These six alien invasive plants cause serious negative impacts on the ecosystems of Mpumalanga province. Perhaps the most significant of these impacts is the widespread loss of habitat. This area experiences heavy invasions of unwanted plant species. Some of the worst invasive species to be recorded include:
1. Lantana (Lantana camara) – A scrambling exotic shrub which invades bushveld and forests across the Mpumalanga province. It is often found along forest edges, rivers and roadsides. Its aromatic leaves are poisonous to livestock. It is spread easily as its seeds are dispersed by birds. Lantana is listed as a Category 1b invader on the National List of Invasive Species. This means that it must be removed.
2. Bugweed (Solanum mauritianum) – Has been recorded in the Sabie area where it is invading a forest and interfering with the natural ecological processes by smothering indigenous plants, changing the habitat for animals and birds. This plant is known to invade Savanna Biome, Grassland Biome, watercourses and wetlands and also forest habitats. This transformer species is listed as Category 1b invader on the National List of Invasive Species.
3. Yellow bells (Tecoma stans) - This invader is prolific around Mbombela (Nelspruit), as well as other regions in the Lowveld. It invades roadsides, riparian areas, waste areas, disturbed sites and rocky sites in tropical and sub-tropical areas, and displaces the indigenous fauna and flora. It is listed under the National Environmental Management Biodiversity Act (NEMBA) as a Category 1b invasive plant.
There are other invasive plants which are not as prominent but are a concern in the province. These plants which have found their way to Mpumalanga include:
4. Pereskia (Pereskia aculeate) – It overtops and smothers other species, including large forest and plantation trees, this effectively destroys the forests. It is reportedly slowly invading some areas in Mpumalanga and people should look out for this invader. It is listed as a Category 1b plant on the National List of Invasive Species, meaning it must be removed.
5. Kudzu vine (Pueraria montana var. lobata) – The health of many forests is threatened by kudzu vines, which is also a problem in the Mpumalanga province, introduced from Japan in the 19th century as an ornamental plant. This vine is so invasive it can completely overgrow an entire forest. In the process, it prevents sunlight from reaching the trees, effectively killing the forest. Additionally, the weight of the thick mats of vines on trees can cause trees to break and fall over. This plant is a Category 1a species under NEMBA.
6. Mauritian hemp (Furcraea foetida) – This invader plant was recorded in Loskop Dam in Mpumalanga a long time ago. It can survive a wide range of environmental conditions, including growth in shallow, infertile soil, on steep cliff-like habitats and rocky edges. Mauritian hemp has the potential to replace our indigenous species and that is why it should raise concerns to the Mbombela residents and Mpumalanga province as a whole. The Category 1a invader should be removed immediately when it has been discovered in a certain area.
The public is encouraged to stay alert of all these invaders and do what you can to help reduce the spread. These are just a few of many invasive species trying to take over.
The law on invasives
National List of Invasive Species (in terms of Section 70 (1) (A)) includes 556 invasive species which are divided into 4 categories, 1a, 1b, 2 and 3.
*Terrestrial and Fresh-water Plants (379); *Marine Plants (4); *Mammals (41); *Birds (24); *Reptiles (30); *Amphibians (7); *Fresh-water Fish (15); *Terrestrial Invertebrates (23); *Fresh-water Invertebrates (9); *Marine Invertebrates (17) and *Microbial Species (7).
These are invasive species which must be combatted and where possible, eradicated. Any form of trade or planting is strictly prohibited. Category 1a species are usually species which are newly established and have small populations.
These are established invasive species which must be controlled and wherever possible, removed and destroyed. Any form of trade or planting is strictly prohibited and landowners are obligated to control Category 1b plants and animals on their properties. A species management plan should be drafted for large properties.
Invasive species or species deemed to be potentially invasive, in which a permit, issued by the Department of Environmental Affairs, is required to carry out a restricted activity. Category 2 species include commercially important species such as pine, wattle and gum trees, as well as certain mammal species bred on game farms. It also includes alien fish species and reptiles and birds found in the exotic pet trade.
Category 2 species revert to Category 1b species when they are no longer under the control of the landowner or when found outside of the demarcated area, such as pines or gums in a wetland or protected area such as a nature reserve or national park.
Invasive species which may remain in prescribed areas or provinces. Further planting, propagation or trade is however, prohibited.