The urgent need for local action to control invasive alien trees in the Mountain Catchment Areas supplying water to the Ladismith area

The urgent need for local action to control invasive alien trees in the Mountain Catchment Areas supplying water to the Ladismith area

Donovan Kotze, 15 October 2019

One of the greatest threats to key water resource areas in the Mountain Catchment Areas of the Western Cape are invasive alien trees1. Dense infestations of hakea and pine trees generally result in more than a 10% increase in water loss to the atmosphere2, and thus if these trees are not controlled then this will result in a reduction in yield of many millions of liters of water, with potentially severe impacts on the businesses and farms which depend on this water, especially during droughts. This has particular relevance to Ladismith and the surrounding farms, with almost all of our water supplied by the Klein Swartberg Mountains.

A few years back, Cape Nature were actively clearing in the mountains above Ladismith, but they are now faced with shrinking resources to carry this out, and have done almost no clearing here in the last few years. Therefore, local action is desperately required. Over the last 15 months, three volunteers (myself, Hugh Sussen and Samantha Adey) have been clearing of invasive alien tress once or twice a month. Over these 15 months, we have systematically covered over 1 500 ha of mainly sparsely infested areas and have cut down more than 4000 trees. However, if we are going to win the battle then several more local volunteers are needed, particularly to help with some of the more densely infested areas which remain.
One of the areas (about 15 ha in size) densely infested with hakea in the catchment of Waterkloof which supplies Ladismith town

If we fail to act now then the problem will soon become much more expensive to deal with in the future and droughts which are already impacting upon local families and businesses will become a greater risk. Thus, it makes good business sense for local farmers and businesses such as Ladismith Cheese and Parmalat to contribute now to controlling invasive alien trees in our precious water source areas and so contribute positively to a more water-secure future for all of Ladismith and its businesses.

Cutting down hakeas and pine trees is hard work, but it is great exercise and very rewarding! And so, by participating in clearing, one is also contributing to one’s own health and personal fulfilment.

1 Cousins S, Singels E, and Kraaij T, 2018. Invasive alien plants in South Africa pose huge risks, but they can be stopped [online].
Richardson D M and vanWilgen B W, 2004. Invasive alien plants in South Africa: how well do we understand the ecological impacts? S. Afr. J. Sci. 100, 45–52.
2 Görgens A and Howard G, 2016. The impacts of different degrees of alien plant invasion on yields from the Western Cape water supply system: Final Report Document produced for CSIR. Aurecon, Cape Town.

Posted on 17 October, 2019 06:29 by tonyrebelo tonyrebelo


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