The research focused on the Thukela River Basin, where farming, overgrazing, the spread of invasive alien plants, bush encroachment, human settlements and mining have damaged fragile savannah and grasslands.
This has hindered the land’s ability to sustain livelihoods and to maintain essential ecosystem services, such as supplying water and trapping carbon.
The research, commissioned by the United Nations Environment Programme and led by Anchor Environmental Consultants, used satellite imagery and ecosystem accounting to map where ecosystem services are provided and where restoration would be most worthwhile.
It found that rehabilitating large areas of grassland — mostly through the removal of invasive alien plants such as thirsty eucalyptus trees, implementing sustainable land management and addressing soil erosion by replanting trees — would improve the river’s basin’s ability to store carbon.
It would also lead to higher stocks of wild foods and medicines, create more productive rangelands for livestock farming and boost water supplies.
The report is part of the natural capital accounting and valuation of ecosystem services project, in which South Africa, Brazil, China, India and Mexico took part. South Africa is a signatory to the United Nations Convention to Combat Desertification and is aiming to achieve land degradation neutrality by 2030.
The catchment area is 2.91-million hectares, occupying about a third of the province.
“It was estimated that almost 555 000ha or 26% of the remaining natural area of the Thukela catchment … was degraded in 2015, the base year for South Africa’s land land degradation neutrality targets,” it says.
The degradation of natural landscapes and ecological infrastructure has significant social, economic and environmental costs.
“Preventing future land degradation is generally far more cost-effective in the long run than aiming to reduce or reverse past degradation. The sooner restoration begins, the better,” the study says.
The research found that for each rand invested in full restoration of ecosystem services, there is a return of at least R1.70. This an underestimate because it includes only selected ecosystem services and not the local multiplier effects of job creation “nor the intangible aesthetic and cultural values associated with restoring landscapes”.
A major concern is the reduction in water yield caused by the spread of invasive species. The avoided losses of yield that accompany restoration were evaluated using the municipal price of water, with the research finding the full restoration scenario would stave off estimated losses of R709-million in 2030.
The annual value of erosion control provided by ecosystems was 2% higher under the full restoration scenario, while on commercial land, grazing capacity was 2.2% higher under restoration compared with the business as usual scenario, “resulting in a gain in the value livestock provisioning service of R92-million per year in the catchment”.
It finds the value of nature-based tourism was expected to climb by 20% to about R95-million in 2030 under the restoration scenario.
“This is not about putting a price tag on every bee and tree,” said William Speller, an ecosystems and biodiversity expert with the programme.
“It’s about understanding that intact ecosystems are ultimately worth more to humanity than when they are destroyed.”