India, Oct. 17 -- We have all been there where we tried solving one problem but created a much larger one. That is what has happened in parts of Kenya. The mathenge tree was planted to hold back desertification. According to a study by Mbaabu and colleagues published in Remote Sensing, the tree's coverage in the lowlands of Baringo County rose from 882 hectares in 1988 to 18,792 hectares in 2016. For herder John Lmakato, the spread of mathenge trees indirectly cost him most of his livestock, as he tells it.

John Lmakato lives at Lerata, a village at the base of Mount Ololokwe in Samburu County. He recalls a time when the rangelands were covered with grass, and his animals roamed free. Now, he says, the land is overgrown with mathenge tre...