What happens after the tree comes down?
Follow the journey
Once an invasive alien tree is felled in the pristine wetlands at Africa’s southernmost tip, the story isn’t over. In fact, it’s only just beginning.
An incredible transformation gets underway: from a tree that causes all sorts of trouble above the ground, to an apartment block for microbes beneath our feet.
Follow the journey from invasive plant to invaluable resource – in a partnership between the Nuwejaars Wetlands SMA and Sequester.
Invasive plants are removed
Invasive alien plants are chopped down out of the Nuwejaars Wetlands and surrounding Critically Endangered fynbos vegetation. The work is undertaken by a contracting team – a small business that receives its livelihood through this green employment.
An invasive
plant calamity
Invasive alien plants choke wetlands, consume large amounts of water and create massive wildfire risks. At the same time, as natural sinks degrade and wildfire risks increase, stored carbon returns to the atmosphere – increasing climate volatility, but also degrading landscapes.
Wood is converted into biochar
The invasive wood is taken to a biochar reactor, where it’s turned into biochar through a process called pyrolysis. The NWSMA has one reactor and aims to increase its reactor capacity over time. Biomass goes in one end, and biochar comes out the other.
What is biochar?
Through the pyrolysis process, a porous, microscopic scaffold or apartment block of almost-pure carbon is created.
This apartment block is incredibly durable – it doesn’t break down like ordinary organic matter. It’s filled with tiny pores that provide the ideal size and structure to house the world of the microbiome, from bacteria and fungi to all the organisms that help make soil healthy. In fact, one teaspoon of biochar can host more microbial cells than there are people on Earth.
Biochar is inoculated with microbe power LIQUID
The biochar is inoculated by the NWSMA’s partner, Sequester, with a special consortium of microbial cultures called the Chartilizer C-43 blend. These cultures were developed through more than 35 years of research by the University of Bologna.
Into the soil
The inoculated biochar is applied to the soil, where it helps kickstart healthy soil systems. In farming environments, a granulated form of the biochar can be applied through a standard fertiliser planter, banded next to the seed. It can also be applied by a compost spread bulker. In gardens and smaller-scale applications, different methods may be used, but the goal remains the same: healthier, more resilient soils.
The Power
Below Ground
| 1 | The cultures
The 43 microbial cultures are specially selected to support soil health. Some fix nitrogen from the atmosphere. Others unlock phosphates and other minerals already present in the soil. Some extend the effective root surface area of plants, while others help suppress soil-borne pathogens.
| 2 | Water retention
Traditional irrigation water often drains quickly through sandy soils. The microscopic pores in biochar help retain water where plants need it. A 2022 study by Stellenbosch University found a tripling of plant-available water capacity in Western Cape sands at a 2% biochar inclusion rate.
| 3 | Nutrient retention
Biochar also helps keep nutrients in the root zone. Studies have shown significant reductions in nitrate leaching. The same Stellenbosch study found a 41% reduction in nitrate leaching during a single season.
| 4 | Carbon stored in the soil
Every tonne of biochar applied to the soil represents approximately 2.4 tonnes of carbon dioxide equivalent removed from the atmosphere. The carbon was originally captured from the air while the plant was growing. Pyrolysis converts that carbon into a stable form that can remain locked away in the soil for hundreds to thousands of years.
And the yield?
The benefits of biochar are often most visible from the second year onwards, with the first year generally considered the establishment phase.
As with any soil intervention, good agronomic guidance is important to ensure:
- Appropriate application rates
- Correct irrigation management
- Soil conditions that support microbial establishment
- Reduced use of fungicides during the initial establishment period
- Good regenerative agricultural practices are implemented
The result is healthier soils, stronger crops, improved water efficiency and increased resilience for the future.
Scale doesn’t matter
From commercial farm to community garden, or domestic plot to garden pot, the effects of biochar are the same. Chartilizer Biochar products and other plant vitality boosters are now available from Sequester.
Going full circle
The income generated helps support the removal of invasive alien plants from the wetlands and fynbos, creating ongoing employment opportunities for restoration teams. In turn, the biomass they remove can be converted into more biochar, helping to build healthier soils and store more carbon. When biochar products are sold and applied to the soil, the story comes full circle.