A report released by the Department of Forestry, Fisheries and the Environment (DFFE) on May 28, finds that biological invasions are the third-largest threat to South Africa’s biodiversity, after cultivation and land degradation, and are responsible for 25% of all biodiversity loss.
The second biological invasions report, titled ‘Status of Biological Invasions and their Management in South Africa in 2019’, estimates that, if biological invasions on grazing land are not controlled, South Africa could lose up to 70% of this valuable natural asset.
In releasing the report, Forestry, Fisheries and the Environment Minister Barbara Creecy said such degradation would reduce the capacity of natural rangelands to support livestock production, thereby threatening rural livelihoods and food production.
Scientific research has shown that one of the key factors driving the accelerated decline of biodiversity is the invasion of alien species and the report reveals several important points in this regard.
Firstly, the report finds that the number of alien plant species in South Africa has increased by 15%, from 1 637 to 1 880, about a third of which are invasive.
Formal assessments of the impact of invasive species are under way using a new United Nations scheme that was developed in collaboration with South African National Biodiversity Institute and the Centre of Excellence for Invasion Biology scientists.
Current estimates suggest the ecological costs of invasive alien plants and animals to be more than R6.5-billion a year, with the main costs associated with losses being those attributed to a decline in ecosystem services, such as water and grazing, and in agriculture, as a result of invasive pests.
The second finding is that invasive trees use between 3% and 5% of South Africa’s surface water runoff each year, a serious problem in an already water scarce country that is increasingly prone to drought.
The third finding is that invasive trees increase the risk and intensity of veld fires, with such fires burning at a higher temperature and containment measures being more difficult.
However, most disturbingly, the report highlights that new alien species continue to arrive every year in South Africa, the DFFE stated.
Among these is the polyphagous shot hole borer beetle, which, with its associated fungus, has already killed thousands of trees in South Africa, and appears set to be one of the most damaging and costly biological invasions faced by the country, the DFFE cautioned.
Nonetheless, Creecy said South Africa was recognised as global leader in invasion science, and that, through regulations promulgated in 2014 and subsequently revised, as well as permitting, there is greater control over individuals who import, grow and trade with invasive species that have commercial value.
Of concern, however, is that although new technologies have been developed to support actions to prevent the introduction of listed species, accidental imports will continue to occur, the DFFE warned.
“It is for this reason that the environmental programmes of the DFFE is spending over a billion rand a year on projects to control biological invasions and create jobs,” she said.
Since the adoption of the Working For… programmes in 2005, Creecy said, the DFFE has been “relentless” in its efforts to effectively manage plant and animal alien and invasive species in South Africa.
An example of this is a recent programme that successfully removed bass from selected wetlands and stretches of river, leading to rapid recovery of native fishes and biodiversity in general.
Further, she said the use of biological control against invasive alien plants had also been shown to have very high positive returns on investment. “Biocontrol is a critical and well-regulated tool to manage biological invasions, with South Africa recognised as a global leader in the field.”
Recognising that alien and invasive species is a multi-faceted problem that needs a multi-faceted approach, Creecy said there was a need to cut through red tape and the silos of different government departments to deal with this through a common national approach.
Accordingly, the DFFE is developing a policy on the management of biological invasions, with its implementation being supported by a ten-year national invasive species strategy and action plan.
The aim of the strategy is to facilitate a cohesive and collaborative approach by government, industry and the broader community in identifying and managing biosecurity risks.
She also announced that South Africa, through the financial support of the Global Environmental Facility, under the biodiversity focal window, had secured funds for a project to enhance the efficient and effective management of high-risk biological invasions.
This project is aimed at directly mitigating the negative impacts of biological invasions on South Africa’s biodiversity, while contributing to the improvement of rural food security and livelihoods.