On the Nuwejaars Wetlands Special Management Area (NWMSA), invasive alien plants have taken over many of the natural landscapes, especially the irreplaceable wetlands and riverbanks. These plants grow fast. And they’re expensive to remove. As a result, thousands of hectares of threatened fynbos, renosterveld and wetlands are invaded in this 47,000-hectare conservation area close to Africa’s southernmost tip.
According to Ross Kettles, Operations Manager of the Nuwejaars River Nature Reserve (NRNR), the non-profit company that manages the NWSMA, these invasive plants are a huge challenge. “It will take decades for us to remove all these invasive plants. And even then, the seedbank of many of these species can last for more than a century in the soil. So this is a multigenerational project.”
Maintaining the gains
Through wonderful donor support over the past number of years, restoration projects have seen thousands of hectares cleared of dense stands of these invasive trees. The NRNR has worked with donors such as WWF South Africa, the Overberg District Municipality, the Western Cape Department of Agriculture and the National Lotteries Commission.
“This support has been vital in addressing the challenge. Now we need to not lose those areas cleared, and keep increasing them. The changing climate also isn’t helping: we’re getting more rain in the warmer weather, which leads to greater numbers of these plants germinating,” says Ross.
It is extremely expensive to remove these plants, with each plant either pulled out by hand or cut down. “That’s why we needed to find ways to be able to sustain clearing efforts in the long term.”
One such opportunity comes in the form of biochar.
Through donor support from the IKI Small Grants programme, which is part of the International Climate Initiative (IKI), the NRNR could buy a biochar reactor and a pelletising plant. Already 600 hectares of lightly infested landscapes in the NWSMA have been cleared of invasive plants, with this biomass fed into the biochar reactor and, through a process of pyrolysis, converted to biochar. Another by-product of the process is wood vinegar, which can be used either as an organic herbicide, insecticide or a fertilizer, depending on the concentration.
Ross says, “Our Bio Agri Biolyser reactor is incredibly efficient – with hardly any smoke or carbon released into the atmosphere, meaning it’s a net negative carbon technology. That’s also why this is the first reactor in South Africa to receive accreditation from Carbon Standards International.” At the same time, the project is creating jobs. Stalwart contractor and Elim resident, Joey Cloete and his team run the reactor. And two more contracting teams, consisting of 20 individuals, receive employment to remove the invasive plants.
Biochar itself has exceptional properties.
It has a carbon content of up to 90% and binds carbon material long-term. It can be used to filter water and smoke, it has medicinal properties and can store carbon in the ground. Because it traps moisture and microbes, it also makes soil more fertile over time, while allowing for better aeration.
“Biochar is the farmer’s friend: it reduces the reliance on irrigation, increases crop yields and reduces reliance on pesticides and herbicides,” he says.
In the NWSMA, biochar and the wood vinegar will be added to animal feed raw ingredients and through the pelletising plant, will be converted into feed pellets.
“Biochar and wood vinegar have many health benefits for the gut health of livestock. And once they pass through the animal’s gut, the carbon will go back into the soil, storing it indefinitely,” Ross adds.
Why these trees need to be removed…
Invasive plants and trees are not only detrimental to natural landscapes and wildlife, but they also exacerbate climate change challenges. According to NRNR Conservation Manager: Planning, Monitoring & Development, Erica Brink, “We’ve seen how these trees burn hotter and more often than natural vegetation. And when they burn, carbon dioxide is released into the atmosphere. They also consume much more water along rivers and in wetlands than natural vegetation. And during times of floods, they uproot easily as the floodwaters come down, causing damage to downstream infrastructure as tonnes of biomass is washed down by the water. What’s more, as they uproot, the carbon that has been naturally stored in our special wetlands’ peat is torn up and released into the atmosphere.”
The natural rewilding and recovery that takes place once these invasive plants are removed has, however, proven to be phenomenal. Erica says, “We’ve found that our wetlands are in a healthy state, and therefore ecological succession takes place when the invasives are removed. We intervene only when areas are degraded to the point that the ecological integrity is compromised beyond natural regeneration. But that’s the absolute exception in our wetlands and our fynbos.”
Images supplied by LoveGreen Communications.
Our sincere thanks to the IKI Small Grants Programme, part of Germany’s International Climate Initiative (IKI), for supporting this project. IKI Small Grants is commissioned by Germany’s Federal Ministry of Economic Affairs and Climate Action (BMWK), the Federal Foreign Office (AA) and Federal Ministry for the Environment, Nature Conservation, Nuclear Safety and Consumer Protection (BMUV) and carried out by Deutsche Gesellschaft für Internationale Zusammenarbeit (GIZ) GmbH.