What Roads Have Wrought by Michelle Nijhuis

“Today, a study in Science Advances synthesizes results from Manaus [a city in northwest Brazil] with those from similar experiments worldwide, confirming what scientists have long suspected: no matter the ecosystem—forest, prairie, patch of moss—the effects of habitat fragmentation are ruinous.””[a] new study, led by Nick Haddad, a professor at North Carolina State University, and co-authored by Laurance and others, found that fragmented habitats lose an average of half of their plant and animal species within twenty years, and that some continue to lose species for thirty years or more. In all of the cases examined, the worst losses occurred in the smallest habitat patches and closest to a habitat edge. The study also demonstrates, using a high-resolution map of global tree cover, that more than seventy per cent of the world’s forest now lies within one kilometre of such an edge. “There are really only two big patches of intact forest left on Earth—the Amazon and the Congo—and they shine out like eyes from the center of the map,” Haddad said.”