'Tree of life' on deathbed
It is not only the rhino that could be driven to extinction by poachers.
Retired rangers, each armed with a rifle and a bicycle, are guarding one of the most threatened species in the Kruger National Park - the pepper-bark tree (Warburgia salutaris).
The tree is well known for its medicinal properties but, while in the past t raditional healers harvested the bark of the tree in a sustainable manner , its commercialisation has led to its being virtually wiped out in South Africa. Now it exists solely in a small area in the park .
"The problem is that we have only one area in the park, near Punda Maria, where the tree occurs," said the park's spokesman, William Mabasa.
"Nothing is left outside the park."
Mabasa said SANParks called four former rangers out of retirement in 2007, and tasked them with protecting the trees.
The bark of the tree is used as a treatment for coughs, colds, chest complaints, fever and malaria.
It has been found that, in addition to the bark, the roots and leaves have medicinal qualities.
Products from the tree are widely available in both raw and tablet-form on the internet.
On one US herbal cure website, 1kg of milled Warburgia leaves was priced at about R3000.
The bark is also popular in traditional markets in Mpumalanga and in muti shops in Johannesburg.
According to SANParks, the tree, which used to be widespread in South Africa, Zimbabwe, Mozambique, Kenya, Madagascar and Swaziland, is now listed on both the International Union for Conservation of Nature and SA National Biodiversity Institute red lists of endangered species. It is believed there are only 10 trees existing in the wild in Zimbabwe.
"They are popular and have been popular for so long that there's no such thing as sustainable harvesting," said Dr Vivienne Williams, a researcher at the University of the Witwatersrand.
Williams said poachers strip the trees of so much of their bark that "they are never given a chance to recover".