Bringing science and development together through news and analysis

  • Invasive weed strangles Zambian park


[LUSAKA] An invasive shrub is upsetting the ecological balance of national parks in Zambia's Kafue Flats and could drive away tourism.

A study by the Environmental Council of Zambia (ECZ), released last month (20 September), shows that the weed Mimosa pigra has covered around 2,900 hectares of the Kafue Flats.

It is interfering with the ecosystems by blocking access to water for animals and birds and displacing animals by reducing available habitat.

M. pigra, a thorny shrub native to tropical America, can grow up to six metres high and forms dense stands that squeeze out other native forms of vegetation.

Director of the ECZ, Edward Zulu, says that the shrub has disturbed animal grazing lands and if it is not quickly controlled the natural habitant for the Kafue lechwe (marsh antelope) and several birds species would be displaced irretrievably.

An ongoing World Bank-funded study into the economic impact of the shrub and other environmental weeds in Zambia suggests that tourists are less inclined to visit areas if migratory water birds are displaced by infestations of waterweed.

The weed could also impact the local economy by disrupting agriculture.

Area member of parliament Highvie Hamududu told SciDev.Net that M. pigra is already decreasing biodiversity in the area and making tourism investors  reluctant to invest.

The Invasive Alien Species project, supported by the UN Environment Programme and the Global Environmental Facility plans to spend about US$2 million before 2009 to control the invasive species in Zambia.

The IAS has advised spraying chemicals to kill the weed, a method which scientists have warned causes damage to other plants, insects and animal species.

Rodwell Chandipo, assistant project coordinator for Removing Barriers to Invasive Plant Management in Africa, part of the IAS project, told SciDev.Net that chemical spraying would soon be initiated to kill the weed, in addition to current mechanical methods of clearance.

Chandipo said that an Environmental Impact Assessment would first be carried out by the ECZ to make sure that the chemical spraying creates no side effects on other plants and animal species.

He added M. pigra was posing a similar challenge in other countries including Ethiopia, Ghana and Uganda.

We encourage you to republish this article online and in print, it’s free under our creative commons attribution license, but please follow some simple guidelines:
  1. You have to credit our authors.
  2. You have to credit SciDev.Net — where possible include our logo with a link back to the original article.
  3. You can simply run the first few lines of the article and then add: “Read the full article on SciDev.Net” containing a link back to the original article.
  4. If you want to also take images published in this story you will need to confirm with the original source if you're licensed to use them.
  5. The easiest way to get the article on your site is to embed the code below.
For more information view our media page and republishing guidelines.