The Survival of Acacia decurrens , Acacia melanoxylon and Populus alba in Vaalwater, Waterberg Biosphere Reserve, Limpopo Province, South Africa

Abstract

Invasive alien plants use survival strategies to outcompete native plants. Invasive alien plants occurring next to water bodies consume lot of water and are difficult to control and remove within their area of existence. Government uses public funds to control and remove invasive alien plants and use different methods to control them. Mechanical control can only be used for specific plants, not for all invasive alien plants existing in field. Only three species of invasive alien plants were sampled in this study, namely; Acacia decurrens, Acacia melanoxylon and Populus alba. Two sites were sampled, one away from the water body and the other site next to the river. Twenty quadrats were sampled per site and trees were controlled through mechanical method of digging the roots and cutting at the ankle and knee height size within the quadrats. Over 18 months monitoring was conducted to check the response of these plants. The results show that, out of twenty quadrats sampled per site, the response of sprouts next to the water body was very successful. All stumps cut at knee level next to the river had sprouts and root suckering was observed more on trees that were closer to the river, especially on Populus alba and Acacia decurrens. This study emphasizes the need to consider the impact of survival strategies of invasive alien plants when controlling them.