Hussein Jillo, a Merti resident, said the species were contributing to a reduction in pastures and changing the flow of water in River Ewaso Nyiro which makes their livestock starve to death.
Mathenge trees, which burst into the limelight during the 1997 El-Nino rains, are evergreen plants that multiply fast while colonising other plants, leading to the loss of farmland and pasture and impoverishing agro-pastoral communities.