The Cape Floral Region is the smallest and most biologically diverse of the world’s six floral kingdoms, where the Cape peninsula alone has more flowering plants than the entire UK. Its attraction to tourists was quantified in a study into the economic value of terrestrial and marine biodiversity in the Cape Floral Region (CFR), published in the journal Biological Conservation last year. The study found that 50% of international tourists visiting South Africa each year included the Western Cape in their travels, many of whom did so in part for the natural environment.
Ecotourism, through the passive enjoyment of the area or more active birding, whale-watching and adventure tourism, were estimated to bring in R6,4-billion to the province annually. The value of fynbos products harvested for the fresh and dried flower industry, thatching, timber and ferns totalled R78-million a year while harvesting of marine products came to R1,3-billion annually.
Bees indigenous to fynbos were cited as an important contributor to pollination of the fruit industry in the area and mountain fynbos catchment areas help regulate the region’s water supply. The study also said that, while overexploitation of resources and transformation of natural vegetation through urban development and agriculture were major threats, alien plants were “the greatest proximate threat to floral diversity”.
South Africa has seen about 8 750 exotic plant species introduced since European mariners and settlers first made landfall 350 years ago. Most of the introductions were for food, fodder, timber and garden decoration and the bulk of these species have remained within the confines of domestication. Of these, about 180 have found conditions to be so comfortable that they have spread into over 10-million hectares of vegetation across the country. Of these, fynbos shrubland is one of the most heavily invaded biomes in South Africa. Exactly what conditions favoured the spread of this handful of species is not fully understood, but the issue is about to receive renewed attention. Earlier this year saw the launch of a new Department of Science and Technology Centre of Excellence for Invasion Biology. Based at Stellenbosch University’s Zoology Department, the centre has members based at institutions across the country and will explore the biology of invasive alien organisms. Researchers will look at the impact of invasive plant and animal species on South Africa’s natural systems and will try to answer questions around the rate of spreading, what conditions facilitate their spread and how they can be controlled. Professor Steven Chown, conservation ecologist at Stellenbosch University’s Department of Zoology and member of the Centre of Excellence, said the team hoped to emerge with a screening system to help prevent the future importation of species which might become invasive. “Many problems with invasives could be resolved beforehand through screening. An example is the controversial potential introduction of bumblebees in the Western Cape to assist with pollination. But we know that in Tasmania they have ‘escaped’ and are causing major problems. They’re pollinating alien plants that weren’t spreading before but now are.
“If we could provide some kind of risk-management and assessment framework we can be aware of which species might result in potential troubles later. It would be good to establish the possible economic benefits of an imported species over the potential long-term costs,” explained Chown. Meanwhile, the government will need to spend a great deal more than it currently is to curtail the problem. A paper published earlier this year in the South African Journal of Science said “a programme to bring invasions under control through clearing would cost an estimated R650-million per year for the next 20 years”, which is “considerably more than the amount currently being spent”.
As long as underspending continues, “the problem (will) increase exponentially and the costs of any future action are raised considerably”.
Working for Water has already spent R3,1-billion nationwide in clearing and weeding since the socioenvironmental project was launched five years ago.