The Right Trees And Plants

Wangari Maathai, a Kenyan activist, showed that tree planting activities in that East African country can mobilise grassroots constituencies and create environmental awareness. Her promotion of the planting of trees to restore natural forests, ecosystems and water catchment areas was the key to her being awarded a Nobel Prize.

Tree planting, under certain circumstances, can be beneficial to the environment which include reduced runoff and soil erosion, decreased sediment levels of rivers, improved water quality and water retention of soils. Natural systems that act as carbon sinks can add considerable value to "offset" the carbon footprint in a convenient, cheap and visible manner. Forest carbon sequestration is generally regarded as a good option based on the relatively modest cost of planting trees, and the high expected effects of carbon dioxide absorption.

Tree planting, however, is not broad forest preservation, nor restoration, but planting of trees in urban areas will definitely lift the ambience of many neighborhoods particularly in otherwise dull and dreary townships.

Tree planting should therefore not only be economical but also appropriate. It is generally acknowledged that South Africa has one of the richest biodiversities in the world, but this is under threat of invader plants. A total of 1 168 indigenous plants are now directly threatened by alien plants.   

The invaders contribute to habitat degradation changing the composition and ecology of particularly some of the highly prized grasslands in the Province. They also choke water courses and generally use more water than indigenous plants.

Some of the worst offenders are;

Black Wattle: Black wattle is the most widespread riverine invader occurring continuously from the Limpopo Province along the eastern seaboard to the Western Cape.

Pom Pom Weed : Very much an ornamental plant first planted upcountry. The Pom Pom weed has large pink flowers. It is an erect perennial herb up to 1.3m tall, with bristly hairs covering the leaves and stems. In the past 5 years it has spread dramatically.

Triffed Weed (Chromolaena odorata): This is one of the most invasive plants not only in South Africa but also the whole of tropical Africa, India and South East Asia. It is a scrambling shrub up to 4m or higher and forms thickets that smother other vegetation. It grows rapidly, flowers within one season and produces vast quantities of windblown seeds that can be disbursed by attaching to fur, feathers, and clothing. The oils in the plant make it flammable even when green.

Lantana Camara: Popularly known as Spanish Flag. It spreads very quickly and is helped by birds. It grows so well that efforts to eradicate it fail. It is resistant to fire and quickly grows again and colonises in burnt areas.

Some alien plants such as Lantana, Oleander and Syringa are poisonous to humans and livestock and others such as bugweed cause allergic reactions in humans.

Contractors are often required to do site clearance and may get into trouble when removing protected tree species designated in terms of the National Forests Act of 1998.In accordance with Notice 1106 of 27 November 2009 issued by the Minister of Agriculture, Forestry and Fisheries no person may cut, disturb, damage or destroy any protected tree or possess, collect ,remove, transport, export , purchase, sell, donate or in any other manner acquire or dispose any protected tree except under a license.

Notice 1106 of 27 November 2009 contains a Schedule listing the protected tree species in terms of the National Tree Number, the Botanical and Common Names.

Pieter Rautenbach