Black wattle (Acacia mearnsii) is the Southern Cape of South Africa’s largest environmental threat. The spread of black wattle has the ability to reduce large areas of biodiversity and destroy pristine wetlands. Black wattle is one of the most widespread and significant invasive alien trees in South Africa, and great concern is frequently expressed over its potential effect on reducing catchment water yields. The species often forms dense stands, maintains a high green leaf area throughout the year, and frequently replaces seasonally dormant grasslands and fynbos.
The species was introduced to South Africa in 1871, initially used as shelter-belts for stock and the wood for fuel and fencing. Later, it was discovered that the bark contained high levels of tannin which could be used for treating hides for leather production. This led to the tree being widely planted to produce tanning extract for the leather industry.
The removal of the black wattle on Gondwana and in the surrounding region is seen as priority by both Gondwana management and the conservation authorities within the region. Black wattle is removed in a number of ways, however each has their economic and environmental challenges. The largest challenge common to all methods of removal is the stimulation of the seedbed. Any flowering black wattle tree has the ability to produce millions of seeds over its life span. These seeds have the ability to remain dormant in the ground for up to 90 years. The follow up on the germination of these seeds is more important than the original eradication.
Gondwana Conservation Foundation has approached the eradication of wattle in a multifaceted way.
- Remove wattle manually in ecologically sensitive regions
- Remove wattle mechanically in less sensitive regions
- Develop satellite industries for the community based on the biomass generated from the removal
- Ensure comprehensive follow up is done in all areas
The Gondwana Conservation Foundation believes that through the manual removal of wattle thousands of jobs can be created. To run a team of 12 individuals costs approximately R2500 per day for the entire team.
How to get involved?
Individuals can get involved by either sponsoring an eradication team or by contributing to machinery that can cover vast distances in appropriate areas.