Conservation Management: Alien Plants
Conservation management in an area is very important in sustaining the natural environment, especially in nature reserves. One of the major conservation issues is that of alien plants and how they negatively affect the environment, or more specifically the indigenous plants around them. It is because of this that these plants have to be controlled or managed, if not eradicated. So conservation management comes in to deal with this predicament.
Alien plants are problematic and more often than not inhibit the growth of other indigenous plants. Control methods need to be implemented in order to reduce the impacts of these alien plants. To give a better understanding of the implications of alien plants, and on the methods of how to remove them, it is better to use an example, described below.
Pompom weed (Campuloclinium macrocephalum) is an alien invasive species, as it is not native to South Africa and originated from South America. It was introduced as an ornamental flower and because it has no natural enemies in this environment the weed outcompeted the indigenous species, invading areas rapidly. Pompom is one of the biggest threats to the grassland environment, as it causes serious degradation to the veld as well as reduced biodiversity. It is unpalatable to large herbivores and is a declared weed of category one under the Conservation of Agricultural Resource Act (Act No 43 of 1983). Plants under this category may not occur on any land or inland water surface in South Africa other than in biological control reserves.
This pinkish flower is known to be a perennial plant, and is quite resistant to fires and frost as it retreats underground during the winter months. This plant produces a lot of seeds that can be dispersed quite easily through wind and people walking amongst the flowers, spreading them as they walk further. The roots of pompoms produce enzymes that prevent natural grasses from growing properly. The aerial sections of the plant are also presumed to limit the growth of surrounding plants.
To regulate and limit the spread of pompom weed there are various control methods that are put into place that can either be chemical or mechanical.
The chemical control method involves a particular herbicide that is applied to the base of the plant, leaves and the stem so to restrict the growth of the plant, and kill it. When herbicides are applied the main aim is to try and apply it as early as possible in the growing season, before the plants flower. So to prevent seeds from spreading from budding flowers.
The mechanical control method involves the top part of the plant, the flower head, being cut off by use of a cutter and carefully placed in a bag. The top parts of the plant that were placed in the bag are then to be burned at a later stage in an appropriate setting.
Did you know? In larger areas where spreading of seeds can be widely distributed, the most appropriate treatment would be to apply a combination of these methods. It is very important for one to be careful when removing flower heads as the plant produces large amounts of seeds which are easily transported by the wind, and should not be allowed to disperse in this way.
