Invading the larder

21 July 2009 | News story

Invasive species can wreak havoc on nature in many different ways, but how do they affect food supply? Here, we look at the case of Ethiopia, which has been badly affected by the spread of the plant Prosopis juliflora, sometimes known as Mesquite.

What’s the problem?

Ethiopia is one of the poorest and least developed countries in the world. There are 31 million people who live on less than half a dollar a day and more than 80 percent of its 84 million people live on just $2 a day.

Every year, six to 13 million people are at risk of starvation due to food shortages. The situation is worst in arid and semi-arid parts of the country. Not only is there not enough rainfall in these areas, they are also economically and politically marginalized and infrastructure there is undeveloped. These conditions make it particularly difficult for local people, dependent on their livestock as a source of food, income, and savings, to secure their livelihoods.

What’s threatening food security?

To make matters worse, in the Afar Region of North-eastern Ethiopia, a non-indigenous plant species, introduced in the late 1970s and early 1980s, has become a noxious invader, colonizing more than 800,000 hectares of arable and pastoral land.

The plant Prosopis juliflora, sometimes known as mesquite, has been identified as a major invasive species for eradication by the Federal Government of Ethiopia. At the national level however, there is no clear policy or legal framework for its control or management.

These plants compete for the land and water people need to grow crops and destroy natural pasture for grazing animals. They displace native trees and can cause health problems for livestock and humans.

In the areas most affected by the plant invasion, local people have become reliant on food aid on average for 5-6 months in good years and for up to 10 months in drought times

What’s the solution?

It is possible to control invasive species, such as prosopis, and stop them spreading to arable and pasturelands if the local people are involved in preventing the spread and are given economic incentives.

In the case of the prosopis invasion in the Afar region, FARM-Africa, an international non-governmental organization, supported communities to set up cooperatives to use the plant to make charcoal, which was then sold to the local charcoal trade in Adama and Addis Ababa.

The prosopis seed pods can also be collected, dried and crushed to make animal fodder that are highly nutritious for domestic animals, such as sheep and goats. Crushing the seeds, and thereby killing them, also reduces their dispersal rate.

These activities not only help control the spread of the invasive plant but give local people a desperately needed source of income to buy food. With the increased income it is possible to clear lands and ensure more sustainable land management for crops and livestock.

Invasive species can have significant adverse socio-economic impacts. Policies need to be in place that give people economic incentives to control their spread. Areas invaded by alien invasive species – as well as those at risk of invasion – need to be mapped properly and more research needs carried out on alternative methods of controlling invasions.