sprayed on the entire plant,” says Jacobs.
Pink tamarisk is a Category One invader in the Northern, Western and Eastern Cape. They may therefore not be planted, sold or kept, and must be removed as they displace indigenous species.
'We bring you the latest Graaff-Reinet, Karoo news'
