India, Oct. 20 -- In Ethiopia, a tree brought in to solve one problem ended up causing a much bigger one. Prosopis was introduced to help, and it has since spread across land herders depend on., and it has since spread across land herders depend on. According to a study in Science of the Total Environment, led by Hailu Shiferaw of Addis Ababa University, it spread by about 31,127 hectares a year between 1986 and 2017. Researchers estimated that land changes in the region reduced ecosystem-service value by about $602 million over 31 years. Ecosystem services are the benefits people obtain from nature.

Prosopis is native to Central and South America. Several Prosopis species and hybrids were planted outside their native range in the 19th a...