Super plant mops up CO2
An extraordinary indigenous plant known as “elephant’s food” could mop up the excess carbon dioxide that causes climate change, while making a fortune on the international carbon trading market.
Scientific evidence gathered in the Eastern Cape over the past seven years and published recently in peer-reviewed literature indicates that the plant, spekboom, has enormous carbon-storing capabilities. Its capacity to offset harmful carbon emissions is equivalent to that of moist, subtropical forest.
Scientists involved in restoring thousands of hectares of spekboom are optimistic about earning carbon credits on the international market, which is worth between €10billion and €20-billion a year in Europe. Their findings suggest that up to four tons of carbon a year would be captured by each hectare.
“Carbon credits are an exciting part of the new 21st-century economies that we need to encourage,” said Richard Cowling of the Nelson Mandela Metropolitan University.
Cowling, recently elected an associate of the National Academy of Sciences in the United States, is one of the Rhodes Restoration Research Group (R3G), which is working on the spekboom project.
Spekboom is an evergreen succulent that can reach a height of 2,5m and occurs mainly in the south-eastern Cape. Normally found in rocky, dry areas, it also does well in watered flower beds.
R3G scientists, collaborating with the Working for Woodlands Project of the Department of Water Affairs and forestry, monitored the restoration of 400ha of degraded spekboom thicket in the Baviaanskloof Nature Reserve, the Addo Elephant National Park and the Great Fish River Reserve.
They noted that spekboom has evolved to withstand moderate browsing by indigenous wildlife such as elephants, rhinos and antelope, which tend to eat it from the top down. Outside protected areas, however, domestic livestock tend to eat the plant from the ground up, often leading to rapid degradation.
Rates of carbon storage by replanted spekboom were measured on a farm near Uitenhage. About 27 years ago the farmer, Graham Slater, became tired of dealing with regular flooding of his barn and set about replanting the adjacent degraded hillslope with spekboom.
“The two-metre-high growth of spekboom on bare ground under only 250mm to 350mm of annual rainfall was almost miraculous,” said Cowling. Each hectare of spekboom on the farm sequestered 4,2 tons of carbon a year.
The R3G project has set up 30 experimental spekboom plots since January and plans to plant up to 300. Browsing by goats and other livestock is not precluded, but needs to be managed.
“The vision is to tap into the international carbon market and thereby restore hundreds of thousands of hectares of degraded thicket, provide tens of thousands of jobs in the process and create a source of income for rural communities for many decades,” Cowling said.
A project for raising carbon credits has been designed by Anthony Mills of the University of Stellenbosch, a member of the R3G group who has published a number of scientific papers on the topic.
“The price of ‘energy’ carbon credits is between €10 and €20 per ton of CO2,” Mills said. “This is expected to exceed €60 by 2030. The bottom line is the carbon market is booming and creating carbon credits is likely to be profitable.”
If the project fails to obtain certification under the clean development mechanism of the Kyoto Protocol on climate change, a process that could be costly and complex, it will investigate selling its carbon credits on a reputable voluntary market system.
The scientists said that spekboom restoration offers huge social benefits in a province with an unemployment rate close to 50%.
Replanting requires intensive labour and there are opportunities for skills development in the monitoring of carbon.
“A project that restores 10 000ha a year would employ about 2 000 labourers. In addition to the jobs there will be numerous long-term benefits to local communities, such as improved pasture and sustained access to fuel wood, timber, fruit and medicines.”