Invasive plants: ecological effects, status, management challenges in Tanzania and the way forward

Abstract

Over decades invasive plants have been exerting negative pressure on native vascular plant’s and hence devastating the stability and productivity of the receiving ecosystem. These effects are usually irreversible if appropriate strategies cannot be taken immediately after invasion, resulting in high cost of managing them both in rangelands and farmlands. With time, these non-edible plant species will result in a decreased grazing or browsing area and can lead to local extinction of native plants and animals due to decreased food availability. Management of invasive weeds has been challenging over years as a result of increasingly failure of chemical control as a method due to evolution of resistant weeds, higher cost of using chemical herbicide and their effects on the environment. While traditional methods such as timely uprooting and cutting presents an alternative for sustainable invasive weeds management they have been associated with promotion of germination of undesired weeds due to soil disturbance. The fact that chemical and traditional methods for invasive weed management are increasing failing nature based invasive plants management approaches such as competitive facilitation of the native plants and the use of other plant species with allelopathic effects can be an alternative management approach. Recently, new weed control mechanisms such as biological control and Integrated Pest Management (IPM) have been recommended to complement both the traditional and chemical control methods for improved performance. Plant-plant competition and allelopathy therefore, as natural plant life phenomenon presents an opportunity for successful invasive weeds management.