Whether tiny fauna like the army worm, tomato leaf miner, and papaya mealybug or flora like the common water hyacinth and Lantana camara: More and more non-native species in Africa are becoming invasive. Spreading rapidly, they damage ecosystems and cause severe crop failures – as seen with the army worm and maize and sorghum crops, two Eastern African staples.
Deliberate introduction of Prosopis juliflora
Not every alien animal or plant species was introduced by accident. Prosopis juliflora, for example – a mimosa plant native to Latin America – was deliberately brought to Eastern Africa about 35 years ago and initially grown on plantations. The tree, called mathenge in Kenya, mrashia in Tanzania, and Woyane hara or Derg hara in Ethiopia, is well-adapted to arid environments. Its roots penetrate up to 50 metres into the ground, enabling it to grow in places too dry for other plants.
Exclusive focus on potential benefits
This made Prosopis juliflora seem promising for water-scarce, overgrazed areas like Baringo County in Kenya, where it was intended to help contain desertification while producing firewood, charcoal, and timber. In areas highly prone to soil erosion, like Afar Region in eastern Ethiopia, the often shrub-like tree was planted in hopes of stabilizing local soils.