Alien Vegetation Removal
Environmental studies commissioned to assist in the establishment of the Reserve confirmed that much of the Reserve´s 265 hectares had been severely overrun by alien vegetation. An intensive alien vegetation removal programme is now underway. New laws obligate property owners to remove invasive alien plants on one’s property. Alien vegetation tends to take over rapidly, making it difficult for indigenous vegetation to grow.
This has an impact on birds, animals and other wildlife, and can ultimately threaten the delicate balance of the natural ecosystem. At the same time as alien plants are being removed, indigenous trees and shrubs are being planted to replace them. A large number of indigenous trees (about 15 – 20 different species) have been planted on the Reserve, with more to come. Trees have been labelled and numbered, both for monitoring purposes and for visitor information.
Understanding the Threats of Alien Vegetation
01
Decline in Biodiversity
Alien vegetation significantly reduces the diversity of plant and animal species, often leading to the extinction of native flora and fauna.
02
Impact on Faunal Composition
03
Water Resource Depletion
04
Reduction in Land Value
05
Tourism and Conservation Value
06
Alterations to Soil and Food Chain
Effective Strategies for Alien Vegetation Management
Comprehensive Approaches to Combat Invasive Species at Modderfontein Reserve
Mechanical removal of the plants
Physical removal
Burning (controlled)
Chemical control
Via the use of specific herbicides on various parts of plants and utilizing various methods such as spraying or painting.
Biological control
The use of the plants´ own natural enemies to combat them
Current Control Programme
Pom pom Weed
(Campuloclinium macrocephalum)
Very aggressive weed causing severe veld degradation. Control requires foliar application (Herbicide is sprayed onto the leaves of the plant) using Access herbicide and yearly follow up to monitor regrowth.
Black Wattle
(Acacia mearnsii)
South Africa´s most prominent invader, listed no. 1 on the list of the World´s Worst Invasive Species. Control programme currently combining mechanical and chemical methods through popping trees out by the roots, cut-stump herbicide application and foliar spraying using Confront herbicide.
Understanding the Legislation
Legislation Regarding Removal of Alien Vegetation
Three Categories of alien and invasive species (According to the Conservation of Agricultural Resources Act (CARA) Act 43 of 1983:
Category 1
Declared weeds
Prohibited plants, which must be controlled or eradicated (except in dedicated areas) that serve no economic purpose and are possibly harmful to humans, animals and the environment (Bromilow, 2012)1. E.g. Pompom weed (Campuloclinium macrocephalum)
Category 2
Declared invader plants with a commercial or utility value
Plants that possess certain useful properties, such as soil stabilisation, fodder etc. “Allowed in demarcated areas under controlled conditions and in biocontrol reserves”(Bromilow, 2012)1. E.g. Black Wattle (Acacie mearnsii)